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-rw-r--r--mozglue/baseprofiler/public/BaseAndGeckoProfilerDetail.h64
-rw-r--r--mozglue/baseprofiler/public/BaseProfileJSONWriter.h600
-rw-r--r--mozglue/baseprofiler/public/BaseProfiler.h506
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerCounts.h280
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerDetail.h285
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerLabels.h178
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerMarkerTypes.h125
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerMarkers.h255
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerMarkersDetail.h741
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerMarkersPrerequisites.h886
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerRAIIMacro.h15
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerSharedLibraries.h170
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerState.h405
-rw-r--r--mozglue/baseprofiler/public/BaseProfilerUtils.h227
-rw-r--r--mozglue/baseprofiler/public/BaseProfilingCategory.h68
-rw-r--r--mozglue/baseprofiler/public/BaseProfilingStack.h517
-rw-r--r--mozglue/baseprofiler/public/BlocksRingBuffer.h999
-rw-r--r--mozglue/baseprofiler/public/FailureLatch.h217
-rw-r--r--mozglue/baseprofiler/public/ModuloBuffer.h618
-rw-r--r--mozglue/baseprofiler/public/PowerOfTwo.h322
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferChunk.h547
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferChunkManager.h134
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h172
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.h444
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferControlledChunkManager.h203
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferEntryKinds.h105
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferEntrySerialization.h1184
-rw-r--r--mozglue/baseprofiler/public/ProfileBufferIndex.h97
-rw-r--r--mozglue/baseprofiler/public/ProfileChunkedBuffer.h1560
-rw-r--r--mozglue/baseprofiler/public/ProfileChunkedBufferDetail.h400
-rw-r--r--mozglue/baseprofiler/public/ProgressLogger.h500
-rw-r--r--mozglue/baseprofiler/public/ProportionValue.h235
-rw-r--r--mozglue/baseprofiler/public/leb128iterator.h207
33 files changed, 13266 insertions, 0 deletions
diff --git a/mozglue/baseprofiler/public/BaseAndGeckoProfilerDetail.h b/mozglue/baseprofiler/public/BaseAndGeckoProfilerDetail.h
new file mode 100644
index 0000000000..f45170c83f
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseAndGeckoProfilerDetail.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Internal Base and Gecko Profiler utilities.
+// It should declare or define things that are used in both profilers, but not
+// needed outside of the profilers.
+// In particular, it is *not* included in popular headers like BaseProfiler.h
+// and GeckoProfiler.h, to avoid rebuilding the world when this is modified.
+
+#ifndef BaseAndGeckoProfilerDetail_h
+#define BaseAndGeckoProfilerDetail_h
+
+#include "mozilla/BaseProfilerUtils.h"
+#include "mozilla/Span.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/Types.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+
+class ProfileBufferChunkManagerWithLocalLimit;
+
+namespace baseprofiler::detail {
+
+[[nodiscard]] MFBT_API TimeStamp GetProfilingStartTime();
+
+[[nodiscard]] MFBT_API UniquePtr<ProfileBufferChunkManagerWithLocalLimit>
+ExtractBaseProfilerChunkManager();
+
+// If the current thread is registered, returns its registration time, otherwise
+// a null timestamp.
+[[nodiscard]] MFBT_API TimeStamp GetThreadRegistrationTime();
+
+} // namespace baseprofiler::detail
+
+namespace profiler::detail {
+
+// True if the filter is exactly "pid:<aPid>".
+[[nodiscard]] MFBT_API bool FilterHasPid(
+ const char* aFilter, baseprofiler::BaseProfilerProcessId aPid =
+ baseprofiler::profiler_current_process_id());
+
+// Only true if the filters only contain "pid:..." strings, and *none* of them
+// is exactly "pid:<aPid>". E.g.:
+// - [], 123 -> false (no pids)
+// - ["main"], 123 -> false (not all pids)
+// - ["main", "pid:123"], 123 -> false (not all pids)
+// - ["pid:123"], 123 -> false (all pids, including "pid:123")
+// - ["pid:123", "pid:456"], 123 -> false (all pids, including "pid:123")
+// - ["pid:456"], 123 -> true (all pids, but no "pid:123")
+// - ["pid:456", "pid:789"], 123 -> true (all pids, but no "pid:123")
+[[nodiscard]] MFBT_API bool FiltersExcludePid(
+ Span<const char* const> aFilters,
+ baseprofiler::BaseProfilerProcessId aPid =
+ baseprofiler::profiler_current_process_id());
+
+} // namespace profiler::detail
+
+} // namespace mozilla
+
+#endif // BaseAndGeckoProfilerDetail_h
diff --git a/mozglue/baseprofiler/public/BaseProfileJSONWriter.h b/mozglue/baseprofiler/public/BaseProfileJSONWriter.h
new file mode 100644
index 0000000000..00a2926366
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfileJSONWriter.h
@@ -0,0 +1,600 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BASEPROFILEJSONWRITER_H
+#define BASEPROFILEJSONWRITER_H
+
+#include "mozilla/FailureLatch.h"
+#include "mozilla/HashFunctions.h"
+#include "mozilla/HashTable.h"
+#include "mozilla/JSONWriter.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/ProgressLogger.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtrExtensions.h"
+
+#include <functional>
+#include <ostream>
+#include <string_view>
+
+namespace mozilla {
+namespace baseprofiler {
+
+class SpliceableJSONWriter;
+
+// On average, profile JSONs are large enough such that we want to avoid
+// reallocating its buffer when expanding. Additionally, the contents of the
+// profile are not accessed until the profile is entirely written. For these
+// reasons we use a chunked writer that keeps an array of chunks, which is
+// concatenated together after writing is finished.
+class ChunkedJSONWriteFunc final : public JSONWriteFunc, public FailureLatch {
+ public:
+ friend class SpliceableJSONWriter;
+
+ explicit ChunkedJSONWriteFunc(FailureLatch& aFailureLatch)
+ : mFailureLatch(WrapNotNullUnchecked(&aFailureLatch)) {
+ (void)AllocChunk(kChunkSize);
+ }
+
+ [[nodiscard]] bool IsEmpty() const {
+ MOZ_ASSERT_IF(!mChunkPtr, !mChunkEnd && mChunkList.length() == 0 &&
+ mChunkLengths.length() == 0);
+ return !mChunkPtr;
+ }
+
+ // Length of data written so far, excluding null terminator.
+ [[nodiscard]] size_t Length() const {
+ MOZ_ASSERT(mChunkLengths.length() == mChunkList.length());
+ size_t totalLen = 0;
+ for (size_t i = 0; i < mChunkLengths.length(); i++) {
+ MOZ_ASSERT(strlen(mChunkList[i].get()) == mChunkLengths[i]);
+ totalLen += mChunkLengths[i];
+ }
+ return totalLen;
+ }
+
+ void Write(const Span<const char>& aStr) final {
+ if (Failed()) {
+ return;
+ }
+
+ MOZ_ASSERT(mChunkPtr >= mChunkList.back().get() && mChunkPtr <= mChunkEnd);
+ MOZ_ASSERT(mChunkEnd >= mChunkList.back().get() + mChunkLengths.back());
+ MOZ_ASSERT(*mChunkPtr == '\0');
+
+ // Most strings to be written are small, but subprocess profiles (e.g.,
+ // from the content process in e10s) may be huge. If the string is larger
+ // than a chunk, allocate its own chunk.
+ char* newPtr;
+ if (aStr.size() >= kChunkSize) {
+ if (!AllocChunk(aStr.size() + 1)) {
+ return;
+ }
+ newPtr = mChunkPtr + aStr.size();
+ } else {
+ newPtr = mChunkPtr + aStr.size();
+ if (newPtr >= mChunkEnd) {
+ if (!AllocChunk(kChunkSize)) {
+ return;
+ }
+ newPtr = mChunkPtr + aStr.size();
+ }
+ }
+
+ memcpy(mChunkPtr, aStr.data(), aStr.size());
+ *newPtr = '\0';
+ mChunkPtr = newPtr;
+ mChunkLengths.back() += aStr.size();
+ }
+
+ [[nodiscard]] bool CopyDataIntoLazilyAllocatedBuffer(
+ const std::function<char*(size_t)>& aAllocator) const {
+ // Request a buffer for the full content plus a null terminator.
+ if (Failed()) {
+ return false;
+ }
+
+ char* ptr = aAllocator(Length() + 1);
+
+ if (!ptr) {
+ // Failed to allocate memory.
+ return false;
+ }
+
+ for (size_t i = 0; i < mChunkList.length(); i++) {
+ size_t len = mChunkLengths[i];
+ memcpy(ptr, mChunkList[i].get(), len);
+ ptr += len;
+ }
+ *ptr = '\0';
+ return true;
+ }
+
+ [[nodiscard]] UniquePtr<char[]> CopyData() const {
+ UniquePtr<char[]> c;
+ if (!CopyDataIntoLazilyAllocatedBuffer([&](size_t allocationSize) {
+ c = MakeUnique<char[]>(allocationSize);
+ return c.get();
+ })) {
+ // Something went wrong, make sure the returned pointer is null even if
+ // the allocation happened.
+ c = nullptr;
+ }
+ return c;
+ }
+
+ void Take(ChunkedJSONWriteFunc&& aOther) {
+ SetFailureFrom(aOther);
+ if (Failed()) {
+ return;
+ }
+
+ for (size_t i = 0; i < aOther.mChunkList.length(); i++) {
+ MOZ_ALWAYS_TRUE(mChunkLengths.append(aOther.mChunkLengths[i]));
+ MOZ_ALWAYS_TRUE(mChunkList.append(std::move(aOther.mChunkList[i])));
+ }
+ mChunkPtr = mChunkList.back().get() + mChunkLengths.back();
+ mChunkEnd = mChunkPtr;
+ aOther.Clear();
+ }
+
+ FAILURELATCH_IMPL_PROXY(*mFailureLatch)
+
+ // Change the failure latch to be used here, and if the previous latch was
+ // already in failure state, set that failure in the new latch.
+ // This allows using this WriteFunc in isolation, before attempting to bring
+ // it into another operation group with its own FailureLatch.
+ void ChangeFailureLatchAndForwardState(FailureLatch& aFailureLatch) {
+ aFailureLatch.SetFailureFrom(*this);
+ mFailureLatch = WrapNotNullUnchecked(&aFailureLatch);
+ }
+
+ private:
+ void Clear() {
+ mChunkPtr = nullptr;
+ mChunkEnd = nullptr;
+ mChunkList.clear();
+ mChunkLengths.clear();
+ }
+
+ void ClearAndSetFailure(std::string aFailure) {
+ Clear();
+ SetFailure(std::move(aFailure));
+ }
+
+ [[nodiscard]] bool ClearAndSetFailureAndFalse(std::string aFailure) {
+ ClearAndSetFailure(std::move(aFailure));
+ return false;
+ }
+
+ [[nodiscard]] bool AllocChunk(size_t aChunkSize) {
+ if (Failed()) {
+ if (mChunkPtr) {
+ // FailureLatch is in failed state, but chunks have not been cleared yet
+ // (error must have happened elsewhere).
+ Clear();
+ }
+ return false;
+ }
+
+ MOZ_ASSERT(mChunkLengths.length() == mChunkList.length());
+ UniquePtr<char[]> newChunk = MakeUniqueFallible<char[]>(aChunkSize);
+ if (!newChunk) {
+ return ClearAndSetFailureAndFalse(
+ "OOM in ChunkedJSONWriteFunc::AllocChunk allocating new chunk");
+ }
+ mChunkPtr = newChunk.get();
+ mChunkEnd = mChunkPtr + aChunkSize;
+ *mChunkPtr = '\0';
+ if (!mChunkLengths.append(0)) {
+ return ClearAndSetFailureAndFalse(
+ "OOM in ChunkedJSONWriteFunc::AllocChunk appending length");
+ }
+ if (!mChunkList.append(std::move(newChunk))) {
+ return ClearAndSetFailureAndFalse(
+ "OOM in ChunkedJSONWriteFunc::AllocChunk appending new chunk");
+ }
+ return true;
+ }
+
+ static const size_t kChunkSize = 4096 * 512;
+
+ // Pointer for writing inside the current chunk.
+ //
+ // The current chunk is always at the back of mChunkList, i.e.,
+ // mChunkList.back() <= mChunkPtr <= mChunkEnd.
+ char* mChunkPtr = nullptr;
+
+ // Pointer to the end of the current chunk.
+ //
+ // The current chunk is always at the back of mChunkList, i.e.,
+ // mChunkEnd >= mChunkList.back() + mChunkLengths.back().
+ char* mChunkEnd = nullptr;
+
+ // List of chunks and their lengths.
+ //
+ // For all i, the length of the string in mChunkList[i] is
+ // mChunkLengths[i].
+ Vector<UniquePtr<char[]>> mChunkList;
+ Vector<size_t> mChunkLengths;
+
+ NotNull<FailureLatch*> mFailureLatch;
+};
+
+struct OStreamJSONWriteFunc final : public JSONWriteFunc {
+ explicit OStreamJSONWriteFunc(std::ostream& aStream) : mStream(aStream) {}
+
+ void Write(const Span<const char>& aStr) final {
+ std::string_view sv(aStr.data(), aStr.size());
+ mStream << sv;
+ }
+
+ std::ostream& mStream;
+};
+
+class UniqueJSONStrings;
+
+class SpliceableJSONWriter : public JSONWriter, public FailureLatch {
+ public:
+ SpliceableJSONWriter(JSONWriteFunc& aWriter, FailureLatch& aFailureLatch)
+ : JSONWriter(aWriter, JSONWriter::SingleLineStyle),
+ mFailureLatch(WrapNotNullUnchecked(&aFailureLatch)) {}
+
+ SpliceableJSONWriter(UniquePtr<JSONWriteFunc> aWriter,
+ FailureLatch& aFailureLatch)
+ : JSONWriter(std::move(aWriter), JSONWriter::SingleLineStyle),
+ mFailureLatch(WrapNotNullUnchecked(&aFailureLatch)) {}
+
+ void StartBareList() { StartCollection(scEmptyString, scEmptyString); }
+
+ void EndBareList() { EndCollection(scEmptyString); }
+
+ // Output a time (int64_t given in nanoseconds) in milliseconds. trim zeroes.
+ // E.g.: 1'234'567'890 -> "1234.56789"
+ void TimeI64NsProperty(const Span<const char>& aMaybePropertyName,
+ int64_t aTime_ns) {
+ if (aTime_ns == 0) {
+ Scalar(aMaybePropertyName, MakeStringSpan("0"));
+ return;
+ }
+
+ static constexpr int64_t million = 1'000'000;
+ const int64_t absNanos = std::abs(aTime_ns);
+ const int64_t integerMilliseconds = absNanos / million;
+ auto remainderNanoseconds = static_cast<uint32_t>(absNanos % million);
+
+ // Plenty enough to fit INT64_MIN (-9223372036854775808).
+ static constexpr size_t DIGITS_MAX = 23;
+ char buf[DIGITS_MAX + 1];
+ int len =
+ snprintf(buf, DIGITS_MAX, (aTime_ns >= 0) ? "%" PRIu64 : "-%" PRIu64,
+ integerMilliseconds);
+ if (remainderNanoseconds != 0) {
+ buf[len++] = '.';
+ // Output up to 6 fractional digits. Exit early if the rest would
+ // be trailing zeros.
+ uint32_t powerOfTen = static_cast<uint32_t>(million / 10);
+ for (;;) {
+ auto digit = remainderNanoseconds / powerOfTen;
+ buf[len++] = '0' + static_cast<char>(digit);
+ remainderNanoseconds %= powerOfTen;
+ if (remainderNanoseconds == 0) {
+ break;
+ }
+ powerOfTen /= 10;
+ if (powerOfTen == 0) {
+ break;
+ }
+ }
+ }
+
+ Scalar(aMaybePropertyName, Span<const char>(buf, len));
+ }
+
+ // Output a (double) time in milliseconds, with at best nanosecond precision.
+ void TimeDoubleMsProperty(const Span<const char>& aMaybePropertyName,
+ double aTime_ms) {
+ const double dTime_ns = aTime_ms * 1'000'000.0;
+ // Make sure it's well within int64_t range.
+ // 2^63 nanoseconds is almost 300 years; these times are relative to
+ // firefox startup, this should be enough for most uses.
+ if (dTime_ns >= 0.0) {
+ MOZ_RELEASE_ASSERT(dTime_ns < double(INT64_MAX - 1));
+ } else {
+ MOZ_RELEASE_ASSERT(dTime_ns > double(INT64_MIN + 2));
+ }
+ // Round to nearest integer nanosecond. The conversion to integer truncates
+ // the fractional part, so first we need to push it 0.5 away from zero.
+ const int64_t iTime_ns =
+ (dTime_ns >= 0.0) ? int64_t(dTime_ns + 0.5) : int64_t(dTime_ns - 0.5);
+ TimeI64NsProperty(aMaybePropertyName, iTime_ns);
+ }
+
+ // Output a (double) time in milliseconds, with at best nanosecond precision.
+ void TimeDoubleMsElement(double aTime_ms) {
+ TimeDoubleMsProperty(nullptr, aTime_ms);
+ }
+
+ // This function must be used to correctly stream timestamps in profiles.
+ // Null timestamps don't output anything.
+ void TimeProperty(const Span<const char>& aMaybePropertyName,
+ const TimeStamp& aTime) {
+ if (!aTime.IsNull()) {
+ TimeDoubleMsProperty(
+ aMaybePropertyName,
+ (aTime - TimeStamp::ProcessCreation()).ToMilliseconds());
+ }
+ }
+
+ void NullElements(uint32_t aCount) {
+ for (uint32_t i = 0; i < aCount; i++) {
+ NullElement();
+ }
+ }
+
+ void Splice(const Span<const char>& aStr) {
+ Separator();
+ WriteFunc().Write(aStr);
+ mNeedComma[mDepth] = true;
+ }
+
+ void Splice(const char* aStr, size_t aLen) {
+ Separator();
+ WriteFunc().Write(Span<const char>(aStr, aLen));
+ mNeedComma[mDepth] = true;
+ }
+
+ // Splice the given JSON directly in, without quoting.
+ void SplicedJSONProperty(const Span<const char>& aMaybePropertyName,
+ const Span<const char>& aJsonValue) {
+ Scalar(aMaybePropertyName, aJsonValue);
+ }
+
+ void CopyAndSplice(const ChunkedJSONWriteFunc& aFunc) {
+ Separator();
+ for (size_t i = 0; i < aFunc.mChunkList.length(); i++) {
+ WriteFunc().Write(
+ Span<const char>(aFunc.mChunkList[i].get(), aFunc.mChunkLengths[i]));
+ }
+ mNeedComma[mDepth] = true;
+ }
+
+ // Takes the chunks from aFunc and write them. If move is not possible
+ // (e.g., using OStreamJSONWriteFunc), aFunc's chunks are copied and its
+ // storage cleared.
+ virtual void TakeAndSplice(ChunkedJSONWriteFunc&& aFunc) {
+ Separator();
+ for (size_t i = 0; i < aFunc.mChunkList.length(); i++) {
+ WriteFunc().Write(
+ Span<const char>(aFunc.mChunkList[i].get(), aFunc.mChunkLengths[i]));
+ }
+ aFunc.mChunkPtr = nullptr;
+ aFunc.mChunkEnd = nullptr;
+ aFunc.mChunkList.clear();
+ aFunc.mChunkLengths.clear();
+ mNeedComma[mDepth] = true;
+ }
+
+ // Set (or reset) the pointer to a UniqueJSONStrings.
+ void SetUniqueStrings(UniqueJSONStrings& aUniqueStrings) {
+ MOZ_RELEASE_ASSERT(!mUniqueStrings);
+ mUniqueStrings = &aUniqueStrings;
+ }
+
+ // Set (or reset) the pointer to a UniqueJSONStrings.
+ void ResetUniqueStrings() {
+ MOZ_RELEASE_ASSERT(mUniqueStrings);
+ mUniqueStrings = nullptr;
+ }
+
+ // Add `aStr` to the unique-strings list (if not already there), and write its
+ // index as a named object property.
+ inline void UniqueStringProperty(const Span<const char>& aName,
+ const Span<const char>& aStr);
+
+ // Add `aStr` to the unique-strings list (if not already there), and write its
+ // index as an array element.
+ inline void UniqueStringElement(const Span<const char>& aStr);
+
+ // THe following functions override JSONWriter functions non-virtually. The
+ // goal is to try and prevent calls that specify a style, which would be
+ // ignored anyway because the whole thing is single-lined. It's fine if some
+ // calls still make it through a `JSONWriter&`, no big deal.
+ void Start() { JSONWriter::Start(); }
+ void StartArrayProperty(const Span<const char>& aName) {
+ JSONWriter::StartArrayProperty(aName);
+ }
+ template <size_t N>
+ void StartArrayProperty(const char (&aName)[N]) {
+ JSONWriter::StartArrayProperty(Span<const char>(aName, N));
+ }
+ void StartArrayElement() { JSONWriter::StartArrayElement(); }
+ void StartObjectProperty(const Span<const char>& aName) {
+ JSONWriter::StartObjectProperty(aName);
+ }
+ template <size_t N>
+ void StartObjectProperty(const char (&aName)[N]) {
+ JSONWriter::StartObjectProperty(Span<const char>(aName, N));
+ }
+ void StartObjectElement() { JSONWriter::StartObjectElement(); }
+
+ FAILURELATCH_IMPL_PROXY(*mFailureLatch)
+
+ protected:
+ NotNull<FailureLatch*> mFailureLatch;
+
+ private:
+ UniqueJSONStrings* mUniqueStrings = nullptr;
+};
+
+class SpliceableChunkedJSONWriter final : public SpliceableJSONWriter {
+ public:
+ explicit SpliceableChunkedJSONWriter(FailureLatch& aFailureLatch)
+ : SpliceableJSONWriter(MakeUnique<ChunkedJSONWriteFunc>(aFailureLatch),
+ aFailureLatch) {}
+
+ // Access the ChunkedJSONWriteFunc as reference-to-const, usually to copy data
+ // out.
+ const ChunkedJSONWriteFunc& ChunkedWriteFunc() const {
+ return ChunkedWriteFuncRef();
+ }
+
+ // Access the ChunkedJSONWriteFunc as rvalue-reference, usually to take its
+ // data out. This writer shouldn't be used anymore after this.
+ ChunkedJSONWriteFunc&& TakeChunkedWriteFunc() {
+ ChunkedJSONWriteFunc& ref = ChunkedWriteFuncRef();
+#ifdef DEBUG
+ mTaken = true;
+#endif //
+ return std::move(ref);
+ }
+
+ // Adopts the chunks from aFunc without copying.
+ void TakeAndSplice(ChunkedJSONWriteFunc&& aFunc) override {
+ MOZ_ASSERT(!mTaken);
+ Separator();
+ ChunkedWriteFuncRef().Take(std::move(aFunc));
+ mNeedComma[mDepth] = true;
+ }
+
+ void ChangeFailureLatchAndForwardState(FailureLatch& aFailureLatch) {
+ mFailureLatch = WrapNotNullUnchecked(&aFailureLatch);
+ return ChunkedWriteFuncRef().ChangeFailureLatchAndForwardState(
+ aFailureLatch);
+ }
+
+ private:
+ const ChunkedJSONWriteFunc& ChunkedWriteFuncRef() const {
+ MOZ_ASSERT(!mTaken);
+ // The WriteFunc was non-fallibly allocated as a ChunkedJSONWriteFunc in the
+ // only constructor above, so it's safe to cast to ChunkedJSONWriteFunc&.
+ return static_cast<const ChunkedJSONWriteFunc&>(WriteFunc());
+ }
+
+ ChunkedJSONWriteFunc& ChunkedWriteFuncRef() {
+ MOZ_ASSERT(!mTaken);
+ // The WriteFunc was non-fallibly allocated as a ChunkedJSONWriteFunc in the
+ // only constructor above, so it's safe to cast to ChunkedJSONWriteFunc&.
+ return static_cast<ChunkedJSONWriteFunc&>(WriteFunc());
+ }
+
+#ifdef DEBUG
+ bool mTaken = false;
+#endif
+};
+
+class JSONSchemaWriter {
+ JSONWriter& mWriter;
+ uint32_t mIndex;
+
+ public:
+ explicit JSONSchemaWriter(JSONWriter& aWriter) : mWriter(aWriter), mIndex(0) {
+ aWriter.StartObjectProperty("schema",
+ SpliceableJSONWriter::SingleLineStyle);
+ }
+
+ void WriteField(const Span<const char>& aName) {
+ mWriter.IntProperty(aName, mIndex++);
+ }
+
+ template <size_t Np1>
+ void WriteField(const char (&aName)[Np1]) {
+ WriteField(Span<const char>(aName, Np1 - 1));
+ }
+
+ ~JSONSchemaWriter() { mWriter.EndObject(); }
+};
+
+// This class helps create an indexed list of unique strings, and inserts the
+// index as a JSON value. The collected list of unique strings can later be
+// inserted as a JSON array.
+// This can be useful for elements/properties with many repeated strings.
+//
+// With only JSONWriter w,
+// `w.WriteElement("a"); w.WriteElement("b"); w.WriteElement("a");`
+// when done inside a JSON array, will generate:
+// `["a", "b", "c"]`
+//
+// With UniqueStrings u,
+// `u.WriteElement(w, "a"); u.WriteElement(w, "b"); u.WriteElement(w, "a");`
+// when done inside a JSON array, will generate:
+// `[0, 1, 0]`
+// and later, `u.SpliceStringTableElements(w)` (inside a JSON array), will
+// output the corresponding indexed list of unique strings:
+// `["a", "b"]`
+class UniqueJSONStrings final : public FailureLatch {
+ public:
+ // Start an empty list of unique strings.
+ MFBT_API explicit UniqueJSONStrings(FailureLatch& aFailureLatch);
+
+ // Start with a copy of the strings from another list.
+ MFBT_API UniqueJSONStrings(FailureLatch& aFailureLatch,
+ const UniqueJSONStrings& aOther,
+ ProgressLogger aProgressLogger);
+
+ MFBT_API ~UniqueJSONStrings();
+
+ // Add `aStr` to the list (if not already there), and write its index as a
+ // named object property.
+ void WriteProperty(SpliceableJSONWriter& aWriter,
+ const Span<const char>& aName,
+ const Span<const char>& aStr) {
+ if (const Maybe<uint32_t> maybeIndex = GetOrAddIndex(aStr); maybeIndex) {
+ aWriter.IntProperty(aName, *maybeIndex);
+ } else {
+ aWriter.SetFailureFrom(*this);
+ }
+ }
+
+ // Add `aStr` to the list (if not already there), and write its index as an
+ // array element.
+ void WriteElement(SpliceableJSONWriter& aWriter,
+ const Span<const char>& aStr) {
+ if (const Maybe<uint32_t> maybeIndex = GetOrAddIndex(aStr); maybeIndex) {
+ aWriter.IntElement(*maybeIndex);
+ } else if (!aWriter.Failed()) {
+ aWriter.SetFailureFrom(*this);
+ }
+ }
+
+ // Splice all collected unique strings into an array. This should only be done
+ // once, and then this UniqueStrings shouldn't be used anymore.
+ MFBT_API void SpliceStringTableElements(SpliceableJSONWriter& aWriter);
+
+ FAILURELATCH_IMPL_PROXY(mStringTableWriter)
+
+ void ChangeFailureLatchAndForwardState(FailureLatch& aFailureLatch) {
+ mStringTableWriter.ChangeFailureLatchAndForwardState(aFailureLatch);
+ }
+
+ private:
+ MFBT_API void ClearAndSetFailure(std::string aFailure);
+
+ // If `aStr` is already listed, return its index.
+ // Otherwise add it to the list and return the new index.
+ MFBT_API Maybe<uint32_t> GetOrAddIndex(const Span<const char>& aStr);
+
+ SpliceableChunkedJSONWriter mStringTableWriter;
+ HashMap<HashNumber, uint32_t> mStringHashToIndexMap;
+};
+
+void SpliceableJSONWriter::UniqueStringProperty(const Span<const char>& aName,
+ const Span<const char>& aStr) {
+ MOZ_RELEASE_ASSERT(mUniqueStrings);
+ mUniqueStrings->WriteProperty(*this, aName, aStr);
+}
+
+// Add `aStr` to the list (if not already there), and write its index as an
+// array element.
+void SpliceableJSONWriter::UniqueStringElement(const Span<const char>& aStr) {
+ MOZ_RELEASE_ASSERT(mUniqueStrings);
+ mUniqueStrings->WriteElement(*this, aStr);
+}
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif // BASEPROFILEJSONWRITER_H
diff --git a/mozglue/baseprofiler/public/BaseProfiler.h b/mozglue/baseprofiler/public/BaseProfiler.h
new file mode 100644
index 0000000000..a085eb9774
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfiler.h
@@ -0,0 +1,506 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The Gecko Profiler is an always-on profiler that takes fast and low overhead
+// samples of the program execution using only userspace functionality for
+// portability. The goal of this module is to provide performance data in a
+// generic cross-platform way without requiring custom tools or kernel support.
+//
+// Samples are collected to form a timeline with optional timeline event
+// (markers) used for filtering. The samples include both native stacks and
+// platform-independent "label stack" frames.
+
+#ifndef BaseProfiler_h
+#define BaseProfiler_h
+
+// This file is safe to include unconditionally, and only defines
+// empty macros if MOZ_GECKO_PROFILER is not set.
+
+// These headers are also safe to include unconditionally, with empty macros if
+// MOZ_GECKO_PROFILER is not set.
+// If your file only uses particular APIs (e.g., only markers), please consider
+// including only the needed headers instead of this one, to reduce compilation
+// dependencies.
+#include "mozilla/BaseProfilerCounts.h"
+#include "mozilla/BaseProfilerLabels.h"
+#include "mozilla/BaseProfilerMarkers.h"
+#include "mozilla/BaseProfilerState.h"
+
+#ifndef MOZ_GECKO_PROFILER
+
+# include "mozilla/UniquePtr.h"
+
+// This file can be #included unconditionally. However, everything within this
+// file must be guarded by a #ifdef MOZ_GECKO_PROFILER, *except* for the
+// following macros and functions, which encapsulate the most common operations
+// and thus avoid the need for many #ifdefs.
+
+# define AUTO_BASE_PROFILER_INIT \
+ ::mozilla::baseprofiler::profiler_init_main_thread_id()
+
+# define BASE_PROFILER_REGISTER_THREAD(name)
+# define BASE_PROFILER_UNREGISTER_THREAD()
+# define AUTO_BASE_PROFILER_REGISTER_THREAD(name)
+
+# define AUTO_BASE_PROFILER_THREAD_SLEEP
+# define AUTO_BASE_PROFILER_THREAD_WAKE
+
+// Function stubs for when MOZ_GECKO_PROFILER is not defined.
+
+namespace mozilla {
+
+namespace baseprofiler {
+// This won't be used, it's just there to allow the empty definition of
+// `profiler_get_backtrace`.
+struct ProfilerBacktrace {};
+using UniqueProfilerBacktrace = UniquePtr<ProfilerBacktrace>;
+
+// Get/Capture-backtrace functions can return nullptr or false, the result
+// should be fed to another empty macro or stub anyway.
+
+static inline UniqueProfilerBacktrace profiler_get_backtrace() {
+ return nullptr;
+}
+
+static inline bool profiler_capture_backtrace_into(
+ ProfileChunkedBuffer& aChunkedBuffer, StackCaptureOptions aCaptureOptions) {
+ return false;
+}
+
+static inline UniquePtr<ProfileChunkedBuffer> profiler_capture_backtrace() {
+ return nullptr;
+}
+
+static inline void profiler_init(void* stackTop) {}
+
+static inline void profiler_shutdown() {}
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#else // !MOZ_GECKO_PROFILER
+
+# include "BaseProfilingStack.h"
+
+# include "mozilla/Assertions.h"
+# include "mozilla/Atomics.h"
+# include "mozilla/Attributes.h"
+# include "mozilla/BaseProfilerRAIIMacro.h"
+# include "mozilla/Maybe.h"
+# include "mozilla/PowerOfTwo.h"
+# include "mozilla/TimeStamp.h"
+# include "mozilla/UniquePtr.h"
+
+# include <functional>
+# include <stdint.h>
+# include <string>
+
+namespace mozilla {
+
+class MallocAllocPolicy;
+class ProfileChunkedBuffer;
+enum class StackCaptureOptions;
+template <class T, size_t MinInlineCapacity, class AllocPolicy>
+class Vector;
+
+namespace baseprofiler {
+
+class ProfilerBacktrace;
+class SpliceableJSONWriter;
+
+//---------------------------------------------------------------------------
+// Start and stop the profiler
+//---------------------------------------------------------------------------
+
+static constexpr PowerOfTwo32 BASE_PROFILER_DEFAULT_ENTRIES =
+# if !defined(GP_PLAT_arm_android)
+ MakePowerOfTwo32<8 * 1024 * 1024>(); // 8M entries = 64MB
+# else
+ MakePowerOfTwo32<2 * 1024 * 1024>(); // 2M entries = 16MB
+# endif
+
+// Startup profiling usually need to capture more data, especially on slow
+// systems.
+// Note: Keep in sync with GeckoThread.maybeStartGeckoProfiler:
+// https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
+static constexpr PowerOfTwo32 BASE_PROFILER_DEFAULT_STARTUP_ENTRIES =
+# if !defined(GP_PLAT_arm_android)
+ mozilla::MakePowerOfTwo32<64 * 1024 * 1024>(); // 64M entries = 512MB
+# else
+ mozilla::MakePowerOfTwo32<8 * 1024 * 1024>(); // 8M entries = 64MB
+# endif
+
+// Note: Keep in sync with GeckoThread.maybeStartGeckoProfiler:
+// https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
+# define BASE_PROFILER_DEFAULT_INTERVAL 1 /* millisecond */
+# define BASE_PROFILER_MAX_INTERVAL 5000 /* milliseconds */
+
+// Initialize the profiler. If MOZ_PROFILER_STARTUP is set the profiler will
+// also be started. This call must happen before any other profiler calls
+// (except profiler_start(), which will call profiler_init() if it hasn't
+// already run).
+MFBT_API void profiler_init(void* stackTop);
+
+# define AUTO_BASE_PROFILER_INIT \
+ ::mozilla::baseprofiler::AutoProfilerInit PROFILER_RAII
+
+// Clean up the profiler module, stopping it if required. This function may
+// also save a shutdown profile if requested. No profiler calls should happen
+// after this point and all profiling stack labels should have been popped.
+MFBT_API void profiler_shutdown();
+
+// Start the profiler -- initializing it first if necessary -- with the
+// selected options. Stops and restarts the profiler if it is already active.
+// After starting the profiler is "active". The samples will be recorded in a
+// circular buffer.
+// "aCapacity" is the maximum number of 8-byte entries in the profiler's
+// circular buffer.
+// "aInterval" the sampling interval, measured in millseconds.
+// "aFeatures" is the feature set. Features unsupported by this
+// platform/configuration are ignored.
+// "aFilters" is the list of thread filters. Threads that do not match any
+// of the filters are not profiled. A filter matches a thread if
+// (a) the thread name contains the filter as a case-insensitive
+// substring, or
+// (b) the filter is of the form "pid:<n>" where n is the process
+// id of the process that the thread is running in.
+// "aDuration" is the duration of entries in the profiler's circular buffer.
+MFBT_API void profiler_start(PowerOfTwo32 aCapacity, double aInterval,
+ uint32_t aFeatures, const char** aFilters,
+ uint32_t aFilterCount,
+ const Maybe<double>& aDuration = Nothing());
+
+// Stop the profiler and discard the profile without saving it. A no-op if the
+// profiler is inactive. After stopping the profiler is "inactive".
+MFBT_API void profiler_stop();
+
+// If the profiler is inactive, start it. If it's already active, restart it if
+// the requested settings differ from the current settings. Both the check and
+// the state change are performed while the profiler state is locked.
+// The only difference to profiler_start is that the current buffer contents are
+// not discarded if the profiler is already running with the requested settings.
+MFBT_API void profiler_ensure_started(
+ PowerOfTwo32 aCapacity, double aInterval, uint32_t aFeatures,
+ const char** aFilters, uint32_t aFilterCount,
+ const Maybe<double>& aDuration = Nothing());
+
+//---------------------------------------------------------------------------
+// Control the profiler
+//---------------------------------------------------------------------------
+
+// Register/unregister threads with the profiler. Both functions operate the
+// same whether the profiler is active or inactive.
+# define BASE_PROFILER_REGISTER_THREAD(name) \
+ do { \
+ char stackTop; \
+ ::mozilla::baseprofiler::profiler_register_thread(name, &stackTop); \
+ } while (0)
+# define BASE_PROFILER_UNREGISTER_THREAD() \
+ ::mozilla::baseprofiler::profiler_unregister_thread()
+MFBT_API ProfilingStack* profiler_register_thread(const char* name,
+ void* guessStackTop);
+MFBT_API void profiler_unregister_thread();
+
+// Registers a DOM Window (the JS global `window`) with the profiler. Each
+// Window _roughly_ corresponds to a single document loaded within a
+// browsing context. Both the Window Id and Browser Id are recorded to allow
+// correlating different Windows loaded within the same tab or frame element.
+//
+// We register pages for each navigations but we do not register
+// history.pushState or history.replaceState since they correspond to the same
+// Inner Window ID. When a browsing context is first loaded, the first url
+// loaded in it will be about:blank. Because of that, this call keeps the first
+// non-about:blank registration of window and discards the previous one.
+//
+// "aTabID" is the BrowserId of that document belongs to.
+// That's used to determine the tab of that page.
+// "aInnerWindowID" is the ID of the `window` global object of that
+// document.
+// "aUrl" is the URL of the page.
+// "aEmbedderInnerWindowID" is the inner window id of embedder. It's used to
+// determine sub documents of a page.
+MFBT_API void profiler_register_page(uint64_t aTabD, uint64_t aInnerWindowID,
+ const std::string& aUrl,
+ uint64_t aEmbedderInnerWindowID);
+
+// Unregister page with the profiler.
+//
+// Take a Inner Window ID and unregister the page entry that has the same ID.
+MFBT_API void profiler_unregister_page(uint64_t aRegisteredInnerWindowID);
+
+// Remove all registered and unregistered pages in the profiler.
+void profiler_clear_all_pages();
+
+class BaseProfilerCount;
+MFBT_API void profiler_add_sampled_counter(BaseProfilerCount* aCounter);
+MFBT_API void profiler_remove_sampled_counter(BaseProfilerCount* aCounter);
+
+// Register and unregister a thread within a scope.
+# define AUTO_BASE_PROFILER_REGISTER_THREAD(name) \
+ ::mozilla::baseprofiler::AutoProfilerRegisterThread PROFILER_RAII(name)
+
+// Pause and resume the profiler. No-ops if the profiler is inactive. While
+// paused the profile will not take any samples and will not record any data
+// into its buffers. The profiler remains fully initialized in this state.
+// This feature will keep JavaScript profiling enabled, thus allowing toggling
+// the profiler without invalidating the JIT.
+MFBT_API void profiler_pause();
+MFBT_API void profiler_resume();
+
+// Only pause and resume the periodic sampling loop, including stack sampling,
+// counters, and profiling overheads.
+MFBT_API void profiler_pause_sampling();
+MFBT_API void profiler_resume_sampling();
+
+// These functions tell the profiler that a thread went to sleep so that we can
+// avoid sampling it while it's sleeping. Calling profiler_thread_sleep()
+// twice without an intervening profiler_thread_wake() is an error. All three
+// functions operate the same whether the profiler is active or inactive.
+MFBT_API void profiler_thread_sleep();
+MFBT_API void profiler_thread_wake();
+
+// Mark a thread as asleep/awake within a scope.
+# define AUTO_BASE_PROFILER_THREAD_SLEEP \
+ ::mozilla::baseprofiler::AutoProfilerThreadSleep PROFILER_RAII
+# define AUTO_BASE_PROFILER_THREAD_WAKE \
+ ::mozilla::baseprofiler::AutoProfilerThreadWake PROFILER_RAII
+
+//---------------------------------------------------------------------------
+// Get information from the profiler
+//---------------------------------------------------------------------------
+
+// Get the params used to start the profiler. Returns 0 and an empty vector
+// (via outparams) if the profile is inactive. It's possible that the features
+// returned may be slightly different to those requested due to required
+// adjustments.
+MFBT_API void profiler_get_start_params(
+ int* aEntrySize, Maybe<double>* aDuration, double* aInterval,
+ uint32_t* aFeatures, Vector<const char*, 0, MallocAllocPolicy>* aFilters);
+
+// The number of milliseconds since the process started. Operates the same
+// whether the profiler is active or inactive.
+MFBT_API double profiler_time();
+
+// An object of this class is passed to profiler_suspend_and_sample_thread().
+// For each stack frame, one of the Collect methods will be called.
+class ProfilerStackCollector {
+ public:
+ // Some collectors need to worry about possibly overwriting previous
+ // generations of data. If that's not an issue, this can return Nothing,
+ // which is the default behaviour.
+ virtual Maybe<uint64_t> SamplePositionInBuffer() { return Nothing(); }
+ virtual Maybe<uint64_t> BufferRangeStart() { return Nothing(); }
+
+ // This method will be called once if the thread being suspended is the main
+ // thread. Default behaviour is to do nothing.
+ virtual void SetIsMainThread() {}
+
+ // WARNING: The target thread is suspended when the Collect methods are
+ // called. Do not try to allocate or acquire any locks, or you could
+ // deadlock. The target thread will have resumed by the time this function
+ // returns.
+
+ virtual void CollectNativeLeafAddr(void* aAddr) = 0;
+
+ virtual void CollectProfilingStackFrame(
+ const ProfilingStackFrame& aFrame) = 0;
+};
+
+// This method suspends the thread identified by aThreadId, samples its
+// profiling stack, JS stack, and (optionally) native stack, passing the
+// collected frames into aCollector. aFeatures dictates which compiler features
+// are used. |Leaf| is the only relevant one.
+// Use `aThreadId`=0 to sample the current thread.
+MFBT_API void profiler_suspend_and_sample_thread(
+ int aThreadId, uint32_t aFeatures, ProfilerStackCollector& aCollector,
+ bool aSampleNative = true);
+
+struct ProfilerBacktraceDestructor {
+ MFBT_API void operator()(ProfilerBacktrace*);
+};
+
+using UniqueProfilerBacktrace =
+ UniquePtr<ProfilerBacktrace, ProfilerBacktraceDestructor>;
+
+// Immediately capture the current thread's call stack, store it in the provided
+// buffer (usually to avoid allocations if you can construct the buffer on the
+// stack). Returns false if unsuccessful, if the profiler is inactive, or if
+// aCaptureOptions is NoStack.
+MFBT_API bool profiler_capture_backtrace_into(
+ ProfileChunkedBuffer& aChunkedBuffer, StackCaptureOptions aCaptureOptions);
+
+// Immediately capture the current thread's call stack, and return it in a
+// ProfileChunkedBuffer (usually for later use in MarkerStack::TakeBacktrace()).
+// May be null if unsuccessful, or if the profiler is inactive.
+MFBT_API UniquePtr<ProfileChunkedBuffer> profiler_capture_backtrace();
+
+// Immediately capture the current thread's call stack, and return it in a
+// ProfilerBacktrace (usually for later use in marker function that take a
+// ProfilerBacktrace). May be null if unsuccessful, or if the profiler is
+// inactive.
+MFBT_API UniqueProfilerBacktrace profiler_get_backtrace();
+
+struct ProfilerStats {
+ unsigned n = 0;
+ double sum = 0;
+ double min = std::numeric_limits<double>::max();
+ double max = 0;
+ void Count(double v) {
+ ++n;
+ sum += v;
+ if (v < min) {
+ min = v;
+ }
+ if (v > max) {
+ max = v;
+ }
+ }
+};
+
+struct ProfilerBufferInfo {
+ // Index of the oldest entry.
+ uint64_t mRangeStart;
+ // Index of the newest entry.
+ uint64_t mRangeEnd;
+ // Buffer capacity in number of 8-byte entries.
+ uint32_t mEntryCount;
+ // Sampling stats: Interval (us) between successive samplings.
+ ProfilerStats mIntervalsUs;
+ // Sampling stats: Total duration (us) of each sampling. (Split detail below.)
+ ProfilerStats mOverheadsUs;
+ // Sampling stats: Time (us) to acquire the lock before sampling.
+ ProfilerStats mLockingsUs;
+ // Sampling stats: Time (us) to discard expired data.
+ ProfilerStats mCleaningsUs;
+ // Sampling stats: Time (us) to collect counter data.
+ ProfilerStats mCountersUs;
+ // Sampling stats: Time (us) to sample thread stacks.
+ ProfilerStats mThreadsUs;
+};
+
+// Get information about the current buffer status.
+// Returns Nothing() if the profiler is inactive.
+//
+// This information may be useful to a user-interface displaying the current
+// status of the profiler, allowing the user to get a sense for how fast the
+// buffer is being written to, and how much data is visible.
+MFBT_API Maybe<ProfilerBufferInfo> profiler_get_buffer_info();
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+namespace mozilla {
+namespace baseprofiler {
+
+//---------------------------------------------------------------------------
+// Put profiling data into the profiler (markers)
+//---------------------------------------------------------------------------
+
+MFBT_API void profiler_add_js_marker(const char* aMarkerName,
+ const char* aMarkerText);
+
+//---------------------------------------------------------------------------
+// Output profiles
+//---------------------------------------------------------------------------
+
+// Set a user-friendly process name, used in JSON stream.
+MFBT_API void profiler_set_process_name(const std::string& aProcessName,
+ const std::string* aETLDplus1);
+
+// Get the profile encoded as a JSON string. A no-op (returning nullptr) if the
+// profiler is inactive.
+// If aIsShuttingDown is true, the current time is included as the process
+// shutdown time in the JSON's "meta" object.
+MFBT_API UniquePtr<char[]> profiler_get_profile(double aSinceTime = 0,
+ bool aIsShuttingDown = false,
+ bool aOnlyThreads = false);
+
+// Write the profile for this process (excluding subprocesses) into aWriter.
+// Returns false if the profiler is inactive.
+MFBT_API bool profiler_stream_json_for_this_process(
+ SpliceableJSONWriter& aWriter, double aSinceTime = 0,
+ bool aIsShuttingDown = false, bool aOnlyThreads = false);
+
+// Get the profile and write it into a file. A no-op if the profile is
+// inactive.
+// Prefixed with "base" to avoid clashing with Gecko Profiler's extern "C"
+// profiler_save_profile_to_file when called from debugger.
+MFBT_API void baseprofiler_save_profile_to_file(const char* aFilename);
+
+//---------------------------------------------------------------------------
+// RAII classes
+//---------------------------------------------------------------------------
+
+class MOZ_RAII AutoProfilerInit {
+ public:
+ explicit AutoProfilerInit() { profiler_init(this); }
+
+ ~AutoProfilerInit() { profiler_shutdown(); }
+
+ private:
+};
+
+// Convenience class to register and unregister a thread with the profiler.
+// Needs to be the first object on the stack of the thread.
+class MOZ_RAII AutoProfilerRegisterThread final {
+ public:
+ explicit AutoProfilerRegisterThread(const char* aName) {
+ profiler_register_thread(aName, this);
+ }
+
+ ~AutoProfilerRegisterThread() { profiler_unregister_thread(); }
+
+ private:
+ AutoProfilerRegisterThread(const AutoProfilerRegisterThread&) = delete;
+ AutoProfilerRegisterThread& operator=(const AutoProfilerRegisterThread&) =
+ delete;
+};
+
+class MOZ_RAII AutoProfilerThreadSleep {
+ public:
+ explicit AutoProfilerThreadSleep() { profiler_thread_sleep(); }
+
+ ~AutoProfilerThreadSleep() { profiler_thread_wake(); }
+
+ private:
+};
+
+// Temporarily wake up the profiling of a thread while servicing events such as
+// Asynchronous Procedure Calls (APCs).
+class MOZ_RAII AutoProfilerThreadWake {
+ public:
+ explicit AutoProfilerThreadWake()
+ : mIssuedWake(profiler_thread_is_sleeping()) {
+ if (mIssuedWake) {
+ profiler_thread_wake();
+ }
+ }
+
+ ~AutoProfilerThreadWake() {
+ if (mIssuedWake) {
+ MOZ_ASSERT(!profiler_thread_is_sleeping());
+ profiler_thread_sleep();
+ }
+ }
+
+ private:
+ bool mIssuedWake;
+};
+
+// Get the MOZ_PROFILER_STARTUP* environment variables that should be
+// supplied to a child process that is about to be launched, in order
+// to make that child process start with the same profiler settings as
+// in the current process. The given function is invoked once for
+// each variable to be set.
+MFBT_API void GetProfilerEnvVarsForChildProcess(
+ std::function<void(const char* key, const char* value)>&& aSetEnv);
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif // !MOZ_GECKO_PROFILER
+
+#endif // BaseProfiler_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerCounts.h b/mozglue/baseprofiler/public/BaseProfilerCounts.h
new file mode 100644
index 0000000000..fbcc713744
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerCounts.h
@@ -0,0 +1,280 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerCounts_h
+#define BaseProfilerCounts_h
+
+#ifndef MOZ_GECKO_PROFILER
+
+# define BASE_PROFILER_DEFINE_COUNT_TOTAL(label, category, description)
+# define BASE_PROFILER_DEFINE_COUNT(label, category, description)
+# define BASE_PROFILER_DEFINE_STATIC_COUNT_TOTAL(label, category, description)
+# define AUTO_BASE_PROFILER_COUNT_TOTAL(label, count)
+# define AUTO_BASE_PROFILER_COUNT(label)
+# define AUTO_BASE_PROFILER_STATIC_COUNT(label, count)
+# define AUTO_BASE_PROFILER_FORCE_ALLOCATION(label)
+
+#else
+
+# include "mozilla/Atomics.h"
+
+namespace mozilla {
+namespace baseprofiler {
+
+class BaseProfilerCount;
+MFBT_API void profiler_add_sampled_counter(BaseProfilerCount* aCounter);
+MFBT_API void profiler_remove_sampled_counter(BaseProfilerCount* aCounter);
+
+typedef Atomic<int64_t, MemoryOrdering::Relaxed> ProfilerAtomicSigned;
+typedef Atomic<uint64_t, MemoryOrdering::Relaxed> ProfilerAtomicUnsigned;
+
+// Counter support
+// There are two types of counters:
+// 1) a simple counter which can be added to or subtracted from. This could
+// track the number of objects of a type, the number of calls to something
+// (reflow, JIT, etc).
+// 2) a combined counter which has the above, plus a number-of-calls counter
+// that is incremented by 1 for each call to modify the count. This provides
+// an optional source for a 'heatmap' of access. This can be used (for
+// example) to track the amount of memory allocated, and provide a heatmap of
+// memory operations (allocs/frees).
+//
+// Counters are sampled by the profiler once per sample-period. At this time,
+// all counters are global to the process. In the future, there might be more
+// versions with per-thread or other discriminators.
+//
+// Typical usage:
+// There are two ways to use counters: With heap-created counter objects,
+// or using macros. Note: the macros use statics, and will be slightly
+// faster/smaller, and you need to care about creating them before using
+// them. They're similar to the use-pattern for the other AUTO_PROFILER*
+// macros, but they do need the PROFILER_DEFINE* to be use to instantiate
+// the statics.
+//
+// PROFILER_DEFINE_COUNT(mything, "JIT", "Some JIT byte count")
+// ...
+// void foo() { ... AUTO_PROFILER_COUNT(mything, number_of_bytes_used); ... }
+//
+// or (to also get a heatmap)
+//
+// PROFILER_DEFINE_COUNT_TOTAL(mything, "JIT", "Some JIT byte count")
+// ...
+// void foo() {
+// ...
+// AUTO_PROFILER_COUNT_TOTAL(mything, number_of_bytes_generated);
+// ...
+// }
+//
+// To use without statics/macros:
+//
+// UniquePtr<ProfilerCounter> myCounter;
+// ...
+// myCounter =
+// MakeUnique<ProfilerCounter>("mything", "JIT", "Some JIT byte count"));
+// ...
+// void foo() { ... myCounter->Add(number_of_bytes_generated0; ... }
+
+class BaseProfilerCount {
+ public:
+ BaseProfilerCount(const char* aLabel, ProfilerAtomicSigned* aCounter,
+ ProfilerAtomicUnsigned* aNumber, const char* aCategory,
+ const char* aDescription)
+ : mLabel(aLabel),
+ mCategory(aCategory),
+ mDescription(aDescription),
+ mCounter(aCounter),
+ mNumber(aNumber) {
+# define COUNTER_CANARY 0xDEADBEEF
+# ifdef DEBUG
+ mCanary = COUNTER_CANARY;
+ mPrevNumber = 0;
+# endif
+ // Can't call profiler_* here since this may be non-xul-library
+ }
+# ifdef DEBUG
+ ~BaseProfilerCount() { mCanary = 0; }
+# endif
+
+ void Sample(int64_t& aCounter, uint64_t& aNumber) {
+ MOZ_ASSERT(mCanary == COUNTER_CANARY);
+
+ aCounter = *mCounter;
+ aNumber = mNumber ? *mNumber : 0;
+# ifdef DEBUG
+ MOZ_ASSERT(aNumber >= mPrevNumber);
+ mPrevNumber = aNumber;
+# endif
+ }
+
+ // We don't define ++ and Add() here, since the static defines directly
+ // increment the atomic counters, and the subclasses implement ++ and
+ // Add() directly.
+
+ // These typically are static strings (for example if you use the macros
+ // below)
+ const char* mLabel;
+ const char* mCategory;
+ const char* mDescription;
+ // We're ok with these being un-ordered in race conditions. These are
+ // pointers because we want to be able to use statics and increment them
+ // directly. Otherwise we could just have them inline, and not need the
+ // constructor args.
+ // These can be static globals (using the macros below), though they
+ // don't have to be - their lifetime must be longer than the use of them
+ // by the profiler (see profiler_add/remove_sampled_counter()). If you're
+ // using a lot of these, they probably should be allocated at runtime (see
+ // class ProfilerCountOnly below).
+ ProfilerAtomicSigned* mCounter;
+ ProfilerAtomicUnsigned* mNumber; // may be null
+
+# ifdef DEBUG
+ uint32_t mCanary;
+ uint64_t mPrevNumber; // value of number from the last Sample()
+# endif
+};
+
+// Designed to be allocated dynamically, and simply incremented with obj++
+// or obj->Add(n)
+class ProfilerCounter final : public BaseProfilerCount {
+ public:
+ ProfilerCounter(const char* aLabel, const char* aCategory,
+ const char* aDescription)
+ : BaseProfilerCount(aLabel, &mCounter, nullptr, aCategory, aDescription) {
+ // Assume we're in libxul
+ profiler_add_sampled_counter(this);
+ }
+
+ virtual ~ProfilerCounter() { profiler_remove_sampled_counter(this); }
+
+ BaseProfilerCount& operator++() {
+ Add(1);
+ return *this;
+ }
+
+ void Add(int64_t aNumber) { mCounter += aNumber; }
+
+ ProfilerAtomicSigned mCounter;
+};
+
+// Also keeps a heatmap (number of calls to ++/Add())
+class ProfilerCounterTotal final : public BaseProfilerCount {
+ public:
+ ProfilerCounterTotal(const char* aLabel, const char* aCategory,
+ const char* aDescription)
+ : BaseProfilerCount(aLabel, &mCounter, &mNumber, aCategory,
+ aDescription) {
+ // Assume we're in libxul
+ profiler_add_sampled_counter(this);
+ }
+
+ virtual ~ProfilerCounterTotal() { profiler_remove_sampled_counter(this); }
+
+ BaseProfilerCount& operator++() {
+ Add(1);
+ return *this;
+ }
+
+ void Add(int64_t aNumber) {
+ mCounter += aNumber;
+ mNumber++;
+ }
+
+ ProfilerAtomicSigned mCounter;
+ ProfilerAtomicUnsigned mNumber;
+};
+
+// Defines a counter that is sampled on each profiler tick, with a running
+// count (signed), and number-of-instances. Note that because these are two
+// independent Atomics, there is a possiblity that count will not include
+// the last call, but number of uses will. I think this is not worth
+// worrying about
+# define BASE_PROFILER_DEFINE_COUNT_TOTAL(label, category, description) \
+ ProfilerAtomicSigned profiler_count_##label(0); \
+ ProfilerAtomicUnsigned profiler_number_##label(0); \
+ const char profiler_category_##label[] = category; \
+ const char profiler_description_##label[] = description; \
+ UniquePtr<::mozilla::baseprofiler::BaseProfilerCount> AutoCount_##label;
+
+// This counts, but doesn't keep track of the number of calls to
+// AUTO_PROFILER_COUNT()
+# define BASE_PROFILER_DEFINE_COUNT(label, category, description) \
+ ProfilerAtomicSigned profiler_count_##label(0); \
+ const char profiler_category_##label[] = category; \
+ const char profiler_description_##label[] = description; \
+ UniquePtr<::mozilla::baseprofiler::BaseProfilerCount> AutoCount_##label;
+
+// This will create a static initializer if used, but avoids a possible
+// allocation.
+# define BASE_PROFILER_DEFINE_STATIC_COUNT_TOTAL(label, category, \
+ description) \
+ ProfilerAtomicSigned profiler_count_##label(0); \
+ ProfilerAtomicUnsigned profiler_number_##label(0); \
+ ::mozilla::baseprofiler::BaseProfilerCount AutoCount_##label( \
+ #label, &profiler_count_##label, &profiler_number_##label, category, \
+ description);
+
+// If we didn't care about static initializers, we could avoid the need for
+// a ptr to the BaseProfilerCount object.
+
+// XXX It would be better to do this without the if() and without the
+// theoretical race to set the UniquePtr (i.e. possible leak).
+# define AUTO_BASE_PROFILER_COUNT_TOTAL(label, count) \
+ do { \
+ profiler_number_##label++; /* do this first*/ \
+ profiler_count_##label += count; \
+ if (!AutoCount_##label) { \
+ /* Ignore that we could call this twice in theory, and that we leak \
+ * them \
+ */ \
+ AutoCount_##label.reset(new BaseProfilerCount( \
+ #label, &profiler_count_##label, &profiler_number_##label, \
+ profiler_category_##label, profiler_description_##label)); \
+ ::mozilla::baseprofiler::profiler_add_sampled_counter( \
+ AutoCount_##label.get()); \
+ } \
+ } while (0)
+
+# define AUTO_BASE_PROFILER_COUNT(label, count) \
+ do { \
+ profiler_count_##label += count; /* do this first*/ \
+ if (!AutoCount_##label) { \
+ /* Ignore that we could call this twice in theory, and that we leak \
+ * them \
+ */ \
+ AutoCount_##label.reset(new BaseProfilerCount( \
+ #label, nullptr, &profiler_number_##label, \
+ profiler_category_##label, profiler_description_##label)); \
+ ::mozilla::baseprofiler::profiler_add_sampled_counter( \
+ AutoCount_##label.get()); \
+ } \
+ } while (0)
+
+# define AUTO_BASE_PROFILER_STATIC_COUNT(label, count) \
+ do { \
+ profiler_number_##label++; /* do this first*/ \
+ profiler_count_##label += count; \
+ } while (0)
+
+// if we need to force the allocation
+# define AUTO_BASE_PROFILER_FORCE_ALLOCATION(label) \
+ do { \
+ if (!AutoCount_##label) { \
+ /* Ignore that we could call this twice in theory, and that we leak \
+ * them \
+ */ \
+ AutoCount_##label.reset( \
+ new ::mozilla::baseprofiler::BaseProfilerCount( \
+ #label, &profiler_count_##label, &profiler_number_##label, \
+ profiler_category_##label, profiler_description_##label)); \
+ } \
+ } while (0)
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif // !MOZ_GECKO_PROFILER
+
+#endif // BaseProfilerCounts_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerDetail.h b/mozglue/baseprofiler/public/BaseProfilerDetail.h
new file mode 100644
index 0000000000..6ecf6e117b
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerDetail.h
@@ -0,0 +1,285 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Internal Base Profiler utilities.
+
+#ifndef BaseProfilerDetail_h
+#define BaseProfilerDetail_h
+
+#include "mozilla/Atomics.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/PlatformMutex.h"
+#include "mozilla/PlatformRWLock.h"
+#include "mozilla/BaseProfilerUtils.h"
+
+namespace mozilla {
+namespace baseprofiler {
+
+namespace detail {
+
+// Thin shell around mozglue PlatformMutex, for Base Profiler internal use.
+class MOZ_CAPABILITY("mutex") BaseProfilerMutex
+ : private ::mozilla::detail::MutexImpl {
+ public:
+ BaseProfilerMutex() : ::mozilla::detail::MutexImpl() {}
+ explicit BaseProfilerMutex(const char* aName)
+ : ::mozilla::detail::MutexImpl(), mName(aName) {}
+
+ BaseProfilerMutex(const BaseProfilerMutex&) = delete;
+ BaseProfilerMutex& operator=(const BaseProfilerMutex&) = delete;
+ BaseProfilerMutex(BaseProfilerMutex&&) = delete;
+ BaseProfilerMutex& operator=(BaseProfilerMutex&&) = delete;
+
+#ifdef DEBUG
+ ~BaseProfilerMutex() {
+ MOZ_ASSERT(!BaseProfilerThreadId::FromNumber(mOwningThreadId).IsSpecified(),
+ "BaseProfilerMutex should have been unlocked when destroyed");
+ }
+#endif // DEBUG
+
+ [[nodiscard]] bool IsLockedOnCurrentThread() const {
+ return BaseProfilerThreadId::FromNumber(mOwningThreadId) ==
+ baseprofiler::profiler_current_thread_id();
+ }
+
+ void AssertCurrentThreadOwns() const MOZ_ASSERT_CAPABILITY(this) {
+ MOZ_ASSERT(IsLockedOnCurrentThread());
+ }
+
+ void Lock() MOZ_CAPABILITY_ACQUIRE() {
+ const BaseProfilerThreadId tid = baseprofiler::profiler_current_thread_id();
+ MOZ_ASSERT(tid.IsSpecified());
+ MOZ_ASSERT(!IsLockedOnCurrentThread(), "Recursive locking");
+ ::mozilla::detail::MutexImpl::lock();
+ MOZ_ASSERT(!BaseProfilerThreadId::FromNumber(mOwningThreadId).IsSpecified(),
+ "Not unlocked properly");
+ mOwningThreadId = tid.ToNumber();
+ }
+
+ [[nodiscard]] bool TryLock() MOZ_TRY_ACQUIRE(true) {
+ const BaseProfilerThreadId tid = baseprofiler::profiler_current_thread_id();
+ MOZ_ASSERT(tid.IsSpecified());
+ MOZ_ASSERT(!IsLockedOnCurrentThread(), "Recursive locking");
+ if (!::mozilla::detail::MutexImpl::tryLock()) {
+ // Failed to lock, nothing more to do.
+ return false;
+ }
+ MOZ_ASSERT(!BaseProfilerThreadId::FromNumber(mOwningThreadId).IsSpecified(),
+ "Not unlocked properly");
+ mOwningThreadId = tid.ToNumber();
+ return true;
+ }
+
+ void Unlock() MOZ_CAPABILITY_RELEASE() {
+ MOZ_ASSERT(IsLockedOnCurrentThread(), "Unlocking when not locked here");
+ // We're still holding the mutex here, so it's safe to just reset
+ // `mOwningThreadId`.
+ mOwningThreadId = BaseProfilerThreadId{}.ToNumber();
+ ::mozilla::detail::MutexImpl::unlock();
+ }
+
+ const char* GetName() const { return mName; }
+
+ private:
+ // Thread currently owning the lock, or 0.
+ // Atomic because it may be read at any time independent of the mutex.
+ // Relaxed because threads only need to know if they own it already, so:
+ // - If it's their id, only *they* wrote that value with a locked mutex.
+ // - If it's different from their thread id it doesn't matter what other
+ // number it is (0 or another id) and that it can change again at any time.
+ Atomic<typename BaseProfilerThreadId::NumberType, MemoryOrdering::Relaxed>
+ mOwningThreadId;
+
+ const char* mName = nullptr;
+};
+
+// RAII class to lock a mutex.
+class MOZ_RAII BaseProfilerAutoLock {
+ public:
+ explicit BaseProfilerAutoLock(BaseProfilerMutex& aMutex) : mMutex(aMutex) {
+ mMutex.Lock();
+ }
+
+ BaseProfilerAutoLock(const BaseProfilerAutoLock&) = delete;
+ BaseProfilerAutoLock& operator=(const BaseProfilerAutoLock&) = delete;
+ BaseProfilerAutoLock(BaseProfilerAutoLock&&) = delete;
+ BaseProfilerAutoLock& operator=(BaseProfilerAutoLock&&) = delete;
+
+ ~BaseProfilerAutoLock() { mMutex.Unlock(); }
+
+ private:
+ BaseProfilerMutex& mMutex;
+};
+
+// Thin shell around mozglue PlatformMutex, for Base Profiler internal use.
+// Actual mutex may be disabled at construction time.
+class BaseProfilerMaybeMutex : private ::mozilla::detail::MutexImpl {
+ public:
+ explicit BaseProfilerMaybeMutex(bool aActivate) {
+ if (aActivate) {
+ mMaybeMutex.emplace();
+ }
+ }
+
+ BaseProfilerMaybeMutex(const BaseProfilerMaybeMutex&) = delete;
+ BaseProfilerMaybeMutex& operator=(const BaseProfilerMaybeMutex&) = delete;
+ BaseProfilerMaybeMutex(BaseProfilerMaybeMutex&&) = delete;
+ BaseProfilerMaybeMutex& operator=(BaseProfilerMaybeMutex&&) = delete;
+
+ ~BaseProfilerMaybeMutex() = default;
+
+ bool IsActivated() const { return mMaybeMutex.isSome(); }
+
+ [[nodiscard]] bool IsActivatedAndLockedOnCurrentThread() const {
+ if (!IsActivated()) {
+ // Not activated, so we can never be locked.
+ return false;
+ }
+ return mMaybeMutex->IsLockedOnCurrentThread();
+ }
+
+ void AssertCurrentThreadOwns() const {
+#ifdef DEBUG
+ if (IsActivated()) {
+ mMaybeMutex->AssertCurrentThreadOwns();
+ }
+#endif // DEBUG
+ }
+
+ MOZ_PUSH_IGNORE_THREAD_SAFETY
+ void Lock() {
+ if (IsActivated()) {
+ mMaybeMutex->Lock();
+ }
+ }
+
+ void Unlock() {
+ if (IsActivated()) {
+ mMaybeMutex->Unlock();
+ }
+ }
+ MOZ_POP_THREAD_SAFETY
+
+ private:
+ Maybe<BaseProfilerMutex> mMaybeMutex;
+};
+
+// RAII class to lock a mutex.
+class MOZ_RAII BaseProfilerMaybeAutoLock {
+ public:
+ explicit BaseProfilerMaybeAutoLock(BaseProfilerMaybeMutex& aMaybeMutex)
+ : mMaybeMutex(aMaybeMutex) {
+ mMaybeMutex.Lock();
+ }
+
+ BaseProfilerMaybeAutoLock(const BaseProfilerMaybeAutoLock&) = delete;
+ BaseProfilerMaybeAutoLock& operator=(const BaseProfilerMaybeAutoLock&) =
+ delete;
+ BaseProfilerMaybeAutoLock(BaseProfilerMaybeAutoLock&&) = delete;
+ BaseProfilerMaybeAutoLock& operator=(BaseProfilerMaybeAutoLock&&) = delete;
+
+ ~BaseProfilerMaybeAutoLock() { mMaybeMutex.Unlock(); }
+
+ private:
+ BaseProfilerMaybeMutex& mMaybeMutex;
+};
+
+class BaseProfilerSharedMutex : public ::mozilla::detail::RWLockImpl {
+ public:
+#ifdef DEBUG
+ ~BaseProfilerSharedMutex() {
+ MOZ_ASSERT(!BaseProfilerThreadId::FromNumber(mOwningThreadId).IsSpecified(),
+ "BaseProfilerMutex should have been unlocked when destroyed");
+ }
+#endif // DEBUG
+
+ [[nodiscard]] bool IsLockedExclusiveOnCurrentThread() const {
+ return BaseProfilerThreadId::FromNumber(mOwningThreadId) ==
+ baseprofiler::profiler_current_thread_id();
+ }
+
+ void LockExclusive() {
+ const BaseProfilerThreadId tid = baseprofiler::profiler_current_thread_id();
+ MOZ_ASSERT(tid.IsSpecified());
+ MOZ_ASSERT(!IsLockedExclusiveOnCurrentThread(), "Recursive locking");
+ ::mozilla::detail::RWLockImpl::writeLock();
+ MOZ_ASSERT(!BaseProfilerThreadId::FromNumber(mOwningThreadId).IsSpecified(),
+ "Not unlocked properly");
+ mOwningThreadId = tid.ToNumber();
+ }
+
+ void UnlockExclusive() {
+ MOZ_ASSERT(IsLockedExclusiveOnCurrentThread(),
+ "Unlocking when not locked here");
+ // We're still holding the mutex here, so it's safe to just reset
+ // `mOwningThreadId`.
+ mOwningThreadId = BaseProfilerThreadId{}.ToNumber();
+ writeUnlock();
+ }
+
+ void LockShared() { readLock(); }
+
+ void UnlockShared() { readUnlock(); }
+
+ private:
+ // Thread currently owning the exclusive lock, or 0.
+ // Atomic because it may be read at any time independent of the mutex.
+ // Relaxed because threads only need to know if they own it already, so:
+ // - If it's their id, only *they* wrote that value with a locked mutex.
+ // - If it's different from their thread id it doesn't matter what other
+ // number it is (0 or another id) and that it can change again at any time.
+ Atomic<typename BaseProfilerThreadId::NumberType, MemoryOrdering::Relaxed>
+ mOwningThreadId;
+};
+
+// RAII class to lock a shared mutex exclusively.
+class MOZ_RAII BaseProfilerAutoLockExclusive {
+ public:
+ explicit BaseProfilerAutoLockExclusive(BaseProfilerSharedMutex& aSharedMutex)
+ : mSharedMutex(aSharedMutex) {
+ mSharedMutex.LockExclusive();
+ }
+
+ BaseProfilerAutoLockExclusive(const BaseProfilerAutoLockExclusive&) = delete;
+ BaseProfilerAutoLockExclusive& operator=(
+ const BaseProfilerAutoLockExclusive&) = delete;
+ BaseProfilerAutoLockExclusive(BaseProfilerAutoLockExclusive&&) = delete;
+ BaseProfilerAutoLockExclusive& operator=(BaseProfilerAutoLockExclusive&&) =
+ delete;
+
+ ~BaseProfilerAutoLockExclusive() { mSharedMutex.UnlockExclusive(); }
+
+ private:
+ BaseProfilerSharedMutex& mSharedMutex;
+};
+
+// RAII class to lock a shared mutex non-exclusively, other
+// BaseProfilerAutoLockShared's may happen in other threads.
+class MOZ_RAII BaseProfilerAutoLockShared {
+ public:
+ explicit BaseProfilerAutoLockShared(BaseProfilerSharedMutex& aSharedMutex)
+ : mSharedMutex(aSharedMutex) {
+ mSharedMutex.LockShared();
+ }
+
+ BaseProfilerAutoLockShared(const BaseProfilerAutoLockShared&) = delete;
+ BaseProfilerAutoLockShared& operator=(const BaseProfilerAutoLockShared&) =
+ delete;
+ BaseProfilerAutoLockShared(BaseProfilerAutoLockShared&&) = delete;
+ BaseProfilerAutoLockShared& operator=(BaseProfilerAutoLockShared&&) = delete;
+
+ ~BaseProfilerAutoLockShared() { mSharedMutex.UnlockShared(); }
+
+ private:
+ BaseProfilerSharedMutex& mSharedMutex;
+};
+
+} // namespace detail
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif // BaseProfilerDetail_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerLabels.h b/mozglue/baseprofiler/public/BaseProfilerLabels.h
new file mode 100644
index 0000000000..8da596e3ab
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerLabels.h
@@ -0,0 +1,178 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This header contains all definitions related to Base Profiler labels (outside
+// of XUL).
+// It is safe to include unconditionally, and only defines empty macros if
+// MOZ_GECKO_PROFILER is not set.
+
+#ifndef BaseProfilerLabels_h
+#define BaseProfilerLabels_h
+
+#ifndef MOZ_GECKO_PROFILER
+
+# define AUTO_BASE_PROFILER_LABEL(label, categoryPair)
+# define AUTO_BASE_PROFILER_LABEL_CATEGORY_PAIR(categoryPair)
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_CSTR(label, categoryPair, cStr)
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_STRING(label, categoryPair, str)
+# define AUTO_BASE_PROFILER_LABEL_FAST(label, categoryPair, ctx)
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_FAST(label, dynamicString, \
+ categoryPair, ctx, flags)
+
+#else // !MOZ_GECKO_PROFILER
+
+# include "BaseProfilingStack.h"
+
+# include "mozilla/Attributes.h"
+# include "mozilla/Maybe.h"
+# include "mozilla/BaseProfilerRAIIMacro.h"
+# include "mozilla/BaseProfilerState.h"
+# include "mozilla/ThreadLocal.h"
+
+# include <stdint.h>
+# include <string>
+
+namespace mozilla::baseprofiler {
+
+// Insert an RAII object in this scope to enter a label stack frame. Any
+// samples collected in this scope will contain this label in their stack.
+// The label argument must be a static C string. It is usually of the
+// form "ClassName::FunctionName". (Ideally we'd use the compiler to provide
+// that for us, but __func__ gives us the function name without the class
+// name.) If the label applies to only part of a function, you can qualify it
+// like this: "ClassName::FunctionName:PartName".
+//
+// Use AUTO_BASE_PROFILER_LABEL_DYNAMIC_* if you want to add additional /
+// dynamic information to the label stack frame.
+# define AUTO_BASE_PROFILER_LABEL(label, categoryPair) \
+ ::mozilla::baseprofiler::AutoProfilerLabel PROFILER_RAII( \
+ label, nullptr, \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair)
+
+// Similar to AUTO_BASE_PROFILER_LABEL, but with only one argument: the category
+// pair. The label string is taken from the category pair. This is convenient
+// for labels like
+// AUTO_BASE_PROFILER_LABEL_CATEGORY_PAIR(GRAPHICS_LayerBuilding) which would
+// otherwise just repeat the string.
+# define AUTO_BASE_PROFILER_LABEL_CATEGORY_PAIR(categoryPair) \
+ ::mozilla::baseprofiler::AutoProfilerLabel PROFILER_RAII( \
+ "", nullptr, \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair, \
+ uint32_t(::mozilla::baseprofiler::ProfilingStackFrame::Flags:: \
+ LABEL_DETERMINED_BY_CATEGORY_PAIR))
+
+// Similar to AUTO_BASE_PROFILER_LABEL, but with an additional string. The
+// inserted RAII object stores the cStr pointer in a field; it does not copy the
+// string.
+//
+// WARNING: This means that the string you pass to this macro needs to live at
+// least until the end of the current scope. Be careful using this macro with
+// ns[C]String; the other AUTO_BASE_PROFILER_LABEL_DYNAMIC_* macros below are
+// preferred because they avoid this problem.
+//
+// If the profiler samples the current thread and walks the label stack while
+// this RAII object is on the stack, it will copy the supplied string into the
+// profile buffer. So there's one string copy operation, and it happens at
+// sample time.
+//
+// Compare this to the plain AUTO_BASE_PROFILER_LABEL macro, which only accepts
+// literal strings: When the label stack frames generated by
+// AUTO_BASE_PROFILER_LABEL are sampled, no string copy needs to be made because
+// the profile buffer can just store the raw pointers to the literal strings.
+// Consequently, AUTO_BASE_PROFILER_LABEL frames take up considerably less space
+// in the profile buffer than AUTO_BASE_PROFILER_LABEL_DYNAMIC_* frames.
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_CSTR(label, categoryPair, cStr) \
+ ::mozilla::baseprofiler::AutoProfilerLabel PROFILER_RAII( \
+ label, cStr, \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair)
+
+// Similar to AUTO_BASE_PROFILER_LABEL_DYNAMIC_CSTR, but takes an std::string.
+//
+// Note: The use of the Maybe<>s ensures the scopes for the dynamic string and
+// the AutoProfilerLabel are appropriate, while also not incurring the runtime
+// cost of the string assignment unless the profiler is active. Therefore,
+// unlike AUTO_BASE_PROFILER_LABEL and AUTO_BASE_PROFILER_LABEL_DYNAMIC_CSTR,
+// this macro doesn't push/pop a label when the profiler is inactive.
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_STRING(label, categoryPair, str) \
+ Maybe<std::string> autoStr; \
+ Maybe<::mozilla::baseprofiler::AutoProfilerLabel> raiiObjectString; \
+ if (::mozilla::baseprofiler::profiler_is_active()) { \
+ autoStr.emplace(str); \
+ raiiObjectString.emplace( \
+ label, autoStr->c_str(), \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair); \
+ }
+
+// Similar to AUTO_BASE_PROFILER_LABEL, but accepting a JSContext* parameter,
+// and a no-op if the profiler is disabled. Used to annotate functions for which
+// overhead in the range of nanoseconds is noticeable. It avoids overhead from
+// the TLS lookup because it can get the ProfilingStack from the JS context, and
+// avoids almost all overhead in the case where the profiler is disabled.
+# define AUTO_BASE_PROFILER_LABEL_FAST(label, categoryPair, ctx) \
+ ::mozilla::baseprofiler::AutoProfilerLabel PROFILER_RAII( \
+ ctx, label, nullptr, \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair)
+
+// Similar to AUTO_BASE_PROFILER_LABEL_FAST, but also takes an extra string and
+// an additional set of flags. The flags parameter should carry values from the
+// ProfilingStackFrame::Flags enum.
+# define AUTO_BASE_PROFILER_LABEL_DYNAMIC_FAST(label, dynamicString, \
+ categoryPair, ctx, flags) \
+ ::mozilla::baseprofiler::AutoProfilerLabel PROFILER_RAII( \
+ ctx, label, dynamicString, \
+ ::mozilla::baseprofiler::ProfilingCategoryPair::categoryPair, flags)
+
+// This class creates a non-owning ProfilingStack reference. Objects of this
+// class are stack-allocated, and so exist within a thread, and are thus bounded
+// by the lifetime of the thread, which ensures that the references held can't
+// be used after the ProfilingStack is destroyed.
+class MOZ_RAII AutoProfilerLabel {
+ public:
+ // This is the AUTO_BASE_PROFILER_LABEL and AUTO_BASE_PROFILER_LABEL_DYNAMIC
+ // variant.
+ AutoProfilerLabel(const char* aLabel, const char* aDynamicString,
+ ProfilingCategoryPair aCategoryPair, uint32_t aFlags = 0) {
+ // Get the ProfilingStack from TLS.
+ Push(GetProfilingStack(), aLabel, aDynamicString, aCategoryPair, aFlags);
+ }
+
+ void Push(ProfilingStack* aProfilingStack, const char* aLabel,
+ const char* aDynamicString, ProfilingCategoryPair aCategoryPair,
+ uint32_t aFlags = 0) {
+ // This function runs both on and off the main thread.
+
+ mProfilingStack = aProfilingStack;
+ if (mProfilingStack) {
+ mProfilingStack->pushLabelFrame(aLabel, aDynamicString, this,
+ aCategoryPair, aFlags);
+ }
+ }
+
+ ~AutoProfilerLabel() {
+ // This function runs both on and off the main thread.
+
+ if (mProfilingStack) {
+ mProfilingStack->pop();
+ }
+ }
+
+ MFBT_API static ProfilingStack* GetProfilingStack();
+
+ private:
+ // We save a ProfilingStack pointer in the ctor so we don't have to redo the
+ // TLS lookup in the dtor.
+ ProfilingStack* mProfilingStack;
+
+ public:
+ // See the comment on the definition in platform.cpp for details about this.
+ static MOZ_THREAD_LOCAL(ProfilingStack*) sProfilingStack;
+};
+
+} // namespace mozilla::baseprofiler
+
+#endif // !MOZ_GECKO_PROFILER
+
+#endif // BaseProfilerLabels_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerMarkerTypes.h b/mozglue/baseprofiler/public/BaseProfilerMarkerTypes.h
new file mode 100644
index 0000000000..404e15c5f6
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerMarkerTypes.h
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerMarkerTypes_h
+#define BaseProfilerMarkerTypes_h
+
+// This header contains common marker type definitions.
+//
+// It #include's "mozilla/BaseProfilerMarkers.h", see that file for how to
+// define other marker types, and how to add markers to the profiler buffers.
+//
+// If you don't need to use these common types, #include
+// "mozilla/BaseProfilerMarkers.h" instead.
+//
+// Types in this files can be defined without relying on xpcom.
+// Others are defined in "ProfilerMarkerTypes.h".
+
+// !!! /!\ WORK IN PROGRESS /!\ !!!
+// This file contains draft marker definitions, but most are not used yet.
+// Further work is needed to complete these definitions, and use them to convert
+// existing PROFILER_ADD_MARKER calls. See meta bug 1661394.
+
+#include "mozilla/BaseProfilerMarkers.h"
+
+namespace mozilla::baseprofiler::markers {
+
+struct MediaSampleMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("MediaSample");
+ }
+ static void StreamJSONMarkerData(SpliceableJSONWriter& aWriter,
+ int64_t aSampleStartTimeUs,
+ int64_t aSampleEndTimeUs,
+ int64_t aQueueLength) {
+ aWriter.IntProperty("sampleStartTimeUs", aSampleStartTimeUs);
+ aWriter.IntProperty("sampleEndTimeUs", aSampleEndTimeUs);
+ aWriter.IntProperty("queueLength", aQueueLength);
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ schema.AddKeyLabelFormat("sampleStartTimeUs", "Sample start time",
+ MS::Format::Microseconds);
+ schema.AddKeyLabelFormat("sampleEndTimeUs", "Sample end time",
+ MS::Format::Microseconds);
+ schema.AddKeyLabelFormat("queueLength", "Queue length",
+ MS::Format::Integer);
+ return schema;
+ }
+};
+
+struct VideoFallingBehindMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("VideoFallingBehind");
+ }
+ static void StreamJSONMarkerData(SpliceableJSONWriter& aWriter,
+ int64_t aVideoFrameStartTimeUs,
+ int64_t aMediaCurrentTimeUs) {
+ aWriter.IntProperty("videoFrameStartTimeUs", aVideoFrameStartTimeUs);
+ aWriter.IntProperty("mediaCurrentTimeUs", aMediaCurrentTimeUs);
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ schema.AddKeyLabelFormat("videoFrameStartTimeUs", "Video frame start time",
+ MS::Format::Microseconds);
+ schema.AddKeyLabelFormat("mediaCurrentTimeUs", "Media current time",
+ MS::Format::Microseconds);
+ return schema;
+ }
+};
+
+struct ContentBuildMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("CONTENT_FULL_PAINT_TIME");
+ }
+ static void StreamJSONMarkerData(SpliceableJSONWriter& aWriter) {}
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ return schema;
+ }
+};
+
+struct MediaEngineMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("MediaEngine");
+ }
+ static void StreamJSONMarkerData(baseprofiler::SpliceableJSONWriter& aWriter,
+ uint64_t aMediaEngineId) {
+ aWriter.IntProperty("id", aMediaEngineId);
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ schema.AddKeyLabelFormat("id", "Id", MS::Format::Integer);
+ return schema;
+ }
+};
+
+struct MediaEngineTextMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("MediaEngineText");
+ }
+ static void StreamJSONMarkerData(baseprofiler::SpliceableJSONWriter& aWriter,
+ uint64_t aMediaEngineId,
+ const ProfilerString8View& aText) {
+ aWriter.IntProperty("id", aMediaEngineId);
+ aWriter.StringProperty("text", aText);
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ schema.AddKeyLabelFormat("id", "Id", MS::Format::Integer);
+ schema.AddKeyLabelFormat("text", "Details", MS::Format::String);
+ return schema;
+ }
+};
+
+} // namespace mozilla::baseprofiler::markers
+
+#endif // BaseProfilerMarkerTypes_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerMarkers.h b/mozglue/baseprofiler/public/BaseProfilerMarkers.h
new file mode 100644
index 0000000000..d706cefd4a
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerMarkers.h
@@ -0,0 +1,255 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Markers are useful to delimit something important happening such as the first
+// paint. Unlike labels, which are only recorded in the profile buffer if a
+// sample is collected while the label is on the label stack, markers will
+// always be recorded in the profile buffer.
+//
+// This header contains basic definitions necessary to create marker types, and
+// to add markers to the profiler buffers.
+//
+// If basic marker types are needed, #include
+// "mozilla/BaseProfilerMarkerTypes.h" instead.
+//
+// But if you want to create your own marker type locally, you can #include this
+// header only; look at mozilla/BaseProfilerMarkerTypes.h for examples of how to
+// define types, and mozilla/BaseProfilerMarkerPrerequisites.h for some
+// supporting types.
+//
+// To then record markers:
+// - Use `baseprofiler::AddMarker(...)` from mozglue or other libraries that
+// are outside of xul, especially if they may happen outside of xpcom's
+// lifetime (typically startup, shutdown, or tests).
+// - Otherwise #include "ProfilerMarkers.h" instead, and use
+// `profiler_add_marker(...)`.
+// See these functions for more details.
+
+#ifndef BaseProfilerMarkers_h
+#define BaseProfilerMarkers_h
+
+#include "mozilla/BaseProfilerMarkersDetail.h"
+#include "mozilla/BaseProfilerLabels.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/Unused.h"
+
+#include <functional>
+#include <string>
+#include <utility>
+
+namespace mozilla::baseprofiler {
+
+#ifdef MOZ_GECKO_PROFILER
+// Forward-declaration. TODO: Move to more common header, see bug 1681416.
+MFBT_API bool profiler_capture_backtrace_into(
+ ProfileChunkedBuffer& aChunkedBuffer, StackCaptureOptions aCaptureOptions);
+
+// Add a marker to a given buffer. `AddMarker()` and related macros should be
+// used in most cases, see below for more information about them and the
+// parameters; This function may be useful when markers need to be recorded in a
+// local buffer outside of the main profiler buffer.
+template <typename MarkerType, typename... PayloadArguments>
+ProfileBufferBlockIndex AddMarkerToBuffer(
+ ProfileChunkedBuffer& aBuffer, const ProfilerString8View& aName,
+ const MarkerCategory& aCategory, MarkerOptions&& aOptions,
+ MarkerType aMarkerType, const PayloadArguments&... aPayloadArguments) {
+ Unused << aMarkerType; // Only the empty object type is useful.
+ AUTO_BASE_PROFILER_LABEL("baseprofiler::AddMarkerToBuffer", PROFILER);
+ return base_profiler_markers_detail::AddMarkerToBuffer<MarkerType>(
+ aBuffer, aName, aCategory, std::move(aOptions),
+ // Do not capture a stack if the NoMarkerStacks feature is set.
+ profiler_active_without_feature(ProfilerFeature::NoMarkerStacks)
+ ? ::mozilla::baseprofiler::profiler_capture_backtrace_into
+ : nullptr,
+ aPayloadArguments...);
+}
+
+// Add a marker (without payload) to a given buffer.
+inline ProfileBufferBlockIndex AddMarkerToBuffer(
+ ProfileChunkedBuffer& aBuffer, const ProfilerString8View& aName,
+ const MarkerCategory& aCategory, MarkerOptions&& aOptions = {}) {
+ return AddMarkerToBuffer(aBuffer, aName, aCategory, std::move(aOptions),
+ markers::NoPayload{});
+}
+#endif // MOZ_GECKO_PROFILER
+
+// Add a marker to the Base Profiler buffer.
+// - aName: Main name of this marker.
+// - aCategory: Category for this marker.
+// - aOptions: Optional settings (such as timing, inner window id,
+// backtrace...), see `MarkerOptions` for details.
+// - aMarkerType: Empty object that specifies the type of marker.
+// - aPayloadArguments: Arguments expected by this marker type's
+// ` StreamJSONMarkerData` function.
+template <typename MarkerType, typename... PayloadArguments>
+ProfileBufferBlockIndex AddMarker(
+ const ProfilerString8View& aName, const MarkerCategory& aCategory,
+ MarkerOptions&& aOptions, MarkerType aMarkerType,
+ const PayloadArguments&... aPayloadArguments) {
+#ifndef MOZ_GECKO_PROFILER
+ return {};
+#else
+ // Record base markers whenever the core buffer is in session.
+ // TODO: When profiler_thread_is_being_profiled becomes available from
+ // mozglue, use it instead.
+ ProfileChunkedBuffer& coreBuffer =
+ ::mozilla::baseprofiler::profiler_get_core_buffer();
+ if (!coreBuffer.IsInSession()) {
+ return {};
+ }
+ return ::mozilla::baseprofiler::AddMarkerToBuffer(
+ coreBuffer, aName, aCategory, std::move(aOptions), aMarkerType,
+ aPayloadArguments...);
+#endif
+}
+
+// Add a marker (without payload) to the Base Profiler buffer.
+inline ProfileBufferBlockIndex AddMarker(const ProfilerString8View& aName,
+ const MarkerCategory& aCategory,
+ MarkerOptions&& aOptions = {}) {
+ return AddMarker(aName, aCategory, std::move(aOptions), markers::NoPayload{});
+}
+
+} // namespace mozilla::baseprofiler
+
+// Same as `AddMarker()` (without payload). This macro is safe to use even if
+// MOZ_GECKO_PROFILER is not #defined.
+#define BASE_PROFILER_MARKER_UNTYPED(markerName, categoryName, ...) \
+ do { \
+ AUTO_PROFILER_STATS(BASE_PROFILER_MARKER_UNTYPED); \
+ ::mozilla::baseprofiler::AddMarker( \
+ markerName, ::mozilla::baseprofiler::category::categoryName, \
+ ##__VA_ARGS__); \
+ } while (false)
+
+// Same as `AddMarker()` (with payload). This macro is safe to use even if
+// MOZ_GECKO_PROFILER is not #defined.
+#define BASE_PROFILER_MARKER(markerName, categoryName, options, MarkerType, \
+ ...) \
+ do { \
+ AUTO_PROFILER_STATS(BASE_PROFILER_MARKER_with_##MarkerType); \
+ ::mozilla::baseprofiler::AddMarker( \
+ markerName, ::mozilla::baseprofiler::category::categoryName, options, \
+ ::mozilla::baseprofiler::markers::MarkerType{}, ##__VA_ARGS__); \
+ } while (false)
+
+namespace mozilla::baseprofiler::markers {
+// Most common marker type. Others are in BaseProfilerMarkerTypes.h.
+struct TextMarker {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("Text");
+ }
+ static void StreamJSONMarkerData(baseprofiler::SpliceableJSONWriter& aWriter,
+ const ProfilerString8View& aText) {
+ aWriter.StringProperty("name", aText);
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ schema.SetChartLabel("{marker.data.name}");
+ schema.SetTableLabel("{marker.name} - {marker.data.name}");
+ schema.AddKeyLabelFormatSearchable("name", "Details", MS::Format::String,
+ MS::Searchable::Searchable);
+ return schema;
+ }
+};
+
+// Keep this struct in sync with the `gecko_profiler::marker::Tracing` Rust
+// counterpart.
+struct Tracing {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("tracing");
+ }
+ static void StreamJSONMarkerData(SpliceableJSONWriter& aWriter,
+ const ProfilerString8View& aCategory) {
+ if (aCategory.Length() != 0) {
+ aWriter.StringProperty("category", aCategory);
+ }
+ }
+ static MarkerSchema MarkerTypeDisplay() {
+ using MS = MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable,
+ MS::Location::TimelineOverview};
+ schema.AddKeyLabelFormatSearchable("category", "Type", MS::Format::String,
+ MS::Searchable::Searchable);
+ return schema;
+ }
+};
+} // namespace mozilla::baseprofiler::markers
+
+// Add a text marker. This macro is safe to use even if MOZ_GECKO_PROFILER is
+// not #defined.
+#define BASE_PROFILER_MARKER_TEXT(markerName, categoryName, options, text) \
+ do { \
+ AUTO_PROFILER_STATS(BASE_PROFILER_MARKER_TEXT); \
+ ::mozilla::baseprofiler::AddMarker( \
+ markerName, ::mozilla::baseprofiler::category::categoryName, options, \
+ ::mozilla::baseprofiler::markers::TextMarker{}, text); \
+ } while (false)
+
+namespace mozilla::baseprofiler {
+
+// RAII object that adds a BASE_PROFILER_MARKER_TEXT when destroyed; the
+// marker's timing will be the interval from construction (unless an instant or
+// start time is already specified in the provided options) until destruction.
+class MOZ_RAII AutoProfilerTextMarker {
+ public:
+ AutoProfilerTextMarker(const char* aMarkerName,
+ const MarkerCategory& aCategory,
+ MarkerOptions&& aOptions, const std::string& aText)
+ : mMarkerName(aMarkerName),
+ mCategory(aCategory),
+ mOptions(std::move(aOptions)),
+ mText(aText) {
+ MOZ_ASSERT(mOptions.Timing().EndTime().IsNull(),
+ "AutoProfilerTextMarker options shouldn't have an end time");
+ if (profiler_is_active_and_unpaused() &&
+ mOptions.Timing().StartTime().IsNull()) {
+ mOptions.Set(MarkerTiming::InstantNow());
+ }
+ }
+
+ ~AutoProfilerTextMarker() {
+ if (profiler_is_active_and_unpaused()) {
+ mOptions.TimingRef().SetIntervalEnd();
+ AUTO_PROFILER_STATS(AUTO_BASE_PROFILER_MARKER_TEXT);
+ AddMarker(ProfilerString8View::WrapNullTerminatedString(mMarkerName),
+ mCategory, std::move(mOptions), markers::TextMarker{}, mText);
+ }
+ }
+
+ protected:
+ const char* mMarkerName;
+ MarkerCategory mCategory;
+ MarkerOptions mOptions;
+ std::string mText;
+};
+
+#ifdef MOZ_GECKO_PROFILER
+extern template MFBT_API ProfileBufferBlockIndex
+AddMarker(const ProfilerString8View&, const MarkerCategory&, MarkerOptions&&,
+ markers::TextMarker, const std::string&);
+
+extern template MFBT_API ProfileBufferBlockIndex
+AddMarkerToBuffer(ProfileChunkedBuffer&, const ProfilerString8View&,
+ const MarkerCategory&, MarkerOptions&&, markers::NoPayload);
+
+extern template MFBT_API ProfileBufferBlockIndex AddMarkerToBuffer(
+ ProfileChunkedBuffer&, const ProfilerString8View&, const MarkerCategory&,
+ MarkerOptions&&, markers::TextMarker, const std::string&);
+#endif // MOZ_GECKO_PROFILER
+
+} // namespace mozilla::baseprofiler
+
+// Creates an AutoProfilerTextMarker RAII object. This macro is safe to use
+// even if MOZ_GECKO_PROFILER is not #defined.
+#define AUTO_BASE_PROFILER_MARKER_TEXT(markerName, categoryName, options, \
+ text) \
+ ::mozilla::baseprofiler::AutoProfilerTextMarker PROFILER_RAII( \
+ markerName, ::mozilla::baseprofiler::category::categoryName, options, \
+ text)
+
+#endif // BaseProfilerMarkers_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerMarkersDetail.h b/mozglue/baseprofiler/public/BaseProfilerMarkersDetail.h
new file mode 100644
index 0000000000..1102499100
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerMarkersDetail.h
@@ -0,0 +1,741 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerMarkersDetail_h
+#define BaseProfilerMarkersDetail_h
+
+#ifndef BaseProfilerMarkers_h
+# error "This header should only be #included by BaseProfilerMarkers.h"
+#endif
+
+#include "mozilla/BaseProfilerMarkersPrerequisites.h"
+
+// ~~ HERE BE DRAGONS ~~
+//
+// Everything below is internal implementation detail, you shouldn't need to
+// look at it unless working on the profiler code.
+
+#include "mozilla/BaseProfileJSONWriter.h"
+#include "mozilla/ProfileBufferEntryKinds.h"
+
+#include <limits>
+#include <tuple>
+#include <type_traits>
+
+namespace mozilla::baseprofiler {
+// Implemented in platform.cpp
+MFBT_API ProfileChunkedBuffer& profiler_get_core_buffer();
+} // namespace mozilla::baseprofiler
+
+namespace mozilla::base_profiler_markers_detail {
+
+struct Streaming {
+ // A `MarkerDataDeserializer` is a free function that can read a serialized
+ // payload from an `EntryReader` and streams it as JSON object properties.
+ using MarkerDataDeserializer = void (*)(ProfileBufferEntryReader&,
+ baseprofiler::SpliceableJSONWriter&);
+
+ // A `MarkerTypeNameFunction` is a free function that returns the name of the
+ // marker type.
+ using MarkerTypeNameFunction = Span<const char> (*)();
+
+ // A `MarkerSchemaFunction` is a free function that returns a
+ // `MarkerSchema`, which contains all the information needed to stream
+ // the display schema associated with a marker type.
+ using MarkerSchemaFunction = MarkerSchema (*)();
+
+ struct MarkerTypeFunctions {
+ MarkerDataDeserializer mMarkerDataDeserializer = nullptr;
+ MarkerTypeNameFunction mMarkerTypeNameFunction = nullptr;
+ MarkerSchemaFunction mMarkerSchemaFunction = nullptr;
+ };
+
+ // A `DeserializerTag` will be added before the payload, to help select the
+ // correct deserializer when reading back the payload.
+ using DeserializerTag = uint8_t;
+
+ // Store a deserializer (and other marker-type-specific functions) and get its
+ // `DeserializerTag`.
+ // This is intended to be only used once per deserializer when a new marker
+ // type is used for the first time, so it should be called to initialize a
+ // `static const` tag that will be re-used by all markers of the corresponding
+ // payload type -- see use below.
+ MFBT_API static DeserializerTag TagForMarkerTypeFunctions(
+ MarkerDataDeserializer aDeserializer,
+ MarkerTypeNameFunction aMarkerTypeNameFunction,
+ MarkerSchemaFunction aMarkerSchemaFunction);
+
+ // Get the `MarkerDataDeserializer` for a given `DeserializerTag`.
+ MFBT_API static MarkerDataDeserializer DeserializerForTag(
+ DeserializerTag aTag);
+
+ // Retrieve all MarkerTypeFunctions's.
+ // While this object lives, no other operations can happen on this list.
+ class LockedMarkerTypeFunctionsList {
+ public:
+ MFBT_API LockedMarkerTypeFunctionsList();
+ MFBT_API ~LockedMarkerTypeFunctionsList();
+
+ LockedMarkerTypeFunctionsList(const LockedMarkerTypeFunctionsList&) =
+ delete;
+ LockedMarkerTypeFunctionsList& operator=(
+ const LockedMarkerTypeFunctionsList&) = delete;
+
+ auto begin() const { return mMarkerTypeFunctionsSpan.begin(); }
+ auto end() const { return mMarkerTypeFunctionsSpan.end(); }
+
+ private:
+ Span<const MarkerTypeFunctions> mMarkerTypeFunctionsSpan;
+ };
+};
+
+// This helper will examine a marker type's `StreamJSONMarkerData` function, see
+// specialization below.
+template <typename T>
+struct StreamFunctionTypeHelper;
+
+// Helper specialization that takes the expected
+// `StreamJSONMarkerData(baseprofiler::SpliceableJSONWriter&, ...)` function and
+// provide information about the `...` parameters.
+template <typename R, typename... As>
+struct StreamFunctionTypeHelper<R(baseprofiler::SpliceableJSONWriter&, As...)> {
+ constexpr static size_t scArity = sizeof...(As);
+ using TupleType =
+ std::tuple<std::remove_cv_t<std::remove_reference_t<As>>...>;
+
+ // Serialization function that takes the exact same parameter types
+ // (const-ref'd) as `StreamJSONMarkerData`. This has to be inside the helper
+ // because only here can we access the raw parameter pack `As...`.
+ // And because we're using the same argument types through
+ // references-to-const, permitted implicit conversions can happen.
+ static ProfileBufferBlockIndex Serialize(
+ ProfileChunkedBuffer& aBuffer, const ProfilerString8View& aName,
+ const MarkerCategory& aCategory, MarkerOptions&& aOptions,
+ Streaming::DeserializerTag aDeserializerTag, const As&... aAs) {
+ // Note that options are first after the entry kind, because they contain
+ // the thread id, which is handled first to filter markers by threads.
+ return aBuffer.PutObjects(ProfileBufferEntryKind::Marker, aOptions, aName,
+ aCategory, aDeserializerTag,
+ MarkerPayloadType::Cpp, aAs...);
+ }
+};
+
+// Helper for a marker type.
+// A marker type is defined in a `struct` with some expected static member
+// functions. See example in BaseProfilerMarkers.h.
+template <typename MarkerType>
+struct MarkerTypeSerialization {
+ // Definitions to access the expected
+ // `StreamJSONMarkerData(baseprofiler::SpliceableJSONWriter&, ...)` function
+ // and its parameters.
+ using StreamFunctionType =
+ StreamFunctionTypeHelper<decltype(MarkerType::StreamJSONMarkerData)>;
+ constexpr static size_t scStreamFunctionParameterCount =
+ StreamFunctionType::scArity;
+ using StreamFunctionUserParametersTuple =
+ typename StreamFunctionType::TupleType;
+ template <size_t i>
+ using StreamFunctionParameter =
+ std::tuple_element_t<i, StreamFunctionUserParametersTuple>;
+
+ template <typename... Ts>
+ static ProfileBufferBlockIndex Serialize(ProfileChunkedBuffer& aBuffer,
+ const ProfilerString8View& aName,
+ const MarkerCategory& aCategory,
+ MarkerOptions&& aOptions,
+ const Ts&... aTs) {
+ static_assert(!std::is_same_v<MarkerType,
+ ::mozilla::baseprofiler::markers::NoPayload>,
+ "NoPayload should have been handled in the caller.");
+ // Register marker type functions, and get the tag for this deserializer.
+ // Note that the tag is stored in a function-static object, and this
+ // function is static in a templated struct, so there should only be one tag
+ // per MarkerType.
+ // Making the tag class-static may have been more efficient (to avoid a
+ // thread-safe init check at every call), but random global static
+ // initialization order would make it more complex to coordinate with
+ // `Streaming::TagForMarkerTypeFunctions()`, and also would add a (small)
+ // cost for everybody, even the majority of users not using the profiler.
+ static const Streaming::DeserializerTag tag =
+ Streaming::TagForMarkerTypeFunctions(Deserialize,
+ MarkerType::MarkerTypeName,
+ MarkerType::MarkerTypeDisplay);
+ return StreamFunctionType::Serialize(aBuffer, aName, aCategory,
+ std::move(aOptions), tag, aTs...);
+ }
+
+ private:
+ // This templated function will recursively deserialize each argument expected
+ // by `MarkerType::StreamJSONMarkerData()` on the stack, and call it at the
+ // end. E.g., for `StreamJSONMarkerData(int, char)`:
+ // - DeserializeArguments<0>(aER, aWriter) reads an int and calls:
+ // - DeserializeArguments<1>(aER, aWriter, const int&) reads a char and calls:
+ // - MarkerType::StreamJSONMarkerData(aWriter, const int&, const char&).
+ // Prototyping on godbolt showed that clang and gcc can flatten these
+ // recursive calls into one function with successive reads followed by the one
+ // stream call; tested up to 40 arguments: https://godbolt.org/z/5KeeM4
+ template <size_t i = 0, typename... Args>
+ static void DeserializeArguments(ProfileBufferEntryReader& aEntryReader,
+ baseprofiler::SpliceableJSONWriter& aWriter,
+ const Args&... aArgs) {
+ static_assert(sizeof...(Args) == i,
+ "We should have collected `i` arguments so far");
+ if constexpr (i < scStreamFunctionParameterCount) {
+ // Deserialize the i-th argument on this stack.
+ auto argument = aEntryReader.ReadObject<StreamFunctionParameter<i>>();
+ // Add our local argument to the next recursive call.
+ DeserializeArguments<i + 1>(aEntryReader, aWriter, aArgs..., argument);
+ } else {
+ // We've read all the arguments, finally call the `StreamJSONMarkerData`
+ // function, which should write the appropriate JSON elements for this
+ // marker type. Note that the MarkerType-specific "type" element is
+ // already written.
+ MarkerType::StreamJSONMarkerData(aWriter, aArgs...);
+ }
+ }
+
+ public:
+ static void Deserialize(ProfileBufferEntryReader& aEntryReader,
+ baseprofiler::SpliceableJSONWriter& aWriter) {
+ aWriter.StringProperty("type", MarkerType::MarkerTypeName());
+ DeserializeArguments(aEntryReader, aWriter);
+ }
+};
+
+template <>
+struct MarkerTypeSerialization<::mozilla::baseprofiler::markers::NoPayload> {
+ // Nothing! NoPayload has special handling avoiding payload work.
+};
+
+template <typename MarkerType, typename... Ts>
+static ProfileBufferBlockIndex AddMarkerWithOptionalStackToBuffer(
+ ProfileChunkedBuffer& aBuffer, const ProfilerString8View& aName,
+ const MarkerCategory& aCategory, MarkerOptions&& aOptions,
+ const Ts&... aTs) {
+ if constexpr (std::is_same_v<MarkerType,
+ ::mozilla::baseprofiler::markers::NoPayload>) {
+ static_assert(sizeof...(Ts) == 0,
+ "NoPayload does not accept any payload arguments.");
+ // Special case for NoPayload where there is a stack or inner window id:
+ // Because these options would be stored in the payload 'data' object, but
+ // there is no such object for NoPayload, we convert the marker to another
+ // type (without user fields in the 'data' object), so that the stack and/or
+ // inner window id are not lost.
+ // TODO: Remove this when bug 1646714 lands.
+ if (aOptions.Stack().GetChunkedBuffer() ||
+ !aOptions.InnerWindowId().IsUnspecified()) {
+ struct NoPayloadUserData {
+ static constexpr Span<const char> MarkerTypeName() {
+ return MakeStringSpan("NoPayloadUserData");
+ }
+ static void StreamJSONMarkerData(
+ baseprofiler::SpliceableJSONWriter& aWriter) {
+ // No user payload.
+ }
+ static mozilla::MarkerSchema MarkerTypeDisplay() {
+ using MS = mozilla::MarkerSchema;
+ MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
+ // No user data to display.
+ return schema;
+ }
+ };
+ return MarkerTypeSerialization<NoPayloadUserData>::Serialize(
+ aBuffer, aName, aCategory, std::move(aOptions));
+ }
+
+ // Note that options are first after the entry kind, because they contain
+ // the thread id, which is handled first to filter markers by threads.
+ return aBuffer.PutObjects(
+ ProfileBufferEntryKind::Marker, std::move(aOptions), aName, aCategory,
+ base_profiler_markers_detail::Streaming::DeserializerTag(0));
+ } else {
+ return MarkerTypeSerialization<MarkerType>::Serialize(
+ aBuffer, aName, aCategory, std::move(aOptions), aTs...);
+ }
+}
+
+// Pointer to a function that can capture a backtrace into the provided
+// `ProfileChunkedBuffer`, and returns true when successful.
+using OptionalBacktraceCaptureFunction = bool (*)(ProfileChunkedBuffer&,
+ StackCaptureOptions);
+
+// Use a pre-allocated and cleared chunked buffer in the main thread's
+// `AddMarkerToBuffer()`.
+// Null if not the main thread, or if profilers are not active.
+MFBT_API ProfileChunkedBuffer* GetClearedBufferForMainThreadAddMarker();
+// Called by the profiler(s) when starting/stopping. Safe to nest.
+MFBT_API void EnsureBufferForMainThreadAddMarker();
+MFBT_API void ReleaseBufferForMainThreadAddMarker();
+
+// Add a marker with the given name, options, and arguments to the given buffer.
+// Because this may be called from either Base or Gecko Profiler functions, the
+// appropriate backtrace-capturing function must also be provided.
+template <typename MarkerType, typename... Ts>
+ProfileBufferBlockIndex AddMarkerToBuffer(
+ ProfileChunkedBuffer& aBuffer, const ProfilerString8View& aName,
+ const MarkerCategory& aCategory, MarkerOptions&& aOptions,
+ OptionalBacktraceCaptureFunction aOptionalBacktraceCaptureFunction,
+ const Ts&... aTs) {
+ if (aOptions.ThreadId().IsUnspecified()) {
+ // If yet unspecified, set thread to this thread where the marker is added.
+ aOptions.Set(MarkerThreadId::CurrentThread());
+ }
+
+ if (aOptions.IsTimingUnspecified()) {
+ // If yet unspecified, set timing to this instant of adding the marker.
+ aOptions.Set(MarkerTiming::InstantNow());
+ }
+
+ StackCaptureOptions captureOptions = aOptions.Stack().CaptureOptions();
+ if (captureOptions != StackCaptureOptions::NoStack &&
+ // Backtrace capture function will be nullptr if the profiler
+ // NoMarkerStacks feature is set.
+ aOptionalBacktraceCaptureFunction != nullptr) {
+ // A capture was requested, let's attempt to do it here&now. This avoids a
+ // lot of allocations that would be necessary if capturing a backtrace
+ // separately.
+ // TODO reduce internal profiler stack levels, see bug 1659872.
+ auto CaptureStackAndAddMarker = [&](ProfileChunkedBuffer& aChunkedBuffer) {
+ aOptions.StackRef().UseRequestedBacktrace(
+ aOptionalBacktraceCaptureFunction(aChunkedBuffer, captureOptions)
+ ? &aChunkedBuffer
+ : nullptr);
+ // This call must be made from here, while chunkedBuffer is in scope.
+ return AddMarkerWithOptionalStackToBuffer<MarkerType>(
+ aBuffer, aName, aCategory, std::move(aOptions), aTs...);
+ };
+
+ if (ProfileChunkedBuffer* buffer = GetClearedBufferForMainThreadAddMarker();
+ buffer) {
+ // Use a pre-allocated buffer for the main thread (because it's the most
+ // used thread, and most sensitive to overhead), so it's only allocated
+ // once. It could be null if this is not the main thread, or no profilers
+ // are currently active.
+ return CaptureStackAndAddMarker(*buffer);
+ }
+ // TODO use a local on-stack byte buffer to remove last allocation.
+ ProfileBufferChunkManagerSingle chunkManager(
+ ProfileBufferChunkManager::scExpectedMaximumStackSize);
+ ProfileChunkedBuffer chunkedBuffer(
+ ProfileChunkedBuffer::ThreadSafety::WithoutMutex, chunkManager);
+ return CaptureStackAndAddMarker(chunkedBuffer);
+ }
+
+ return AddMarkerWithOptionalStackToBuffer<MarkerType>(
+ aBuffer, aName, aCategory, std::move(aOptions), aTs...);
+}
+
+// Assuming aEntryReader points right after the entry type (being Marker), this
+// reads the remainder of the marker and outputs it.
+// - GetWriterForThreadCallback, called first, after the thread id is read:
+// (ThreadId) -> SpliceableJSONWriter* or null
+// If null, nothing will be output, but aEntryReader will still be read fully.
+// - StackCallback, only called if GetWriterForThreadCallback didn't return
+// null, and if the marker contains a stack:
+// (ProfileChunkedBuffer&) -> void
+// - RustMarkerCallback, only called if GetWriterForThreadCallback didn't return
+// null, and if the marker contains a Rust payload:
+// (DeserializerTag) -> void
+template <typename GetWriterForThreadCallback, typename StackCallback,
+ typename RustMarkerCallback>
+void DeserializeAfterKindAndStream(
+ ProfileBufferEntryReader& aEntryReader,
+ GetWriterForThreadCallback&& aGetWriterForThreadCallback,
+ StackCallback&& aStackCallback, RustMarkerCallback&& aRustMarkerCallback) {
+ // Each entry is made up of the following:
+ // ProfileBufferEntry::Kind::Marker, <- already read by caller
+ // options, <- next location in entries
+ // name,
+ // payload
+ const MarkerOptions options = aEntryReader.ReadObject<MarkerOptions>();
+
+ baseprofiler::SpliceableJSONWriter* writer =
+ std::forward<GetWriterForThreadCallback>(aGetWriterForThreadCallback)(
+ options.ThreadId().ThreadId());
+ if (!writer) {
+ // No writer associated with this thread id, drop it.
+ aEntryReader.SetRemainingBytes(0);
+ return;
+ }
+
+ // Write the information to JSON with the following schema:
+ // [name, startTime, endTime, phase, category, data]
+ writer->StartArrayElement();
+ {
+ writer->UniqueStringElement(aEntryReader.ReadObject<ProfilerString8View>());
+
+ const double startTime = options.Timing().GetStartTime();
+ writer->TimeDoubleMsElement(startTime);
+
+ const double endTime = options.Timing().GetEndTime();
+ writer->TimeDoubleMsElement(endTime);
+
+ writer->IntElement(static_cast<int64_t>(options.Timing().MarkerPhase()));
+
+ MarkerCategory category = aEntryReader.ReadObject<MarkerCategory>();
+ writer->IntElement(static_cast<int64_t>(category.GetCategory()));
+
+ if (const auto tag =
+ aEntryReader.ReadObject<mozilla::base_profiler_markers_detail::
+ Streaming::DeserializerTag>();
+ tag != 0) {
+ writer->StartObjectElement();
+ {
+ // Stream "common props".
+
+ // TODO: Move this to top-level tuple, when frontend supports it.
+ if (!options.InnerWindowId().IsUnspecified()) {
+ // Here, we are converting uint64_t to double. Both Browsing Context
+ // and Inner Window IDs are created using
+ // `nsContentUtils::GenerateProcessSpecificId`, which is specifically
+ // designed to only use 53 of the 64 bits to be lossless when passed
+ // into and out of JS as a double.
+ writer->DoubleProperty(
+ "innerWindowID",
+ static_cast<double>(options.InnerWindowId().Id()));
+ }
+
+ // TODO: Move this to top-level tuple, when frontend supports it.
+ if (ProfileChunkedBuffer* chunkedBuffer =
+ options.Stack().GetChunkedBuffer();
+ chunkedBuffer) {
+ writer->StartObjectProperty("stack");
+ { std::forward<StackCallback>(aStackCallback)(*chunkedBuffer); }
+ writer->EndObject();
+ }
+
+ auto payloadType = static_cast<mozilla::MarkerPayloadType>(
+ aEntryReader.ReadObject<
+ std::underlying_type_t<mozilla::MarkerPayloadType>>());
+
+ // Stream the payload, including the type.
+ switch (payloadType) {
+ case mozilla::MarkerPayloadType::Cpp: {
+ mozilla::base_profiler_markers_detail::Streaming::
+ MarkerDataDeserializer deserializer =
+ mozilla::base_profiler_markers_detail::Streaming::
+ DeserializerForTag(tag);
+ MOZ_RELEASE_ASSERT(deserializer);
+ deserializer(aEntryReader, *writer);
+ MOZ_ASSERT(aEntryReader.RemainingBytes() == 0u);
+ break;
+ }
+ case mozilla::MarkerPayloadType::Rust:
+ std::forward<RustMarkerCallback>(aRustMarkerCallback)(tag);
+ MOZ_ASSERT(aEntryReader.RemainingBytes() == 0u);
+ break;
+ default:
+ MOZ_ASSERT_UNREACHABLE("Unknown payload type.");
+ break;
+ }
+ }
+ writer->EndObject();
+ }
+ }
+ writer->EndArray();
+ MOZ_ASSERT(aEntryReader.RemainingBytes() == 0u);
+}
+
+} // namespace mozilla::base_profiler_markers_detail
+
+namespace mozilla {
+
+// ----------------------------------------------------------------------------
+// Serializer, Deserializer: ProfilerStringView<CHAR>
+
+// The serialization starts with a ULEB128 number that encodes both whether the
+// ProfilerStringView is literal (Least Significant Bit = 0) or not (LSB = 1),
+// plus the string length (excluding null terminator) in bytes, shifted left by
+// 1 bit. Following that number:
+// - If literal, the string pointer value.
+// - If non-literal, the contents as bytes (excluding null terminator if any).
+template <typename CHAR>
+struct ProfileBufferEntryWriter::Serializer<ProfilerStringView<CHAR>> {
+ static Length Bytes(const ProfilerStringView<CHAR>& aString) {
+ MOZ_RELEASE_ASSERT(
+ aString.Length() < std::numeric_limits<Length>::max() / 2,
+ "Double the string length doesn't fit in Length type");
+ const Length stringLength = static_cast<Length>(aString.Length());
+ if (aString.IsLiteral()) {
+ // Literal -> Length shifted left and LSB=0, then pointer.
+ return ULEB128Size(stringLength << 1 | 0u) +
+ static_cast<ProfileChunkedBuffer::Length>(sizeof(const CHAR*));
+ }
+ // Non-literal -> Length shifted left and LSB=1, then string size in bytes.
+ return ULEB128Size((stringLength << 1) | 1u) + stringLength * sizeof(CHAR);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const ProfilerStringView<CHAR>& aString) {
+ MOZ_RELEASE_ASSERT(
+ aString.Length() < std::numeric_limits<Length>::max() / 2,
+ "Double the string length doesn't fit in Length type");
+ const Span<const CHAR> span = aString;
+ if (aString.IsLiteral()) {
+ // Literal -> Length shifted left and LSB=0, then pointer.
+ aEW.WriteULEB128(span.Length() << 1 | 0u);
+ aEW.WriteObject(WrapProfileBufferRawPointer(span.Elements()));
+ return;
+ }
+ // Non-literal -> Length shifted left and LSB=1, then string size in bytes.
+ aEW.WriteULEB128(span.Length() << 1 | 1u);
+ aEW.WriteBytes(span.Elements(), span.LengthBytes());
+ }
+};
+
+template <typename CHAR>
+struct ProfileBufferEntryReader::Deserializer<ProfilerStringView<CHAR>> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ ProfilerStringView<CHAR>& aString) {
+ aString = Read(aER);
+ }
+
+ static ProfilerStringView<CHAR> Read(ProfileBufferEntryReader& aER) {
+ const Length lengthAndIsLiteral = aER.ReadULEB128<Length>();
+ const Length stringLength = lengthAndIsLiteral >> 1;
+ if ((lengthAndIsLiteral & 1u) == 0u) {
+ // LSB==0 -> Literal string, read the string pointer.
+ return ProfilerStringView<CHAR>(
+ aER.ReadObject<const CHAR*>(), stringLength,
+ ProfilerStringView<CHAR>::Ownership::Literal);
+ }
+ // LSB==1 -> Not a literal string.
+ ProfileBufferEntryReader::DoubleSpanOfConstBytes spans =
+ aER.ReadSpans(stringLength * sizeof(CHAR));
+ if (MOZ_LIKELY(spans.IsSingleSpan()) &&
+ reinterpret_cast<uintptr_t>(spans.mFirstOrOnly.Elements()) %
+ alignof(CHAR) ==
+ 0u) {
+ // Only a single span, correctly aligned for the CHAR type, we can just
+ // refer to it directly, assuming that this ProfilerStringView will not
+ // outlive the chunk.
+ return ProfilerStringView<CHAR>(
+ reinterpret_cast<const CHAR*>(spans.mFirstOrOnly.Elements()),
+ stringLength, ProfilerStringView<CHAR>::Ownership::Reference);
+ } else {
+ // Two spans, we need to concatenate them; or one span, but misaligned.
+ // Allocate a buffer to store the string (plus terminal, for safety), and
+ // give it to the ProfilerStringView; Note that this is a secret use of
+ // ProfilerStringView, which is intended to only be used between
+ // deserialization and JSON streaming.
+ CHAR* buffer = new CHAR[stringLength + 1];
+ spans.CopyBytesTo(buffer);
+ buffer[stringLength] = CHAR(0);
+ return ProfilerStringView<CHAR>(
+ buffer, stringLength,
+ ProfilerStringView<CHAR>::Ownership::OwnedThroughStringView);
+ }
+ }
+};
+
+// Serializer, Deserializer: MarkerCategory
+
+// The serialization contains both category numbers encoded as ULEB128.
+template <>
+struct ProfileBufferEntryWriter::Serializer<MarkerCategory> {
+ static Length Bytes(const MarkerCategory& aCategory) {
+ return ULEB128Size(static_cast<uint32_t>(aCategory.CategoryPair()));
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const MarkerCategory& aCategory) {
+ aEW.WriteULEB128(static_cast<uint32_t>(aCategory.CategoryPair()));
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<MarkerCategory> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ MarkerCategory& aCategory) {
+ aCategory = Read(aER);
+ }
+
+ static MarkerCategory Read(ProfileBufferEntryReader& aER) {
+ return MarkerCategory(static_cast<baseprofiler::ProfilingCategoryPair>(
+ aER.ReadULEB128<uint32_t>()));
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Serializer, Deserializer: MarkerTiming
+
+// The serialization starts with the marker phase, followed by one or two
+// timestamps as needed.
+template <>
+struct ProfileBufferEntryWriter::Serializer<MarkerTiming> {
+ static Length Bytes(const MarkerTiming& aTiming) {
+ MOZ_ASSERT(!aTiming.IsUnspecified());
+ const auto phase = aTiming.MarkerPhase();
+ switch (phase) {
+ case MarkerTiming::Phase::Instant:
+ return SumBytes(phase, aTiming.StartTime());
+ case MarkerTiming::Phase::Interval:
+ return SumBytes(phase, aTiming.StartTime(), aTiming.EndTime());
+ case MarkerTiming::Phase::IntervalStart:
+ return SumBytes(phase, aTiming.StartTime());
+ case MarkerTiming::Phase::IntervalEnd:
+ return SumBytes(phase, aTiming.EndTime());
+ default:
+ MOZ_RELEASE_ASSERT(phase == MarkerTiming::Phase::Instant ||
+ phase == MarkerTiming::Phase::Interval ||
+ phase == MarkerTiming::Phase::IntervalStart ||
+ phase == MarkerTiming::Phase::IntervalEnd);
+ return 0; // Only to avoid build errors.
+ }
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const MarkerTiming& aTiming) {
+ MOZ_ASSERT(!aTiming.IsUnspecified());
+ const auto phase = aTiming.MarkerPhase();
+ switch (phase) {
+ case MarkerTiming::Phase::Instant:
+ aEW.WriteObjects(phase, aTiming.StartTime());
+ return;
+ case MarkerTiming::Phase::Interval:
+ aEW.WriteObjects(phase, aTiming.StartTime(), aTiming.EndTime());
+ return;
+ case MarkerTiming::Phase::IntervalStart:
+ aEW.WriteObjects(phase, aTiming.StartTime());
+ return;
+ case MarkerTiming::Phase::IntervalEnd:
+ aEW.WriteObjects(phase, aTiming.EndTime());
+ return;
+ default:
+ MOZ_RELEASE_ASSERT(phase == MarkerTiming::Phase::Instant ||
+ phase == MarkerTiming::Phase::Interval ||
+ phase == MarkerTiming::Phase::IntervalStart ||
+ phase == MarkerTiming::Phase::IntervalEnd);
+ return;
+ }
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<MarkerTiming> {
+ static void ReadInto(ProfileBufferEntryReader& aER, MarkerTiming& aTiming) {
+ aTiming.mPhase = aER.ReadObject<MarkerTiming::Phase>();
+ switch (aTiming.mPhase) {
+ case MarkerTiming::Phase::Instant:
+ aTiming.mStartTime = aER.ReadObject<TimeStamp>();
+ aTiming.mEndTime = TimeStamp{};
+ break;
+ case MarkerTiming::Phase::Interval:
+ aTiming.mStartTime = aER.ReadObject<TimeStamp>();
+ aTiming.mEndTime = aER.ReadObject<TimeStamp>();
+ break;
+ case MarkerTiming::Phase::IntervalStart:
+ aTiming.mStartTime = aER.ReadObject<TimeStamp>();
+ aTiming.mEndTime = TimeStamp{};
+ break;
+ case MarkerTiming::Phase::IntervalEnd:
+ aTiming.mStartTime = TimeStamp{};
+ aTiming.mEndTime = aER.ReadObject<TimeStamp>();
+ break;
+ default:
+ MOZ_RELEASE_ASSERT(aTiming.mPhase == MarkerTiming::Phase::Instant ||
+ aTiming.mPhase == MarkerTiming::Phase::Interval ||
+ aTiming.mPhase ==
+ MarkerTiming::Phase::IntervalStart ||
+ aTiming.mPhase == MarkerTiming::Phase::IntervalEnd);
+ break;
+ }
+ }
+
+ static MarkerTiming Read(ProfileBufferEntryReader& aER) {
+ TimeStamp start;
+ TimeStamp end;
+ auto phase = aER.ReadObject<MarkerTiming::Phase>();
+ switch (phase) {
+ case MarkerTiming::Phase::Instant:
+ start = aER.ReadObject<TimeStamp>();
+ break;
+ case MarkerTiming::Phase::Interval:
+ start = aER.ReadObject<TimeStamp>();
+ end = aER.ReadObject<TimeStamp>();
+ break;
+ case MarkerTiming::Phase::IntervalStart:
+ start = aER.ReadObject<TimeStamp>();
+ break;
+ case MarkerTiming::Phase::IntervalEnd:
+ end = aER.ReadObject<TimeStamp>();
+ break;
+ default:
+ MOZ_RELEASE_ASSERT(phase == MarkerTiming::Phase::Instant ||
+ phase == MarkerTiming::Phase::Interval ||
+ phase == MarkerTiming::Phase::IntervalStart ||
+ phase == MarkerTiming::Phase::IntervalEnd);
+ break;
+ }
+ return MarkerTiming(start, end, phase);
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Serializer, Deserializer: MarkerStack
+
+// The serialization only contains the `ProfileChunkedBuffer` from the
+// backtrace; if there is no backtrace or if it's empty, this will implicitly
+// store a nullptr (see
+// `ProfileBufferEntryWriter::Serializer<ProfilerChunkedBuffer*>`).
+template <>
+struct ProfileBufferEntryWriter::Serializer<MarkerStack> {
+ static Length Bytes(const MarkerStack& aStack) {
+ return SumBytes(aStack.GetChunkedBuffer());
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW, const MarkerStack& aStack) {
+ aEW.WriteObject(aStack.GetChunkedBuffer());
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<MarkerStack> {
+ static void ReadInto(ProfileBufferEntryReader& aER, MarkerStack& aStack) {
+ aStack = Read(aER);
+ }
+
+ static MarkerStack Read(ProfileBufferEntryReader& aER) {
+ return MarkerStack(aER.ReadObject<UniquePtr<ProfileChunkedBuffer>>());
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Serializer, Deserializer: MarkerOptions
+
+// The serialization contains all members (either trivially-copyable, or they
+// provide their specialization above).
+template <>
+struct ProfileBufferEntryWriter::Serializer<MarkerOptions> {
+ static Length Bytes(const MarkerOptions& aOptions) {
+ return SumBytes(aOptions.ThreadId(), aOptions.Timing(), aOptions.Stack(),
+ aOptions.InnerWindowId());
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const MarkerOptions& aOptions) {
+ aEW.WriteObjects(aOptions.ThreadId(), aOptions.Timing(), aOptions.Stack(),
+ aOptions.InnerWindowId());
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<MarkerOptions> {
+ static void ReadInto(ProfileBufferEntryReader& aER, MarkerOptions& aOptions) {
+ aER.ReadIntoObjects(aOptions.mThreadId, aOptions.mTiming, aOptions.mStack,
+ aOptions.mInnerWindowId);
+ }
+
+ static MarkerOptions Read(ProfileBufferEntryReader& aER) {
+ MarkerOptions options;
+ ReadInto(aER, options);
+ return options;
+ }
+};
+
+} // namespace mozilla
+
+#endif // BaseProfilerMarkersDetail_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerMarkersPrerequisites.h b/mozglue/baseprofiler/public/BaseProfilerMarkersPrerequisites.h
new file mode 100644
index 0000000000..15fd729d0c
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerMarkersPrerequisites.h
@@ -0,0 +1,886 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This header contains basic definitions required to create marker types, and
+// to add markers to the profiler buffers.
+//
+// In most cases, #include "mozilla/BaseProfilerMarkers.h" instead, or
+// #include "mozilla/BaseProfilerMarkerTypes.h" for common marker types.
+
+#ifndef BaseProfilerMarkersPrerequisites_h
+#define BaseProfilerMarkersPrerequisites_h
+
+namespace mozilla {
+
+enum class StackCaptureOptions {
+ NoStack, // No stack captured.
+ Full, // Capture a full stack, including label frames, JS frames and
+ // native frames.
+ NonNative, // Capture a stack without native frames for reduced overhead.
+};
+
+}
+
+#include "BaseProfilingCategory.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/ProfileChunkedBuffer.h"
+#include "mozilla/BaseProfilerState.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/Variant.h"
+
+#include <initializer_list>
+#include <string_view>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace mozilla {
+
+// Return a NotNull<const CHAR*> pointing at the literal empty string `""`.
+template <typename CHAR>
+constexpr const CHAR* LiteralEmptyStringPointer() {
+ static_assert(std::is_same_v<CHAR, char> || std::is_same_v<CHAR, char16_t>,
+ "Only char and char16_t are supported in Firefox");
+ if constexpr (std::is_same_v<CHAR, char>) {
+ return "";
+ }
+ if constexpr (std::is_same_v<CHAR, char16_t>) {
+ return u"";
+ }
+}
+
+// Return a string_view<CHAR> pointing at the literal empty string.
+template <typename CHAR>
+constexpr std::basic_string_view<CHAR> LiteralEmptyStringView() {
+ static_assert(std::is_same_v<CHAR, char> || std::is_same_v<CHAR, char16_t>,
+ "Only char and char16_t are supported in Firefox");
+ // Use `operator""sv()` from <string_view>.
+ using namespace std::literals::string_view_literals;
+ if constexpr (std::is_same_v<CHAR, char>) {
+ return ""sv;
+ }
+ if constexpr (std::is_same_v<CHAR, char16_t>) {
+ return u""sv;
+ }
+}
+
+// General string view, optimized for short on-stack life before serialization,
+// and between deserialization and JSON-streaming.
+template <typename CHAR>
+class MOZ_STACK_CLASS ProfilerStringView {
+ public:
+ // Default constructor points at "" (literal empty string).
+ constexpr ProfilerStringView() = default;
+
+ // Don't allow copy.
+ ProfilerStringView(const ProfilerStringView&) = delete;
+ ProfilerStringView& operator=(const ProfilerStringView&) = delete;
+
+ // Allow move. For consistency the moved-from string is always reset to "".
+ constexpr ProfilerStringView(ProfilerStringView&& aOther)
+ : mStringView(std::move(aOther.mStringView)),
+ mOwnership(aOther.mOwnership) {
+ if (mOwnership == Ownership::OwnedThroughStringView) {
+ // We now own the buffer, make the other point at the literal "".
+ aOther.mStringView = LiteralEmptyStringView<CHAR>();
+ aOther.mOwnership = Ownership::Literal;
+ }
+ }
+ constexpr ProfilerStringView& operator=(ProfilerStringView&& aOther) {
+ mStringView = std::move(aOther.mStringView);
+ mOwnership = aOther.mOwnership;
+ if (mOwnership == Ownership::OwnedThroughStringView) {
+ // We now own the buffer, make the other point at the literal "".
+ aOther.mStringView = LiteralEmptyStringView<CHAR>();
+ aOther.mOwnership = Ownership::Literal;
+ }
+ return *this;
+ }
+
+ ~ProfilerStringView() {
+ if (MOZ_UNLIKELY(mOwnership == Ownership::OwnedThroughStringView)) {
+ // We own the buffer pointed at by mStringView, destroy it.
+ // This is only used between deserialization and streaming.
+ delete mStringView.data();
+ }
+ }
+
+ // Implicit construction from nullptr, points at "" (literal empty string).
+ constexpr MOZ_IMPLICIT ProfilerStringView(decltype(nullptr)) {}
+
+ // Implicit constructor from a literal string.
+ template <size_t Np1>
+ constexpr MOZ_IMPLICIT ProfilerStringView(const CHAR (&aLiteralString)[Np1])
+ : ProfilerStringView(aLiteralString, Np1 - 1, Ownership::Literal) {}
+
+ // Constructor from a non-literal string.
+ constexpr ProfilerStringView(const CHAR* aString, size_t aLength)
+ : ProfilerStringView(aString, aLength, Ownership::Reference) {}
+
+ // Implicit constructor from a string_view.
+ constexpr MOZ_IMPLICIT ProfilerStringView(
+ const std::basic_string_view<CHAR>& aStringView)
+ : ProfilerStringView(aStringView.data(), aStringView.length(),
+ Ownership::Reference) {}
+
+ // Implicit constructor from an expiring string_view. We assume that the
+ // pointed-at string will outlive this ProfilerStringView.
+ constexpr MOZ_IMPLICIT ProfilerStringView(
+ std::basic_string_view<CHAR>&& aStringView)
+ : ProfilerStringView(aStringView.data(), aStringView.length(),
+ Ownership::Reference) {}
+
+ // Implicit constructor from std::string.
+ constexpr MOZ_IMPLICIT ProfilerStringView(
+ const std::basic_string<CHAR>& aString)
+ : ProfilerStringView(aString.data(), aString.length(),
+ Ownership::Reference) {}
+
+ // Construction from a raw pointer to a null-terminated string.
+ // This is a named class-static function to make it more obvious where work is
+ // being done (to determine the string length), and encourage users to instead
+ // provide a length, if already known.
+ // TODO: Find callers and convert them to constructor instead if possible.
+ static constexpr ProfilerStringView WrapNullTerminatedString(
+ const CHAR* aString) {
+ return ProfilerStringView(
+ aString, aString ? std::char_traits<CHAR>::length(aString) : 0,
+ Ownership::Reference);
+ }
+
+ // Implicit constructor for an object with member functions `Data()`
+ // `Length()`, and `IsLiteral()`, common in xpcom strings.
+ template <
+ typename String,
+ typename DataReturnType = decltype(std::declval<const String>().Data()),
+ typename LengthReturnType =
+ decltype(std::declval<const String>().Length()),
+ typename IsLiteralReturnType =
+ decltype(std::declval<const String>().IsLiteral()),
+ typename =
+ std::enable_if_t<std::is_convertible_v<DataReturnType, const CHAR*> &&
+ std::is_integral_v<LengthReturnType> &&
+ std::is_same_v<IsLiteralReturnType, bool>>>
+ constexpr MOZ_IMPLICIT ProfilerStringView(const String& aString)
+ : ProfilerStringView(
+ static_cast<const CHAR*>(aString.Data()), aString.Length(),
+ aString.IsLiteral() ? Ownership::Literal : Ownership::Reference) {}
+
+ [[nodiscard]] constexpr const std::basic_string_view<CHAR>& StringView()
+ const {
+ return mStringView;
+ }
+
+ [[nodiscard]] constexpr size_t Length() const { return mStringView.length(); }
+
+ [[nodiscard]] constexpr bool IsLiteral() const {
+ return mOwnership == Ownership::Literal;
+ }
+ [[nodiscard]] constexpr bool IsReference() const {
+ return mOwnership == Ownership::Reference;
+ }
+ // No `IsOwned...()` because it's a secret, only used internally!
+
+ [[nodiscard]] Span<const CHAR> AsSpan() const {
+ return Span<const CHAR>(mStringView.data(), mStringView.length());
+ }
+ [[nodiscard]] operator Span<const CHAR>() const { return AsSpan(); }
+
+ private:
+ enum class Ownership { Literal, Reference, OwnedThroughStringView };
+
+ // Allow deserializer to store anything here.
+ friend ProfileBufferEntryReader::Deserializer<ProfilerStringView>;
+
+ constexpr ProfilerStringView(const CHAR* aString, size_t aLength,
+ Ownership aOwnership)
+ : mStringView(aString ? std::basic_string_view<CHAR>(aString, aLength)
+ : LiteralEmptyStringView<CHAR>()),
+ mOwnership(aString ? aOwnership : Ownership::Literal) {}
+
+ // String view to an outside string (literal or reference).
+ // We may actually own the pointed-at buffer, but it is only used internally
+ // between deserialization and JSON streaming.
+ std::basic_string_view<CHAR> mStringView = LiteralEmptyStringView<CHAR>();
+
+ Ownership mOwnership = Ownership::Literal;
+};
+
+using ProfilerString8View = ProfilerStringView<char>;
+using ProfilerString16View = ProfilerStringView<char16_t>;
+
+// This compulsory marker parameter contains the required category information.
+class MarkerCategory {
+ public:
+ // Constructor from category pair (includes both super- and sub-categories).
+ constexpr explicit MarkerCategory(
+ baseprofiler::ProfilingCategoryPair aCategoryPair)
+ : mCategoryPair(aCategoryPair) {}
+
+ // Returns the stored category pair.
+ constexpr baseprofiler::ProfilingCategoryPair CategoryPair() const {
+ return mCategoryPair;
+ }
+
+ // Returns the super-category from the stored category pair.
+ baseprofiler::ProfilingCategory GetCategory() const {
+ return GetProfilingCategoryPairInfo(mCategoryPair).mCategory;
+ }
+
+ private:
+ baseprofiler::ProfilingCategoryPair mCategoryPair =
+ baseprofiler::ProfilingCategoryPair::OTHER;
+};
+
+namespace baseprofiler::category {
+
+// Each category pair name constructs a MarkerCategory.
+// E.g.: mozilla::baseprofiler::category::OTHER_Profiling
+// Profiler macros will take the category name alone without namespace.
+// E.g.: `PROFILER_MARKER_UNTYPED("name", OTHER_Profiling)`
+#define CATEGORY_ENUM_BEGIN_CATEGORY(name, labelAsString, color)
+#define CATEGORY_ENUM_SUBCATEGORY(supercategory, name, labelAsString) \
+ static constexpr MarkerCategory name{ProfilingCategoryPair::name};
+#define CATEGORY_ENUM_END_CATEGORY
+MOZ_PROFILING_CATEGORY_LIST(CATEGORY_ENUM_BEGIN_CATEGORY,
+ CATEGORY_ENUM_SUBCATEGORY,
+ CATEGORY_ENUM_END_CATEGORY)
+#undef CATEGORY_ENUM_BEGIN_CATEGORY
+#undef CATEGORY_ENUM_SUBCATEGORY
+#undef CATEGORY_ENUM_END_CATEGORY
+
+// Import `MarkerCategory` into this namespace. This will allow using this type
+// dynamically in macros that prepend `::mozilla::baseprofiler::category::` to
+// the given category, e.g.:
+// `PROFILER_MARKER_UNTYPED("name", MarkerCategory(...))`
+using MarkerCategory = ::mozilla::MarkerCategory;
+
+} // namespace baseprofiler::category
+
+// The classes below are all embedded in a `MarkerOptions` object.
+class MarkerOptions;
+
+// This marker option captures a given thread id.
+// If left unspecified (by default construction) during the add-marker call, the
+// current thread id will be used then.
+class MarkerThreadId {
+ public:
+ // Default constructor, keeps the thread id unspecified.
+ constexpr MarkerThreadId() = default;
+
+ // Constructor from a given thread id.
+ constexpr explicit MarkerThreadId(
+ baseprofiler::BaseProfilerThreadId aThreadId)
+ : mThreadId(aThreadId) {}
+
+ // Use the current thread's id.
+ static MarkerThreadId CurrentThread() {
+ return MarkerThreadId(baseprofiler::profiler_current_thread_id());
+ }
+
+ // Use the main thread's id. This can be useful to record a marker from a
+ // possibly-unregistered thread, and display it in the main thread track.
+ static MarkerThreadId MainThread() {
+ return MarkerThreadId(baseprofiler::profiler_main_thread_id());
+ }
+
+ [[nodiscard]] constexpr baseprofiler::BaseProfilerThreadId ThreadId() const {
+ return mThreadId;
+ }
+
+ [[nodiscard]] constexpr bool IsUnspecified() const {
+ return !mThreadId.IsSpecified();
+ }
+
+ private:
+ baseprofiler::BaseProfilerThreadId mThreadId;
+};
+
+// This marker option contains marker timing information.
+// This class encapsulates the logic for correctly storing a marker based on its
+// Use the static methods to create the MarkerTiming. This is a transient object
+// that is being used to enforce the constraints of the combinations of the
+// data.
+class MarkerTiming {
+ public:
+ // The following static methods are used to create the MarkerTiming based on
+ // the type that it is.
+
+ static MarkerTiming InstantAt(const TimeStamp& aTime) {
+ MOZ_ASSERT(!aTime.IsNull(), "Time is null for an instant marker.");
+ return MarkerTiming{aTime, TimeStamp{}, MarkerTiming::Phase::Instant};
+ }
+
+ static MarkerTiming InstantNow() { return InstantAt(TimeStamp::Now()); }
+
+ static MarkerTiming Interval(const TimeStamp& aStartTime,
+ const TimeStamp& aEndTime) {
+ MOZ_ASSERT(!aStartTime.IsNull(),
+ "Start time is null for an interval marker.");
+ MOZ_ASSERT(!aEndTime.IsNull(), "End time is null for an interval marker.");
+ return MarkerTiming{aStartTime, aEndTime, MarkerTiming::Phase::Interval};
+ }
+
+ static MarkerTiming IntervalUntilNowFrom(const TimeStamp& aStartTime) {
+ return Interval(aStartTime, TimeStamp::Now());
+ }
+
+ static MarkerTiming IntervalStart(const TimeStamp& aTime = TimeStamp::Now()) {
+ MOZ_ASSERT(!aTime.IsNull(), "Time is null for an interval start marker.");
+ return MarkerTiming{aTime, TimeStamp{}, MarkerTiming::Phase::IntervalStart};
+ }
+
+ static MarkerTiming IntervalEnd(const TimeStamp& aTime = TimeStamp::Now()) {
+ MOZ_ASSERT(!aTime.IsNull(), "Time is null for an interval end marker.");
+ return MarkerTiming{TimeStamp{}, aTime, MarkerTiming::Phase::IntervalEnd};
+ }
+
+ // Set the interval end in this timing.
+ // If there was already a start time, this makes it a full interval.
+ void SetIntervalEnd(const TimeStamp& aTime = TimeStamp::Now()) {
+ MOZ_ASSERT(!aTime.IsNull(), "Time is null for an interval end marker.");
+ mEndTime = aTime;
+ mPhase = mStartTime.IsNull() ? Phase::IntervalEnd : Phase::Interval;
+ }
+
+ [[nodiscard]] const TimeStamp& StartTime() const { return mStartTime; }
+ [[nodiscard]] const TimeStamp& EndTime() const { return mEndTime; }
+
+ enum class Phase : uint8_t {
+ Instant = 0,
+ Interval = 1,
+ IntervalStart = 2,
+ IntervalEnd = 3,
+ };
+
+ [[nodiscard]] Phase MarkerPhase() const {
+ MOZ_ASSERT(!IsUnspecified());
+ return mPhase;
+ }
+
+ // The following getter methods are used to put the value into the buffer for
+ // storage.
+ [[nodiscard]] double GetStartTime() const {
+ MOZ_ASSERT(!IsUnspecified());
+ // If mStartTime is null (e.g., for IntervalEnd), this will output 0.0 as
+ // expected.
+ return MarkerTiming::timeStampToDouble(mStartTime);
+ }
+
+ [[nodiscard]] double GetEndTime() const {
+ MOZ_ASSERT(!IsUnspecified());
+ // If mEndTime is null (e.g., for Instant or IntervalStart), this will
+ // output 0.0 as expected.
+ return MarkerTiming::timeStampToDouble(mEndTime);
+ }
+
+ [[nodiscard]] uint8_t GetPhase() const {
+ MOZ_ASSERT(!IsUnspecified());
+ return static_cast<uint8_t>(mPhase);
+ }
+
+ // This is a constructor for Rust FFI bindings. It must not be used outside of
+ // this! Please see the other static constructors above.
+ static void UnsafeConstruct(MarkerTiming* aMarkerTiming,
+ const TimeStamp& aStartTime,
+ const TimeStamp& aEndTime, Phase aPhase) {
+ new (aMarkerTiming) MarkerTiming{aStartTime, aEndTime, aPhase};
+ }
+
+ private:
+ friend ProfileBufferEntryWriter::Serializer<MarkerTiming>;
+ friend ProfileBufferEntryReader::Deserializer<MarkerTiming>;
+ friend MarkerOptions;
+
+ // Default timing leaves it internally "unspecified", serialization getters
+ // and add-marker functions will default to `InstantNow()`.
+ constexpr MarkerTiming() = default;
+
+ // This should only be used by internal profiler code.
+ [[nodiscard]] bool IsUnspecified() const {
+ return mStartTime.IsNull() && mEndTime.IsNull();
+ }
+
+ // Full constructor, used by static factory functions.
+ constexpr MarkerTiming(const TimeStamp& aStartTime, const TimeStamp& aEndTime,
+ Phase aPhase)
+ : mStartTime(aStartTime), mEndTime(aEndTime), mPhase(aPhase) {}
+
+ static double timeStampToDouble(const TimeStamp& time) {
+ if (time.IsNull()) {
+ // The Phase lets us know not to use this value.
+ return 0;
+ }
+ return (time - TimeStamp::ProcessCreation()).ToMilliseconds();
+ }
+
+ TimeStamp mStartTime;
+ TimeStamp mEndTime;
+ Phase mPhase = Phase::Instant;
+};
+
+// This marker option allows three cases:
+// - By default, no stacks are captured.
+// - The caller can request a stack capture, and the add-marker code will take
+// care of it in the most efficient way.
+// - The caller can still provide an existing backtrace, for cases where a
+// marker reports something that happened elsewhere.
+class MarkerStack {
+ public:
+ // Default constructor, no capture.
+ constexpr MarkerStack() = default;
+
+ // Disallow copy.
+ MarkerStack(const MarkerStack&) = delete;
+ MarkerStack& operator=(const MarkerStack&) = delete;
+
+ // Allow move.
+ MarkerStack(MarkerStack&& aOther)
+ : mCaptureOptions(aOther.mCaptureOptions),
+ mOptionalChunkedBufferStorage(
+ std::move(aOther.mOptionalChunkedBufferStorage)),
+ mChunkedBuffer(aOther.mChunkedBuffer) {
+ AssertInvariants();
+ aOther.Clear();
+ }
+ MarkerStack& operator=(MarkerStack&& aOther) {
+ mCaptureOptions = aOther.mCaptureOptions;
+ mOptionalChunkedBufferStorage =
+ std::move(aOther.mOptionalChunkedBufferStorage);
+ mChunkedBuffer = aOther.mChunkedBuffer;
+ AssertInvariants();
+ aOther.Clear();
+ return *this;
+ }
+
+ // Take ownership of a backtrace. If null or empty, equivalent to NoStack().
+ explicit MarkerStack(UniquePtr<ProfileChunkedBuffer>&& aExternalChunkedBuffer)
+ : mOptionalChunkedBufferStorage(
+ (!aExternalChunkedBuffer || aExternalChunkedBuffer->IsEmpty())
+ ? nullptr
+ : std::move(aExternalChunkedBuffer)),
+ mChunkedBuffer(mOptionalChunkedBufferStorage.get()) {
+ AssertInvariants();
+ }
+
+ // Use an existing backtrace stored elsewhere, which the user must guarantee
+ // is alive during the add-marker call. If empty, equivalent to NoStack().
+ explicit MarkerStack(ProfileChunkedBuffer& aExternalChunkedBuffer)
+ : mChunkedBuffer(aExternalChunkedBuffer.IsEmpty()
+ ? nullptr
+ : &aExternalChunkedBuffer) {
+ AssertInvariants();
+ }
+
+ // Don't capture a stack in this marker.
+ static MarkerStack NoStack() {
+ return MarkerStack(StackCaptureOptions::NoStack);
+ }
+
+ // Capture a stack when adding this marker.
+ static MarkerStack Capture(
+ StackCaptureOptions aCaptureOptions = StackCaptureOptions::Full) {
+ // Actual capture will be handled inside profiler_add_marker.
+ return MarkerStack(aCaptureOptions);
+ }
+
+ // Optionally capture a stack, useful for avoiding long-winded ternaries.
+ static MarkerStack MaybeCapture(bool aDoCapture) {
+ return aDoCapture ? Capture() : NoStack();
+ }
+
+ // Use an existing backtrace stored elsewhere, which the user must guarantee
+ // is alive during the add-marker call. If empty, equivalent to NoStack().
+ static MarkerStack UseBacktrace(
+ ProfileChunkedBuffer& aExternalChunkedBuffer) {
+ return MarkerStack(aExternalChunkedBuffer);
+ }
+
+ // Take ownership of a backtrace previously captured with
+ // `profiler_capture_backtrace()`. If null, equivalent to NoStack().
+ static MarkerStack TakeBacktrace(
+ UniquePtr<ProfileChunkedBuffer>&& aExternalChunkedBuffer) {
+ return MarkerStack(std::move(aExternalChunkedBuffer));
+ }
+
+ // Construct with the given capture options.
+ static MarkerStack WithCaptureOptions(StackCaptureOptions aCaptureOptions) {
+ return MarkerStack(aCaptureOptions);
+ }
+
+ [[nodiscard]] StackCaptureOptions CaptureOptions() const {
+ return mCaptureOptions;
+ }
+
+ ProfileChunkedBuffer* GetChunkedBuffer() const { return mChunkedBuffer; }
+
+ // Use backtrace after a request. If null, equivalent to NoStack().
+ void UseRequestedBacktrace(ProfileChunkedBuffer* aExternalChunkedBuffer) {
+ MOZ_RELEASE_ASSERT(mCaptureOptions != StackCaptureOptions::NoStack);
+ mCaptureOptions = StackCaptureOptions::NoStack;
+ if (aExternalChunkedBuffer && !aExternalChunkedBuffer->IsEmpty()) {
+ // We only need to use the provided buffer if it is not empty.
+ mChunkedBuffer = aExternalChunkedBuffer;
+ }
+ AssertInvariants();
+ }
+
+ void Clear() {
+ mCaptureOptions = StackCaptureOptions::NoStack;
+ mOptionalChunkedBufferStorage.reset();
+ mChunkedBuffer = nullptr;
+ AssertInvariants();
+ }
+
+ private:
+ explicit MarkerStack(StackCaptureOptions aCaptureOptions)
+ : mCaptureOptions(aCaptureOptions) {
+ AssertInvariants();
+ }
+
+ // This should be called after every constructor and non-const function.
+ void AssertInvariants() const {
+#ifdef DEBUG
+ if (mCaptureOptions != StackCaptureOptions::NoStack) {
+ MOZ_ASSERT(!mOptionalChunkedBufferStorage,
+ "We should not hold a buffer when capture is requested");
+ MOZ_ASSERT(!mChunkedBuffer,
+ "We should not point at a buffer when capture is requested");
+ } else {
+ if (mOptionalChunkedBufferStorage) {
+ MOZ_ASSERT(mChunkedBuffer == mOptionalChunkedBufferStorage.get(),
+ "Non-null mOptionalChunkedBufferStorage must be pointed-at "
+ "by mChunkedBuffer");
+ }
+ if (mChunkedBuffer) {
+ MOZ_ASSERT(!mChunkedBuffer->IsEmpty(),
+ "Non-null mChunkedBuffer must not be empty");
+ }
+ }
+#endif // DEBUG
+ }
+
+ StackCaptureOptions mCaptureOptions = StackCaptureOptions::NoStack;
+
+ // Optional storage for the backtrace, in case it was captured before the
+ // add-marker call.
+ UniquePtr<ProfileChunkedBuffer> mOptionalChunkedBufferStorage;
+
+ // If not null, this points to the backtrace. It may point to a backtrace
+ // temporarily stored on the stack, or to mOptionalChunkedBufferStorage.
+ ProfileChunkedBuffer* mChunkedBuffer = nullptr;
+};
+
+// This marker option captures a given inner window id.
+class MarkerInnerWindowId {
+ public:
+ // Default constructor, it leaves the id unspecified.
+ constexpr MarkerInnerWindowId() = default;
+
+ // Constructor with a specified inner window id.
+ constexpr explicit MarkerInnerWindowId(uint64_t i) : mInnerWindowId(i) {}
+
+ // Constructor with either specified inner window id or Nothing.
+ constexpr explicit MarkerInnerWindowId(const Maybe<uint64_t>& i)
+ : mInnerWindowId(i.valueOr(scNoId)) {}
+
+ // Explicit option with unspecified id.
+ constexpr static MarkerInnerWindowId NoId() { return MarkerInnerWindowId{}; }
+
+ [[nodiscard]] bool IsUnspecified() const { return mInnerWindowId == scNoId; }
+
+ [[nodiscard]] constexpr uint64_t Id() const { return mInnerWindowId; }
+
+ private:
+ static constexpr uint64_t scNoId = 0;
+ uint64_t mInnerWindowId = scNoId;
+};
+
+// This class combines each of the possible marker options above.
+class MarkerOptions {
+ public:
+ // Constructor from individual options (including none).
+ // Implicit to allow `{}` and one option type as-is.
+ // Options that are not provided here are defaulted. In particular, timing
+ // defaults to `MarkerTiming::InstantNow()` when the marker is recorded.
+ template <typename... Options>
+ MOZ_IMPLICIT MarkerOptions(Options&&... aOptions) {
+ (Set(std::forward<Options>(aOptions)), ...);
+ }
+
+ // Disallow copy.
+ MarkerOptions(const MarkerOptions&) = delete;
+ MarkerOptions& operator=(const MarkerOptions&) = delete;
+
+ // Allow move.
+ MarkerOptions(MarkerOptions&&) = default;
+ MarkerOptions& operator=(MarkerOptions&&) = default;
+
+ // The embedded `MarkerTiming` hasn't been specified yet.
+ [[nodiscard]] bool IsTimingUnspecified() const {
+ return mTiming.IsUnspecified();
+ }
+
+ // Each option may be added in a chain by e.g.:
+ // `options.Set(MarkerThreadId(123)).Set(MarkerTiming::IntervalEnd())`.
+ // When passed to an add-marker function, it must be an rvalue, either created
+ // on the spot, or `std::move`d from storage, e.g.:
+ // `PROFILER_MARKER_UNTYPED("...", std::move(options).Set(...))`;
+ //
+ // Options can be read by their name (without "Marker"), e.g.: `o.ThreadId()`.
+ // Add "Ref" for a non-const reference, e.g.: `o.ThreadIdRef() = ...;`
+#define FUNCTIONS_ON_MEMBER(NAME) \
+ MarkerOptions& Set(Marker##NAME&& a##NAME)& { \
+ m##NAME = std::move(a##NAME); \
+ return *this; \
+ } \
+ \
+ MarkerOptions&& Set(Marker##NAME&& a##NAME)&& { \
+ m##NAME = std::move(a##NAME); \
+ return std::move(*this); \
+ } \
+ \
+ const Marker##NAME& NAME() const { return m##NAME; } \
+ \
+ Marker##NAME& NAME##Ref() { return m##NAME; }
+
+ FUNCTIONS_ON_MEMBER(ThreadId);
+ FUNCTIONS_ON_MEMBER(Timing);
+ FUNCTIONS_ON_MEMBER(Stack);
+ FUNCTIONS_ON_MEMBER(InnerWindowId);
+#undef FUNCTIONS_ON_MEMBER
+
+ private:
+ friend ProfileBufferEntryReader::Deserializer<MarkerOptions>;
+
+ MarkerThreadId mThreadId;
+ MarkerTiming mTiming;
+ MarkerStack mStack;
+ MarkerInnerWindowId mInnerWindowId;
+};
+
+} // namespace mozilla
+
+namespace mozilla::baseprofiler::markers {
+
+// Default marker payload types, with no extra information, not even a marker
+// type and payload. This is intended for label-only markers.
+struct NoPayload final {};
+
+} // namespace mozilla::baseprofiler::markers
+
+namespace mozilla {
+
+class JSONWriter;
+
+// This class collects all the information necessary to stream the JSON schema
+// that informs the front-end how to display a type of markers.
+// It will be created and populated in `MarkerTypeDisplay()` functions in each
+// marker type definition, see Add/Set functions.
+class MarkerSchema {
+ public:
+ enum class Location : unsigned {
+ MarkerChart,
+ MarkerTable,
+ // This adds markers to the main marker timeline in the header.
+ TimelineOverview,
+ // In the timeline, this is a section that breaks out markers that are
+ // related to memory. When memory counters are enabled, this is its own
+ // track, otherwise it is displayed with the main thread.
+ TimelineMemory,
+ // This adds markers to the IPC timeline area in the header.
+ TimelineIPC,
+ // This adds markers to the FileIO timeline area in the header.
+ TimelineFileIO,
+ // TODO - This is not supported yet.
+ StackChart
+ };
+
+ // Used as constructor parameter, to explicitly specify that the location (and
+ // other display options) are handled as a special case in the front-end.
+ // In this case, *no* schema will be output for this type.
+ struct SpecialFrontendLocation {};
+
+ enum class Format {
+ // ----------------------------------------------------
+ // String types.
+
+ // Show the URL, and handle PII sanitization
+ Url,
+ // Show the file path, and handle PII sanitization.
+ FilePath,
+ // Important, do not put URL or file path information here, as it will not
+ // be sanitized. Please be careful with including other types of PII here as
+ // well.
+ // e.g. "Label: Some String"
+ String,
+
+ // ----------------------------------------------------
+ // Numeric types
+
+ // For time data that represents a duration of time.
+ // e.g. "Label: 5s, 5ms, 5μs"
+ Duration,
+ // Data that happened at a specific time, relative to the start of the
+ // profile. e.g. "Label: 15.5s, 20.5ms, 30.5μs"
+ Time,
+ // The following are alternatives to display a time only in a specific unit
+ // of time.
+ Seconds, // "Label: 5s"
+ Milliseconds, // "Label: 5ms"
+ Microseconds, // "Label: 5μs"
+ Nanoseconds, // "Label: 5ns"
+ // e.g. "Label: 5.55mb, 5 bytes, 312.5kb"
+ Bytes,
+ // This should be a value between 0 and 1.
+ // "Label: 50%"
+ Percentage,
+ // The integer should be used for generic representations of numbers.
+ // Do not use it for time information.
+ // "Label: 52, 5,323, 1,234,567"
+ Integer,
+ // The decimal should be used for generic representations of numbers.
+ // Do not use it for time information.
+ // "Label: 52.23, 0.0054, 123,456.78"
+ Decimal
+ };
+
+ enum class Searchable { NotSearchable, Searchable };
+
+ // Marker schema, with a non-empty list of locations where markers should be
+ // shown.
+ // Tech note: Even though `aLocations` are templated arguments, they are
+ // assigned to an `enum class` object, so they can only be of that enum type.
+ template <typename... Locations>
+ explicit MarkerSchema(Location aLocation, Locations... aLocations)
+ : mLocations{aLocation, aLocations...} {}
+
+ // Alternative constructor for MarkerSchema.
+ explicit MarkerSchema(const mozilla::MarkerSchema::Location* aLocations,
+ size_t aLength)
+ : mLocations(aLocations, aLocations + aLength) {}
+
+ // Marker schema for types that have special frontend handling.
+ // Nothing else should be set in this case.
+ // Implicit to allow quick return from MarkerTypeDisplay functions.
+ MOZ_IMPLICIT MarkerSchema(SpecialFrontendLocation) {}
+
+ // Caller must specify location(s) or SpecialFrontendLocation above.
+ MarkerSchema() = delete;
+
+ // Optional labels in the marker chart, the chart tooltip, and the marker
+ // table. If not provided, the marker "name" will be used. The given string
+ // can contain element keys in braces to include data elements streamed by
+ // `StreamJSONMarkerData()`. E.g.: "This is {text}"
+
+#define LABEL_SETTER(name) \
+ MarkerSchema& Set##name(std::string a##name) { \
+ m##name = std::move(a##name); \
+ return *this; \
+ }
+
+ LABEL_SETTER(ChartLabel)
+ LABEL_SETTER(TooltipLabel)
+ LABEL_SETTER(TableLabel)
+
+#undef LABEL_SETTER
+
+ MarkerSchema& SetAllLabels(std::string aText) {
+ // Here we set the same text in each label.
+ // TODO: Move to a single "label" field once the front-end allows it.
+ SetChartLabel(aText);
+ SetTooltipLabel(aText);
+ SetTableLabel(std::move(aText));
+ return *this;
+ }
+
+ // Each data element that is streamed by `StreamJSONMarkerData()` can be
+ // displayed as indicated by using one of the `Add...` function below.
+ // Each `Add...` will add a line in the full marker description. Parameters:
+ // - `aKey`: Element property name as streamed by `StreamJSONMarkerData()`.
+ // - `aLabel`: Optional prefix. Defaults to the key name.
+ // - `aFormat`: How to format the data element value, see `Format` above.
+ // - `aSearchable`: Optional, indicates if the value is used in searches,
+ // defaults to false.
+
+ MarkerSchema& AddKeyFormat(std::string aKey, Format aFormat) {
+ mData.emplace_back(mozilla::VariantType<DynamicData>{},
+ DynamicData{std::move(aKey), mozilla::Nothing{}, aFormat,
+ mozilla::Nothing{}});
+ return *this;
+ }
+
+ MarkerSchema& AddKeyLabelFormat(std::string aKey, std::string aLabel,
+ Format aFormat) {
+ mData.emplace_back(
+ mozilla::VariantType<DynamicData>{},
+ DynamicData{std::move(aKey), mozilla::Some(std::move(aLabel)), aFormat,
+ mozilla::Nothing{}});
+ return *this;
+ }
+
+ MarkerSchema& AddKeyFormatSearchable(std::string aKey, Format aFormat,
+ Searchable aSearchable) {
+ mData.emplace_back(mozilla::VariantType<DynamicData>{},
+ DynamicData{std::move(aKey), mozilla::Nothing{}, aFormat,
+ mozilla::Some(aSearchable)});
+ return *this;
+ }
+
+ MarkerSchema& AddKeyLabelFormatSearchable(std::string aKey,
+ std::string aLabel, Format aFormat,
+ Searchable aSearchable) {
+ mData.emplace_back(
+ mozilla::VariantType<DynamicData>{},
+ DynamicData{std::move(aKey), mozilla::Some(std::move(aLabel)), aFormat,
+ mozilla::Some(aSearchable)});
+ return *this;
+ }
+
+ // The display may also include static rows.
+
+ MarkerSchema& AddStaticLabelValue(std::string aLabel, std::string aValue) {
+ mData.emplace_back(mozilla::VariantType<StaticData>{},
+ StaticData{std::move(aLabel), std::move(aValue)});
+ return *this;
+ }
+
+ // Internal streaming function.
+ MFBT_API void Stream(JSONWriter& aWriter, const Span<const char>& aName) &&;
+
+ private:
+ MFBT_API static Span<const char> LocationToStringSpan(Location aLocation);
+ MFBT_API static Span<const char> FormatToStringSpan(Format aFormat);
+
+ // List of marker display locations. Empty for SpecialFrontendLocation.
+ std::vector<Location> mLocations;
+ // Labels for different places.
+ std::string mChartLabel;
+ std::string mTooltipLabel;
+ std::string mTableLabel;
+ // Main display, made of zero or more rows of key+label+format or label+value.
+ private:
+ struct DynamicData {
+ std::string mKey;
+ mozilla::Maybe<std::string> mLabel;
+ Format mFormat;
+ mozilla::Maybe<Searchable> mSearchable;
+ };
+ struct StaticData {
+ std::string mLabel;
+ std::string mValue;
+ };
+ using DataRow = mozilla::Variant<DynamicData, StaticData>;
+ using DataRowVector = std::vector<DataRow>;
+
+ DataRowVector mData;
+};
+
+} // namespace mozilla
+
+#endif // BaseProfilerMarkersPrerequisites_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerRAIIMacro.h b/mozglue/baseprofiler/public/BaseProfilerRAIIMacro.h
new file mode 100644
index 0000000000..b89f7e1f77
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerRAIIMacro.h
@@ -0,0 +1,15 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerRAIIMacro_h
+#define BaseProfilerRAIIMacro_h
+
+// Macros used by the AUTO_PROFILER_* macros to generate unique variable names.
+#define PROFILER_RAII_PASTE(id, line) id##line
+#define PROFILER_RAII_EXPAND(id, line) PROFILER_RAII_PASTE(id, line)
+#define PROFILER_RAII PROFILER_RAII_EXPAND(raiiObject, __LINE__)
+
+#endif // BaseProfilerRAIIMacro_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerSharedLibraries.h b/mozglue/baseprofiler/public/BaseProfilerSharedLibraries.h
new file mode 100644
index 0000000000..705ca55f4b
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerSharedLibraries.h
@@ -0,0 +1,170 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BASE_PROFILER_SHARED_LIBRARIES_H_
+#define BASE_PROFILER_SHARED_LIBRARIES_H_
+
+#include "BaseProfiler.h"
+
+#ifndef MOZ_GECKO_PROFILER
+# error Do not #include this header when MOZ_GECKO_PROFILER is not #defined.
+#endif
+
+#include <algorithm>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string>
+#include <vector>
+
+class SharedLibrary {
+ public:
+ SharedLibrary(uintptr_t aStart, uintptr_t aEnd, uintptr_t aOffset,
+ const std::string& aBreakpadId, const std::string& aCodeId,
+ const std::string& aModuleName, const std::string& aModulePath,
+ const std::string& aDebugName, const std::string& aDebugPath,
+ const std::string& aVersion, const char* aArch)
+ : mStart(aStart),
+ mEnd(aEnd),
+ mOffset(aOffset),
+ mBreakpadId(aBreakpadId),
+ mCodeId(aCodeId),
+ mModuleName(aModuleName),
+ mModulePath(aModulePath),
+ mDebugName(aDebugName),
+ mDebugPath(aDebugPath),
+ mVersion(aVersion),
+ mArch(aArch) {}
+
+ SharedLibrary(const SharedLibrary& aEntry)
+ : mStart(aEntry.mStart),
+ mEnd(aEntry.mEnd),
+ mOffset(aEntry.mOffset),
+ mBreakpadId(aEntry.mBreakpadId),
+ mCodeId(aEntry.mCodeId),
+ mModuleName(aEntry.mModuleName),
+ mModulePath(aEntry.mModulePath),
+ mDebugName(aEntry.mDebugName),
+ mDebugPath(aEntry.mDebugPath),
+ mVersion(aEntry.mVersion),
+ mArch(aEntry.mArch) {}
+
+ SharedLibrary& operator=(const SharedLibrary& aEntry) {
+ // Gracefully handle self assignment
+ if (this == &aEntry) return *this;
+
+ mStart = aEntry.mStart;
+ mEnd = aEntry.mEnd;
+ mOffset = aEntry.mOffset;
+ mBreakpadId = aEntry.mBreakpadId;
+ mCodeId = aEntry.mCodeId;
+ mModuleName = aEntry.mModuleName;
+ mModulePath = aEntry.mModulePath;
+ mDebugName = aEntry.mDebugName;
+ mDebugPath = aEntry.mDebugPath;
+ mVersion = aEntry.mVersion;
+ mArch = aEntry.mArch;
+ return *this;
+ }
+
+ bool operator==(const SharedLibrary& other) const {
+ return (mStart == other.mStart) && (mEnd == other.mEnd) &&
+ (mOffset == other.mOffset) && (mModuleName == other.mModuleName) &&
+ (mModulePath == other.mModulePath) &&
+ (mDebugName == other.mDebugName) &&
+ (mDebugPath == other.mDebugPath) &&
+ (mBreakpadId == other.mBreakpadId) && (mCodeId == other.mCodeId) &&
+ (mVersion == other.mVersion) && (mArch == other.mArch);
+ }
+
+ uintptr_t GetStart() const { return mStart; }
+ uintptr_t GetEnd() const { return mEnd; }
+ uintptr_t GetOffset() const { return mOffset; }
+ const std::string& GetBreakpadId() const { return mBreakpadId; }
+ const std::string& GetCodeId() const { return mCodeId; }
+ const std::string& GetModuleName() const { return mModuleName; }
+ const std::string& GetModulePath() const { return mModulePath; }
+ const std::string& GetDebugName() const { return mDebugName; }
+ const std::string& GetDebugPath() const { return mDebugPath; }
+ const std::string& GetVersion() const { return mVersion; }
+ const std::string& GetArch() const { return mArch; }
+
+ private:
+ SharedLibrary() : mStart{0}, mEnd{0}, mOffset{0} {}
+
+ uintptr_t mStart;
+ uintptr_t mEnd;
+ uintptr_t mOffset;
+ std::string mBreakpadId;
+ // A string carrying an identifier for a binary.
+ //
+ // All platforms have different formats:
+ // - Windows: The code ID for a Windows PE file.
+ // It's the PE timestamp and PE image size.
+ // - macOS: The code ID for a macOS / iOS binary (mach-O).
+ // It's the mach-O UUID without dashes and without the trailing 0 for the
+ // breakpad ID.
+ // - Linux/Android: The code ID for a Linux ELF file.
+ // It's the complete build ID, as hex string.
+ std::string mCodeId;
+ std::string mModuleName;
+ std::string mModulePath;
+ std::string mDebugName;
+ std::string mDebugPath;
+ std::string mVersion;
+ std::string mArch;
+};
+
+static bool CompareAddresses(const SharedLibrary& first,
+ const SharedLibrary& second) {
+ return first.GetStart() < second.GetStart();
+}
+
+class SharedLibraryInfo {
+ public:
+ static SharedLibraryInfo GetInfoForSelf();
+#ifdef XP_WIN
+ static SharedLibraryInfo GetInfoFromPath(const wchar_t* aPath);
+#endif
+
+ static void Initialize();
+
+ SharedLibraryInfo() {}
+
+ void AddSharedLibrary(SharedLibrary entry) { mEntries.push_back(entry); }
+
+ const SharedLibrary& GetEntry(size_t i) const { return mEntries[i]; }
+
+ SharedLibrary& GetMutableEntry(size_t i) { return mEntries[i]; }
+
+ // Removes items in the range [first, last)
+ // i.e. element at the "last" index is not removed
+ void RemoveEntries(size_t first, size_t last) {
+ mEntries.erase(mEntries.begin() + first, mEntries.begin() + last);
+ }
+
+ bool Contains(const SharedLibrary& searchItem) const {
+ return (mEntries.end() !=
+ std::find(mEntries.begin(), mEntries.end(), searchItem));
+ }
+
+ size_t GetSize() const { return mEntries.size(); }
+
+ void SortByAddress() {
+ std::sort(mEntries.begin(), mEntries.end(), CompareAddresses);
+ }
+
+ void Clear() { mEntries.clear(); }
+
+ private:
+#ifdef XP_WIN
+ void AddSharedLibraryFromModuleInfo(const wchar_t* aModulePath,
+ mozilla::Maybe<HMODULE> aModule);
+#endif
+
+ std::vector<SharedLibrary> mEntries;
+};
+
+#endif // BASE_PROFILER_SHARED_LIBRARIES_H_
diff --git a/mozglue/baseprofiler/public/BaseProfilerState.h b/mozglue/baseprofiler/public/BaseProfilerState.h
new file mode 100644
index 0000000000..15be2743a4
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerState.h
@@ -0,0 +1,405 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The Gecko Profiler is an always-on profiler that takes fast and low overhead
+// samples of the program execution using only userspace functionality for
+// portability. The goal of this module is to provide performance data in a
+// generic cross-platform way without requiring custom tools or kernel support.
+//
+// Samples are collected to form a timeline with optional timeline event
+// (markers) used for filtering. The samples include both native stacks and
+// platform-independent "label stack" frames.
+
+#ifndef BaseProfilerState_h
+#define BaseProfilerState_h
+
+// This header contains most functions that give information about the Base
+// Profiler: Whether it is active or not, paused, the selected features, and
+// some generic process and thread information.
+// It is safe to include unconditionally, but uses of structs and functions must
+// be guarded by `#ifdef MOZ_GECKO_PROFILER`.
+
+#include "mozilla/BaseProfilerUtils.h"
+
+#ifndef MOZ_GECKO_PROFILER
+
+# define AUTO_PROFILER_STATS(name)
+
+namespace mozilla::baseprofiler {
+
+[[nodiscard]] inline bool profiler_is_active() { return false; }
+[[nodiscard]] inline bool profiler_is_active_and_unpaused() { return false; }
+
+} // namespace mozilla::baseprofiler
+
+#else // !MOZ_GECKO_PROFILER
+
+# include "mozilla/Atomics.h"
+# include "mozilla/Maybe.h"
+
+# include <stdint.h>
+# include <string>
+
+// Uncomment the following line to display profiler runtime statistics at
+// shutdown.
+// # define PROFILER_RUNTIME_STATS
+
+# ifdef PROFILER_RUNTIME_STATS
+# include "mozilla/TimeStamp.h"
+# endif
+
+namespace mozilla::baseprofiler {
+
+# ifdef PROFILER_RUNTIME_STATS
+// This class gathers durations and displays some basic stats when destroyed.
+// It is intended to be used as a static variable (see `AUTO_PROFILER_STATS`
+// below), to display stats at the end of the program.
+class StaticBaseProfilerStats {
+ public:
+ explicit StaticBaseProfilerStats(const char* aName) : mName(aName) {}
+
+ ~StaticBaseProfilerStats() {
+ // Using unsigned long long for computations and printfs.
+ using ULL = unsigned long long;
+ ULL n = static_cast<ULL>(mNumberDurations);
+ if (n != 0) {
+ ULL sumNs = static_cast<ULL>(mSumDurationsNs);
+ printf(
+ "[%d] Profiler stats `%s`: %llu ns / %llu = %llu ns, max %llu ns\n",
+ int(profiler_current_process_id().ToNumber()), mName, sumNs, n,
+ sumNs / n, static_cast<ULL>(mLongestDurationNs));
+ } else {
+ printf("[%d] Profiler stats `%s`: (nothing)\n",
+ int(profiler_current_process_id().ToNumber()), mName);
+ }
+ }
+
+ void AddDurationFrom(TimeStamp aStart) {
+ DurationNs duration = static_cast<DurationNs>(
+ (TimeStamp::Now() - aStart).ToMicroseconds() * 1000 + 0.5);
+ mSumDurationsNs += duration;
+ ++mNumberDurations;
+ // Update mLongestDurationNs if this one is longer.
+ for (;;) {
+ DurationNs longest = mLongestDurationNs;
+ if (MOZ_LIKELY(longest >= duration)) {
+ // This duration is not the longest, nothing to do.
+ break;
+ }
+ if (MOZ_LIKELY(mLongestDurationNs.compareExchange(longest, duration))) {
+ // Successfully updated `mLongestDurationNs` with the new value.
+ break;
+ }
+ // Otherwise someone else just updated `mLongestDurationNs`, we need to
+ // try again by looping.
+ }
+ }
+
+ private:
+ using DurationNs = uint64_t;
+ using Count = uint32_t;
+
+ Atomic<DurationNs> mSumDurationsNs{0};
+ Atomic<DurationNs> mLongestDurationNs{0};
+ Atomic<Count> mNumberDurations{0};
+ const char* mName;
+};
+
+// RAII object that measure its scoped lifetime duration and reports it to a
+// `StaticBaseProfilerStats`.
+class MOZ_RAII AutoProfilerStats {
+ public:
+ explicit AutoProfilerStats(StaticBaseProfilerStats& aStats)
+ : mStats(aStats), mStart(TimeStamp::Now()) {}
+
+ ~AutoProfilerStats() { mStats.AddDurationFrom(mStart); }
+
+ private:
+ StaticBaseProfilerStats& mStats;
+ TimeStamp mStart;
+};
+
+// Macro that should be used to collect basic statistics from measurements of
+// block durations, from where this macro is, until the end of its enclosing
+// scope. The name is used in the static variable name and when displaying stats
+// at the end of the program; Another location could use the same name but their
+// stats will not be combined, so use different name if these locations should
+// be distinguished.
+# define AUTO_PROFILER_STATS(name) \
+ static ::mozilla::baseprofiler::StaticBaseProfilerStats sStat##name( \
+ #name); \
+ ::mozilla::baseprofiler::AutoProfilerStats autoStat##name(sStat##name);
+
+# else // PROFILER_RUNTIME_STATS
+
+# define AUTO_PROFILER_STATS(name)
+
+# endif // PROFILER_RUNTIME_STATS else
+
+//---------------------------------------------------------------------------
+// Profiler features
+//---------------------------------------------------------------------------
+
+# if defined(__APPLE__) && defined(__aarch64__)
+# define POWER_HELP "Sample per process power use"
+# elif defined(__APPLE__) && defined(__x86_64__)
+# define POWER_HELP \
+ "Record the power used by the entire system with each sample."
+# elif defined(__linux__) && defined(__x86_64__)
+# define POWER_HELP \
+ "Record the power used by the entire system with each sample. " \
+ "Only available with Intel CPUs and requires setting " \
+ "the sysctl kernel.perf_event_paranoid to 0."
+# elif defined(_MSC_VER)
+# define POWER_HELP \
+ "Record the value of every energy meter available on the system with " \
+ "each sample. Only available on Windows 11 with Intel CPUs."
+# else
+# define POWER_HELP "Not supported on this platform."
+# endif
+
+// Higher-order macro containing all the feature info in one place. Define
+// |MACRO| appropriately to extract the relevant parts. Note that the number
+// values are used internally only and so can be changed without consequence.
+// Any changes to this list should also be applied to the feature list in
+// toolkit/components/extensions/schemas/geckoProfiler.json.
+// *** Synchronize with lists in ProfilerState.h and geckoProfiler.json ***
+# define BASE_PROFILER_FOR_EACH_FEATURE(MACRO) \
+ MACRO(0, "java", Java, "Profile Java code, Android only") \
+ \
+ MACRO(1, "js", JS, \
+ "Get the JS engine to expose the JS stack to the profiler") \
+ \
+ MACRO(2, "mainthreadio", MainThreadIO, "Add main thread file I/O") \
+ \
+ MACRO(3, "fileio", FileIO, \
+ "Add file I/O from all profiled threads, implies mainthreadio") \
+ \
+ MACRO(4, "fileioall", FileIOAll, \
+ "Add file I/O from all threads, implies fileio") \
+ \
+ MACRO(5, "nomarkerstacks", NoMarkerStacks, \
+ "Markers do not capture stacks, to reduce overhead") \
+ \
+ MACRO(6, "screenshots", Screenshots, \
+ "Take a snapshot of the window on every composition") \
+ \
+ MACRO(7, "seqstyle", SequentialStyle, \
+ "Disable parallel traversal in styling") \
+ \
+ MACRO(8, "stackwalk", StackWalk, \
+ "Walk the C++ stack, not available on all platforms") \
+ \
+ MACRO(9, "jsallocations", JSAllocations, \
+ "Have the JavaScript engine track allocations") \
+ \
+ MACRO(10, "nostacksampling", NoStackSampling, \
+ "Disable all stack sampling: Cancels \"js\", \"stackwalk\" and " \
+ "labels") \
+ \
+ MACRO(11, "nativeallocations", NativeAllocations, \
+ "Collect the stacks from a smaller subset of all native " \
+ "allocations, biasing towards collecting larger allocations") \
+ \
+ MACRO(12, "ipcmessages", IPCMessages, \
+ "Have the IPC layer track cross-process messages") \
+ \
+ MACRO(13, "audiocallbacktracing", AudioCallbackTracing, \
+ "Audio callback tracing") \
+ \
+ MACRO(14, "cpu", CPUUtilization, "CPU utilization") \
+ \
+ MACRO(15, "notimerresolutionchange", NoTimerResolutionChange, \
+ "Do not adjust the timer resolution for fast sampling, so that " \
+ "other Firefox timers do not get affected") \
+ \
+ MACRO(16, "cpuallthreads", CPUAllThreads, \
+ "Sample the CPU utilization of all registered threads") \
+ \
+ MACRO(17, "samplingallthreads", SamplingAllThreads, \
+ "Sample the stacks of all registered threads") \
+ \
+ MACRO(18, "markersallthreads", MarkersAllThreads, \
+ "Record markers from all registered threads") \
+ \
+ MACRO(19, "unregisteredthreads", UnregisteredThreads, \
+ "Discover and profile unregistered threads -- beware: expensive!") \
+ \
+ MACRO(20, "processcpu", ProcessCPU, \
+ "Sample the CPU utilization of each process") \
+ \
+ MACRO(21, "power", Power, POWER_HELP)
+// *** Synchronize with lists in ProfilerState.h and geckoProfiler.json ***
+
+struct ProfilerFeature {
+# define DECLARE(n_, str_, Name_, desc_) \
+ static constexpr uint32_t Name_ = (1u << n_); \
+ [[nodiscard]] static constexpr bool Has##Name_(uint32_t aFeatures) { \
+ return aFeatures & Name_; \
+ } \
+ static constexpr void Set##Name_(uint32_t& aFeatures) { \
+ aFeatures |= Name_; \
+ } \
+ static constexpr void Clear##Name_(uint32_t& aFeatures) { \
+ aFeatures &= ~Name_; \
+ }
+
+ // Define a bitfield constant, a getter, and two setters for each feature.
+ BASE_PROFILER_FOR_EACH_FEATURE(DECLARE)
+
+# undef DECLARE
+};
+
+namespace detail {
+
+// RacyFeatures is only defined in this header file so that its methods can
+// be inlined into profiler_is_active(). Please do not use anything from the
+// detail namespace outside the profiler.
+
+// Within the profiler's code, the preferred way to check profiler activeness
+// and features is via ActivePS(). However, that requires locking gPSMutex.
+// There are some hot operations where absolute precision isn't required, so we
+// duplicate the activeness/feature state in a lock-free manner in this class.
+class RacyFeatures {
+ public:
+ MFBT_API static void SetActive(uint32_t aFeatures);
+
+ MFBT_API static void SetInactive();
+
+ MFBT_API static void SetPaused();
+
+ MFBT_API static void SetUnpaused();
+
+ MFBT_API static void SetSamplingPaused();
+
+ MFBT_API static void SetSamplingUnpaused();
+
+ [[nodiscard]] MFBT_API static mozilla::Maybe<uint32_t> FeaturesIfActive() {
+ if (uint32_t af = sActiveAndFeatures; af & Active) {
+ // Active, remove the Active&Paused bits to get all features.
+ return Some(af & ~(Active | Paused | SamplingPaused));
+ }
+ return Nothing();
+ }
+
+ [[nodiscard]] MFBT_API static bool IsActive();
+
+ [[nodiscard]] MFBT_API static bool IsActiveWithFeature(uint32_t aFeature);
+
+ [[nodiscard]] MFBT_API static bool IsActiveWithoutFeature(uint32_t aFeature);
+
+ // True if profiler is active, and not fully paused.
+ // Note that periodic sampling *could* be paused!
+ [[nodiscard]] MFBT_API static bool IsActiveAndUnpaused();
+
+ // True if profiler is active, and sampling is not paused (though generic
+ // `SetPaused()` or specific `SetSamplingPaused()`).
+ [[nodiscard]] MFBT_API static bool IsActiveAndSamplingUnpaused();
+
+ private:
+ static constexpr uint32_t Active = 1u << 31;
+ static constexpr uint32_t Paused = 1u << 30;
+ static constexpr uint32_t SamplingPaused = 1u << 29;
+
+// Ensure Active/Paused don't overlap with any of the feature bits.
+# define NO_OVERLAP(n_, str_, Name_, desc_) \
+ static_assert(ProfilerFeature::Name_ != SamplingPaused, \
+ "bad feature value");
+
+ BASE_PROFILER_FOR_EACH_FEATURE(NO_OVERLAP);
+
+# undef NO_OVERLAP
+
+ // We combine the active bit with the feature bits so they can be read or
+ // written in a single atomic operation.
+ // TODO: Could this be MFBT_DATA for better inlining optimization?
+ static Atomic<uint32_t, MemoryOrdering::Relaxed> sActiveAndFeatures;
+};
+
+MFBT_API bool IsThreadBeingProfiled();
+
+} // namespace detail
+
+//---------------------------------------------------------------------------
+// Get information from the profiler
+//---------------------------------------------------------------------------
+
+// Is the profiler active? Note: the return value of this function can become
+// immediately out-of-date. E.g. the profile might be active but then
+// profiler_stop() is called immediately afterward. One common and reasonable
+// pattern of usage is the following:
+//
+// if (profiler_is_active()) {
+// ExpensiveData expensiveData = CreateExpensiveData();
+// PROFILER_OPERATION(expensiveData);
+// }
+//
+// where PROFILER_OPERATION is a no-op if the profiler is inactive. In this
+// case the profiler_is_active() check is just an optimization -- it prevents
+// us calling CreateExpensiveData() unnecessarily in most cases, but the
+// expensive data will end up being created but not used if another thread
+// stops the profiler between the CreateExpensiveData() and PROFILER_OPERATION
+// calls.
+[[nodiscard]] inline bool profiler_is_active() {
+ return baseprofiler::detail::RacyFeatures::IsActive();
+}
+
+// Same as profiler_is_active(), but also checks if the profiler is not paused.
+[[nodiscard]] inline bool profiler_is_active_and_unpaused() {
+ return baseprofiler::detail::RacyFeatures::IsActiveAndUnpaused();
+}
+
+// Is the profiler active and unpaused, and is the current thread being
+// profiled? (Same caveats and recommented usage as profiler_is_active().)
+[[nodiscard]] inline bool profiler_thread_is_being_profiled() {
+ return baseprofiler::detail::RacyFeatures::IsActiveAndUnpaused() &&
+ baseprofiler::detail::IsThreadBeingProfiled();
+}
+
+// Is the profiler active and paused? Returns false if the profiler is inactive.
+[[nodiscard]] MFBT_API bool profiler_is_paused();
+
+// Is the profiler active and sampling is paused? Returns false if the profiler
+// is inactive.
+[[nodiscard]] MFBT_API bool profiler_is_sampling_paused();
+
+// Is the current thread sleeping?
+[[nodiscard]] MFBT_API bool profiler_thread_is_sleeping();
+
+// Get all the features supported by the profiler that are accepted by
+// profiler_start(). The result is the same whether the profiler is active or
+// not.
+[[nodiscard]] MFBT_API uint32_t profiler_get_available_features();
+
+// Returns the full feature set if the profiler is active.
+// Note: the return value can become immediately out-of-date, much like the
+// return value of profiler_is_active().
+[[nodiscard]] inline mozilla::Maybe<uint32_t> profiler_features_if_active() {
+ return baseprofiler::detail::RacyFeatures::FeaturesIfActive();
+}
+
+// Check if a profiler feature (specified via the ProfilerFeature type) is
+// active. Returns false if the profiler is inactive. Note: the return value
+// can become immediately out-of-date, much like the return value of
+// profiler_is_active().
+[[nodiscard]] MFBT_API bool profiler_feature_active(uint32_t aFeature);
+
+// Check if the profiler is active without a feature (specified via the
+// ProfilerFeature type). Note: the return value can become immediately
+// out-of-date, much like the return value of profiler_is_active().
+[[nodiscard]] MFBT_API bool profiler_active_without_feature(uint32_t aFeature);
+
+// Returns true if any of the profiler mutexes are currently locked *on the
+// current thread*. This may be used by re-entrant code that may call profiler
+// functions while the same of a different profiler mutex is locked, which could
+// deadlock.
+[[nodiscard]] bool profiler_is_locked_on_current_thread();
+
+} // namespace mozilla::baseprofiler
+
+#endif // !MOZ_GECKO_PROFILER
+
+#endif // BaseProfilerState_h
diff --git a/mozglue/baseprofiler/public/BaseProfilerUtils.h b/mozglue/baseprofiler/public/BaseProfilerUtils.h
new file mode 100644
index 0000000000..ab02e03b95
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilerUtils.h
@@ -0,0 +1,227 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilerUtils_h
+#define BaseProfilerUtils_h
+
+// This header contains most process- and thread-related functions.
+// It is safe to include unconditionally.
+
+// --------------------------------------------- WASI process & thread ids
+#if defined(__wasi__)
+
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = unsigned;
+using ThreadIdType = unsigned;
+} // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Windows process & thread ids
+#elif defined(XP_WIN)
+
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = int;
+using ThreadIdType = unsigned long;
+} // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Non-Windows process id
+#else
+// All non-Windows platforms are assumed to be POSIX, which has getpid().
+
+# include <unistd.h>
+namespace mozilla::baseprofiler::detail {
+using ProcessIdType = decltype(getpid());
+} // namespace mozilla::baseprofiler::detail
+
+// --------------------------------------------- Non-Windows thread id
+// ------------------------------------------------------- macOS
+# if defined(XP_MACOSX)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = uint64_t;
+} // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Android
+// Test Android before Linux, because Linux includes Android.
+# elif defined(__ANDROID__) || defined(ANDROID)
+
+# include <sys/types.h>
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = decltype(gettid());
+} // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Linux
+# elif defined(XP_LINUX)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = long;
+} // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- FreeBSD
+# elif defined(XP_FREEBSD)
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = long;
+} // namespace mozilla::baseprofiler::detail
+
+// ------------------------------------------------------- Others
+# else
+
+# include <thread>
+
+namespace mozilla::baseprofiler::detail {
+using ThreadIdType = std::thread::id;
+} // namespace mozilla::baseprofiler::detail
+
+# endif
+#endif // End of non-XP_WIN.
+
+#include <stdint.h>
+#include <string.h>
+#include <type_traits>
+
+namespace mozilla::baseprofiler {
+
+// Trivially-copyable class containing a process id. It may be left unspecified.
+class BaseProfilerProcessId {
+ public:
+ using NativeType = detail::ProcessIdType;
+
+ using NumberType =
+ std::conditional_t<(sizeof(NativeType) <= 4), uint32_t, uint64_t>;
+ static_assert(sizeof(NativeType) <= sizeof(NumberType));
+
+ // Unspecified process id.
+ constexpr BaseProfilerProcessId() = default;
+
+ [[nodiscard]] constexpr bool IsSpecified() const {
+ return mProcessId != scUnspecified;
+ }
+
+ // Construct from a native type.
+ [[nodiscard]] static BaseProfilerProcessId FromNativeId(
+ const NativeType& aNativeProcessId) {
+ BaseProfilerProcessId id;
+ // Convert trivially-copyable native id by copying its bits.
+ static_assert(std::is_trivially_copyable_v<NativeType>);
+ memcpy(&id.mProcessId, &aNativeProcessId, sizeof(NativeType));
+ return id;
+ }
+
+ // Get the process id as a number, which may be unspecified.
+ // This should only be used for serialization or logging.
+ [[nodiscard]] constexpr NumberType ToNumber() const { return mProcessId; }
+
+ // BaseProfilerProcessId from given number (which may be unspecified).
+ constexpr static BaseProfilerProcessId FromNumber(
+ const NumberType& aProcessId) {
+ BaseProfilerProcessId id;
+ id.mProcessId = aProcessId;
+ return id;
+ }
+
+ [[nodiscard]] constexpr bool operator==(
+ const BaseProfilerProcessId& aOther) const {
+ return mProcessId == aOther.mProcessId;
+ }
+ [[nodiscard]] constexpr bool operator!=(
+ const BaseProfilerProcessId& aOther) const {
+ return mProcessId != aOther.mProcessId;
+ }
+
+ private:
+ static constexpr NumberType scUnspecified = 0;
+ NumberType mProcessId = scUnspecified;
+};
+
+// Check traits. These should satisfy usage in std::atomic.
+static_assert(std::is_trivially_copyable_v<BaseProfilerProcessId>);
+static_assert(std::is_copy_constructible_v<BaseProfilerProcessId>);
+static_assert(std::is_move_constructible_v<BaseProfilerProcessId>);
+static_assert(std::is_copy_assignable_v<BaseProfilerProcessId>);
+static_assert(std::is_move_assignable_v<BaseProfilerProcessId>);
+
+// Trivially-copyable class containing a thread id. It may be left unspecified.
+class BaseProfilerThreadId {
+ public:
+ using NativeType = detail::ThreadIdType;
+
+ using NumberType =
+ std::conditional_t<(sizeof(NativeType) <= 4), uint32_t, uint64_t>;
+ static_assert(sizeof(NativeType) <= sizeof(NumberType));
+
+ // Unspecified thread id.
+ constexpr BaseProfilerThreadId() = default;
+
+ [[nodiscard]] constexpr bool IsSpecified() const {
+ return mThreadId != scUnspecified;
+ }
+
+ // Construct from a native type.
+ [[nodiscard]] static BaseProfilerThreadId FromNativeId(
+ const NativeType& aNativeThreadId) {
+ BaseProfilerThreadId id;
+ // Convert trivially-copyable native id by copying its bits.
+ static_assert(std::is_trivially_copyable_v<NativeType>);
+ memcpy(&id.mThreadId, &aNativeThreadId, sizeof(NativeType));
+ return id;
+ }
+
+ // Get the thread id as a number, which may be unspecified.
+ // This should only be used for serialization or logging.
+ [[nodiscard]] constexpr NumberType ToNumber() const { return mThreadId; }
+
+ // BaseProfilerThreadId from given number (which may be unspecified).
+ constexpr static BaseProfilerThreadId FromNumber(
+ const NumberType& aThreadId) {
+ BaseProfilerThreadId id;
+ id.mThreadId = aThreadId;
+ return id;
+ }
+
+ [[nodiscard]] constexpr bool operator==(
+ const BaseProfilerThreadId& aOther) const {
+ return mThreadId == aOther.mThreadId;
+ }
+ [[nodiscard]] constexpr bool operator!=(
+ const BaseProfilerThreadId& aOther) const {
+ return mThreadId != aOther.mThreadId;
+ }
+
+ private:
+ static constexpr NumberType scUnspecified = 0;
+ NumberType mThreadId = scUnspecified;
+};
+
+// Check traits. These should satisfy usage in std::atomic.
+static_assert(std::is_trivially_copyable_v<BaseProfilerThreadId>);
+static_assert(std::is_copy_constructible_v<BaseProfilerThreadId>);
+static_assert(std::is_move_constructible_v<BaseProfilerThreadId>);
+static_assert(std::is_copy_assignable_v<BaseProfilerThreadId>);
+static_assert(std::is_move_assignable_v<BaseProfilerThreadId>);
+
+} // namespace mozilla::baseprofiler
+
+#include "mozilla/Types.h"
+
+namespace mozilla::baseprofiler {
+
+// Get the current process's ID.
+[[nodiscard]] MFBT_API BaseProfilerProcessId profiler_current_process_id();
+
+// Get the current thread's ID.
+[[nodiscard]] MFBT_API BaseProfilerThreadId profiler_current_thread_id();
+
+// Must be called at least once from the main thread, before any other main-
+// thread id function.
+MFBT_API void profiler_init_main_thread_id();
+
+[[nodiscard]] MFBT_API BaseProfilerThreadId profiler_main_thread_id();
+
+[[nodiscard]] MFBT_API bool profiler_is_main_thread();
+
+} // namespace mozilla::baseprofiler
+
+#endif // BaseProfilerUtils_h
diff --git a/mozglue/baseprofiler/public/BaseProfilingCategory.h b/mozglue/baseprofiler/public/BaseProfilingCategory.h
new file mode 100644
index 0000000000..2e80950966
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilingCategory.h
@@ -0,0 +1,68 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilingCategory_h
+#define BaseProfilingCategory_h
+
+#include "mozilla/Types.h"
+
+#include <cstdint>
+
+#include "ProfilingCategoryList.h"
+
+namespace mozilla {
+namespace baseprofiler {
+
+// clang-format off
+
+// An enum that lists all possible category pairs in one list.
+// This is the enum that is used in profiler stack labels. Having one list that
+// includes subcategories from all categories in one list allows assigning the
+// category pair to a stack label with just one number.
+#define CATEGORY_ENUM_BEGIN_CATEGORY(name, labelAsString, color)
+#define CATEGORY_ENUM_SUBCATEGORY(supercategory, name, labelAsString) name,
+#define CATEGORY_ENUM_END_CATEGORY
+enum class ProfilingCategoryPair : uint32_t {
+ MOZ_PROFILING_CATEGORY_LIST(CATEGORY_ENUM_BEGIN_CATEGORY,
+ CATEGORY_ENUM_SUBCATEGORY,
+ CATEGORY_ENUM_END_CATEGORY)
+ COUNT,
+ LAST = COUNT - 1,
+};
+#undef CATEGORY_ENUM_BEGIN_CATEGORY
+#undef CATEGORY_ENUM_SUBCATEGORY
+#undef CATEGORY_ENUM_END_CATEGORY
+
+// An enum that lists just the categories without their subcategories.
+#define SUPERCATEGORY_ENUM_BEGIN_CATEGORY(name, labelAsString, color) name,
+#define SUPERCATEGORY_ENUM_SUBCATEGORY(supercategory, name, labelAsString)
+#define SUPERCATEGORY_ENUM_END_CATEGORY
+enum class ProfilingCategory : uint32_t {
+ MOZ_PROFILING_CATEGORY_LIST(SUPERCATEGORY_ENUM_BEGIN_CATEGORY,
+ SUPERCATEGORY_ENUM_SUBCATEGORY,
+ SUPERCATEGORY_ENUM_END_CATEGORY)
+ COUNT,
+ LAST = COUNT - 1,
+};
+#undef SUPERCATEGORY_ENUM_BEGIN_CATEGORY
+#undef SUPERCATEGORY_ENUM_SUBCATEGORY
+#undef SUPERCATEGORY_ENUM_END_CATEGORY
+
+// clang-format on
+
+struct ProfilingCategoryPairInfo {
+ ProfilingCategory mCategory;
+ uint32_t mSubcategoryIndex;
+ const char* mLabel;
+};
+
+MFBT_API const ProfilingCategoryPairInfo& GetProfilingCategoryPairInfo(
+ ProfilingCategoryPair aCategoryPair);
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif /* BaseProfilingCategory_h */
diff --git a/mozglue/baseprofiler/public/BaseProfilingStack.h b/mozglue/baseprofiler/public/BaseProfilingStack.h
new file mode 100644
index 0000000000..2e3781cf17
--- /dev/null
+++ b/mozglue/baseprofiler/public/BaseProfilingStack.h
@@ -0,0 +1,517 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BaseProfilingStack_h
+#define BaseProfilingStack_h
+
+#ifndef MOZ_GECKO_PROFILER
+# error Do not #include this header when MOZ_GECKO_PROFILER is not #defined.
+#endif
+
+#include "BaseProfilingCategory.h"
+
+#include "mozilla/Atomics.h"
+
+#include <stdint.h>
+
+// This file defines the classes ProfilingStack and ProfilingStackFrame.
+// The ProfilingStack manages an array of ProfilingStackFrames.
+// It keeps track of the "label stack" and the JS interpreter stack.
+// The two stack types are interleaved.
+//
+// Usage:
+//
+// ProfilingStack* profilingStack = ...;
+//
+// // For label frames:
+// profilingStack->pushLabelFrame(...);
+// // Execute some code. When finished, pop the frame:
+// profilingStack->pop();
+//
+// // For JS stack frames:
+// profilingStack->pushJSFrame(...);
+// // Execute some code. When finished, pop the frame:
+// profilingStack->pop();
+//
+//
+// Concurrency considerations
+//
+// A thread's profiling stack (and the frames inside it) is only modified by
+// that thread. However, the profiling stack can be *read* by a different
+// thread, the sampler thread: Whenever the profiler wants to sample a given
+// thread A, the following happens:
+// (1) Thread A is suspended.
+// (2) The sampler thread (thread S) reads the ProfilingStack of thread A,
+// including all ProfilingStackFrames that are currently in that stack
+// (profilingStack->frames[0..profilingStack->stackSize()]).
+// (3) Thread A is resumed.
+//
+// Thread suspension is achieved using platform-specific APIs; refer to each
+// platform's Sampler::SuspendAndSampleAndResumeThread implementation in
+// platform-*.cpp for details.
+//
+// When the thread is suspended, the values in profilingStack->stackPointer and
+// in the stack frame range
+// profilingStack->frames[0..profilingStack->stackPointer] need to be in a
+// consistent state, so that thread S does not read partially- constructed stack
+// frames. More specifically, we have two requirements:
+// (1) When adding a new frame at the top of the stack, its ProfilingStackFrame
+// data needs to be put in place *before* the stackPointer is incremented,
+// and the compiler + CPU need to know that this order matters.
+// (2) When popping an frame from the stack and then preparing the
+// ProfilingStackFrame data for the next frame that is about to be pushed,
+// the decrement of the stackPointer in pop() needs to happen *before* the
+// ProfilingStackFrame for the new frame is being popuplated, and the
+// compiler + CPU need to know that this order matters.
+//
+// We can express the relevance of these orderings in multiple ways.
+// Option A is to make stackPointer an atomic with SequentiallyConsistent
+// memory ordering. This would ensure that no writes in thread A would be
+// reordered across any writes to stackPointer, which satisfies requirements
+// (1) and (2) at the same time. Option A is the simplest.
+// Option B is to use ReleaseAcquire memory ordering both for writes to
+// stackPointer *and* for writes to ProfilingStackFrame fields. Release-stores
+// ensure that all writes that happened *before this write in program order* are
+// not reordered to happen after this write. ReleaseAcquire ordering places no
+// requirements on the ordering of writes that happen *after* this write in
+// program order.
+// Using release-stores for writes to stackPointer expresses requirement (1),
+// and using release-stores for writes to the ProfilingStackFrame fields
+// expresses requirement (2).
+//
+// Option B is more complicated than option A, but has much better performance
+// on x86/64: In a microbenchmark run on a Macbook Pro from 2017, switching
+// from option A to option B reduced the overhead of pushing+popping a
+// ProfilingStackFrame by 10 nanoseconds.
+// On x86/64, release-stores require no explicit hardware barriers or lock
+// instructions.
+// On ARM/64, option B may be slower than option A, because the compiler will
+// generate hardware barriers for every single release-store instead of just
+// for the writes to stackPointer. However, the actual performance impact of
+// this has not yet been measured on ARM, so we're currently using option B
+// everywhere. This is something that we may want to change in the future once
+// we've done measurements.
+
+namespace mozilla {
+namespace baseprofiler {
+
+// A call stack can be specified to the JS engine such that all JS entry/exits
+// to functions push/pop a stack frame to/from the specified stack.
+//
+// For more detailed information, see vm/GeckoProfiler.h.
+//
+class ProfilingStackFrame {
+ // A ProfilingStackFrame represents either a label frame or a JS frame.
+
+ // WARNING WARNING WARNING
+ //
+ // All the fields below are Atomic<...,ReleaseAcquire>. This is needed so
+ // that writes to these fields are release-writes, which ensures that
+ // earlier writes in this thread don't get reordered after the writes to
+ // these fields. In particular, the decrement of the stack pointer in
+ // ProfilingStack::pop() is a write that *must* happen before the values in
+ // this ProfilingStackFrame are changed. Otherwise, the sampler thread might
+ // see an inconsistent state where the stack pointer still points to a
+ // ProfilingStackFrame which has already been popped off the stack and whose
+ // fields have now been partially repopulated with new values.
+ // See the "Concurrency considerations" paragraph at the top of this file
+ // for more details.
+
+ // Descriptive label for this stack frame. Must be a static string! Can be
+ // an empty string, but not a null pointer.
+ Atomic<const char*, ReleaseAcquire> label_;
+
+ // An additional descriptive string of this frame which is combined with
+ // |label_| in profiler output. Need not be (and usually isn't) static. Can
+ // be null.
+ Atomic<const char*, ReleaseAcquire> dynamicString_;
+
+ // Stack pointer for non-JS stack frames, the script pointer otherwise.
+ Atomic<void*, ReleaseAcquire> spOrScript;
+
+ // ID of the JS Realm for JS stack frames.
+ // Must not be used on non-JS frames; it'll contain either the default 0,
+ // or a leftover value from a previous JS stack frame that was using this
+ // ProfilingStackFrame object.
+ mozilla::Atomic<uint64_t, mozilla::ReleaseAcquire> realmID_;
+
+ // The bytecode offset for JS stack frames.
+ // Must not be used on non-JS frames; it'll contain either the default 0,
+ // or a leftover value from a previous JS stack frame that was using this
+ // ProfilingStackFrame object.
+ Atomic<int32_t, ReleaseAcquire> pcOffsetIfJS_;
+
+ // Bits 0...8 hold the Flags. Bits 9...31 hold the category pair.
+ Atomic<uint32_t, ReleaseAcquire> flagsAndCategoryPair_;
+
+ public:
+ ProfilingStackFrame() = default;
+ ProfilingStackFrame& operator=(const ProfilingStackFrame& other) {
+ label_ = other.label();
+ dynamicString_ = other.dynamicString();
+ void* spScript = other.spOrScript;
+ spOrScript = spScript;
+ int32_t offsetIfJS = other.pcOffsetIfJS_;
+ pcOffsetIfJS_ = offsetIfJS;
+ int64_t realmID = other.realmID_;
+ realmID_ = realmID;
+ uint32_t flagsAndCategory = other.flagsAndCategoryPair_;
+ flagsAndCategoryPair_ = flagsAndCategory;
+ return *this;
+ }
+
+ // Reserve up to 16 bits for flags, and 16 for category pair.
+ enum class Flags : uint32_t {
+ // The first three flags describe the kind of the frame and are
+ // mutually exclusive. (We still give them individual bits for
+ // simplicity.)
+
+ // A regular label frame. These usually come from AutoProfilerLabel.
+ IS_LABEL_FRAME = 1 << 0,
+
+ // A special frame indicating the start of a run of JS profiling stack
+ // frames. IS_SP_MARKER_FRAME frames are ignored, except for the sp
+ // field. These frames are needed to get correct ordering between JS
+ // and LABEL frames because JS frames don't carry sp information.
+ // SP is short for "stack pointer".
+ IS_SP_MARKER_FRAME = 1 << 1,
+
+ // A JS frame.
+ IS_JS_FRAME = 1 << 2,
+
+ // An interpreter JS frame that has OSR-ed into baseline. IS_JS_FRAME
+ // frames can have this flag set and unset during their lifetime.
+ // JS_OSR frames are ignored.
+ JS_OSR = 1 << 3,
+
+ // The next three are mutually exclusive.
+ // By default, for profiling stack frames that have both a label and a
+ // dynamic string, the two strings are combined into one string of the
+ // form "<label> <dynamicString>" during JSON serialization. The
+ // following flags can be used to change this preset.
+ STRING_TEMPLATE_METHOD = 1 << 4, // "<label>.<dynamicString>"
+ STRING_TEMPLATE_GETTER = 1 << 5, // "get <label>.<dynamicString>"
+ STRING_TEMPLATE_SETTER = 1 << 6, // "set <label>.<dynamicString>"
+
+ // If set, causes this stack frame to be marked as "relevantForJS" in
+ // the profile JSON, which will make it show up in the "JS only" call
+ // tree view.
+ RELEVANT_FOR_JS = 1 << 7,
+
+ // If set, causes the label on this ProfilingStackFrame to be ignored
+ // and to be replaced by the subcategory's label.
+ LABEL_DETERMINED_BY_CATEGORY_PAIR = 1 << 8,
+
+ // Frame dynamic string does not contain user data.
+ NONSENSITIVE = 1 << 9,
+
+ // A JS Baseline Interpreter frame.
+ IS_BLINTERP_FRAME = 1 << 10,
+
+ FLAGS_BITCOUNT = 16,
+ FLAGS_MASK = (1 << FLAGS_BITCOUNT) - 1
+ };
+
+ static_assert(
+ uint32_t(ProfilingCategoryPair::LAST) <=
+ (UINT32_MAX >> uint32_t(Flags::FLAGS_BITCOUNT)),
+ "Too many category pairs to fit into u32 with together with the "
+ "reserved bits for the flags");
+
+ bool isLabelFrame() const {
+ return uint32_t(flagsAndCategoryPair_) & uint32_t(Flags::IS_LABEL_FRAME);
+ }
+
+ bool isSpMarkerFrame() const {
+ return uint32_t(flagsAndCategoryPair_) &
+ uint32_t(Flags::IS_SP_MARKER_FRAME);
+ }
+
+ bool isJsFrame() const {
+ return uint32_t(flagsAndCategoryPair_) & uint32_t(Flags::IS_JS_FRAME);
+ }
+
+ bool isOSRFrame() const {
+ return uint32_t(flagsAndCategoryPair_) & uint32_t(Flags::JS_OSR);
+ }
+
+ void setIsOSRFrame(bool isOSR) {
+ if (isOSR) {
+ flagsAndCategoryPair_ =
+ uint32_t(flagsAndCategoryPair_) | uint32_t(Flags::JS_OSR);
+ } else {
+ flagsAndCategoryPair_ =
+ uint32_t(flagsAndCategoryPair_) & ~uint32_t(Flags::JS_OSR);
+ }
+ }
+
+ const char* label() const {
+ uint32_t flagsAndCategoryPair = flagsAndCategoryPair_;
+ if (flagsAndCategoryPair &
+ uint32_t(Flags::LABEL_DETERMINED_BY_CATEGORY_PAIR)) {
+ auto categoryPair = ProfilingCategoryPair(
+ flagsAndCategoryPair >> uint32_t(Flags::FLAGS_BITCOUNT));
+ return GetProfilingCategoryPairInfo(categoryPair).mLabel;
+ }
+ return label_;
+ }
+
+ const char* dynamicString() const { return dynamicString_; }
+
+ void initLabelFrame(const char* aLabel, const char* aDynamicString, void* sp,
+ ProfilingCategoryPair aCategoryPair, uint32_t aFlags) {
+ label_ = aLabel;
+ dynamicString_ = aDynamicString;
+ spOrScript = sp;
+ // pcOffsetIfJS_ is not set and must not be used on label frames.
+ flagsAndCategoryPair_ =
+ uint32_t(Flags::IS_LABEL_FRAME) |
+ (uint32_t(aCategoryPair) << uint32_t(Flags::FLAGS_BITCOUNT)) | aFlags;
+ MOZ_ASSERT(isLabelFrame());
+ }
+
+ void initSpMarkerFrame(void* sp) {
+ label_ = "";
+ dynamicString_ = nullptr;
+ spOrScript = sp;
+ // pcOffsetIfJS_ is not set and must not be used on sp marker frames.
+ flagsAndCategoryPair_ = uint32_t(Flags::IS_SP_MARKER_FRAME) |
+ (uint32_t(ProfilingCategoryPair::OTHER)
+ << uint32_t(Flags::FLAGS_BITCOUNT));
+ MOZ_ASSERT(isSpMarkerFrame());
+ }
+
+ void initJsFrame(const char* aLabel, const char* aDynamicString,
+ void* /* JSScript* */ aScript, int32_t aOffset,
+ uint64_t aRealmID) {
+ label_ = aLabel;
+ dynamicString_ = aDynamicString;
+ spOrScript = aScript;
+ pcOffsetIfJS_ = aOffset;
+ realmID_ = aRealmID;
+ flagsAndCategoryPair_ =
+ uint32_t(Flags::IS_JS_FRAME) | (uint32_t(ProfilingCategoryPair::JS)
+ << uint32_t(Flags::FLAGS_BITCOUNT));
+ MOZ_ASSERT(isJsFrame());
+ }
+
+ uint32_t flags() const {
+ return uint32_t(flagsAndCategoryPair_) & uint32_t(Flags::FLAGS_MASK);
+ }
+
+ ProfilingCategoryPair categoryPair() const {
+ return ProfilingCategoryPair(flagsAndCategoryPair_ >>
+ uint32_t(Flags::FLAGS_BITCOUNT));
+ }
+
+ uint64_t realmID() const { return realmID_; }
+
+ void* stackAddress() const {
+ MOZ_ASSERT(!isJsFrame());
+ return spOrScript;
+ }
+
+ // Note that the pointer returned might be invalid.
+ void* rawScript() const {
+ MOZ_ASSERT(isJsFrame());
+ return spOrScript;
+ }
+ void setRawScript(void* aScript) {
+ MOZ_ASSERT(isJsFrame());
+ spOrScript = aScript;
+ }
+
+ int32_t pcOffset() const {
+ MOZ_ASSERT(isJsFrame());
+ return pcOffsetIfJS_;
+ }
+
+ void setPCOffset(int32_t aOffset) {
+ MOZ_ASSERT(isJsFrame());
+ pcOffsetIfJS_ = aOffset;
+ }
+
+ // The offset of a pc into a script's code can actually be 0, so to
+ // signify a nullptr pc, use a -1 index. This is checked against in
+ // pc() and setPC() to set/get the right pc.
+ static const int32_t NullPCOffset = -1;
+};
+
+// Each thread has its own ProfilingStack. That thread modifies the
+// ProfilingStack, pushing and popping elements as necessary.
+//
+// The ProfilingStack is also read periodically by the profiler's sampler
+// thread. This happens only when the thread that owns the ProfilingStack is
+// suspended. So there are no genuine parallel accesses.
+//
+// However, it is possible for pushing/popping to be interrupted by a periodic
+// sample. Because of this, we need pushing/popping to be effectively atomic.
+//
+// - When pushing a new frame, we increment the stack pointer -- making the new
+// frame visible to the sampler thread -- only after the new frame has been
+// fully written. The stack pointer is Atomic<uint32_t,ReleaseAcquire>, so
+// the increment is a release-store, which ensures that this store is not
+// reordered before the writes of the frame.
+//
+// - When popping an old frame, the only operation is the decrementing of the
+// stack pointer, which is obviously atomic.
+//
+class ProfilingStack final {
+ public:
+ ProfilingStack() = default;
+
+ MFBT_API ~ProfilingStack();
+
+ void pushLabelFrame(const char* label, const char* dynamicString, void* sp,
+ ProfilingCategoryPair categoryPair, uint32_t flags = 0) {
+ // This thread is the only one that ever changes the value of
+ // stackPointer.
+ // Store the value of the atomic in a non-atomic local variable so that
+ // the compiler won't generate two separate loads from the atomic for
+ // the size check and the frames[] array indexing operation.
+ uint32_t stackPointerVal = stackPointer;
+
+ if (MOZ_UNLIKELY(stackPointerVal >= capacity)) {
+ ensureCapacitySlow();
+ }
+ frames[stackPointerVal].initLabelFrame(label, dynamicString, sp,
+ categoryPair, flags);
+
+ // This must happen at the end! The compiler will not reorder this
+ // update because stackPointer is Atomic<..., ReleaseAcquire>, so any
+ // the writes above will not be reordered below the stackPointer store.
+ // Do the read and the write as two separate statements, in order to
+ // make it clear that we don't need an atomic increment, which would be
+ // more expensive on x86 than the separate operations done here.
+ // However, don't use stackPointerVal here; instead, allow the compiler
+ // to turn this store into a non-atomic increment instruction which
+ // takes up less code size.
+ stackPointer = stackPointer + 1;
+ }
+
+ void pushSpMarkerFrame(void* sp) {
+ uint32_t oldStackPointer = stackPointer;
+
+ if (MOZ_UNLIKELY(oldStackPointer >= capacity)) {
+ ensureCapacitySlow();
+ }
+ frames[oldStackPointer].initSpMarkerFrame(sp);
+
+ // This must happen at the end, see the comment in pushLabelFrame.
+ stackPointer = oldStackPointer + 1;
+ }
+
+ void pushJsOffsetFrame(const char* label, const char* dynamicString,
+ void* script, int32_t offset, uint64_t aRealmID) {
+ // This thread is the only one that ever changes the value of
+ // stackPointer. Only load the atomic once.
+ uint32_t oldStackPointer = stackPointer;
+
+ if (MOZ_UNLIKELY(oldStackPointer >= capacity)) {
+ ensureCapacitySlow();
+ }
+ frames[oldStackPointer].initJsFrame(label, dynamicString, script, offset,
+ aRealmID);
+
+ // This must happen at the end, see the comment in pushLabelFrame.
+ stackPointer = stackPointer + 1;
+ }
+
+ void pop() {
+ MOZ_ASSERT(stackPointer > 0);
+ // Do the read and the write as two separate statements, in order to
+ // make it clear that we don't need an atomic decrement, which would be
+ // more expensive on x86 than the separate operations done here.
+ // This thread is the only one that ever changes the value of
+ // stackPointer.
+ uint32_t oldStackPointer = stackPointer;
+ stackPointer = oldStackPointer - 1;
+ }
+
+ uint32_t stackSize() const { return stackPointer; }
+ uint32_t stackCapacity() const { return capacity; }
+
+ private:
+ // Out of line path for expanding the buffer, since otherwise this would get
+ // inlined in every DOM WebIDL call.
+ MFBT_API MOZ_COLD void ensureCapacitySlow();
+
+ // No copying.
+ ProfilingStack(const ProfilingStack&) = delete;
+ void operator=(const ProfilingStack&) = delete;
+
+ // No moving either.
+ ProfilingStack(ProfilingStack&&) = delete;
+ void operator=(ProfilingStack&&) = delete;
+
+ uint32_t capacity = 0;
+
+ public:
+ // The pointer to the stack frames, this is read from the profiler thread and
+ // written from the current thread.
+ //
+ // This is effectively a unique pointer.
+ Atomic<ProfilingStackFrame*, SequentiallyConsistent> frames{nullptr};
+
+ // This may exceed the capacity, so instead use the stackSize() method to
+ // determine the number of valid frames in stackFrames. When this is less
+ // than stackCapacity(), it refers to the first free stackframe past the top
+ // of the in-use stack (i.e. frames[stackPointer - 1] is the top stack
+ // frame).
+ //
+ // WARNING WARNING WARNING
+ //
+ // This is an atomic variable that uses ReleaseAcquire memory ordering.
+ // See the "Concurrency considerations" paragraph at the top of this file
+ // for more details.
+ Atomic<uint32_t, ReleaseAcquire> stackPointer{0};
+};
+
+class AutoGeckoProfilerEntry;
+class GeckoProfilerEntryMarker;
+class GeckoProfilerBaselineOSRMarker;
+
+class GeckoProfilerThread {
+ friend class AutoGeckoProfilerEntry;
+ friend class GeckoProfilerEntryMarker;
+ friend class GeckoProfilerBaselineOSRMarker;
+
+ ProfilingStack* profilingStack_;
+
+ // Same as profilingStack_ if the profiler is currently active, otherwise
+ // null.
+ ProfilingStack* profilingStackIfEnabled_;
+
+ public:
+ MFBT_API GeckoProfilerThread();
+
+ uint32_t stackPointer() {
+ MOZ_ASSERT(infraInstalled());
+ return profilingStack_->stackPointer;
+ }
+ ProfilingStackFrame* stack() { return profilingStack_->frames; }
+ ProfilingStack* getProfilingStack() { return profilingStack_; }
+ ProfilingStack* getProfilingStackIfEnabled() {
+ return profilingStackIfEnabled_;
+ }
+
+ /*
+ * True if the profiler infrastructure is setup. Should be true in builds
+ * that include profiler support except during early startup or late
+ * shutdown. Unrelated to the presence of the Gecko Profiler addon.
+ */
+ bool infraInstalled() { return profilingStack_ != nullptr; }
+
+ MFBT_API void setProfilingStack(ProfilingStack* profilingStack, bool enabled);
+ void enable(bool enable) {
+ profilingStackIfEnabled_ = enable ? profilingStack_ : nullptr;
+ }
+};
+
+} // namespace baseprofiler
+} // namespace mozilla
+
+#endif /* BaseProfilingStack_h */
diff --git a/mozglue/baseprofiler/public/BlocksRingBuffer.h b/mozglue/baseprofiler/public/BlocksRingBuffer.h
new file mode 100644
index 0000000000..32cbe6b93c
--- /dev/null
+++ b/mozglue/baseprofiler/public/BlocksRingBuffer.h
@@ -0,0 +1,999 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BlocksRingBuffer_h
+#define BlocksRingBuffer_h
+
+#include "mozilla/BaseProfilerDetail.h"
+#include "mozilla/ModuloBuffer.h"
+#include "mozilla/ProfileBufferIndex.h"
+#include "mozilla/ScopeExit.h"
+
+#include <functional>
+#include <string>
+#include <tuple>
+#include <utility>
+
+namespace mozilla {
+
+// Thread-safe Ring buffer that can store blocks of different sizes during
+// defined sessions.
+// Each *block* contains an *entry* and the entry size:
+// [ entry_size | entry ] [ entry_size | entry ] ...
+// *In-session* is a period of time during which `BlocksRingBuffer` allows
+// reading and writing. *Out-of-session*, the `BlocksRingBuffer` object is
+// still valid, but contains no data, and gracefully denies accesses.
+//
+// To write an entry, the buffer reserves a block of sufficient size (to contain
+// user data of predetermined size), writes the entry size, and lets the caller
+// fill the entry contents using ModuloBuffer::Iterator APIs and a few entry-
+// specific APIs. E.g.:
+// ```
+// BlockRingsBuffer brb(PowerOfTwo<BlockRingsBuffer::Length>(1024));
+// brb.ReserveAndPut([]() { return sizeof(123); },
+// [&](ProfileBufferEntryWriter& aEW) {
+// aEW.WriteObject(123);
+// });
+// ```
+// Other `Put...` functions may be used as shortcuts for simple entries.
+// The objects given to the caller's callbacks should only be used inside the
+// callbacks and not stored elsewhere, because they keep their own references to
+// the BlocksRingBuffer and therefore should not live longer.
+// Different type of objects may be serialized into an entry, see `Serializer`
+// for more information.
+//
+// When reading data, the buffer iterates over blocks (it knows how to read the
+// entry size, and therefore move to the next block), and lets the caller read
+// the entry inside of each block. E.g.:
+// ```
+// brb.Read([](BlocksRingBuffer::Reader aR) {}
+// for (ProfileBufferEntryReader aER : aR) {
+// /* Use ProfileBufferEntryReader functions to read serialized objects. */
+// int n = aER.ReadObject<int>();
+// }
+// });
+// ```
+// Different type of objects may be deserialized from an entry, see
+// `Deserializer` for more information.
+//
+// The caller may retrieve the `ProfileBufferBlockIndex` corresponding to an
+// entry (`ProfileBufferBlockIndex` is an opaque type preventing the user from
+// modifying it). That index may later be used to get back to that particular
+// entry if it still exists.
+class BlocksRingBuffer {
+ public:
+ // Using ModuloBuffer as underlying circular byte buffer.
+ using Buffer = ModuloBuffer<uint32_t, ProfileBufferIndex>;
+ using Byte = Buffer::Byte;
+
+ // Length type for total buffer (as PowerOfTwo<Length>) and each entry.
+ using Length = uint32_t;
+
+ enum class ThreadSafety { WithoutMutex, WithMutex };
+
+ // Default constructor starts out-of-session (nothing to read or write).
+ explicit BlocksRingBuffer(ThreadSafety aThreadSafety)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex) {}
+
+ // Create a buffer of the given length.
+ explicit BlocksRingBuffer(ThreadSafety aThreadSafety,
+ PowerOfTwo<Length> aLength)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex),
+ mMaybeUnderlyingBuffer(Some(UnderlyingBuffer(aLength))) {}
+
+ // Take ownership of an existing buffer.
+ BlocksRingBuffer(ThreadSafety aThreadSafety,
+ UniquePtr<Buffer::Byte[]> aExistingBuffer,
+ PowerOfTwo<Length> aLength)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex),
+ mMaybeUnderlyingBuffer(
+ Some(UnderlyingBuffer(std::move(aExistingBuffer), aLength))) {}
+
+ // Use an externally-owned buffer.
+ BlocksRingBuffer(ThreadSafety aThreadSafety, Buffer::Byte* aExternalBuffer,
+ PowerOfTwo<Length> aLength)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex),
+ mMaybeUnderlyingBuffer(
+ Some(UnderlyingBuffer(aExternalBuffer, aLength))) {}
+
+ // Destructor doesn't need to do anything special. (Clearing entries would
+ // only update indices and stats, which won't be accessible after the object
+ // is destroyed anyway.)
+ ~BlocksRingBuffer() = default;
+
+ // Remove underlying buffer, if any.
+ void Reset() {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ ResetUnderlyingBuffer();
+ }
+
+ // Create a buffer of the given length.
+ void Set(PowerOfTwo<Length> aLength) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ ResetUnderlyingBuffer();
+ mMaybeUnderlyingBuffer.emplace(aLength);
+ }
+
+ // Take ownership of an existing buffer.
+ void Set(UniquePtr<Buffer::Byte[]> aExistingBuffer,
+ PowerOfTwo<Length> aLength) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ ResetUnderlyingBuffer();
+ mMaybeUnderlyingBuffer.emplace(std::move(aExistingBuffer), aLength);
+ }
+
+ // Use an externally-owned buffer.
+ void Set(Buffer::Byte* aExternalBuffer, PowerOfTwo<Length> aLength) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ ResetUnderlyingBuffer();
+ mMaybeUnderlyingBuffer.emplace(aExternalBuffer, aLength);
+ }
+
+ // This cannot change during the lifetime of this buffer, so there's no need
+ // to lock.
+ bool IsThreadSafe() const { return mMutex.IsActivated(); }
+
+ [[nodiscard]] bool IsInSession() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return !!mMaybeUnderlyingBuffer;
+ }
+
+ // Lock the buffer mutex and run the provided callback.
+ // This can be useful when the caller needs to explicitly lock down this
+ // buffer, but not do anything else with it.
+ template <typename Callback>
+ auto LockAndRun(Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return std::forward<Callback>(aCallback)();
+ }
+
+ // Buffer length in bytes.
+ Maybe<PowerOfTwo<Length>> BufferLength() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return mMaybeUnderlyingBuffer.map([](const UnderlyingBuffer& aBuffer) {
+ return aBuffer.mBuffer.BufferLength();
+ });
+ ;
+ }
+
+ // Size of external resources.
+ size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ if (!mMaybeUnderlyingBuffer) {
+ return 0;
+ }
+ return mMaybeUnderlyingBuffer->mBuffer.SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ // Snapshot of the buffer state.
+ struct State {
+ // Index to the first block.
+ ProfileBufferBlockIndex mRangeStart;
+
+ // Index past the last block. Equals mRangeStart if empty.
+ ProfileBufferBlockIndex mRangeEnd;
+
+ // Number of blocks that have been pushed into this buffer.
+ uint64_t mPushedBlockCount = 0;
+
+ // Number of blocks that have been removed from this buffer.
+ // Note: Live entries = pushed - cleared.
+ uint64_t mClearedBlockCount = 0;
+ };
+
+ // Get a snapshot of the current state.
+ // When out-of-session, mFirstReadIndex==mNextWriteIndex, and
+ // mPushedBlockCount==mClearedBlockCount==0.
+ // Note that these may change right after this thread-safe call, so they
+ // should only be used for statistical purposes.
+ State GetState() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return {
+ mFirstReadIndex, mNextWriteIndex,
+ mMaybeUnderlyingBuffer ? mMaybeUnderlyingBuffer->mPushedBlockCount : 0,
+ mMaybeUnderlyingBuffer ? mMaybeUnderlyingBuffer->mClearedBlockCount
+ : 0};
+ }
+
+ class Reader;
+
+ // Class that can iterate through blocks and provide
+ // `ProfileBufferEntryReader`s.
+ // Created through `Reader`, lives within a lock guard lifetime.
+ class BlockIterator {
+ public:
+#ifdef DEBUG
+ ~BlockIterator() {
+ // No BlockIterator should live outside of a mutexed call.
+ mRing->mMutex.AssertCurrentThreadOwns();
+ }
+#endif // DEBUG
+
+ // Comparison with other iterator, mostly used in range-for loops.
+ bool operator==(const BlockIterator aRhs) const {
+ MOZ_ASSERT(mRing == aRhs.mRing);
+ return mBlockIndex == aRhs.mBlockIndex;
+ }
+ bool operator!=(const BlockIterator aRhs) const {
+ MOZ_ASSERT(mRing == aRhs.mRing);
+ return mBlockIndex != aRhs.mBlockIndex;
+ }
+
+ // Advance to next BlockIterator.
+ BlockIterator& operator++() {
+ mBlockIndex = NextBlockIndex();
+ return *this;
+ }
+
+ // Dereferencing creates a `ProfileBufferEntryReader` for the entry inside
+ // this block.
+ ProfileBufferEntryReader operator*() const {
+ return mRing->ReaderInBlockAt(mBlockIndex);
+ }
+
+ // True if this iterator is just past the last entry.
+ bool IsAtEnd() const {
+ MOZ_ASSERT(mBlockIndex <= BufferRangeEnd());
+ return mBlockIndex == BufferRangeEnd();
+ }
+
+ // Can be used as reference to come back to this entry with `ReadAt()`.
+ ProfileBufferBlockIndex CurrentBlockIndex() const { return mBlockIndex; }
+
+ // Index past the end of this block, which is the start of the next block.
+ ProfileBufferBlockIndex NextBlockIndex() const {
+ MOZ_ASSERT(!IsAtEnd());
+ const Length entrySize =
+ mRing->ReaderInBlockAt(mBlockIndex).RemainingBytes();
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mBlockIndex.ConvertToProfileBufferIndex() + ULEB128Size(entrySize) +
+ entrySize);
+ }
+
+ // Index of the first block in the whole buffer.
+ ProfileBufferBlockIndex BufferRangeStart() const {
+ return mRing->mFirstReadIndex;
+ }
+
+ // Index past the last block in the whole buffer.
+ ProfileBufferBlockIndex BufferRangeEnd() const {
+ return mRing->mNextWriteIndex;
+ }
+
+ private:
+ // Only a Reader can instantiate a BlockIterator.
+ friend class Reader;
+
+ BlockIterator(const BlocksRingBuffer& aRing,
+ ProfileBufferBlockIndex aBlockIndex)
+ : mRing(WrapNotNull(&aRing)), mBlockIndex(aBlockIndex) {
+ // No BlockIterator should live outside of a mutexed call.
+ mRing->mMutex.AssertCurrentThreadOwns();
+ }
+
+ // Using a non-null pointer instead of a reference, to allow copying.
+ // This BlockIterator should only live inside one of the thread-safe
+ // BlocksRingBuffer functions, for this reference to stay valid.
+ NotNull<const BlocksRingBuffer*> mRing;
+ ProfileBufferBlockIndex mBlockIndex;
+ };
+
+ // Class that can create `BlockIterator`s (e.g., for range-for), or just
+ // iterate through entries; lives within a lock guard lifetime.
+ class MOZ_RAII Reader {
+ public:
+ Reader(const Reader&) = delete;
+ Reader& operator=(const Reader&) = delete;
+ Reader(Reader&&) = delete;
+ Reader& operator=(Reader&&) = delete;
+
+#ifdef DEBUG
+ ~Reader() {
+ // No Reader should live outside of a mutexed call.
+ mRing.mMutex.AssertCurrentThreadOwns();
+ }
+#endif // DEBUG
+
+ // Index of the first block in the whole buffer.
+ ProfileBufferBlockIndex BufferRangeStart() const {
+ return mRing.mFirstReadIndex;
+ }
+
+ // Index past the last block in the whole buffer.
+ ProfileBufferBlockIndex BufferRangeEnd() const {
+ return mRing.mNextWriteIndex;
+ }
+
+ // Iterators to the first and past-the-last blocks.
+ // Compatible with range-for (see `ForEach` below as example).
+ BlockIterator begin() const {
+ return BlockIterator(mRing, BufferRangeStart());
+ }
+ // Note that a `BlockIterator` at the `end()` should not be dereferenced, as
+ // there is no actual block there!
+ BlockIterator end() const { return BlockIterator(mRing, BufferRangeEnd()); }
+
+ // Get a `BlockIterator` at the given `ProfileBufferBlockIndex`, clamped to
+ // the stored range. Note that a `BlockIterator` at the `end()` should not
+ // be dereferenced, as there is no actual block there!
+ BlockIterator At(ProfileBufferBlockIndex aBlockIndex) const {
+ if (aBlockIndex < BufferRangeStart()) {
+ // Anything before the range (including null ProfileBufferBlockIndex) is
+ // clamped at the beginning.
+ return begin();
+ }
+ // Otherwise we at least expect the index to be valid (pointing exactly at
+ // a live block, or just past the end.)
+ mRing.AssertBlockIndexIsValidOrEnd(aBlockIndex);
+ return BlockIterator(mRing, aBlockIndex);
+ }
+
+ // Run `aCallback(ProfileBufferEntryReader&)` on each entry from first to
+ // last. Callback should not store `ProfileBufferEntryReader`, as it may
+ // become invalid after this thread-safe call.
+ template <typename Callback>
+ void ForEach(Callback&& aCallback) const {
+ for (ProfileBufferEntryReader reader : *this) {
+ aCallback(reader);
+ }
+ }
+
+ private:
+ friend class BlocksRingBuffer;
+
+ explicit Reader(const BlocksRingBuffer& aRing) : mRing(aRing) {
+ // No Reader should live outside of a mutexed call.
+ mRing.mMutex.AssertCurrentThreadOwns();
+ }
+
+ // This Reader should only live inside one of the thread-safe
+ // BlocksRingBuffer functions, for this reference to stay valid.
+ const BlocksRingBuffer& mRing;
+ };
+
+ // Call `aCallback(BlocksRingBuffer::Reader*)` (nullptr when out-of-session),
+ // and return whatever `aCallback` returns. Callback should not store
+ // `Reader`, because it may become invalid after this call.
+ template <typename Callback>
+ auto Read(Callback&& aCallback) const {
+ {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_LIKELY(mMaybeUnderlyingBuffer)) {
+ Reader reader(*this);
+ return std::forward<Callback>(aCallback)(&reader);
+ }
+ }
+ return std::forward<Callback>(aCallback)(nullptr);
+ }
+
+ // Call `aCallback(ProfileBufferEntryReader&)` on each item.
+ // Callback should not store `ProfileBufferEntryReader`, because it may become
+ // invalid after this call.
+ template <typename Callback>
+ void ReadEach(Callback&& aCallback) const {
+ Read([&](Reader* aReader) {
+ if (MOZ_LIKELY(aReader)) {
+ aReader->ForEach(aCallback);
+ }
+ });
+ }
+
+ // Call `aCallback(Maybe<ProfileBufferEntryReader>&&)` on the entry at
+ // the given ProfileBufferBlockIndex; The `Maybe` will be `Nothing` if
+ // out-of-session, or if that entry doesn't exist anymore, or if we've reached
+ // just past the last entry. Return whatever `aCallback` returns. Callback
+ // should not store `ProfileBufferEntryReader`, because it may become invalid
+ // after this call.
+ template <typename Callback>
+ auto ReadAt(ProfileBufferBlockIndex aBlockIndex, Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ MOZ_ASSERT(aBlockIndex <= mNextWriteIndex);
+ Maybe<ProfileBufferEntryReader> maybeEntryReader;
+ if (MOZ_LIKELY(mMaybeUnderlyingBuffer) && aBlockIndex >= mFirstReadIndex &&
+ aBlockIndex < mNextWriteIndex) {
+ AssertBlockIndexIsValid(aBlockIndex);
+ maybeEntryReader.emplace(ReaderInBlockAt(aBlockIndex));
+ }
+ return std::forward<Callback>(aCallback)(std::move(maybeEntryReader));
+ }
+
+ // Main function to write entries.
+ // Reserve `aCallbackBytes()` bytes, call `aCallback()` with a pointer to an
+ // on-stack temporary ProfileBufferEntryWriter (nullptr when out-of-session),
+ // and return whatever `aCallback` returns. Callback should not store
+ // `ProfileBufferEntryWriter`, because it may become invalid after this
+ // thread-safe call. Note: `aCallbackBytes` is a callback instead of a simple
+ // value, to delay this potentially-expensive computation until after we're
+ // checked that we're in-session; use `Put(Length, Callback)` below if you
+ // know the size already.
+ template <typename CallbackBytes, typename Callback>
+ auto ReserveAndPut(CallbackBytes aCallbackBytes, Callback&& aCallback) {
+ Maybe<ProfileBufferEntryWriter> maybeEntryWriter;
+
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+
+ if (MOZ_LIKELY(mMaybeUnderlyingBuffer)) {
+ const Length entryBytes = std::forward<CallbackBytes>(aCallbackBytes)();
+ MOZ_RELEASE_ASSERT(entryBytes > 0);
+ const Length bufferBytes =
+ mMaybeUnderlyingBuffer->mBuffer.BufferLength().Value();
+ MOZ_RELEASE_ASSERT(entryBytes <= bufferBytes - ULEB128Size(entryBytes),
+ "Entry would wrap and overwrite itself");
+ // Compute block size from the requested entry size.
+ const Length blockBytes = ULEB128Size(entryBytes) + entryBytes;
+ // We will put this new block at the end of the current buffer.
+ const ProfileBufferIndex blockIndex =
+ mNextWriteIndex.ConvertToProfileBufferIndex();
+ // Compute the end of this new block.
+ const ProfileBufferIndex blockEnd = blockIndex + blockBytes;
+ while (blockEnd >
+ mFirstReadIndex.ConvertToProfileBufferIndex() + bufferBytes) {
+ // About to trample on an old block.
+ ProfileBufferEntryReader reader = ReaderInBlockAt(mFirstReadIndex);
+ mMaybeUnderlyingBuffer->mClearedBlockCount += 1;
+ // Move the buffer reading start past this cleared block.
+ mFirstReadIndex = ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mFirstReadIndex.ConvertToProfileBufferIndex() +
+ ULEB128Size(reader.RemainingBytes()) + reader.RemainingBytes());
+ }
+ // Store the new end of buffer.
+ mNextWriteIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(blockEnd);
+ mMaybeUnderlyingBuffer->mPushedBlockCount += 1;
+ // Finally, let aCallback write into the entry.
+ mMaybeUnderlyingBuffer->mBuffer.EntryWriterFromTo(maybeEntryWriter,
+ blockIndex, blockEnd);
+ MOZ_ASSERT(maybeEntryWriter.isSome(),
+ "Non-empty entry should always create an EntryWriter");
+ maybeEntryWriter->WriteULEB128(entryBytes);
+ MOZ_ASSERT(maybeEntryWriter->RemainingBytes() == entryBytes);
+ }
+
+#ifdef DEBUG
+ auto checkAllWritten = MakeScopeExit([&]() {
+ MOZ_ASSERT(!maybeEntryWriter || maybeEntryWriter->RemainingBytes() == 0);
+ });
+#endif // DEBUG
+ return std::forward<Callback>(aCallback)(maybeEntryWriter);
+ }
+
+ // Add a new entry of known size, call `aCallback` with a pointer to a
+ // temporary ProfileBufferEntryWriter (can be null when out-of-session), and
+ // return whatever `aCallback` returns. Callback should not store the
+ // `ProfileBufferEntryWriter`, as it may become invalid after this thread-safe
+ // call.
+ template <typename Callback>
+ auto Put(Length aBytes, Callback&& aCallback) {
+ return ReserveAndPut([aBytes]() { return aBytes; },
+ std::forward<Callback>(aCallback));
+ }
+
+ // Add a new entry copied from the given buffer, return block index.
+ ProfileBufferBlockIndex PutFrom(const void* aSrc, Length aBytes) {
+ return ReserveAndPut([aBytes]() { return aBytes; },
+ [&](Maybe<ProfileBufferEntryWriter>& aEntryWriter) {
+ if (MOZ_UNLIKELY(aEntryWriter.isNothing())) {
+ // Out-of-session, return "empty" index.
+ return ProfileBufferBlockIndex{};
+ }
+ aEntryWriter->WriteBytes(aSrc, aBytes);
+ return aEntryWriter->CurrentBlockIndex();
+ });
+ }
+
+ // Add a new single entry with *all* given object (using a Serializer for
+ // each), return block index.
+ template <typename... Ts>
+ ProfileBufferBlockIndex PutObjects(const Ts&... aTs) {
+ static_assert(sizeof...(Ts) > 0,
+ "PutObjects must be given at least one object.");
+ return ReserveAndPut(
+ [&]() { return ProfileBufferEntryWriter::SumBytes(aTs...); },
+ [&](Maybe<ProfileBufferEntryWriter>& aEntryWriter) {
+ if (MOZ_UNLIKELY(aEntryWriter.isNothing())) {
+ // Out-of-session, return "empty" index.
+ return ProfileBufferBlockIndex{};
+ }
+ aEntryWriter->WriteObjects(aTs...);
+ return aEntryWriter->CurrentBlockIndex();
+ });
+ }
+
+ // Add a new entry copied from the given object, return block index.
+ template <typename T>
+ ProfileBufferBlockIndex PutObject(const T& aOb) {
+ return PutObjects(aOb);
+ }
+
+ // Append the contents of another BlocksRingBuffer to this one.
+ ProfileBufferBlockIndex AppendContents(const BlocksRingBuffer& aSrc) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+
+ if (MOZ_UNLIKELY(!mMaybeUnderlyingBuffer)) {
+ // We are out-of-session, could not append contents.
+ return ProfileBufferBlockIndex{};
+ }
+
+ baseprofiler::detail::BaseProfilerMaybeAutoLock srcLock(aSrc.mMutex);
+
+ if (MOZ_UNLIKELY(!aSrc.mMaybeUnderlyingBuffer)) {
+ // The other BRB is out-of-session, nothing to copy, we're done.
+ return ProfileBufferBlockIndex{};
+ }
+
+ const ProfileBufferIndex srcStartIndex =
+ aSrc.mFirstReadIndex.ConvertToProfileBufferIndex();
+ const ProfileBufferIndex srcEndIndex =
+ aSrc.mNextWriteIndex.ConvertToProfileBufferIndex();
+ const Length bytesToCopy = static_cast<Length>(srcEndIndex - srcStartIndex);
+
+ if (MOZ_UNLIKELY(bytesToCopy == 0)) {
+ // The other BRB is empty, nothing to copy, we're done.
+ return ProfileBufferBlockIndex{};
+ }
+
+ const Length bufferBytes =
+ mMaybeUnderlyingBuffer->mBuffer.BufferLength().Value();
+
+ MOZ_RELEASE_ASSERT(bytesToCopy <= bufferBytes,
+ "Entry would wrap and overwrite itself");
+
+ // We will put all copied blocks at the end of the current buffer.
+ const ProfileBufferIndex dstStartIndex =
+ mNextWriteIndex.ConvertToProfileBufferIndex();
+ // Compute where the copy will end...
+ const ProfileBufferIndex dstEndIndex = dstStartIndex + bytesToCopy;
+
+ while (dstEndIndex >
+ mFirstReadIndex.ConvertToProfileBufferIndex() + bufferBytes) {
+ // About to trample on an old block.
+ ProfileBufferEntryReader reader = ReaderInBlockAt(mFirstReadIndex);
+ mMaybeUnderlyingBuffer->mClearedBlockCount += 1;
+ // Move the buffer reading start past this cleared block.
+ mFirstReadIndex = ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mFirstReadIndex.ConvertToProfileBufferIndex() +
+ ULEB128Size(reader.RemainingBytes()) + reader.RemainingBytes());
+ }
+
+ // Store the new end of buffer.
+ mNextWriteIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(dstEndIndex);
+ // Update our pushed count with the number of live blocks we are copying.
+ mMaybeUnderlyingBuffer->mPushedBlockCount +=
+ aSrc.mMaybeUnderlyingBuffer->mPushedBlockCount -
+ aSrc.mMaybeUnderlyingBuffer->mClearedBlockCount;
+
+ auto reader = aSrc.mMaybeUnderlyingBuffer->mBuffer.EntryReaderFromTo(
+ srcStartIndex, srcEndIndex, nullptr, nullptr);
+ auto writer = mMaybeUnderlyingBuffer->mBuffer.EntryWriterFromTo(
+ dstStartIndex, dstEndIndex);
+ writer.WriteFromReader(reader, bytesToCopy);
+
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(dstStartIndex);
+ }
+
+ // Clear all entries: Move read index to the end so that these entries cannot
+ // be read anymore.
+ void Clear() {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ ClearAllEntries();
+ }
+
+ // Clear all entries strictly before aBlockIndex, and move read index to the
+ // end so that these entries cannot be read anymore.
+ void ClearBefore(ProfileBufferBlockIndex aBlockIndex) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (!mMaybeUnderlyingBuffer) {
+ return;
+ }
+ // Don't accept a not-yet-written index. One-past-the-end is ok.
+ MOZ_ASSERT(aBlockIndex <= mNextWriteIndex);
+ if (aBlockIndex <= mFirstReadIndex) {
+ // Already cleared.
+ return;
+ }
+ if (aBlockIndex == mNextWriteIndex) {
+ // Right past the end, just clear everything.
+ ClearAllEntries();
+ return;
+ }
+ // Otherwise we need to clear a subset of entries.
+ AssertBlockIndexIsValid(aBlockIndex);
+ // Just count skipped entries.
+ Reader reader(*this);
+ BlockIterator it = reader.begin();
+ for (; it.CurrentBlockIndex() < aBlockIndex; ++it) {
+ MOZ_ASSERT(it.CurrentBlockIndex() < reader.end().CurrentBlockIndex());
+ mMaybeUnderlyingBuffer->mClearedBlockCount += 1;
+ }
+ MOZ_ASSERT(it.CurrentBlockIndex() == aBlockIndex);
+ // Move read index to given index, so there's effectively no more entries
+ // before.
+ mFirstReadIndex = aBlockIndex;
+ }
+
+#ifdef DEBUG
+ void Dump() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (!mMaybeUnderlyingBuffer) {
+ printf("empty BlocksRingBuffer\n");
+ return;
+ }
+ using ULL = unsigned long long;
+ printf("start=%llu (%llu) end=%llu (%llu) - ",
+ ULL(mFirstReadIndex.ConvertToProfileBufferIndex()),
+ ULL(mFirstReadIndex.ConvertToProfileBufferIndex() &
+ (mMaybeUnderlyingBuffer->mBuffer.BufferLength().Value() - 1)),
+ ULL(mNextWriteIndex.ConvertToProfileBufferIndex()),
+ ULL(mNextWriteIndex.ConvertToProfileBufferIndex() &
+ (mMaybeUnderlyingBuffer->mBuffer.BufferLength().Value() - 1)));
+ mMaybeUnderlyingBuffer->mBuffer.Dump();
+ }
+#endif // DEBUG
+
+ private:
+ // In DEBUG mode, assert that `aBlockIndex` is a valid index for a live block.
+ // (Not just in range, but points exactly at the start of a block.)
+ // Slow, so avoid it for internal checks; this is more to check what callers
+ // provide us.
+ void AssertBlockIndexIsValid(ProfileBufferBlockIndex aBlockIndex) const {
+#ifdef DEBUG
+ mMutex.AssertCurrentThreadOwns();
+ MOZ_ASSERT(aBlockIndex >= mFirstReadIndex);
+ MOZ_ASSERT(aBlockIndex < mNextWriteIndex);
+ // Quick check (default), or slow check (change '1' to '0') below:
+# if 1
+ // Quick check that this looks like a valid block start.
+ // Read the entry size at the start of the block.
+ const Length entryBytes = ReaderInBlockAt(aBlockIndex).RemainingBytes();
+ MOZ_ASSERT(entryBytes > 0, "Empty entries are not allowed");
+ MOZ_ASSERT(
+ entryBytes < mMaybeUnderlyingBuffer->mBuffer.BufferLength().Value() -
+ ULEB128Size(entryBytes),
+ "Entry would wrap and overwrite itself");
+ // The end of the block should be inside the live buffer range.
+ MOZ_ASSERT(aBlockIndex.ConvertToProfileBufferIndex() +
+ ULEB128Size(entryBytes) + entryBytes <=
+ mNextWriteIndex.ConvertToProfileBufferIndex());
+# else
+ // Slow check that the index is really the start of the block.
+ // This kills performances, as it reads from the first index until
+ // aBlockIndex. Only use to debug issues locally.
+ Reader reader(*this);
+ BlockIterator it = reader.begin();
+ for (; it.CurrentBlockIndex() < aBlockIndex; ++it) {
+ MOZ_ASSERT(it.CurrentBlockIndex() < reader.end().CurrentBlockIndex());
+ }
+ MOZ_ASSERT(it.CurrentBlockIndex() == aBlockIndex);
+# endif
+#endif // DEBUG
+ }
+
+ // In DEBUG mode, assert that `aBlockIndex` is a valid index for a live block,
+ // or is just past-the-end. (Not just in range, but points exactly at the
+ // start of a block.) Slow, so avoid it for internal checks; this is more to
+ // check what callers provide us.
+ void AssertBlockIndexIsValidOrEnd(ProfileBufferBlockIndex aBlockIndex) const {
+#ifdef DEBUG
+ mMutex.AssertCurrentThreadOwns();
+ if (aBlockIndex == mNextWriteIndex) {
+ return;
+ }
+ AssertBlockIndexIsValid(aBlockIndex);
+#endif // DEBUG
+ }
+
+ // Create a reader for the block starting at aBlockIndex.
+ ProfileBufferEntryReader ReaderInBlockAt(
+ ProfileBufferBlockIndex aBlockIndex) const {
+ mMutex.AssertCurrentThreadOwns();
+ MOZ_ASSERT(mMaybeUnderlyingBuffer.isSome());
+ MOZ_ASSERT(aBlockIndex >= mFirstReadIndex);
+ MOZ_ASSERT(aBlockIndex < mNextWriteIndex);
+ // Create a reader from the given index until the end of the buffer.
+ ProfileBufferEntryReader reader =
+ mMaybeUnderlyingBuffer->mBuffer.EntryReaderFromTo(
+ aBlockIndex.ConvertToProfileBufferIndex(),
+ mNextWriteIndex.ConvertToProfileBufferIndex(), nullptr, nullptr);
+ // Read the block size at the beginning.
+ const Length entryBytes = reader.ReadULEB128<Length>();
+ // Make sure we don't overshoot the buffer.
+ MOZ_RELEASE_ASSERT(entryBytes <= reader.RemainingBytes());
+ ProfileBufferIndex nextBlockIndex =
+ aBlockIndex.ConvertToProfileBufferIndex() + ULEB128Size(entryBytes) +
+ entryBytes;
+ // And reduce the reader to the entry area. Only provide a next-block-index
+ // if it's not at the end of the buffer (i.e., there's an actual block
+ // there).
+ reader = mMaybeUnderlyingBuffer->mBuffer.EntryReaderFromTo(
+ aBlockIndex.ConvertToProfileBufferIndex() + ULEB128Size(entryBytes),
+ nextBlockIndex, aBlockIndex,
+ (nextBlockIndex < mNextWriteIndex.ConvertToProfileBufferIndex())
+ ? ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ nextBlockIndex)
+ : ProfileBufferBlockIndex{});
+ return reader;
+ }
+
+ ProfileBufferEntryReader FullBufferReader() const {
+ mMutex.AssertCurrentThreadOwns();
+ if (!mMaybeUnderlyingBuffer) {
+ return {};
+ }
+ return mMaybeUnderlyingBuffer->mBuffer.EntryReaderFromTo(
+ mFirstReadIndex.ConvertToProfileBufferIndex(),
+ mNextWriteIndex.ConvertToProfileBufferIndex(), nullptr, nullptr);
+ }
+
+ // Clear all entries: Move read index to the end so that these entries cannot
+ // be read anymore.
+ void ClearAllEntries() {
+ mMutex.AssertCurrentThreadOwns();
+ if (!mMaybeUnderlyingBuffer) {
+ return;
+ }
+ // Mark all entries pushed so far as cleared.
+ mMaybeUnderlyingBuffer->mClearedBlockCount =
+ mMaybeUnderlyingBuffer->mPushedBlockCount;
+ // Move read index to write index, so there's effectively no more entries
+ // that can be read. (Not setting both to 0, in case user is keeping
+ // `ProfileBufferBlockIndex`'es to old entries.)
+ mFirstReadIndex = mNextWriteIndex;
+ }
+
+ // If there is an underlying buffer, clear all entries, and discard the
+ // buffer. This BlocksRingBuffer will now gracefully reject all API calls, and
+ // is in a state where a new underlying buffer may be set.
+ void ResetUnderlyingBuffer() {
+ mMutex.AssertCurrentThreadOwns();
+ if (!mMaybeUnderlyingBuffer) {
+ return;
+ }
+ ClearAllEntries();
+ mMaybeUnderlyingBuffer.reset();
+ }
+
+ // Used to de/serialize a BlocksRingBuffer (e.g., containing a backtrace).
+ friend ProfileBufferEntryWriter::Serializer<BlocksRingBuffer>;
+ friend ProfileBufferEntryReader::Deserializer<BlocksRingBuffer>;
+ friend ProfileBufferEntryWriter::Serializer<UniquePtr<BlocksRingBuffer>>;
+ friend ProfileBufferEntryReader::Deserializer<UniquePtr<BlocksRingBuffer>>;
+
+ // Mutex guarding the following members.
+ mutable baseprofiler::detail::BaseProfilerMaybeMutex mMutex;
+
+ struct UnderlyingBuffer {
+ // Create a buffer of the given length.
+ explicit UnderlyingBuffer(PowerOfTwo<Length> aLength) : mBuffer(aLength) {
+ MOZ_ASSERT(aLength.Value() > ULEB128MaxSize<Length>(),
+ "Buffer should be able to contain more than a block size");
+ }
+
+ // Take ownership of an existing buffer.
+ UnderlyingBuffer(UniquePtr<Buffer::Byte[]> aExistingBuffer,
+ PowerOfTwo<Length> aLength)
+ : mBuffer(std::move(aExistingBuffer), aLength) {
+ MOZ_ASSERT(aLength.Value() > ULEB128MaxSize<Length>(),
+ "Buffer should be able to contain more than a block size");
+ }
+
+ // Use an externally-owned buffer.
+ UnderlyingBuffer(Buffer::Byte* aExternalBuffer, PowerOfTwo<Length> aLength)
+ : mBuffer(aExternalBuffer, aLength) {
+ MOZ_ASSERT(aLength.Value() > ULEB128MaxSize<Length>(),
+ "Buffer should be able to contain more than a block size");
+ }
+
+ // Only allow move-construction.
+ UnderlyingBuffer(UnderlyingBuffer&&) = default;
+
+ // Copies and move-assignment are explictly disallowed.
+ UnderlyingBuffer(const UnderlyingBuffer&) = delete;
+ UnderlyingBuffer& operator=(const UnderlyingBuffer&) = delete;
+ UnderlyingBuffer& operator=(UnderlyingBuffer&&) = delete;
+
+ // Underlying circular byte buffer.
+ Buffer mBuffer;
+
+ // Statistics.
+ uint64_t mPushedBlockCount = 0;
+ uint64_t mClearedBlockCount = 0;
+ };
+
+ // Underlying buffer, with stats.
+ // Only valid during in-session period.
+ Maybe<UnderlyingBuffer> mMaybeUnderlyingBuffer;
+
+ // Index to the first block to be read (or cleared). Initialized to 1 because
+ // 0 is reserved for the "empty" ProfileBufferBlockIndex value. Kept between
+ // sessions, so that stored indices from one session will be gracefully denied
+ // in future sessions.
+ ProfileBufferBlockIndex mFirstReadIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ ProfileBufferIndex(1));
+ // Index where the next new block should be allocated. Initialized to 1
+ // because 0 is reserved for the "empty" ProfileBufferBlockIndex value. Kept
+ // between sessions, so that stored indices from one session will be
+ // gracefully denied in future sessions.
+ ProfileBufferBlockIndex mNextWriteIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ ProfileBufferIndex(1));
+};
+
+// ----------------------------------------------------------------------------
+// BlocksRingBuffer serialization
+
+// A BlocksRingBuffer can hide another one!
+// This will be used to store marker backtraces; They can be read back into a
+// UniquePtr<BlocksRingBuffer>.
+// Format: len (ULEB128) | start | end | buffer (len bytes) | pushed | cleared
+// len==0 marks an out-of-session buffer, or empty buffer.
+template <>
+struct ProfileBufferEntryWriter::Serializer<BlocksRingBuffer> {
+ static Length Bytes(const BlocksRingBuffer& aBuffer) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(aBuffer.mMutex);
+ if (aBuffer.mMaybeUnderlyingBuffer.isNothing()) {
+ // Out-of-session, we only need 1 byte to store a length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ const auto start = aBuffer.mFirstReadIndex.ConvertToProfileBufferIndex();
+ const auto end = aBuffer.mNextWriteIndex.ConvertToProfileBufferIndex();
+ const auto len = end - start;
+ if (len == 0) {
+ // In-session but empty, also store a length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ return ULEB128Size(len) + sizeof(start) + sizeof(end) + len +
+ sizeof(aBuffer.mMaybeUnderlyingBuffer->mPushedBlockCount) +
+ sizeof(aBuffer.mMaybeUnderlyingBuffer->mClearedBlockCount);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const BlocksRingBuffer& aBuffer) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(aBuffer.mMutex);
+ if (aBuffer.mMaybeUnderlyingBuffer.isNothing()) {
+ // Out-of-session, only store a length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ const auto start = aBuffer.mFirstReadIndex.ConvertToProfileBufferIndex();
+ const auto end = aBuffer.mNextWriteIndex.ConvertToProfileBufferIndex();
+ MOZ_ASSERT(end - start <= std::numeric_limits<Length>::max());
+ const auto len = static_cast<Length>(end - start);
+ if (len == 0) {
+ // In-session but empty, only store a length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ // In-session.
+ // Store buffer length, start and end indices.
+ aEW.WriteULEB128<Length>(len);
+ aEW.WriteObject(start);
+ aEW.WriteObject(end);
+ // Write all the bytes.
+ auto reader = aBuffer.FullBufferReader();
+ aEW.WriteFromReader(reader, reader.RemainingBytes());
+ // And write stats.
+ aEW.WriteObject(aBuffer.mMaybeUnderlyingBuffer->mPushedBlockCount);
+ aEW.WriteObject(aBuffer.mMaybeUnderlyingBuffer->mClearedBlockCount);
+ }
+};
+
+// A serialized BlocksRingBuffer can be read into an empty buffer (either
+// out-of-session, or in-session with enough room).
+template <>
+struct ProfileBufferEntryReader::Deserializer<BlocksRingBuffer> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ BlocksRingBuffer& aBuffer) {
+ // Expect an empty buffer, as we're going to overwrite it.
+ MOZ_ASSERT(aBuffer.GetState().mRangeStart == aBuffer.GetState().mRangeEnd);
+ // Read the stored buffer length.
+ const auto len = aER.ReadULEB128<Length>();
+ if (len == 0) {
+ // 0-length means an "uninteresting" buffer, just return now.
+ return;
+ }
+ // We have a non-empty buffer to read.
+ if (aBuffer.BufferLength().isSome()) {
+ // Output buffer is in-session (i.e., it already has a memory buffer
+ // attached). Make sure the caller allocated enough space.
+ MOZ_RELEASE_ASSERT(aBuffer.BufferLength()->Value() >= len);
+ } else {
+ // Output buffer is out-of-session, attach a new memory buffer.
+ aBuffer.Set(PowerOfTwo<Length>(len));
+ MOZ_ASSERT(aBuffer.BufferLength()->Value() >= len);
+ }
+ // Read start and end indices.
+ const auto start = aER.ReadObject<ProfileBufferIndex>();
+ aBuffer.mFirstReadIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(start);
+ const auto end = aER.ReadObject<ProfileBufferIndex>();
+ aBuffer.mNextWriteIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(end);
+ MOZ_ASSERT(end - start == len);
+ // Copy bytes into the buffer.
+ auto writer =
+ aBuffer.mMaybeUnderlyingBuffer->mBuffer.EntryWriterFromTo(start, end);
+ writer.WriteFromReader(aER, end - start);
+ MOZ_ASSERT(writer.RemainingBytes() == 0);
+ // Finally copy stats.
+ aBuffer.mMaybeUnderlyingBuffer->mPushedBlockCount = aER.ReadObject<
+ decltype(aBuffer.mMaybeUnderlyingBuffer->mPushedBlockCount)>();
+ aBuffer.mMaybeUnderlyingBuffer->mClearedBlockCount = aER.ReadObject<
+ decltype(aBuffer.mMaybeUnderlyingBuffer->mClearedBlockCount)>();
+ }
+
+ // We cannot output a BlocksRingBuffer object (not copyable), use `ReadInto()`
+ // or `aER.ReadObject<UniquePtr<BlocksRinbBuffer>>()` instead.
+ static BlocksRingBuffer Read(ProfileBufferEntryReader& aER) = delete;
+};
+
+// A BlocksRingBuffer is usually refererenced through a UniquePtr, for
+// convenience we support (de)serializing that UniquePtr directly.
+// This is compatible with the non-UniquePtr serialization above, with a null
+// pointer being treated like an out-of-session or empty buffer; and any of
+// these would be deserialized into a null pointer.
+template <>
+struct ProfileBufferEntryWriter::Serializer<UniquePtr<BlocksRingBuffer>> {
+ static Length Bytes(const UniquePtr<BlocksRingBuffer>& aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ // Otherwise write the pointed-at BlocksRingBuffer (which could be
+ // out-of-session or empty.)
+ return SumBytes(*aBufferUPtr);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const UniquePtr<BlocksRingBuffer>& aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ // Otherwise write the pointed-at BlocksRingBuffer (which could be
+ // out-of-session or empty.)
+ aEW.WriteObject(*aBufferUPtr);
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<UniquePtr<BlocksRingBuffer>> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ UniquePtr<BlocksRingBuffer>& aBuffer) {
+ aBuffer = Read(aER);
+ }
+
+ static UniquePtr<BlocksRingBuffer> Read(ProfileBufferEntryReader& aER) {
+ UniquePtr<BlocksRingBuffer> bufferUPtr;
+ // Keep a copy of the reader before reading the length, so we can restart
+ // from here below.
+ ProfileBufferEntryReader readerBeforeLen = aER;
+ // Read the stored buffer length.
+ const auto len = aER.ReadULEB128<Length>();
+ if (len == 0) {
+ // 0-length means an "uninteresting" buffer, just return nullptr.
+ return bufferUPtr;
+ }
+ // We have a non-empty buffer.
+ // allocate an empty BlocksRingBuffer without mutex.
+ bufferUPtr = MakeUnique<BlocksRingBuffer>(
+ BlocksRingBuffer::ThreadSafety::WithoutMutex);
+ // Rewind the reader before the length and deserialize the contents, using
+ // the non-UniquePtr Deserializer.
+ aER = readerBeforeLen;
+ aER.ReadIntoObject(*bufferUPtr);
+ return bufferUPtr;
+ }
+};
+
+} // namespace mozilla
+
+#endif // BlocksRingBuffer_h
diff --git a/mozglue/baseprofiler/public/FailureLatch.h b/mozglue/baseprofiler/public/FailureLatch.h
new file mode 100644
index 0000000000..10205e009b
--- /dev/null
+++ b/mozglue/baseprofiler/public/FailureLatch.h
@@ -0,0 +1,217 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This header contains an interface `FailureLatch`, and some implementation
+// helpers that may be used across a range of classes and functions to handle
+// failures at any point during a process, and share that failure state so that
+// the process may gracefully stop quickly and report the first error.
+//
+// It could be thought as a replacement for C++ exceptions, but it's less strong
+// (cancellations may be delayed).
+// Now, if possible, mozilla::Result may be a better option as C++ exceptions
+// replacement, as it is more visible in all affected functions.
+// Consider FailureLatch if failures may happen in different places, but where
+// `return`ing this potential failure from all functions would be too arduous.
+
+#ifndef mozilla_FailureLatch_h
+#define mozilla_FailureLatch_h
+
+#include <mozilla/Assertions.h>
+
+#include <string>
+
+namespace mozilla {
+
+// ----------------------------------------------------------------------------
+// Main interface
+// ----------------------------------------------------------------------------
+
+// Interface handling a failure latch (starting in a successful state, the first
+// failure gets recorded, subsequent failures are ignored.)
+class FailureLatch {
+ public:
+ virtual ~FailureLatch() = default;
+
+ // Can this ever fail? (This may influence how some code deals with
+ // failures, e.g., if infallible, OOMs should assert&crash.)
+ [[nodiscard]] virtual bool Fallible() const = 0;
+
+ // Set latch in its failed state because of an external cause.
+ // The first call sets the reason, subsequent calls are ignored.
+ virtual void SetFailure(std::string aReason) = 0;
+
+ // Has there been any failure so far?
+ [[nodiscard]] virtual bool Failed() const = 0;
+
+ // Return first failure string, may be null if not failed yet.
+ [[nodiscard]] virtual const char* GetFailure() const = 0;
+
+ // Retrieve the one source FailureLatch. It could reference `*this`!
+ // This may be used by dependent proxy FailureLatch'es to find where to
+ // redirect calls.
+ [[nodiscard]] virtual const FailureLatch& SourceFailureLatch() const = 0;
+ [[nodiscard]] virtual FailureLatch& SourceFailureLatch() = 0;
+
+ // Non-virtual helpers.
+
+ // Transfer any failure from another FailureLatch.
+ void SetFailureFrom(const FailureLatch& aOther) {
+ if (Failed()) {
+ return;
+ }
+ if (const char* otherFailure = aOther.GetFailure(); otherFailure) {
+ SetFailure(otherFailure);
+ }
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Concrete implementations
+// ----------------------------------------------------------------------------
+
+// Concrete infallible FailureLatch class.
+// Any `SetFailure` leads to an assert-crash, so the final runtime result can
+// always be assumed to be succesful.
+class FailureLatchInfallibleSource final : public FailureLatch {
+ public:
+ [[nodiscard]] bool Fallible() const final { return false; }
+
+ void SetFailure(std::string aReason) final {
+ MOZ_RELEASE_ASSERT(false,
+ "SetFailure in infallible FailureLatchInfallibleSource");
+ }
+
+ [[nodiscard]] bool Failed() const final { return false; }
+
+ [[nodiscard]] const char* GetFailure() const final { return nullptr; }
+
+ [[nodiscard]] const ::mozilla::FailureLatch& SourceFailureLatch()
+ const final {
+ return *this;
+ }
+
+ [[nodiscard]] ::mozilla::FailureLatch& SourceFailureLatch() final {
+ return *this;
+ }
+
+ // Singleton FailureLatchInfallibleSource that may be used as default
+ // FailureLatch proxy.
+ static FailureLatchInfallibleSource& Singleton() {
+ static FailureLatchInfallibleSource singleton;
+ return singleton;
+ }
+};
+
+// Concrete FailureLatch class, intended to be intantiated as an object shared
+// between classes and functions that are part of a long operation, so that
+// failures can happen anywhere and be visible everywhere.
+// Not thread-safe.
+class FailureLatchSource final : public FailureLatch {
+ public:
+ [[nodiscard]] bool Fallible() const final { return true; }
+
+ void SetFailure(std::string aReason) final {
+ if (!mFailed) {
+ mFailed = true;
+ mReason = std::move(aReason);
+ }
+ }
+
+ [[nodiscard]] bool Failed() const final { return mFailed; }
+
+ [[nodiscard]] const char* GetFailure() const final {
+ return mFailed ? mReason.c_str() : nullptr;
+ }
+
+ [[nodiscard]] const FailureLatch& SourceFailureLatch() const final {
+ return *this;
+ }
+
+ [[nodiscard]] FailureLatch& SourceFailureLatch() final { return *this; }
+
+ private:
+ bool mFailed = false;
+ std::string mReason;
+};
+
+// ----------------------------------------------------------------------------
+// Helper macros, to be used in FailureLatch-derived classes
+// ----------------------------------------------------------------------------
+
+// Classes deriving from FailureLatch can use this to forward virtual calls to
+// another FailureLatch.
+#define FAILURELATCH_IMPL_PROXY(FAILURELATCH_REF) \
+ [[nodiscard]] bool Fallible() const final { \
+ return static_cast<const ::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .Fallible(); \
+ } \
+ void SetFailure(std::string aReason) final { \
+ static_cast<::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .SetFailure(std::move(aReason)); \
+ } \
+ [[nodiscard]] bool Failed() const final { \
+ return static_cast<const ::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .Failed(); \
+ } \
+ [[nodiscard]] const char* GetFailure() const final { \
+ return static_cast<const ::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .GetFailure(); \
+ } \
+ [[nodiscard]] const FailureLatch& SourceFailureLatch() const final { \
+ return static_cast<const ::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .SourceFailureLatch(); \
+ } \
+ [[nodiscard]] FailureLatch& SourceFailureLatch() final { \
+ return static_cast<::mozilla::FailureLatch&>(FAILURELATCH_REF) \
+ .SourceFailureLatch(); \
+ }
+
+// Classes deriving from FailureLatch can use this to forward virtual calls to
+// another FailureLatch through a pointer, unless it's null in which case act
+// like an infallible FailureLatch.
+#define FAILURELATCH_IMPL_PROXY_OR_INFALLIBLE(FAILURELATCH_PTR, CLASS_NAME) \
+ [[nodiscard]] bool Fallible() const final { \
+ return FAILURELATCH_PTR \
+ ? static_cast<const ::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->Fallible() \
+ : false; \
+ } \
+ void SetFailure(std::string aReason) final { \
+ if (FAILURELATCH_PTR) { \
+ static_cast<::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->SetFailure(std::move(aReason)); \
+ } else { \
+ MOZ_RELEASE_ASSERT(false, "SetFailure in infallible " #CLASS_NAME); \
+ } \
+ } \
+ [[nodiscard]] bool Failed() const final { \
+ return FAILURELATCH_PTR \
+ ? static_cast<const ::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->Failed() \
+ : false; \
+ } \
+ [[nodiscard]] const char* GetFailure() const final { \
+ return FAILURELATCH_PTR \
+ ? static_cast<const ::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->GetFailure() \
+ : nullptr; \
+ } \
+ [[nodiscard]] const FailureLatch& SourceFailureLatch() const final { \
+ return FAILURELATCH_PTR \
+ ? static_cast<const ::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->SourceFailureLatch() \
+ : ::mozilla::FailureLatchInfallibleSource::Singleton(); \
+ } \
+ [[nodiscard]] FailureLatch& SourceFailureLatch() final { \
+ return FAILURELATCH_PTR \
+ ? static_cast<::mozilla::FailureLatch*>(FAILURELATCH_PTR) \
+ ->SourceFailureLatch() \
+ : ::mozilla::FailureLatchInfallibleSource::Singleton(); \
+ }
+
+} // namespace mozilla
+
+#endif /* mozilla_FailureLatch_h */
diff --git a/mozglue/baseprofiler/public/ModuloBuffer.h b/mozglue/baseprofiler/public/ModuloBuffer.h
new file mode 100644
index 0000000000..80e765279e
--- /dev/null
+++ b/mozglue/baseprofiler/public/ModuloBuffer.h
@@ -0,0 +1,618 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ModuloBuffer_h
+#define ModuloBuffer_h
+
+#include "mozilla/leb128iterator.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/PowerOfTwo.h"
+#include "mozilla/ProfileBufferEntrySerialization.h"
+#include "mozilla/UniquePtr.h"
+
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <type_traits>
+
+namespace mozilla {
+
+// The ModuloBuffer class is a circular buffer that holds raw byte values, with
+// data-read/write helpers.
+//
+// OffsetT: Type of the internal offset into the buffer of bytes, it should be
+// large enough to access all bytes of the buffer. It will also be used as
+// Length (in bytes) of the buffer and of any subset. Default uint32_t
+// IndexT: Type of the external index, it should be large enough that overflows
+// should not happen during the lifetime of the ModuloBuffer.
+//
+// The basic usage is to create an iterator-like object with `ReaderAt(Index)`
+// or `WriterAt(Index)`, and use it to read/write data blobs. Iterators
+// automatically manage the wrap-around (through "Modulo", which is effectively
+// an AND-masking with the PowerOfTwo buffer size.)
+//
+// There is zero safety: No thread safety, no checks that iterators may be
+// overwriting data that's still to be read, etc. It's up to the caller to add
+// adequate checks.
+// The intended use is as an underlying buffer for a safer container.
+template <typename OffsetT = uint32_t, typename IndexT = uint64_t>
+class ModuloBuffer {
+ public:
+ using Byte = uint8_t;
+ static_assert(sizeof(Byte) == 1, "ModuloBuffer::Byte must be 1 byte");
+ using Offset = OffsetT;
+ static_assert(!std::numeric_limits<Offset>::is_signed,
+ "ModuloBuffer::Offset must be an unsigned integral type");
+ using Length = Offset;
+ using Index = IndexT;
+ static_assert(!std::numeric_limits<Index>::is_signed,
+ "ModuloBuffer::Index must be an unsigned integral type");
+ static_assert(sizeof(Index) >= sizeof(Offset),
+ "ModuloBuffer::Index size must >= Offset");
+
+ // Create a buffer of the given length.
+ explicit ModuloBuffer(PowerOfTwo<Length> aLength)
+ : mMask(aLength.Mask()),
+ mBuffer(WrapNotNull(new Byte[aLength.Value()])),
+ mBufferDeleter([](Byte* aBuffer) { delete[] aBuffer; }) {}
+
+ // Take ownership of an existing buffer. Existing contents is ignored.
+ // Done by extracting the raw pointer from UniquePtr<Byte[]>, and adding
+ // an equivalent `delete[]` in `mBufferDeleter`.
+ ModuloBuffer(UniquePtr<Byte[]> aExistingBuffer, PowerOfTwo<Length> aLength)
+ : mMask(aLength.Mask()),
+ mBuffer(WrapNotNull(aExistingBuffer.release())),
+ mBufferDeleter([](Byte* aBuffer) { delete[] aBuffer; }) {}
+
+ // Use an externally-owned buffer. Existing contents is ignored.
+ ModuloBuffer(Byte* aExternalBuffer, PowerOfTwo<Length> aLength)
+ : mMask(aLength.Mask()), mBuffer(WrapNotNull(aExternalBuffer)) {}
+
+ // Disallow copying, as we may uniquely own the resource.
+ ModuloBuffer(const ModuloBuffer& aOther) = delete;
+ ModuloBuffer& operator=(const ModuloBuffer& aOther) = delete;
+
+ // Allow move-construction. Stealing ownership if the original had it.
+ // This effectively prevents copy construction, and all assignments; needed so
+ // that a ModuloBuffer may be initialized from a separate construction.
+ // The moved-from ModuloBuffer still points at the resource but doesn't own
+ // it, so it won't try to free it; but accesses are not guaranteed, so it
+ // should not be used anymore.
+ ModuloBuffer(ModuloBuffer&& aOther)
+ : mMask(std::move(aOther.mMask)),
+ mBuffer(std::move(aOther.mBuffer)),
+ mBufferDeleter(std::move(aOther.mBufferDeleter)) {
+ // The above move leaves `aOther.mBufferDeleter` in a valid state but with
+ // an unspecified value, so it could theoretically still contain the
+ // original function, which would be bad because we don't want aOther to
+ // delete the resource that `this` now owns.
+ if (aOther.mBufferDeleter) {
+ // `aOther` still had a non-empty deleter, reset it.
+ aOther.mBufferDeleter = nullptr;
+ }
+ }
+
+ // Disallow assignment, as we have some `const` members.
+ ModuloBuffer& operator=(ModuloBuffer&& aOther) = delete;
+
+ // Destructor, deletes the resource if we uniquely own it.
+ ~ModuloBuffer() {
+ if (mBufferDeleter) {
+ mBufferDeleter(mBuffer);
+ }
+ }
+
+ PowerOfTwo<Length> BufferLength() const {
+ return PowerOfTwo<Length>(mMask.MaskValue() + 1);
+ }
+
+ // Size of external resources.
+ // Note: `mBufferDeleter`'s potential external data (for its captures) is not
+ // included, as it's hidden in the `std::function` implementation.
+ size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ if (!mBufferDeleter) {
+ // If we don't have a buffer deleter, assume we don't own the data, so
+ // it's probably on the stack, or should be reported by its owner.
+ return 0;
+ }
+ return aMallocSizeOf(mBuffer);
+ }
+
+ size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ ProfileBufferEntryReader EntryReaderFromTo(
+ Index aStart, Index aEnd, ProfileBufferBlockIndex aBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex) const {
+ using EntrySpan = Span<const ProfileBufferEntryReader::Byte>;
+ if (aStart == aEnd) {
+ return ProfileBufferEntryReader{};
+ }
+ // Don't allow over-wrapping.
+ MOZ_ASSERT(aEnd - aStart <= mMask.MaskValue() + 1);
+ // Start offset in 0 .. (buffer size - 1)
+ Offset start = static_cast<Offset>(aStart) & mMask;
+ // End offset in 1 .. (buffer size)
+ Offset end = (static_cast<Offset>(aEnd - 1) & mMask) + 1;
+ if (start < end) {
+ // Segment doesn't cross buffer threshold, one span is enough.
+ return ProfileBufferEntryReader{EntrySpan(&mBuffer[start], end - start),
+ aBlockIndex, aNextBlockIndex};
+ }
+ // Segment crosses buffer threshold, we need one span until the end and one
+ // span restarting at the beginning of the buffer.
+ return ProfileBufferEntryReader{
+ EntrySpan(&mBuffer[start], mMask.MaskValue() + 1 - start),
+ EntrySpan(&mBuffer[0], end), aBlockIndex, aNextBlockIndex};
+ }
+
+ // Return an entry writer for the given range.
+ ProfileBufferEntryWriter EntryWriterFromTo(Index aStart, Index aEnd) const {
+ using EntrySpan = Span<ProfileBufferEntryReader::Byte>;
+ if (aStart == aEnd) {
+ return ProfileBufferEntryWriter{};
+ }
+ MOZ_ASSERT(aEnd - aStart <= mMask.MaskValue() + 1);
+ // Start offset in 0 .. (buffer size - 1)
+ Offset start = static_cast<Offset>(aStart) & mMask;
+ // End offset in 1 .. (buffer size)
+ Offset end = (static_cast<Offset>(aEnd - 1) & mMask) + 1;
+ if (start < end) {
+ // Segment doesn't cross buffer threshold, one span is enough.
+ return ProfileBufferEntryWriter{
+ EntrySpan(&mBuffer[start], end - start),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aStart),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aEnd)};
+ }
+ // Segment crosses buffer threshold, we need one span until the end and one
+ // span restarting at the beginning of the buffer.
+ return ProfileBufferEntryWriter{
+ EntrySpan(&mBuffer[start], mMask.MaskValue() + 1 - start),
+ EntrySpan(&mBuffer[0], end),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aStart),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aEnd)};
+ }
+
+ // Emplace an entry writer into `aMaybeEntryWriter` for the given range.
+ void EntryWriterFromTo(Maybe<ProfileBufferEntryWriter>& aMaybeEntryWriter,
+ Index aStart, Index aEnd) const {
+ MOZ_ASSERT(aMaybeEntryWriter.isNothing(),
+ "Reference entry writer should be Nothing.");
+ using EntrySpan = Span<ProfileBufferEntryReader::Byte>;
+ if (aStart == aEnd) {
+ return;
+ }
+ MOZ_ASSERT(aEnd - aStart <= mMask.MaskValue() + 1);
+ // Start offset in 0 .. (buffer size - 1)
+ Offset start = static_cast<Offset>(aStart) & mMask;
+ // End offset in 1 .. (buffer size)
+ Offset end = (static_cast<Offset>(aEnd - 1) & mMask) + 1;
+ if (start < end) {
+ // Segment doesn't cross buffer threshold, one span is enough.
+ aMaybeEntryWriter.emplace(
+ EntrySpan(&mBuffer[start], end - start),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aStart),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aEnd));
+ } else {
+ // Segment crosses buffer threshold, we need one span until the end and
+ // one span restarting at the beginning of the buffer.
+ aMaybeEntryWriter.emplace(
+ EntrySpan(&mBuffer[start], mMask.MaskValue() + 1 - start),
+ EntrySpan(&mBuffer[0], end),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aStart),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(aEnd));
+ }
+ }
+
+ // All ModuloBuffer operations should be done through this iterator, which has
+ // an effectively infinite range. The underlying wrapping-around is hidden.
+ // Use `ReaderAt(Index)` or `WriterAt(Index)` to create it.
+ //
+ // `const Iterator<...>` means the iterator itself cannot change, i.e., it
+ // cannot move, and only its const methods are available. Note that these
+ // const methods may still be used to modify the buffer contents (e.g.:
+ // `operator*()`, `Poke()`).
+ //
+ // `Iterator</*IsBufferConst=*/true>` means the buffer contents cannot be
+ // modified, i.e., write operations are forbidden, but the iterator may still
+ // move if non-const itself.
+ template <bool IsBufferConst>
+ class Iterator {
+ // Alias to const- or mutable-`ModuloBuffer` depending on `IsBufferConst`.
+ using ConstOrMutableBuffer =
+ std::conditional_t<IsBufferConst, const ModuloBuffer, ModuloBuffer>;
+
+ // Implementation note about the strange enable-if's below:
+ // `template <bool NotIBC = !IsBufferConst> enable_if_t<NotIBC>`
+ // which intuitively could be simplified to:
+ // `enable_if_t<!IsBufferConst>`
+ // The former extra-templated syntax is in fact necessary to delay
+ // instantiation of these functions until they are actually needed.
+ //
+ // If we were just doing `enable_if_t<!IsBufferConst>`, this would only
+ // depend on the *class* (`ModuloBuffer<...>::Iterator`), which gets
+ // instantiated when a `ModuloBuffer` is created with some template
+ // arguments; at that point, all non-templated methods get instantiated, so
+ // there's no "SFINAE" happening, and `enable_if_t<...>` is actually doing
+ // `typename enable_if<...>::type` on the spot, but there is no `type` if
+ // `IsBufferConst` is true, so it just fails right away. E.g.:
+ // error: no type named 'type' in 'std::enable_if<false, void>';
+ // 'enable_if' cannot be used to disable this declaration
+ // note: in instantiation of template type alias 'enable_if_t'
+ // > std::enable_if_t<!IsBufferConst> WriteObject(const T& aObject) {
+ // in instantiation of template class
+ // 'mozilla::ModuloBuffer<...>::Iterator<true>'
+ // > auto it = mb.ReaderAt(1);
+ //
+ // By adding another template level `template <bool NotIsBufferConst =
+ // !IsBufferConst>`, the instantiation is delayed until the function is
+ // actually invoked somewhere, e.g. `it.Poke(...);`.
+ // So at that invocation point, the compiler looks for a "Poke" name in it,
+ // and considers potential template instantiations that could work. The
+ // `enable_if_t` is *now* attempted, with `NotIsBufferConst` taking its
+ // value from `!IsBufferConst`:
+ // - If `IsBufferConst` is false, `NotIsBufferConst` is true,
+ // `enable_if<NotIsBufferConst>` does define a `type` (`void` by default),
+ // so `enable_if_t` happily becomes `void`, the function exists and may be
+ // called.
+ // - Otherwise if `IsBufferConst` is true, `NotIsBufferConst` is false,
+ // `enable_if<NotIsBufferConst>` does *not* define a `type`, therefore
+ // `enable_if_t` produces an error because there is no `type`. Now "SFINAE"
+ // happens: This "Substitution Failure Is Not An Error" (by itself)... But
+ // then, there are no other functions named "Poke" as requested in the
+ // `it.Poke(...);` call, so we are now getting an error (can't find
+ // function), as expected because `it` had `IsBufferConst`==true. (But at
+ // least the compiler waited until this invocation attempt before outputting
+ // an error.)
+ //
+ // C++ is fun!
+
+ public:
+ // These definitions are expected by std functions, to recognize this as an
+ // iterator. See https://en.cppreference.com/w/cpp/iterator/iterator_traits
+ using difference_type = Index;
+ using value_type = Byte;
+ using pointer = std::conditional_t<IsBufferConst, const Byte*, Byte*>;
+ using reference = std::conditional_t<IsBufferConst, const Byte&, Byte&>;
+ using iterator_category = std::random_access_iterator_tag;
+
+ // Can always copy/assign from the same kind of iterator.
+ Iterator(const Iterator& aRhs) = default;
+ Iterator& operator=(const Iterator& aRhs) = default;
+
+ // Can implicitly copy an Iterator-to-mutable (reader+writer) to
+ // Iterator-to-const (reader-only), but not the reverse.
+ template <bool IsRhsBufferConst,
+ typename = std::enable_if_t<(!IsRhsBufferConst) && IsBufferConst>>
+ MOZ_IMPLICIT Iterator(const Iterator<IsRhsBufferConst>& aRhs)
+ : mModuloBuffer(aRhs.mModuloBuffer), mIndex(aRhs.mIndex) {}
+
+ // Can implicitly assign from an Iterator-to-mutable (reader+writer) to
+ // Iterator-to-const (reader-only), but not the reverse.
+ template <bool IsRhsBufferConst,
+ typename = std::enable_if_t<(!IsRhsBufferConst) && IsBufferConst>>
+ Iterator& operator=(const Iterator<IsRhsBufferConst>& aRhs) {
+ mModuloBuffer = aRhs.mModuloBuffer;
+ mIndex = aRhs.mIndex;
+ return *this;
+ }
+
+ // Current location of the iterator in the `Index` range.
+ // Note that due to wrapping, multiple indices may effectively point at the
+ // same byte in the buffer.
+ Index CurrentIndex() const { return mIndex; }
+
+ // Location comparison in the `Index` range. I.e., two `Iterator`s may look
+ // unequal, but refer to the same buffer location.
+ // Must be on the same buffer.
+ bool operator==(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex == aRhs.mIndex;
+ }
+ bool operator!=(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex != aRhs.mIndex;
+ }
+ bool operator<(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex < aRhs.mIndex;
+ }
+ bool operator<=(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex <= aRhs.mIndex;
+ }
+ bool operator>(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex > aRhs.mIndex;
+ }
+ bool operator>=(const Iterator& aRhs) const {
+ MOZ_ASSERT(mModuloBuffer == aRhs.mModuloBuffer);
+ return mIndex >= aRhs.mIndex;
+ }
+
+ // Movement in the `Index` range.
+ Iterator& operator++() {
+ ++mIndex;
+ return *this;
+ }
+ Iterator operator++(int) {
+ Iterator here(*mModuloBuffer, mIndex);
+ ++mIndex;
+ return here;
+ }
+ Iterator& operator--() {
+ --mIndex;
+ return *this;
+ }
+ Iterator operator--(int) {
+ Iterator here(*mModuloBuffer, mIndex);
+ --mIndex;
+ return here;
+ }
+ Iterator& operator+=(Length aLength) {
+ mIndex += aLength;
+ return *this;
+ }
+ Iterator operator+(Length aLength) const {
+ return Iterator(*mModuloBuffer, mIndex + aLength);
+ }
+ friend Iterator operator+(Length aLength, const Iterator& aIt) {
+ return aIt + aLength;
+ }
+ Iterator& operator-=(Length aLength) {
+ mIndex -= aLength;
+ return *this;
+ }
+ Iterator operator-(Length aLength) const {
+ return Iterator(*mModuloBuffer, mIndex - aLength);
+ }
+
+ // Distance from `aRef` to here in the `Index` range.
+ // May be negative (as 2's complement) if `aRef > *this`.
+ Index operator-(const Iterator& aRef) const {
+ MOZ_ASSERT(mModuloBuffer == aRef.mModuloBuffer);
+ return mIndex - aRef.mIndex;
+ }
+
+ // Dereference a single byte (read-only if `IsBufferConst` is true).
+ reference operator*() const {
+ return mModuloBuffer->mBuffer[OffsetInBuffer()];
+ }
+
+ // Random-access dereference.
+ reference operator[](Length aLength) const { return *(*this + aLength); }
+
+ // Write data (if `IsBufferConst` is false) but don't move iterator.
+ template <bool NotIsBufferConst = !IsBufferConst>
+ std::enable_if_t<NotIsBufferConst> Poke(const void* aSrc,
+ Length aLength) const {
+ // Don't allow data larger than the buffer.
+ MOZ_ASSERT(aLength <= mModuloBuffer->BufferLength().Value());
+ // Offset inside the buffer (corresponding to our Index).
+ Offset offset = OffsetInBuffer();
+ // Compute remaining bytes between this offset and the end of the buffer.
+ Length remaining = mModuloBuffer->BufferLength().Value() - offset;
+ if (MOZ_LIKELY(remaining >= aLength)) {
+ // Enough space to write everything before the end.
+ memcpy(&mModuloBuffer->mBuffer[offset], aSrc, aLength);
+ } else {
+ // Not enough space. Write as much as possible before the end.
+ memcpy(&mModuloBuffer->mBuffer[offset], aSrc, remaining);
+ // And then continue from the beginning of the buffer.
+ memcpy(&mModuloBuffer->mBuffer[0],
+ static_cast<const Byte*>(aSrc) + remaining,
+ (aLength - remaining));
+ }
+ }
+
+ // Write object data (if `IsBufferConst` is false) but don't move iterator.
+ // Note that this copies bytes from the object, with the intent to read them
+ // back later. Restricted to trivially-copyable types, which support this
+ // without Undefined Behavior!
+ template <typename T, bool NotIsBufferConst = !IsBufferConst>
+ std::enable_if_t<NotIsBufferConst> PokeObject(const T& aObject) const {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "PokeObject<T> - T must be trivially copyable");
+ return Poke(&aObject, sizeof(T));
+ }
+
+ // Write data (if `IsBufferConst` is false) and move iterator ahead.
+ template <bool NotIsBufferConst = !IsBufferConst>
+ std::enable_if_t<NotIsBufferConst> Write(const void* aSrc, Length aLength) {
+ Poke(aSrc, aLength);
+ mIndex += aLength;
+ }
+
+ // Write object data (if `IsBufferConst` is false) and move iterator ahead.
+ // Note that this copies bytes from the object, with the intent to read them
+ // back later. Restricted to trivially-copyable types, which support this
+ // without Undefined Behavior!
+ template <typename T, bool NotIsBufferConst = !IsBufferConst>
+ std::enable_if_t<NotIsBufferConst> WriteObject(const T& aObject) {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "WriteObject<T> - T must be trivially copyable");
+ return Write(&aObject, sizeof(T));
+ }
+
+ // Number of bytes needed to represent `aValue` in unsigned LEB128.
+ template <typename T>
+ static unsigned ULEB128Size(T aValue) {
+ return ::mozilla::ULEB128Size(aValue);
+ }
+
+ // Write number as unsigned LEB128 (if `IsBufferConst` is false) and move
+ // iterator ahead.
+ template <typename T, bool NotIsBufferConst = !IsBufferConst>
+ std::enable_if_t<NotIsBufferConst> WriteULEB128(T aValue) {
+ ::mozilla::WriteULEB128(aValue, *this);
+ }
+
+ // Read data but don't move iterator.
+ void Peek(void* aDst, Length aLength) const {
+ // Don't allow data larger than the buffer.
+ MOZ_ASSERT(aLength <= mModuloBuffer->BufferLength().Value());
+ // Offset inside the buffer (corresponding to our Index).
+ Offset offset = OffsetInBuffer();
+ // Compute remaining bytes between this offset and the end of the buffer.
+ Length remaining = mModuloBuffer->BufferLength().Value() - offset;
+ if (MOZ_LIKELY(remaining >= aLength)) {
+ // Can read everything we need before the end of the buffer.
+ memcpy(aDst, &mModuloBuffer->mBuffer[offset], aLength);
+ } else {
+ // Read as much as possible before the end of the buffer.
+ memcpy(aDst, &mModuloBuffer->mBuffer[offset], remaining);
+ // And then continue from the beginning of the buffer.
+ memcpy(static_cast<Byte*>(aDst) + remaining, &mModuloBuffer->mBuffer[0],
+ (aLength - remaining));
+ }
+ }
+
+ // Read data into an object but don't move iterator.
+ // Note that this overwrites `aObject` with bytes from the buffer.
+ // Restricted to trivially-copyable types, which support this without
+ // Undefined Behavior!
+ template <typename T>
+ void PeekIntoObject(T& aObject) const {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "PeekIntoObject<T> - T must be trivially copyable");
+ Peek(&aObject, sizeof(T));
+ }
+
+ // Read data as an object but don't move iterator.
+ // Note that this creates an default `T` first, and then overwrites it with
+ // bytes from the buffer. Restricted to trivially-copyable types, which
+ // support this without Undefined Behavior!
+ template <typename T>
+ T PeekObject() const {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "PeekObject<T> - T must be trivially copyable");
+ T object;
+ PeekIntoObject(object);
+ return object;
+ }
+
+ // Read data and move iterator ahead.
+ void Read(void* aDst, Length aLength) {
+ Peek(aDst, aLength);
+ mIndex += aLength;
+ }
+
+ // Read data into a mutable iterator and move both iterators ahead.
+ void ReadInto(Iterator</* IsBufferConst */ false>& aDst, Length aLength) {
+ // Don't allow data larger than the buffer.
+ MOZ_ASSERT(aLength <= mModuloBuffer->BufferLength().Value());
+ MOZ_ASSERT(aLength <= aDst.mModuloBuffer->BufferLength().Value());
+ // Offset inside the buffer (corresponding to our Index).
+ Offset offset = OffsetInBuffer();
+ // Compute remaining bytes between this offset and the end of the buffer.
+ Length remaining = mModuloBuffer->BufferLength().Value() - offset;
+ if (MOZ_LIKELY(remaining >= aLength)) {
+ // Can read everything we need before the end of the buffer.
+ aDst.Write(&mModuloBuffer->mBuffer[offset], aLength);
+ } else {
+ // Read as much as possible before the end of the buffer.
+ aDst.Write(&mModuloBuffer->mBuffer[offset], remaining);
+ // And then continue from the beginning of the buffer.
+ aDst.Write(&mModuloBuffer->mBuffer[0], (aLength - remaining));
+ }
+ mIndex += aLength;
+ }
+
+ // Read data into an object and move iterator ahead.
+ // Note that this overwrites `aObject` with bytes from the buffer.
+ // Restricted to trivially-copyable types, which support this without
+ // Undefined Behavior!
+ template <typename T>
+ void ReadIntoObject(T& aObject) {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "ReadIntoObject<T> - T must be trivially copyable");
+ Read(&aObject, sizeof(T));
+ }
+
+ // Read data as an object and move iterator ahead.
+ // Note that this creates an default `T` first, and then overwrites it with
+ // bytes from the buffer. Restricted to trivially-copyable types, which
+ // support this without Undefined Behavior!
+ template <typename T>
+ T ReadObject() {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "ReadObject<T> - T must be trivially copyable");
+ T object;
+ ReadIntoObject(object);
+ return object;
+ }
+
+ // Read an unsigned LEB128 number and move iterator ahead.
+ template <typename T>
+ T ReadULEB128() {
+ return ::mozilla::ReadULEB128<T>(*this);
+ }
+
+ private:
+ // Only a ModuloBuffer can instantiate its iterator.
+ friend class ModuloBuffer;
+
+ Iterator(ConstOrMutableBuffer& aBuffer, Index aIndex)
+ : mModuloBuffer(WrapNotNull(&aBuffer)), mIndex(aIndex) {}
+
+ // Convert the Iterator's mIndex into an offset inside the byte buffer.
+ Offset OffsetInBuffer() const {
+ return static_cast<Offset>(mIndex) & mModuloBuffer->mMask;
+ }
+
+ // ModuloBuffer that this Iterator operates on.
+ // Using a non-null pointer instead of a reference, to allow re-assignment
+ // of an Iterator variable.
+ NotNull<ConstOrMutableBuffer*> mModuloBuffer;
+
+ // Position of this iterator in the wider `Index` range. (Will be wrapped
+ // around as needed when actually accessing bytes from the buffer.)
+ Index mIndex;
+ };
+
+ // Shortcut to iterator to const (read-only) data.
+ using Reader = Iterator<true>;
+ // Shortcut to iterator to non-const (read/write) data.
+ using Writer = Iterator<false>;
+
+ // Create an iterator to const data at the given index.
+ Reader ReaderAt(Index aIndex) const { return Reader(*this, aIndex); }
+
+ // Create an iterator to non-const data at the given index.
+ Writer WriterAt(Index aIndex) { return Writer(*this, aIndex); }
+
+#ifdef DEBUG
+ void Dump() const {
+ Length len = BufferLength().Value();
+ if (len > 128) {
+ len = 128;
+ }
+ for (Length i = 0; i < len; ++i) {
+ printf("%02x ", mBuffer[i]);
+ }
+ printf("\n");
+ }
+#endif // DEBUG
+
+ private:
+ // Mask used to convert an index to an offset in `mBuffer`
+ const PowerOfTwoMask<Offset> mMask;
+
+ // Buffer data. `const NotNull<...>` shows that `mBuffer is `const`, and
+ // `Byte* const` shows that the pointer cannot be changed to point at
+ // something else, but the pointed-at `Byte`s are writable.
+ const NotNull<Byte* const> mBuffer;
+
+ // Function used to release the buffer resource (if needed).
+ std::function<void(Byte*)> mBufferDeleter;
+};
+
+} // namespace mozilla
+
+#endif // ModuloBuffer_h
diff --git a/mozglue/baseprofiler/public/PowerOfTwo.h b/mozglue/baseprofiler/public/PowerOfTwo.h
new file mode 100644
index 0000000000..7d396c15e6
--- /dev/null
+++ b/mozglue/baseprofiler/public/PowerOfTwo.h
@@ -0,0 +1,322 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// PowerOfTwo is a value type that always hold a power of 2.
+// It has the same size as their underlying unsigned type, but offer the
+// guarantee of being a power of 2, which permits some optimizations when
+// involved in modulo operations (using masking instead of actual modulo).
+//
+// PowerOfTwoMask contains a mask corresponding to a power of 2.
+// E.g., 2^8 is 256 or 0x100, the corresponding mask is 2^8-1 or 255 or 0xFF.
+// It should be used instead of PowerOfTwo in situations where most operations
+// would be modulo, this saves having to recompute the mask from the stored
+// power of 2.
+//
+// One common use would be for ring-buffer containers with a power-of-2 size,
+// where an index is usually converted to an in-buffer offset by `i % size`.
+// Instead, the container could store a PowerOfTwo or PowerOfTwoMask, and do
+// `i % p2` or `i & p2m`, which is more efficient than for arbitrary sizes.
+//
+// Shortcuts for common 32- and 64-bit values: PowerOfTwo32, etc.
+//
+// To create constexpr constants, use MakePowerOfTwo<Type, Value>(), etc.
+
+#ifndef PowerOfTwo_h
+#define PowerOfTwo_h
+
+#include "mozilla/MathAlgorithms.h"
+
+#include <limits>
+
+namespace mozilla {
+
+// Compute the smallest power of 2 greater than or equal to aInput, except if
+// that would overflow in which case the highest possible power of 2 if chosen.
+// 0->1, 1->1, 2->2, 3->4, ... 2^31->2^31, 2^31+1->2^31 (for uint32_t), etc.
+template <typename T>
+T FriendlyRoundUpPow2(T aInput) {
+ // This is the same code as `RoundUpPow2()`, except we handle any type (that
+ // CeilingLog2 supports) and allow the greater-than-max-power case.
+ constexpr T max = T(1) << (sizeof(T) * CHAR_BIT - 1);
+ if (aInput >= max) {
+ return max;
+ }
+ return T(1) << CeilingLog2(aInput);
+}
+
+namespace detail {
+// Same function name `CountLeadingZeroes` with uint32_t and uint64_t overloads.
+inline uint_fast8_t CountLeadingZeroes(uint32_t aValue) {
+ MOZ_ASSERT(aValue != 0);
+ return detail::CountLeadingZeroes32(aValue);
+}
+inline uint_fast8_t CountLeadingZeroes(uint64_t aValue) {
+ MOZ_ASSERT(aValue != 0);
+ return detail::CountLeadingZeroes64(aValue);
+}
+// Refuse anything else.
+template <typename T>
+inline uint_fast8_t CountLeadingZeroes(T aValue) = delete;
+} // namespace detail
+
+// Compute the smallest 2^N-1 mask where aInput can fit.
+// I.e., `x & mask == x`, but `x & (mask >> 1) != x`.
+// Or looking at binary, we want a mask with as many leading zeroes as the
+// input, by right-shifting a full mask: (8-bit examples)
+// input: 00000000 00000001 00000010 00010110 01111111 10000000
+// N leading 0s: ^^^^^^^^ 8 ^^^^^^^ 7 ^^^^^^ 6 ^^^ 3 ^ 1 0
+// full mask: 11111111 11111111 11111111 11111111 11111111 11111111
+// full mask >> N: 00000000 00000001 00000011 00011111 01111111 11111111
+template <typename T>
+T RoundUpPow2Mask(T aInput) {
+ // Special case, as CountLeadingZeroes(0) is undefined. (And even if that was
+ // defined, shifting by the full type size is also undefined!)
+ if (aInput == 0) {
+ return 0;
+ }
+ return T(-1) >> detail::CountLeadingZeroes(aInput);
+}
+
+template <typename T>
+class PowerOfTwoMask;
+
+template <typename T, T Mask>
+constexpr PowerOfTwoMask<T> MakePowerOfTwoMask();
+
+template <typename T>
+class PowerOfTwo;
+
+template <typename T, T Value>
+constexpr PowerOfTwo<T> MakePowerOfTwo();
+
+// PowerOfTwoMask will always contain a mask for a power of 2, which is useful
+// for power-of-2 modulo operations (e.g., to keep an index inside a power-of-2
+// container).
+// Use this instead of PowerOfTwo if masking is the primary use of the value.
+//
+// Note that this class can store a "full" mask where all bits are set, so it
+// works for mask corresponding to the power of 2 that would overflow `T`
+// (e.g., 2^32 for uint32_t gives a mask of 2^32-1, which fits in a uint32_t).
+// For this reason there is no API that computes the power of 2 corresponding to
+// the mask; But this can be done explicitly with `MaskValue() + 1`, which may
+// be useful for computing things like distance-to-the-end by doing
+// `MaskValue() + 1 - offset`, which works fine with unsigned number types.
+template <typename T>
+class PowerOfTwoMask {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "PowerOfTwoMask must use an unsigned type");
+
+ public:
+ // Construct a power of 2 mask where the given value can fit.
+ // Cannot be constexpr because of `RoundUpPow2Mask()`.
+ explicit PowerOfTwoMask(T aInput) : mMask(RoundUpPow2Mask(aInput)) {}
+
+ // Compute the mask corresponding to a PowerOfTwo.
+ // This saves having to compute the nearest 2^N-1.
+ // Not a conversion constructor, as that could be ambiguous whether we'd want
+ // the mask corresponding to the power of 2 (2^N -> 2^N-1), or the mask that
+ // can *contain* the PowerOfTwo value (2^N -> 2^(N+1)-1).
+ // Note: Not offering reverse PowerOfTwoMark-to-PowerOfTwo conversion, because
+ // that could result in an unexpected 0 result for the largest possible mask.
+ template <typename U>
+ static constexpr PowerOfTwoMask<U> MaskForPowerOfTwo(
+ const PowerOfTwo<U>& aP2) {
+ return PowerOfTwoMask(aP2);
+ }
+
+ // Allow smaller unsigned types as input.
+ // Bigger or signed types must be explicitly converted by the caller.
+ template <typename U>
+ explicit constexpr PowerOfTwoMask(U aInput)
+ : mMask(RoundUpPow2Mask(static_cast<T>(aInput))) {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "PowerOfTwoMask does not accept signed types");
+ static_assert(sizeof(U) <= sizeof(T),
+ "PowerOfTwoMask does not accept bigger types");
+ }
+
+ constexpr T MaskValue() const { return mMask; }
+
+ // `x & aPowerOfTwoMask` just works.
+ template <typename U>
+ friend U operator&(U aNumber, PowerOfTwoMask aP2M) {
+ return static_cast<U>(aNumber & aP2M.MaskValue());
+ }
+
+ // `aPowerOfTwoMask & x` just works.
+ template <typename U>
+ friend constexpr U operator&(PowerOfTwoMask aP2M, U aNumber) {
+ return static_cast<U>(aP2M.MaskValue() & aNumber);
+ }
+
+ // `x % aPowerOfTwoMask(2^N-1)` is equivalent to `x % 2^N` but is more
+ // optimal by doing `x & (2^N-1)`.
+ // Useful for templated code doing modulo with a template argument type.
+ template <typename U>
+ friend constexpr U operator%(U aNumerator, PowerOfTwoMask aDenominator) {
+ return aNumerator & aDenominator.MaskValue();
+ }
+
+ constexpr bool operator==(const PowerOfTwoMask& aRhs) const {
+ return mMask == aRhs.mMask;
+ }
+ constexpr bool operator!=(const PowerOfTwoMask& aRhs) const {
+ return mMask != aRhs.mMask;
+ }
+
+ private:
+ // Trust `PowerOfTwo` to call the private Trusted constructor below.
+ friend class PowerOfTwo<T>;
+
+ // Trust `MakePowerOfTwoMask()` to call the private Trusted constructor below.
+ template <typename U, U Mask>
+ friend constexpr PowerOfTwoMask<U> MakePowerOfTwoMask();
+
+ struct Trusted {
+ T mMask;
+ };
+ // Construct the mask corresponding to a PowerOfTwo.
+ // This saves having to compute the nearest 2^N-1.
+ // Note: Not a public PowerOfTwo->PowerOfTwoMask conversion constructor, as
+ // that could be ambiguous whether we'd want the mask corresponding to the
+ // power of 2 (2^N -> 2^N-1), or the mask that can *contain* the PowerOfTwo
+ // value (2^N -> 2^(N+1)-1).
+ explicit constexpr PowerOfTwoMask(const Trusted& aP2) : mMask(aP2.mMask) {}
+
+ T mMask = 0;
+};
+
+// Make a PowerOfTwoMask constant, statically-checked.
+template <typename T, T Mask>
+constexpr PowerOfTwoMask<T> MakePowerOfTwoMask() {
+ static_assert(Mask == T(-1) || IsPowerOfTwo(Mask + 1),
+ "MakePowerOfTwoMask<T, Mask>: Mask must be 2^N-1");
+ using Trusted = typename PowerOfTwoMask<T>::Trusted;
+ return PowerOfTwoMask<T>(Trusted{Mask});
+}
+
+// PowerOfTwo will always contain a power of 2.
+template <typename T>
+class PowerOfTwo {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "PowerOfTwo must use an unsigned type");
+
+ public:
+ // Construct a power of 2 that can fit the given value, or the highest power
+ // of 2 possible.
+ // Caller should explicitly check/assert `Value() <= aInput` if they want to.
+ // Cannot be constexpr because of `FriendlyRoundUpPow2()`.
+ explicit PowerOfTwo(T aInput) : mValue(FriendlyRoundUpPow2(aInput)) {}
+
+ // Allow smaller unsigned types as input.
+ // Bigger or signed types must be explicitly converted by the caller.
+ template <typename U>
+ explicit PowerOfTwo(U aInput)
+ : mValue(FriendlyRoundUpPow2(static_cast<T>(aInput))) {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "PowerOfTwo does not accept signed types");
+ static_assert(sizeof(U) <= sizeof(T),
+ "PowerOfTwo does not accept bigger types");
+ }
+
+ constexpr T Value() const { return mValue; }
+
+ // Binary mask corresponding to the power of 2, useful for modulo.
+ // E.g., `x & powerOfTwo(y).Mask()` == `x % powerOfTwo(y)`.
+ // Consider PowerOfTwoMask class instead of PowerOfTwo if masking is the
+ // primary use case.
+ constexpr T MaskValue() const { return mValue - 1; }
+
+ // PowerOfTwoMask corresponding to this power of 2, useful for modulo.
+ constexpr PowerOfTwoMask<T> Mask() const {
+ using Trusted = typename PowerOfTwoMask<T>::Trusted;
+ return PowerOfTwoMask<T>(Trusted{MaskValue()});
+ }
+
+ // `x % aPowerOfTwo` works optimally.
+ // Useful for templated code doing modulo with a template argument type.
+ // Use PowerOfTwoMask class instead if masking is the primary use case.
+ template <typename U>
+ friend constexpr U operator%(U aNumerator, PowerOfTwo aDenominator) {
+ return aNumerator & aDenominator.MaskValue();
+ }
+
+ constexpr bool operator==(const PowerOfTwo& aRhs) const {
+ return mValue == aRhs.mValue;
+ }
+ constexpr bool operator!=(const PowerOfTwo& aRhs) const {
+ return mValue != aRhs.mValue;
+ }
+ constexpr bool operator<(const PowerOfTwo& aRhs) const {
+ return mValue < aRhs.mValue;
+ }
+ constexpr bool operator<=(const PowerOfTwo& aRhs) const {
+ return mValue <= aRhs.mValue;
+ }
+ constexpr bool operator>(const PowerOfTwo& aRhs) const {
+ return mValue > aRhs.mValue;
+ }
+ constexpr bool operator>=(const PowerOfTwo& aRhs) const {
+ return mValue >= aRhs.mValue;
+ }
+
+ private:
+ // Trust `MakePowerOfTwo()` to call the private Trusted constructor below.
+ template <typename U, U Value>
+ friend constexpr PowerOfTwo<U> MakePowerOfTwo();
+
+ struct Trusted {
+ T mValue;
+ };
+ // Construct a PowerOfTwo with the given trusted value.
+ // This saves having to compute the nearest 2^N.
+ // Note: Not offering PowerOfTwoMark-to-PowerOfTwo conversion, because that
+ // could result in an unexpected 0 result for the largest possible mask.
+ explicit constexpr PowerOfTwo(const Trusted& aP2) : mValue(aP2.mValue) {}
+
+ // The smallest power of 2 is 2^0 == 1.
+ T mValue = 1;
+};
+
+// Make a PowerOfTwo constant, statically-checked.
+template <typename T, T Value>
+constexpr PowerOfTwo<T> MakePowerOfTwo() {
+ static_assert(IsPowerOfTwo(Value),
+ "MakePowerOfTwo<T, Value>: Value must be 2^N");
+ using Trusted = typename PowerOfTwo<T>::Trusted;
+ return PowerOfTwo<T>(Trusted{Value});
+}
+
+// Shortcuts for the most common types and functions.
+
+using PowerOfTwoMask32 = PowerOfTwoMask<uint32_t>;
+using PowerOfTwo32 = PowerOfTwo<uint32_t>;
+using PowerOfTwoMask64 = PowerOfTwoMask<uint64_t>;
+using PowerOfTwo64 = PowerOfTwo<uint64_t>;
+
+template <uint32_t Mask>
+constexpr PowerOfTwoMask32 MakePowerOfTwoMask32() {
+ return MakePowerOfTwoMask<uint32_t, Mask>();
+}
+
+template <uint32_t Value>
+constexpr PowerOfTwo32 MakePowerOfTwo32() {
+ return MakePowerOfTwo<uint32_t, Value>();
+}
+
+template <uint64_t Mask>
+constexpr PowerOfTwoMask64 MakePowerOfTwoMask64() {
+ return MakePowerOfTwoMask<uint64_t, Mask>();
+}
+
+template <uint64_t Value>
+constexpr PowerOfTwo64 MakePowerOfTwo64() {
+ return MakePowerOfTwo<uint64_t, Value>();
+}
+
+} // namespace mozilla
+
+#endif // PowerOfTwo_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferChunk.h b/mozglue/baseprofiler/public/ProfileBufferChunk.h
new file mode 100644
index 0000000000..9ba2483372
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferChunk.h
@@ -0,0 +1,547 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferChunk_h
+#define ProfileBufferChunk_h
+
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/ProfileBufferIndex.h"
+#include "mozilla/Span.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtr.h"
+
+#if defined(MOZ_MEMORY)
+# include "mozmemory.h"
+#endif
+
+#include <algorithm>
+#include <limits>
+#include <type_traits>
+
+#ifdef DEBUG
+# include <cstdio>
+#endif
+
+namespace mozilla {
+
+// Represents a single chunk of memory, with a link to the next chunk (or null).
+//
+// A chunk is made of an internal header (which contains a public part) followed
+// by user-accessible bytes.
+//
+// +---------------+---------+----------------------------------------------+
+// | public Header | private | memory containing user blocks |
+// +---------------+---------+----------------------------------------------+
+// <---------------BufferBytes()------------------>
+// <------------------------------ChunkBytes()------------------------------>
+//
+// The chunk can reserve "blocks", but doesn't know the internal contents of
+// each block, it only knows where the first one starts, and where the last one
+// ends (which is where the next one will begin, if not already out of range).
+// It is up to the user to add structure to each block so that they can be
+// distinguished when later read.
+//
+// +---------------+---------+----------------------------------------------+
+// | public Header | private | [1st block]...[last full block] |
+// +---------------+---------+----------------------------------------------+
+// ChunkHeader().mOffsetFirstBlock ^ ^
+// ChunkHeader().mOffsetPastLastBlock --'
+//
+// It is possible to attempt to reserve more than the remaining space, in which
+// case only what is available is returned. The caller is responsible for using
+// another chunk, reserving a block "tail" in it, and using both parts to
+// constitute a full block. (This initial tail may be empty in some chunks.)
+//
+// +---------------+---------+----------------------------------------------+
+// | public Header | private | tail][1st block]...[last full block][head... |
+// +---------------+---------+----------------------------------------------+
+// ChunkHeader().mOffsetFirstBlock ^ ^
+// ChunkHeader().mOffsetPastLastBlock --'
+//
+// Each Chunk has an internal state (checked in DEBUG builds) that directs how
+// to use it during creation, initialization, use, end of life, recycling, and
+// destruction. See `State` below for details.
+// In particular:
+// - `ReserveInitialBlockAsTail()` must be called before the first `Reserve()`
+// after construction or recycling, even with a size of 0 (no actual tail),
+// - `MarkDone()` and `MarkRecycled()` must be called as appropriate.
+class ProfileBufferChunk {
+ public:
+ using Byte = uint8_t;
+ using Length = uint32_t;
+
+ using SpanOfBytes = Span<Byte>;
+
+ // Hint about the size of the metadata (public and private headers).
+ // `Create()` below takes the minimum *buffer* size, so the minimum total
+ // Chunk size is at least `SizeofChunkMetadata() + aMinBufferBytes`.
+ [[nodiscard]] static constexpr Length SizeofChunkMetadata() {
+ return static_cast<Length>(sizeof(InternalHeader));
+ }
+
+ // Allocate space for a chunk with a given minimum size, and construct it.
+ // The actual size may be higher, to match the actual space taken in the
+ // memory pool.
+ [[nodiscard]] static UniquePtr<ProfileBufferChunk> Create(
+ Length aMinBufferBytes) {
+ // We need at least one byte, to cover the always-present `mBuffer` byte.
+ aMinBufferBytes = std::max(aMinBufferBytes, Length(1));
+ // Trivial struct with the same alignment as `ProfileBufferChunk`, and size
+ // equal to that alignment, because typically the sizeof of an object is
+ // a multiple of its alignment.
+ struct alignas(alignof(InternalHeader)) ChunkStruct {
+ Byte c[alignof(InternalHeader)];
+ };
+ static_assert(std::is_trivial_v<ChunkStruct>,
+ "ChunkStruct must be trivial to avoid any construction");
+ // Allocate an array of that struct, enough to contain the expected
+ // `ProfileBufferChunk` (with its header+buffer).
+ size_t count = (sizeof(InternalHeader) + aMinBufferBytes +
+ (alignof(InternalHeader) - 1)) /
+ alignof(InternalHeader);
+#if defined(MOZ_MEMORY)
+ // Potentially expand the array to use more of the effective allocation.
+ count = (malloc_good_size(count * sizeof(ChunkStruct)) +
+ (sizeof(ChunkStruct) - 1)) /
+ sizeof(ChunkStruct);
+#endif
+ auto chunkStorage = MakeUnique<ChunkStruct[]>(count);
+ MOZ_ASSERT(reinterpret_cast<uintptr_t>(chunkStorage.get()) %
+ alignof(InternalHeader) ==
+ 0);
+ // After the allocation, compute the actual chunk size (including header).
+ const size_t chunkBytes = count * sizeof(ChunkStruct);
+ MOZ_ASSERT(chunkBytes >= sizeof(ProfileBufferChunk),
+ "Not enough space to construct a ProfileBufferChunk");
+ MOZ_ASSERT(chunkBytes <=
+ static_cast<size_t>(std::numeric_limits<Length>::max()));
+ // Compute the size of the user-accessible buffer inside the chunk.
+ const Length bufferBytes =
+ static_cast<Length>(chunkBytes - sizeof(InternalHeader));
+ MOZ_ASSERT(bufferBytes >= aMinBufferBytes,
+ "Not enough space for minimum buffer size");
+ // Construct the header at the beginning of the allocated array, with the
+ // known buffer size.
+ new (chunkStorage.get()) ProfileBufferChunk(bufferBytes);
+ // We now have a proper `ProfileBufferChunk` object, create the appropriate
+ // UniquePtr for it.
+ UniquePtr<ProfileBufferChunk> chunk{
+ reinterpret_cast<ProfileBufferChunk*>(chunkStorage.release())};
+ MOZ_ASSERT(
+ size_t(reinterpret_cast<const char*>(
+ &chunk.get()->BufferSpan()[bufferBytes - 1]) -
+ reinterpret_cast<const char*>(chunk.get())) == chunkBytes - 1,
+ "Buffer span spills out of chunk allocation");
+ return chunk;
+ }
+
+#ifdef DEBUG
+ ~ProfileBufferChunk() {
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::InUse);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Full);
+ MOZ_ASSERT(mInternalHeader.mState == InternalHeader::State::Created ||
+ mInternalHeader.mState == InternalHeader::State::Done ||
+ mInternalHeader.mState == InternalHeader::State::Recycled);
+ }
+#endif
+
+ // Must be called with the first block tail (may be empty), which will be
+ // skipped if the reader starts with this ProfileBufferChunk.
+ [[nodiscard]] SpanOfBytes ReserveInitialBlockAsTail(Length aTailSize) {
+#ifdef DEBUG
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::InUse);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Full);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Done);
+ MOZ_ASSERT(mInternalHeader.mState == InternalHeader::State::Created ||
+ mInternalHeader.mState == InternalHeader::State::Recycled);
+ mInternalHeader.mState = InternalHeader::State::InUse;
+#endif
+ mInternalHeader.mHeader.mOffsetFirstBlock = aTailSize;
+ mInternalHeader.mHeader.mOffsetPastLastBlock = aTailSize;
+ mInternalHeader.mHeader.mStartTimeStamp = TimeStamp::Now();
+ return SpanOfBytes(&mBuffer, aTailSize);
+ }
+
+ struct ReserveReturn {
+ SpanOfBytes mSpan;
+ ProfileBufferBlockIndex mBlockRangeIndex;
+ };
+
+ // Reserve a block of up to `aBlockSize` bytes, and return a Span to it, and
+ // its starting index. The actual size may be smaller, if the block cannot fit
+ // in the remaining space.
+ [[nodiscard]] ReserveReturn ReserveBlock(Length aBlockSize) {
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Created);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Full);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Done);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Recycled);
+ MOZ_ASSERT(mInternalHeader.mState == InternalHeader::State::InUse);
+ MOZ_ASSERT(RangeStart() != 0,
+ "Expected valid range start before first Reserve()");
+ const Length blockOffset = mInternalHeader.mHeader.mOffsetPastLastBlock;
+ Length reservedSize = aBlockSize;
+ if (MOZ_UNLIKELY(aBlockSize >= RemainingBytes())) {
+ reservedSize = RemainingBytes();
+#ifdef DEBUG
+ mInternalHeader.mState = InternalHeader::State::Full;
+#endif
+ }
+ mInternalHeader.mHeader.mOffsetPastLastBlock += reservedSize;
+ mInternalHeader.mHeader.mBlockCount += 1;
+ return {SpanOfBytes(&mBuffer + blockOffset, reservedSize),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mInternalHeader.mHeader.mRangeStart + blockOffset)};
+ }
+
+ // When a chunk will not be used to store more blocks (because it is full, or
+ // because the profiler will not add more data), it should be marked "done".
+ // Access to its content is still allowed.
+ void MarkDone() {
+#ifdef DEBUG
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Created);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Done);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Recycled);
+ MOZ_ASSERT(mInternalHeader.mState == InternalHeader::State::InUse ||
+ mInternalHeader.mState == InternalHeader::State::Full);
+ mInternalHeader.mState = InternalHeader::State::Done;
+#endif
+ mInternalHeader.mHeader.mDoneTimeStamp = TimeStamp::Now();
+ }
+
+ // A "Done" chunk may be recycled, to avoid allocating a new one.
+ void MarkRecycled() {
+#ifdef DEBUG
+ // We also allow Created and already-Recycled chunks to be recycled, this
+ // way it's easier to recycle chunks when their state is not easily
+ // trackable.
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::InUse);
+ MOZ_ASSERT(mInternalHeader.mState != InternalHeader::State::Full);
+ MOZ_ASSERT(mInternalHeader.mState == InternalHeader::State::Created ||
+ mInternalHeader.mState == InternalHeader::State::Done ||
+ mInternalHeader.mState == InternalHeader::State::Recycled);
+ mInternalHeader.mState = InternalHeader::State::Recycled;
+#endif
+ // Reset all header fields, in case this recycled chunk gets read.
+ mInternalHeader.mHeader.Reset();
+ }
+
+ // Public header, meant to uniquely identify a chunk, it may be shared with
+ // other processes to coordinate global memory handling.
+ struct Header {
+ explicit Header(Length aBufferBytes) : mBufferBytes(aBufferBytes) {}
+
+ // Reset all members to their as-new values (apart from the buffer size,
+ // which cannot change), ready for re-use.
+ void Reset() {
+ mOffsetFirstBlock = 0;
+ mOffsetPastLastBlock = 0;
+ mStartTimeStamp = TimeStamp{};
+ mDoneTimeStamp = TimeStamp{};
+ mBlockCount = 0;
+ mRangeStart = 0;
+ mProcessId = 0;
+ }
+
+ // Note: Part of the ordering of members below is to avoid unnecessary
+ // padding.
+
+ // Members managed by the ProfileBufferChunk.
+
+ // Offset of the first block (past the initial tail block, which may be 0).
+ Length mOffsetFirstBlock = 0;
+ // Offset past the last byte of the last reserved block
+ // It may be past mBufferBytes when last block continues in the next
+ // ProfileBufferChunk. It may be before mBufferBytes if ProfileBufferChunk
+ // is marked "Done" before the end is reached.
+ Length mOffsetPastLastBlock = 0;
+ // Timestamp when the buffer becomes in-use, ready to record data.
+ TimeStamp mStartTimeStamp;
+ // Timestamp when the buffer is "Done" (which happens when the last block is
+ // written). This will be used to find and discard the oldest
+ // ProfileBufferChunk.
+ TimeStamp mDoneTimeStamp;
+ // Number of bytes in the buffer, set once at construction time.
+ const Length mBufferBytes;
+ // Number of reserved blocks (including final one even if partial, but
+ // excluding initial tail).
+ Length mBlockCount = 0;
+
+ // Meta-data set by the user.
+
+ // Index of the first byte of this ProfileBufferChunk, relative to all
+ // Chunks for this process. Index 0 is reserved as nullptr-like index,
+ // mRangeStart should be set to a non-0 value before the first `Reserve()`.
+ ProfileBufferIndex mRangeStart = 0;
+ // Process writing to this ProfileBufferChunk.
+ int mProcessId = 0;
+
+ // A bit of spare space (necessary here because of the alignment due to
+ // other members), may be later repurposed for extra data.
+ const int mPADDING = 0;
+ };
+
+ [[nodiscard]] const Header& ChunkHeader() const {
+ return mInternalHeader.mHeader;
+ }
+
+ [[nodiscard]] Length BufferBytes() const {
+ return ChunkHeader().mBufferBytes;
+ }
+
+ // Total size of the chunk (buffer + header).
+ [[nodiscard]] Length ChunkBytes() const {
+ return static_cast<Length>(sizeof(InternalHeader)) + BufferBytes();
+ }
+
+ // Size of external resources, in this case all the following chunks.
+ [[nodiscard]] size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ const ProfileBufferChunk* const next = GetNext();
+ return next ? next->SizeOfIncludingThis(aMallocSizeOf) : 0;
+ }
+
+ // Size of this chunk and all following ones.
+ [[nodiscard]] size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+ // Just in case `aMallocSizeOf` falls back on just `sizeof`, make sure we
+ // account for at least the actual Chunk requested allocation size.
+ return std::max<size_t>(aMallocSizeOf(this), ChunkBytes()) +
+ SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ [[nodiscard]] Length RemainingBytes() const {
+ return BufferBytes() - OffsetPastLastBlock();
+ }
+
+ [[nodiscard]] Length OffsetFirstBlock() const {
+ return ChunkHeader().mOffsetFirstBlock;
+ }
+
+ [[nodiscard]] Length OffsetPastLastBlock() const {
+ return ChunkHeader().mOffsetPastLastBlock;
+ }
+
+ [[nodiscard]] Length BlockCount() const { return ChunkHeader().mBlockCount; }
+
+ [[nodiscard]] int ProcessId() const { return ChunkHeader().mProcessId; }
+
+ void SetProcessId(int aProcessId) {
+ mInternalHeader.mHeader.mProcessId = aProcessId;
+ }
+
+ // Global range index at the start of this Chunk.
+ [[nodiscard]] ProfileBufferIndex RangeStart() const {
+ return ChunkHeader().mRangeStart;
+ }
+
+ void SetRangeStart(ProfileBufferIndex aRangeStart) {
+ mInternalHeader.mHeader.mRangeStart = aRangeStart;
+ }
+
+ // Get a read-only Span to the buffer. It is up to the caller to decypher the
+ // contents, based on known offsets and the internal block structure.
+ [[nodiscard]] Span<const Byte> BufferSpan() const {
+ return Span<const Byte>(&mBuffer, BufferBytes());
+ }
+
+ [[nodiscard]] Byte ByteAt(Length aOffset) const {
+ MOZ_ASSERT(aOffset < OffsetPastLastBlock());
+ return *(&mBuffer + aOffset);
+ }
+
+ [[nodiscard]] ProfileBufferChunk* GetNext() {
+ return mInternalHeader.mNext.get();
+ }
+ [[nodiscard]] const ProfileBufferChunk* GetNext() const {
+ return mInternalHeader.mNext.get();
+ }
+
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> ReleaseNext() {
+ return std::move(mInternalHeader.mNext);
+ }
+
+ void InsertNext(UniquePtr<ProfileBufferChunk>&& aChunk) {
+ if (!aChunk) {
+ return;
+ }
+ aChunk->SetLast(ReleaseNext());
+ mInternalHeader.mNext = std::move(aChunk);
+ }
+
+ // Find the last chunk in this chain (it may be `this`).
+ [[nodiscard]] ProfileBufferChunk* Last() {
+ ProfileBufferChunk* chunk = this;
+ for (;;) {
+ ProfileBufferChunk* next = chunk->GetNext();
+ if (!next) {
+ return chunk;
+ }
+ chunk = next;
+ }
+ }
+ [[nodiscard]] const ProfileBufferChunk* Last() const {
+ const ProfileBufferChunk* chunk = this;
+ for (;;) {
+ const ProfileBufferChunk* next = chunk->GetNext();
+ if (!next) {
+ return chunk;
+ }
+ chunk = next;
+ }
+ }
+
+ void SetLast(UniquePtr<ProfileBufferChunk>&& aChunk) {
+ if (!aChunk) {
+ return;
+ }
+ Last()->mInternalHeader.mNext = std::move(aChunk);
+ }
+
+ // Join two possibly-null chunk lists.
+ [[nodiscard]] static UniquePtr<ProfileBufferChunk> Join(
+ UniquePtr<ProfileBufferChunk>&& aFirst,
+ UniquePtr<ProfileBufferChunk>&& aLast) {
+ if (aFirst) {
+ aFirst->SetLast(std::move(aLast));
+ return std::move(aFirst);
+ }
+ return std::move(aLast);
+ }
+
+#ifdef DEBUG
+ void Dump(std::FILE* aFile = stdout) const {
+ fprintf(aFile,
+ "Chunk[%p] chunkSize=%u bufferSize=%u state=%s rangeStart=%u "
+ "firstBlockOffset=%u offsetPastLastBlock=%u blockCount=%u",
+ this, unsigned(ChunkBytes()), unsigned(BufferBytes()),
+ mInternalHeader.StateString(), unsigned(RangeStart()),
+ unsigned(OffsetFirstBlock()), unsigned(OffsetPastLastBlock()),
+ unsigned(BlockCount()));
+ const auto len = OffsetPastLastBlock();
+ constexpr unsigned columns = 16;
+ unsigned char ascii[columns + 1];
+ ascii[columns] = '\0';
+ for (Length i = 0; i < len; ++i) {
+ if (i % columns == 0) {
+ fprintf(aFile, "\n %4u=0x%03x:", unsigned(i), unsigned(i));
+ for (unsigned a = 0; a < columns; ++a) {
+ ascii[a] = ' ';
+ }
+ }
+ unsigned char sep = ' ';
+ if (i == OffsetFirstBlock()) {
+ if (i == OffsetPastLastBlock()) {
+ sep = '#';
+ } else {
+ sep = '[';
+ }
+ } else if (i == OffsetPastLastBlock()) {
+ sep = ']';
+ }
+ unsigned char c = *(&mBuffer + i);
+ fprintf(aFile, "%c%02x", sep, c);
+
+ if (i == len - 1) {
+ if (i + 1 == OffsetPastLastBlock()) {
+ // Special case when last block ends right at the end.
+ fprintf(aFile, "]");
+ } else {
+ fprintf(aFile, " ");
+ }
+ } else if (i % columns == columns - 1) {
+ fprintf(aFile, " ");
+ }
+
+ ascii[i % columns] = (c >= ' ' && c <= '~') ? c : '.';
+
+ if (i % columns == columns - 1) {
+ fprintf(aFile, " %s", ascii);
+ }
+ }
+
+ if (len % columns < columns - 1) {
+ for (Length i = len % columns; i < columns; ++i) {
+ fprintf(aFile, " ");
+ }
+ fprintf(aFile, " %s", ascii);
+ }
+
+ fprintf(aFile, "\n");
+ }
+#endif // DEBUG
+
+ private:
+ // ProfileBufferChunk constructor. Use static `Create()` to allocate and
+ // construct a ProfileBufferChunk.
+ explicit ProfileBufferChunk(Length aBufferBytes)
+ : mInternalHeader(aBufferBytes) {}
+
+ // This internal header starts with the public `Header`, and adds some data
+ // only necessary for local handling.
+ // This encapsulation is also necessary to perform placement-new in
+ // `Create()`.
+ struct InternalHeader {
+ explicit InternalHeader(Length aBufferBytes) : mHeader(aBufferBytes) {}
+
+ Header mHeader;
+ UniquePtr<ProfileBufferChunk> mNext;
+
+#ifdef DEBUG
+ enum class State {
+ Created, // Self-set. Just constructed, waiting for initial block tail.
+ InUse, // Ready to accept blocks.
+ Full, // Self-set. Blocks reach the end (or further).
+ Done, // Blocks won't be added anymore.
+ Recycled // Still full of data, but expecting an initial block tail.
+ };
+
+ State mState = State::Created;
+ // Transition table: (X=unexpected)
+ // Method \ State Created InUse Full Done Recycled
+ // ReserveInitialBlockAsTail InUse X X X InUse
+ // Reserve X InUse/Full X X X
+ // MarkDone X Done Done X X
+ // MarkRecycled X X X Recycled X
+ // destructor ok X X ok ok
+
+ const char* StateString() const {
+ switch (mState) {
+ case State::Created:
+ return "Created";
+ case State::InUse:
+ return "InUse";
+ case State::Full:
+ return "Full";
+ case State::Done:
+ return "Done";
+ case State::Recycled:
+ return "Recycled";
+ default:
+ return "?";
+ }
+ }
+#else // DEBUG
+ const char* StateString() const { return "(non-DEBUG)"; }
+#endif
+ };
+
+ InternalHeader mInternalHeader;
+
+ // KEEP THIS LAST!
+ // First byte of the buffer. Note that ProfileBufferChunk::Create allocates a
+ // bigger block, such that `mBuffer` is the first of `mBufferBytes` available
+ // bytes.
+ // The initialization is not strictly needed, because bytes should only be
+ // read after they have been written and `mOffsetPastLastBlock` has been
+ // updated. However:
+ // - Reviewbot complains that it's not initialized.
+ // - It's cheap to initialize one byte.
+ // - In the worst case (reading does happen), zero is not a valid entry size
+ // and should get caught in entry readers.
+ Byte mBuffer = '\0';
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferChunk_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferChunkManager.h b/mozglue/baseprofiler/public/ProfileBufferChunkManager.h
new file mode 100644
index 0000000000..e7f12bf21f
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferChunkManager.h
@@ -0,0 +1,134 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferChunkManager_h
+#define ProfileBufferChunkManager_h
+
+#include "mozilla/ProfileBufferChunk.h"
+#include "mozilla/ScopeExit.h"
+
+#include <functional>
+
+namespace mozilla {
+
+// Manages the ProfileBufferChunks for this process.
+// The main user of this class is the buffer that needs chunks to store its
+// data.
+// The main ProfileBufferChunks responsibilities are:
+// - It can create new chunks, they are called "unreleased".
+// - Later these chunks are returned here, and become "released".
+// - The manager is free to destroy or recycle the oldest released chunks
+// (usually to reclaim memory), and will inform the user through a provided
+// callback.
+// - The user may access still-alive released chunks.
+class ProfileBufferChunkManager {
+ public:
+ virtual ~ProfileBufferChunkManager()
+#ifdef DEBUG
+ {
+ MOZ_ASSERT(!mUser, "Still registered when being destroyed");
+ }
+#else
+ = default;
+#endif
+
+ // Expected maximum size needed to store one stack sample.
+ // Most ChunkManager sub-classes will require chunk sizes, this can serve as
+ // a minimum recommendation to hold most backtraces.
+ constexpr static ProfileBufferChunk::Length scExpectedMaximumStackSize =
+ 128 * 1024;
+
+ // Estimated maximum buffer size.
+ [[nodiscard]] virtual size_t MaxTotalSize() const = 0;
+
+ // Create or recycle a chunk right now. May return null in case of allocation
+ // failure.
+ // Note that the chunk-destroyed callback may be invoked during this call;
+ // user should be careful with reentrancy issues.
+ [[nodiscard]] virtual UniquePtr<ProfileBufferChunk> GetChunk() = 0;
+
+ // `aChunkReceiver` may be called with a new or recycled chunk, or nullptr.
+ // (See `FulfillChunkRequests()` regarding when the callback may happen.)
+ virtual void RequestChunk(
+ std::function<void(UniquePtr<ProfileBufferChunk>)>&& aChunkReceiver) = 0;
+
+ // This method may be invoked at any time on any thread (and not necessarily
+ // by the main user of this class), to do the work necessary to respond to a
+ // previous `RequestChunk()`.
+ // It is optional: If it is never called, or called too late, the user is
+ // responsible for directly calling `GetChunk()` when a chunk is really
+ // needed (or it should at least fail gracefully).
+ // The idea is to fulfill chunk request on a separate thread, and most
+ // importantly outside of profiler calls, to avoid doing expensive memory
+ // allocations during these calls.
+ virtual void FulfillChunkRequests() = 0;
+
+ // One chunk is released by the user, the ProfileBufferChunkManager should
+ // keep it as long as possible (depending on local or global memory/time
+ // limits). Note that the chunk-destroyed callback may be invoked during this
+ // call; user should be careful with reentrancy issues.
+ virtual void ReleaseChunk(UniquePtr<ProfileBufferChunk> aChunk) = 0;
+
+ // `aChunkDestroyedCallback` will be called whenever the contents of a
+ // previously-released chunk is about to be destroyed or recycled.
+ // Note that it may be called during other functions above, or at other times
+ // from the same or other threads; user should be careful with reentrancy
+ // issues.
+ virtual void SetChunkDestroyedCallback(
+ std::function<void(const ProfileBufferChunk&)>&&
+ aChunkDestroyedCallback) = 0;
+
+ // Give away all released chunks that have not yet been destroyed.
+ [[nodiscard]] virtual UniquePtr<ProfileBufferChunk>
+ GetExtantReleasedChunks() = 0;
+
+ // Let a callback see all released chunks that have not yet been destroyed, if
+ // any. Return whatever the callback returns.
+ template <typename Callback>
+ [[nodiscard]] auto PeekExtantReleasedChunks(Callback&& aCallback) {
+ const ProfileBufferChunk* chunks = PeekExtantReleasedChunksAndLock();
+ auto unlock =
+ MakeScopeExit([&]() { UnlockAfterPeekExtantReleasedChunks(); });
+ return std::forward<Callback>(aCallback)(chunks);
+ }
+
+ // Chunks that were still unreleased will never be released.
+ virtual void ForgetUnreleasedChunks() = 0;
+
+ [[nodiscard]] virtual size_t SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf) const = 0;
+ [[nodiscard]] virtual size_t SizeOfIncludingThis(
+ MallocSizeOf aMallocSizeOf) const = 0;
+
+ protected:
+ // Derived classes to implement `PeekExtantReleasedChunks` through these:
+ virtual const ProfileBufferChunk* PeekExtantReleasedChunksAndLock() = 0;
+ virtual void UnlockAfterPeekExtantReleasedChunks() = 0;
+
+#ifdef DEBUG
+ public:
+ // DEBUG checks ensuring that this manager and its users avoid UAFs.
+ // Derived classes should assert that mUser is not null in their functions.
+
+ void RegisteredWith(const void* aUser) {
+ MOZ_ASSERT(!mUser);
+ MOZ_ASSERT(aUser);
+ mUser = aUser;
+ }
+
+ void DeregisteredFrom(const void* aUser) {
+ MOZ_ASSERT(mUser == aUser);
+ mUser = nullptr;
+ }
+
+ protected:
+ const void* mUser = nullptr;
+#endif // DEBUG
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferChunkManager_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h b/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h
new file mode 100644
index 0000000000..c91b38cbdb
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h
@@ -0,0 +1,172 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferChunkManagerSingle_h
+#define ProfileBufferChunkManagerSingle_h
+
+#include "mozilla/ProfileBufferChunkManager.h"
+
+#ifdef DEBUG
+# include "mozilla/Atomics.h"
+#endif // DEBUG
+
+namespace mozilla {
+
+// Manages only one Chunk.
+// The first call to `Get`/`RequestChunk()` will retrieve the one chunk, and all
+// subsequent calls will return nullptr. That chunk may still be released, but
+// it will never be destroyed or recycled.
+// Unlike others, this manager may be `Reset()`, to allow another round of
+// small-data gathering.
+// The main use is with short-lived ProfileChunkedBuffers that collect little
+// data that can fit in one chunk, e.g., capturing one stack.
+// It is not thread-safe.
+class ProfileBufferChunkManagerSingle final : public ProfileBufferChunkManager {
+ public:
+ using Length = ProfileBufferChunk::Length;
+
+ // Use a preallocated chunk. (Accepting null to gracefully handle OOM.)
+ explicit ProfileBufferChunkManagerSingle(UniquePtr<ProfileBufferChunk> aChunk)
+ : mInitialChunk(std::move(aChunk)),
+ mBufferBytes(mInitialChunk ? mInitialChunk->BufferBytes() : 0) {
+ MOZ_ASSERT(!mInitialChunk || !mInitialChunk->GetNext(),
+ "Expected at most one chunk");
+ }
+
+ // ChunkMinBufferBytes: Minimum number of user-available bytes in the Chunk.
+ // Note that Chunks use a bit more memory for their header.
+ explicit ProfileBufferChunkManagerSingle(Length aChunkMinBufferBytes)
+ : mInitialChunk(ProfileBufferChunk::Create(aChunkMinBufferBytes)),
+ mBufferBytes(mInitialChunk ? mInitialChunk->BufferBytes() : 0) {}
+
+#ifdef DEBUG
+ ~ProfileBufferChunkManagerSingle() { MOZ_ASSERT(mVirtuallyLocked == false); }
+#endif // DEBUG
+
+ // Reset this manager, using the provided chunk (probably coming from the
+ // ProfileChunkedBuffer that just used it); if null, fallback on current or
+ // released chunk.
+ void Reset(UniquePtr<ProfileBufferChunk> aPossibleChunk) {
+ if (aPossibleChunk) {
+ mInitialChunk = std::move(aPossibleChunk);
+ mReleasedChunk = nullptr;
+ } else if (!mInitialChunk) {
+ MOZ_ASSERT(!!mReleasedChunk, "Can't reset properly!");
+ mInitialChunk = std::move(mReleasedChunk);
+ }
+
+ if (mInitialChunk) {
+ mInitialChunk->MarkRecycled();
+ mBufferBytes = mInitialChunk->BufferBytes();
+ } else {
+ mBufferBytes = 0;
+ }
+ }
+
+ [[nodiscard]] size_t MaxTotalSize() const final { return mBufferBytes; }
+
+ // One of `GetChunk` and `RequestChunk` will only work the very first time (if
+ // there's even a chunk).
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> GetChunk() final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return std::move(mInitialChunk);
+ }
+
+ void RequestChunk(std::function<void(UniquePtr<ProfileBufferChunk>)>&&
+ aChunkReceiver) final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ // Simple retrieval.
+ std::move(aChunkReceiver)(GetChunk());
+ }
+
+ void FulfillChunkRequests() final {
+ // Nothing to do here.
+ }
+
+ void ReleaseChunk(UniquePtr<ProfileBufferChunk> aChunk) final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ if (!aChunk) {
+ return;
+ }
+ MOZ_ASSERT(!mReleasedChunk, "Unexpected 2nd released chunk");
+ MOZ_ASSERT(!aChunk->GetNext(), "Only expected one released chunk");
+ mReleasedChunk = std::move(aChunk);
+ }
+
+ void SetChunkDestroyedCallback(
+ std::function<void(const ProfileBufferChunk&)>&& aChunkDestroyedCallback)
+ final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ // The chunk-destroyed callback will never actually be called, but we keep
+ // the callback here in case the caller expects it to live as long as this
+ // manager.
+ mChunkDestroyedCallback = std::move(aChunkDestroyedCallback);
+ }
+
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> GetExtantReleasedChunks() final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return std::move(mReleasedChunk);
+ }
+
+ void ForgetUnreleasedChunks() final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ }
+
+ [[nodiscard]] size_t SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf) const final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ size_t size = 0;
+ if (mInitialChunk) {
+ size += mInitialChunk->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ if (mReleasedChunk) {
+ size += mReleasedChunk->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ // Note: Missing size of std::function external resources (if any).
+ return size;
+ }
+
+ [[nodiscard]] size_t SizeOfIncludingThis(
+ MallocSizeOf aMallocSizeOf) const final {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ protected:
+ // This manager is not thread-safe, so there's not actual locking needed.
+ const ProfileBufferChunk* PeekExtantReleasedChunksAndLock() final {
+ MOZ_ASSERT(mVirtuallyLocked.compareExchange(false, true));
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return mReleasedChunk.get();
+ }
+ void UnlockAfterPeekExtantReleasedChunks() final {
+ MOZ_ASSERT(mVirtuallyLocked.compareExchange(true, false));
+ }
+
+ private:
+ // Initial chunk created with this manager, given away at first Get/Request.
+ UniquePtr<ProfileBufferChunk> mInitialChunk;
+
+ // Storage for the released chunk (which should probably not happen, as it
+ // means the chunk is full).
+ UniquePtr<ProfileBufferChunk> mReleasedChunk;
+
+ // Size of the one chunk we're managing. Stored here, because the chunk may
+ // be moved out and inaccessible from here.
+ Length mBufferBytes;
+
+ // The chunk-destroyed callback will never actually be called, but we keep it
+ // here in case the caller expects it to live as long as this manager.
+ std::function<void(const ProfileBufferChunk&)> mChunkDestroyedCallback;
+
+#ifdef DEBUG
+ mutable Atomic<bool> mVirtuallyLocked{false};
+#endif // DEBUG
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferChunkManagerSingle_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.h b/mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.h
new file mode 100644
index 0000000000..034279809d
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.h
@@ -0,0 +1,444 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferChunkManagerWithLocalLimit_h
+#define ProfileBufferChunkManagerWithLocalLimit_h
+
+#include "BaseProfiler.h"
+#include "mozilla/BaseProfilerDetail.h"
+#include "mozilla/ProfileBufferChunkManager.h"
+#include "mozilla/ProfileBufferControlledChunkManager.h"
+#include "mozilla/mozalloc.h"
+
+#include <utility>
+
+namespace mozilla {
+
+// Manages the Chunks for this process in a thread-safe manner, with a maximum
+// size per process.
+//
+// "Unreleased" chunks are not owned here, only "released" chunks can be
+// destroyed or recycled when reaching the memory limit, so it is theoretically
+// possible to break that limit, if:
+// - The user of this class doesn't release their chunks, AND/OR
+// - The limit is too small (e.g., smaller than 2 or 3 chunks, which should be
+// the usual number of unreleased chunks in flight).
+// In this case, it just means that we will use more memory than allowed,
+// potentially risking OOMs. Hopefully this shouldn't happen in real code,
+// assuming that the user is doing the right thing and releasing chunks ASAP,
+// and that the memory limit is reasonably large.
+class ProfileBufferChunkManagerWithLocalLimit final
+ : public ProfileBufferChunkManager,
+ public ProfileBufferControlledChunkManager {
+ public:
+ using Length = ProfileBufferChunk::Length;
+
+ // MaxTotalBytes: Maximum number of bytes allocated in all local Chunks.
+ // ChunkMinBufferBytes: Minimum number of user-available bytes in each Chunk.
+ // Note that Chunks use a bit more memory for their header.
+ explicit ProfileBufferChunkManagerWithLocalLimit(size_t aMaxTotalBytes,
+ Length aChunkMinBufferBytes)
+ : mMaxTotalBytes(aMaxTotalBytes),
+ mChunkMinBufferBytes(aChunkMinBufferBytes) {}
+
+ ~ProfileBufferChunkManagerWithLocalLimit() {
+ if (mUpdateCallback) {
+ // Signal the end of this callback.
+ std::move(mUpdateCallback)(Update(nullptr));
+ }
+ }
+
+ [[nodiscard]] size_t MaxTotalSize() const final {
+ // `mMaxTotalBytes` is `const` so there is no need to lock the mutex.
+ return mMaxTotalBytes;
+ }
+
+ [[nodiscard]] size_t TotalSize() const { return mTotalBytes; }
+
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> GetChunk() final {
+ AUTO_PROFILER_STATS(Local_GetChunk);
+
+ ChunkAndUpdate chunkAndUpdate = [&]() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ return GetChunk(lock);
+ }();
+
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback && !chunkAndUpdate.second.IsNotUpdate()) {
+ mUpdateCallback(std::move(chunkAndUpdate.second));
+ }
+
+ return std::move(chunkAndUpdate.first);
+ }
+
+ void RequestChunk(std::function<void(UniquePtr<ProfileBufferChunk>)>&&
+ aChunkReceiver) final {
+ AUTO_PROFILER_STATS(Local_RequestChunk);
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ if (mChunkReceiver) {
+ // We already have a chunk receiver, meaning a request is pending.
+ return;
+ }
+ // Store the chunk receiver. This indicates that a request is pending, and
+ // it will be handled in the next `FulfillChunkRequests()` call.
+ mChunkReceiver = std::move(aChunkReceiver);
+ }
+
+ void FulfillChunkRequests() final {
+ AUTO_PROFILER_STATS(Local_FulfillChunkRequests);
+ std::function<void(UniquePtr<ProfileBufferChunk>)> chunkReceiver;
+ ChunkAndUpdate chunkAndUpdate = [&]() -> ChunkAndUpdate {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ if (!mChunkReceiver) {
+ // No receiver means no pending request, we're done.
+ return {};
+ }
+ // Otherwise there is a request, extract the receiver to call below.
+ std::swap(chunkReceiver, mChunkReceiver);
+ MOZ_ASSERT(!mChunkReceiver, "mChunkReceiver should have been emptied");
+ // And allocate the requested chunk. This may fail, it's fine, we're
+ // letting the receiver know about it.
+ AUTO_PROFILER_STATS(Local_FulfillChunkRequests_GetChunk);
+ return GetChunk(lock);
+ }();
+
+ if (chunkReceiver) {
+ {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback && !chunkAndUpdate.second.IsNotUpdate()) {
+ mUpdateCallback(std::move(chunkAndUpdate.second));
+ }
+ }
+
+ // Invoke callback outside of lock, so that it can use other chunk manager
+ // functions if needed.
+ // Note that this means there could be a race, where another request
+ // happens now and even gets fulfilled before this one is! It should be
+ // rare, and shouldn't be a problem anyway, the user will still get their
+ // requested chunks, new/recycled chunks look the same so their order
+ // doesn't matter.
+ std::move(chunkReceiver)(std::move(chunkAndUpdate.first));
+ }
+ }
+
+ void ReleaseChunk(UniquePtr<ProfileBufferChunk> aChunk) final {
+ if (!aChunk) {
+ return;
+ }
+
+ MOZ_RELEASE_ASSERT(!aChunk->GetNext(), "ReleaseChunk only accepts 1 chunk");
+ MOZ_RELEASE_ASSERT(!aChunk->ChunkHeader().mDoneTimeStamp.IsNull(),
+ "Released chunk should have a 'Done' timestamp");
+
+ Update update = [&]() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ MOZ_ASSERT(mUser, "Not registered yet");
+ // Keep a pointer to the first newly-released chunk, so we can use it to
+ // prepare an update (after `aChunk` is moved-from).
+ const ProfileBufferChunk* const newlyReleasedChunk = aChunk.get();
+ // Transfer the chunk size from the unreleased bucket to the released one.
+ mUnreleasedBufferBytes -= aChunk->BufferBytes();
+ mReleasedBufferBytes += aChunk->BufferBytes();
+ if (!mReleasedChunks) {
+ // No other released chunks at the moment, we're starting the list.
+ MOZ_ASSERT(mReleasedBufferBytes == aChunk->BufferBytes());
+ mReleasedChunks = std::move(aChunk);
+ } else {
+ // Insert aChunk in mReleasedChunks to keep done-timestamp order.
+ const TimeStamp& releasedChunkDoneTimeStamp =
+ aChunk->ChunkHeader().mDoneTimeStamp;
+ if (releasedChunkDoneTimeStamp <
+ mReleasedChunks->ChunkHeader().mDoneTimeStamp) {
+ // aChunk is the oldest -> Insert at the beginning.
+ aChunk->SetLast(std::move(mReleasedChunks));
+ mReleasedChunks = std::move(aChunk);
+ } else {
+ // Go through the already-released chunk list, and insert aChunk
+ // before the first younger released chunk, or at the end.
+ ProfileBufferChunk* chunk = mReleasedChunks.get();
+ for (;;) {
+ ProfileBufferChunk* const nextChunk = chunk->GetNext();
+ if (!nextChunk || releasedChunkDoneTimeStamp <
+ nextChunk->ChunkHeader().mDoneTimeStamp) {
+ // Either we're at the last released chunk, or the next released
+ // chunk is younger -> Insert right after this released chunk.
+ chunk->InsertNext(std::move(aChunk));
+ break;
+ }
+ chunk = nextChunk;
+ }
+ }
+ }
+
+ return Update(mUnreleasedBufferBytes, mReleasedBufferBytes,
+ mReleasedChunks.get(), newlyReleasedChunk);
+ }();
+
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback && !update.IsNotUpdate()) {
+ mUpdateCallback(std::move(update));
+ }
+ }
+
+ void SetChunkDestroyedCallback(
+ std::function<void(const ProfileBufferChunk&)>&& aChunkDestroyedCallback)
+ final {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ MOZ_ASSERT(mUser, "Not registered yet");
+ mChunkDestroyedCallback = std::move(aChunkDestroyedCallback);
+ }
+
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> GetExtantReleasedChunks() final {
+ UniquePtr<ProfileBufferChunk> chunks;
+ size_t unreleasedBufferBytes = [&]() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ MOZ_ASSERT(mUser, "Not registered yet");
+ mReleasedBufferBytes = 0;
+ chunks = std::move(mReleasedChunks);
+ return mUnreleasedBufferBytes;
+ }();
+
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback) {
+ mUpdateCallback(Update(unreleasedBufferBytes, 0, nullptr, nullptr));
+ }
+
+ return chunks;
+ }
+
+ void ForgetUnreleasedChunks() final {
+ Update update = [&]() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ MOZ_ASSERT(mUser, "Not registered yet");
+ mUnreleasedBufferBytes = 0;
+ return Update(0, mReleasedBufferBytes, mReleasedChunks.get(), nullptr);
+ }();
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback) {
+ mUpdateCallback(std::move(update));
+ }
+ }
+
+ [[nodiscard]] size_t SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf) const final {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ return SizeOfExcludingThis(aMallocSizeOf, lock);
+ }
+
+ [[nodiscard]] size_t SizeOfIncludingThis(
+ MallocSizeOf aMallocSizeOf) const final {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf, lock);
+ }
+
+ void SetUpdateCallback(UpdateCallback&& aUpdateCallback) final {
+ {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ if (mUpdateCallback) {
+ // Signal the end of the previous callback.
+ std::move(mUpdateCallback)(Update(nullptr));
+ mUpdateCallback = nullptr;
+ }
+ }
+
+ if (aUpdateCallback) {
+ Update initialUpdate = [&]() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ return Update(mUnreleasedBufferBytes, mReleasedBufferBytes,
+ mReleasedChunks.get(), nullptr);
+ }();
+
+ baseprofiler::detail::BaseProfilerAutoLock lock(mUpdateCallbackMutex);
+ MOZ_ASSERT(!mUpdateCallback, "Only one update callback allowed");
+ mUpdateCallback = std::move(aUpdateCallback);
+ mUpdateCallback(std::move(initialUpdate));
+ }
+ }
+
+ void DestroyChunksAtOrBefore(TimeStamp aDoneTimeStamp) final {
+ MOZ_ASSERT(!aDoneTimeStamp.IsNull());
+ baseprofiler::detail::BaseProfilerAutoLock lock(mMutex);
+ for (;;) {
+ if (!mReleasedChunks) {
+ // We don't own any released chunks (anymore), we're done.
+ break;
+ }
+ if (mReleasedChunks->ChunkHeader().mDoneTimeStamp > aDoneTimeStamp) {
+ // The current chunk is strictly after the given timestamp, we're done.
+ break;
+ }
+ // We've found a chunk at or before the timestamp, discard it.
+ DiscardOldestReleasedChunk(lock);
+ }
+ }
+
+ protected:
+ const ProfileBufferChunk* PeekExtantReleasedChunksAndLock() final
+ MOZ_CAPABILITY_ACQUIRE(mMutex) {
+ mMutex.Lock();
+ MOZ_ASSERT(mUser, "Not registered yet");
+ return mReleasedChunks.get();
+ }
+ void UnlockAfterPeekExtantReleasedChunks() final
+ MOZ_CAPABILITY_RELEASE(mMutex) {
+ mMutex.Unlock();
+ }
+
+ private:
+ size_t MaybeRecycleChunkAndGetDeallocatedSize(
+ UniquePtr<ProfileBufferChunk>&& chunk,
+ const baseprofiler::detail::BaseProfilerAutoLock& aLock) {
+ // Try to recycle big-enough chunks. (All chunks should have the same size,
+ // but it's a cheap test and may allow future adjustments based on actual
+ // data rate.)
+ if (chunk->BufferBytes() >= mChunkMinBufferBytes) {
+ // We keep up to two recycled chunks at any time.
+ if (!mRecycledChunks) {
+ mRecycledChunks = std::move(chunk);
+ return 0;
+ } else if (!mRecycledChunks->GetNext()) {
+ mRecycledChunks->InsertNext(std::move(chunk));
+ return 0;
+ }
+ }
+ return moz_malloc_usable_size(chunk.get());
+ }
+
+ UniquePtr<ProfileBufferChunk> TakeRecycledChunk(
+ const baseprofiler::detail::BaseProfilerAutoLock& aLock) {
+ UniquePtr<ProfileBufferChunk> recycled;
+ if (mRecycledChunks) {
+ recycled = std::exchange(mRecycledChunks, mRecycledChunks->ReleaseNext());
+ recycled->MarkRecycled();
+ }
+ return recycled;
+ }
+
+ void DiscardOldestReleasedChunk(
+ const baseprofiler::detail::BaseProfilerAutoLock& aLock) {
+ MOZ_ASSERT(!!mReleasedChunks);
+ UniquePtr<ProfileBufferChunk> oldest =
+ std::exchange(mReleasedChunks, mReleasedChunks->ReleaseNext());
+ mReleasedBufferBytes -= oldest->BufferBytes();
+ if (mChunkDestroyedCallback) {
+ // Inform the user that we're going to destroy this chunk.
+ mChunkDestroyedCallback(*oldest);
+ }
+
+ mTotalBytes -=
+ MaybeRecycleChunkAndGetDeallocatedSize(std::move(oldest), aLock);
+ }
+
+ using ChunkAndUpdate = std::pair<UniquePtr<ProfileBufferChunk>, Update>;
+ [[nodiscard]] ChunkAndUpdate GetChunk(
+ const baseprofiler::detail::BaseProfilerAutoLock& aLock) {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ // After this function, the total memory consumption will be the sum of:
+ // - Bytes from released (i.e., full) chunks,
+ // - Bytes from unreleased (still in use) chunks,
+ // - Bytes from the chunk we want to create/recycle. (Note that we don't
+ // count the extra bytes of chunk header, and of extra allocation ability,
+ // for the new chunk, as it's assumed to be negligible compared to the
+ // total memory limit.)
+ // If this total is higher than the local limit, we'll want to destroy
+ // the oldest released chunks until we're under the limit; if any, we may
+ // recycle one of them to avoid a deallocation followed by an allocation.
+ while (mReleasedBufferBytes + mUnreleasedBufferBytes +
+ mChunkMinBufferBytes >=
+ mMaxTotalBytes &&
+ !!mReleasedChunks) {
+ // We have reached the local limit, discard the oldest released chunk.
+ DiscardOldestReleasedChunk(aLock);
+ }
+
+ // Extract the recycled chunk, if any.
+ ChunkAndUpdate chunkAndUpdate{TakeRecycledChunk(aLock), Update()};
+ UniquePtr<ProfileBufferChunk>& chunk = chunkAndUpdate.first;
+
+ if (!chunk) {
+ // No recycled chunk -> Create a chunk now. (This could still fail.)
+ chunk = ProfileBufferChunk::Create(mChunkMinBufferBytes);
+ mTotalBytes += moz_malloc_usable_size(chunk.get());
+ }
+
+ if (chunk) {
+ // We do have a chunk (recycled or new), record its size as "unreleased".
+ mUnreleasedBufferBytes += chunk->BufferBytes();
+
+ chunkAndUpdate.second =
+ Update(mUnreleasedBufferBytes, mReleasedBufferBytes,
+ mReleasedChunks.get(), nullptr);
+ }
+
+ return chunkAndUpdate;
+ }
+
+ [[nodiscard]] size_t SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf,
+ const baseprofiler::detail::BaseProfilerAutoLock&) const {
+ MOZ_ASSERT(mUser, "Not registered yet");
+ size_t size = 0;
+ if (mReleasedChunks) {
+ size += mReleasedChunks->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ if (mRecycledChunks) {
+ size += mRecycledChunks->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ // Note: Missing size of std::function external resources (if any).
+ return size;
+ }
+
+ // Maxumum number of bytes that should be used by all unreleased and released
+ // chunks. Note that only released chunks can be destroyed here, so it is the
+ // responsibility of the user to properly release their chunks when possible.
+ const size_t mMaxTotalBytes;
+
+ // Minimum number of bytes that new chunks should be able to store.
+ // Used when calling `ProfileBufferChunk::Create()`.
+ const Length mChunkMinBufferBytes;
+
+ // Mutex guarding the following members.
+ mutable baseprofiler::detail::BaseProfilerMutex mMutex;
+
+ // Number of bytes currently held in chunks that have been given away (through
+ // `GetChunk` or `RequestChunk`) and not released yet.
+ size_t mUnreleasedBufferBytes = 0;
+
+ // Number of bytes currently held in chunks that have been released and stored
+ // in `mReleasedChunks` below.
+ size_t mReleasedBufferBytes = 0;
+
+ // Total allocated size (used to substract it from memory counters).
+ size_t mTotalBytes = 0;
+
+ // List of all released chunks. The oldest one should be at the start of the
+ // list, and may be destroyed or recycled when the memory limit is reached.
+ UniquePtr<ProfileBufferChunk> mReleasedChunks;
+
+ // This may hold chunks that were released then slated for destruction, they
+ // will be reused next time an allocation would have been needed.
+ UniquePtr<ProfileBufferChunk> mRecycledChunks;
+
+ // Optional callback used to notify the user when a chunk is about to be
+ // destroyed or recycled. (The data content is always destroyed, but the chunk
+ // container may be reused.)
+ std::function<void(const ProfileBufferChunk&)> mChunkDestroyedCallback;
+
+ // Callback set from `RequestChunk()`, until it is serviced in
+ // `FulfillChunkRequests()`. There can only be one request in flight.
+ std::function<void(UniquePtr<ProfileBufferChunk>)> mChunkReceiver;
+
+ // Separate mutex guarding mUpdateCallback, so that it may be invoked outside
+ // of the main buffer `mMutex`.
+ mutable baseprofiler::detail::BaseProfilerMutex mUpdateCallbackMutex;
+
+ UpdateCallback mUpdateCallback;
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferChunkManagerWithLocalLimit_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferControlledChunkManager.h b/mozglue/baseprofiler/public/ProfileBufferControlledChunkManager.h
new file mode 100644
index 0000000000..45b39b163c
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferControlledChunkManager.h
@@ -0,0 +1,203 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferControlledChunkManager_h
+#define ProfileBufferControlledChunkManager_h
+
+#include "mozilla/ProfileBufferChunk.h"
+
+#include <functional>
+#include <vector>
+
+namespace mozilla {
+
+// A "Controlled" chunk manager will provide updates about chunks that it
+// creates, releases, and destroys; and it can destroy released chunks as
+// requested.
+class ProfileBufferControlledChunkManager {
+ public:
+ using Length = ProfileBufferChunk::Length;
+
+ virtual ~ProfileBufferControlledChunkManager() = default;
+
+ // Minimum amount of chunk metadata to be transferred between processes.
+ struct ChunkMetadata {
+ // Timestamp when chunk was marked "done", which is used to:
+ // - determine its age, so the oldest one will be destroyed first,
+ // - uniquely identify this chunk in this process. (The parent process is
+ // responsible for associating this timestamp to its process id.)
+ TimeStamp mDoneTimeStamp;
+ // Size of this chunk's buffer.
+ Length mBufferBytes;
+
+ ChunkMetadata(TimeStamp aDoneTimeStamp, Length aBufferBytes)
+ : mDoneTimeStamp(aDoneTimeStamp), mBufferBytes(aBufferBytes) {}
+ };
+
+ // Class collecting all information necessary to describe updates that
+ // happened in a chunk manager.
+ // An update can be folded into a previous update.
+ class Update {
+ public:
+ // Construct a "not-an-Update" object, which should only be used after a
+ // real update is folded into it.
+ Update() = default;
+
+ // Construct a "final" Update, which marks the end of all updates from a
+ // chunk manager.
+ explicit Update(decltype(nullptr)) : mUnreleasedBytes(FINAL) {}
+
+ // Construct an Update from the given data and released chunks.
+ // The chunk pointers may be null, and it doesn't matter if
+ // `aNewlyReleasedChunks` is already linked to `aExistingReleasedChunks` or
+ // not.
+ Update(size_t aUnreleasedBytes, size_t aReleasedBytes,
+ const ProfileBufferChunk* aExistingReleasedChunks,
+ const ProfileBufferChunk* aNewlyReleasedChunks)
+ : mUnreleasedBytes(aUnreleasedBytes),
+ mReleasedBytes(aReleasedBytes),
+ mOldestDoneTimeStamp(
+ aExistingReleasedChunks
+ ? aExistingReleasedChunks->ChunkHeader().mDoneTimeStamp
+ : TimeStamp{}) {
+ MOZ_RELEASE_ASSERT(
+ !IsNotUpdate(),
+ "Empty update should only be constructed with default constructor");
+ MOZ_RELEASE_ASSERT(
+ !IsFinal(),
+ "Final update should only be constructed with nullptr constructor");
+ for (const ProfileBufferChunk* chunk = aNewlyReleasedChunks; chunk;
+ chunk = chunk->GetNext()) {
+ mNewlyReleasedChunks.emplace_back(ChunkMetadata{
+ chunk->ChunkHeader().mDoneTimeStamp, chunk->BufferBytes()});
+ }
+ }
+
+ // Construct an Update from raw data.
+ // This may be used to re-construct an Update that was previously
+ // serialized.
+ Update(size_t aUnreleasedBytes, size_t aReleasedBytes,
+ TimeStamp aOldestDoneTimeStamp,
+ std::vector<ChunkMetadata>&& aNewlyReleasedChunks)
+ : mUnreleasedBytes(aUnreleasedBytes),
+ mReleasedBytes(aReleasedBytes),
+ mOldestDoneTimeStamp(aOldestDoneTimeStamp),
+ mNewlyReleasedChunks(std::move(aNewlyReleasedChunks)) {}
+
+ // Clear the Update completely and return it to a "not-an-Update" state.
+ void Clear() {
+ mUnreleasedBytes = NO_UPDATE;
+ mReleasedBytes = 0;
+ mOldestDoneTimeStamp = TimeStamp{};
+ mNewlyReleasedChunks.clear();
+ }
+
+ bool IsNotUpdate() const { return mUnreleasedBytes == NO_UPDATE; }
+
+ bool IsFinal() const { return mUnreleasedBytes == FINAL; }
+
+ size_t UnreleasedBytes() const {
+ MOZ_RELEASE_ASSERT(!IsNotUpdate(),
+ "Cannot access UnreleasedBytes from empty update");
+ MOZ_RELEASE_ASSERT(!IsFinal(),
+ "Cannot access UnreleasedBytes from final update");
+ return mUnreleasedBytes;
+ }
+
+ size_t ReleasedBytes() const {
+ MOZ_RELEASE_ASSERT(!IsNotUpdate(),
+ "Cannot access ReleasedBytes from empty update");
+ MOZ_RELEASE_ASSERT(!IsFinal(),
+ "Cannot access ReleasedBytes from final update");
+ return mReleasedBytes;
+ }
+
+ TimeStamp OldestDoneTimeStamp() const {
+ MOZ_RELEASE_ASSERT(!IsNotUpdate(),
+ "Cannot access OldestDoneTimeStamp from empty update");
+ MOZ_RELEASE_ASSERT(!IsFinal(),
+ "Cannot access OldestDoneTimeStamp from final update");
+ return mOldestDoneTimeStamp;
+ }
+
+ const std::vector<ChunkMetadata>& NewlyReleasedChunksRef() const {
+ MOZ_RELEASE_ASSERT(
+ !IsNotUpdate(),
+ "Cannot access NewlyReleasedChunksRef from empty update");
+ MOZ_RELEASE_ASSERT(
+ !IsFinal(), "Cannot access NewlyReleasedChunksRef from final update");
+ return mNewlyReleasedChunks;
+ }
+
+ // Fold a later update into this one.
+ void Fold(Update&& aNewUpdate) {
+ MOZ_ASSERT(
+ !IsFinal() || aNewUpdate.IsFinal(),
+ "There shouldn't be another non-final update after the final update");
+
+ if (IsNotUpdate() || aNewUpdate.IsFinal()) {
+ // We were empty, or the new update is the final update, we just switch
+ // to that new update.
+ *this = std::move(aNewUpdate);
+ return;
+ }
+
+ mUnreleasedBytes = aNewUpdate.mUnreleasedBytes;
+ mReleasedBytes = aNewUpdate.mReleasedBytes;
+ if (!aNewUpdate.mOldestDoneTimeStamp.IsNull()) {
+ MOZ_ASSERT(mOldestDoneTimeStamp.IsNull() ||
+ mOldestDoneTimeStamp <= aNewUpdate.mOldestDoneTimeStamp);
+ mOldestDoneTimeStamp = aNewUpdate.mOldestDoneTimeStamp;
+ auto it = mNewlyReleasedChunks.begin();
+ while (it != mNewlyReleasedChunks.end() &&
+ it->mDoneTimeStamp < mOldestDoneTimeStamp) {
+ it = mNewlyReleasedChunks.erase(it);
+ }
+ }
+ if (!aNewUpdate.mNewlyReleasedChunks.empty()) {
+ mNewlyReleasedChunks.reserve(mNewlyReleasedChunks.size() +
+ aNewUpdate.mNewlyReleasedChunks.size());
+ mNewlyReleasedChunks.insert(mNewlyReleasedChunks.end(),
+ aNewUpdate.mNewlyReleasedChunks.begin(),
+ aNewUpdate.mNewlyReleasedChunks.end());
+ }
+ }
+
+ private:
+ static const size_t NO_UPDATE = size_t(-1);
+ static const size_t FINAL = size_t(-2);
+
+ size_t mUnreleasedBytes = NO_UPDATE;
+ size_t mReleasedBytes = 0;
+ TimeStamp mOldestDoneTimeStamp;
+ std::vector<ChunkMetadata> mNewlyReleasedChunks;
+ };
+
+ using UpdateCallback = std::function<void(Update&&)>;
+
+ // This *may* be set (or reset) by an object that needs to know about all
+ // chunk updates that happen in this manager. The main use will be to
+ // coordinate the global memory usage of Firefox.
+ // If a non-empty callback is given, it will be immediately invoked with the
+ // current state.
+ // When the callback is about to be destroyed (by overwriting it here, or in
+ // the class destructor), it will be invoked one last time with an empty
+ // update.
+ // Note that the callback (even the first current-state callback) will be
+ // invoked from inside a locked scope, so it should *not* call other functions
+ // of the chunk manager. A side benefit of this locking is that it guarantees
+ // that no two invocations can overlap.
+ virtual void SetUpdateCallback(UpdateCallback&& aUpdateCallback) = 0;
+
+ // This is a request to destroy all chunks before the given timestamp.
+ // This timestamp should be one that was given in a previous UpdateCallback
+ // call. Obviously, only released chunks can be destroyed.
+ virtual void DestroyChunksAtOrBefore(TimeStamp aDoneTimeStamp) = 0;
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferControlledChunkManager_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferEntryKinds.h b/mozglue/baseprofiler/public/ProfileBufferEntryKinds.h
new file mode 100644
index 0000000000..cd5912c49b
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferEntryKinds.h
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferEntryKinds_h
+#define ProfileBufferEntryKinds_h
+
+#include "mozilla/BaseProfilerUtils.h"
+
+#include <cstdint>
+
+namespace mozilla {
+
+// This is equal to sizeof(double), which is the largest non-char variant in
+// |u|.
+static constexpr size_t ProfileBufferEntryNumChars = 8;
+
+// NOTE! If you add entries, you need to verify if they need to be added to the
+// switch statement in DuplicateLastSample!
+// This will evaluate the MACRO with (KIND, TYPE, SIZE)
+#define FOR_EACH_PROFILE_BUFFER_ENTRY_KIND(MACRO) \
+ MACRO(CategoryPair, int, sizeof(int)) \
+ MACRO(CollectionStart, double, sizeof(double)) \
+ MACRO(CollectionEnd, double, sizeof(double)) \
+ MACRO(Label, const char*, sizeof(const char*)) \
+ MACRO(FrameFlags, uint64_t, sizeof(uint64_t)) \
+ MACRO(DynamicStringFragment, char*, ProfileBufferEntryNumChars) \
+ MACRO(JitReturnAddr, void*, sizeof(void*)) \
+ MACRO(InnerWindowID, uint64_t, sizeof(uint64_t)) \
+ MACRO(LineNumber, int, sizeof(int)) \
+ MACRO(ColumnNumber, int, sizeof(int)) \
+ MACRO(NativeLeafAddr, void*, sizeof(void*)) \
+ MACRO(Pause, double, sizeof(double)) \
+ MACRO(Resume, double, sizeof(double)) \
+ MACRO(PauseSampling, double, sizeof(double)) \
+ MACRO(ResumeSampling, double, sizeof(double)) \
+ MACRO(Responsiveness, double, sizeof(double)) \
+ MACRO(ThreadId, ::mozilla::baseprofiler::BaseProfilerThreadId, \
+ sizeof(::mozilla::baseprofiler::BaseProfilerThreadId)) \
+ MACRO(Time, double, sizeof(double)) \
+ MACRO(TimeBeforeCompactStack, double, sizeof(double)) \
+ MACRO(TimeBeforeSameSample, double, sizeof(double)) \
+ MACRO(CounterId, void*, sizeof(void*)) \
+ MACRO(CounterKey, uint64_t, sizeof(uint64_t)) \
+ MACRO(Number, uint64_t, sizeof(uint64_t)) \
+ MACRO(Count, int64_t, sizeof(int64_t)) \
+ MACRO(ProfilerOverheadTime, double, sizeof(double)) \
+ MACRO(ProfilerOverheadDuration, double, sizeof(double))
+
+// The `Kind` is a single byte identifying the type of data that is actually
+// stored in a `ProfileBufferEntry`, as per the list in
+// `FOR_EACH_PROFILE_BUFFER_ENTRY_KIND`.
+//
+// This byte is also used to identify entries in ProfileChunkedBuffer blocks,
+// for both "legacy" entries that do contain a `ProfileBufferEntry`, and for
+// new types of entries that may carry more data of different types.
+// TODO: Eventually each type of "legacy" entry should be replaced with newer,
+// more efficient kinds of entries (e.g., stack frames could be stored in one
+// bigger entry, instead of multiple `ProfileBufferEntry`s); then we could
+// discard `ProfileBufferEntry` and move this enum to a more appropriate spot.
+enum class ProfileBufferEntryKind : uint8_t {
+ INVALID = 0,
+#define KIND(KIND, TYPE, SIZE) KIND,
+ FOR_EACH_PROFILE_BUFFER_ENTRY_KIND(KIND)
+#undef KIND
+
+ // Any value under `LEGACY_LIMIT` represents a `ProfileBufferEntry`.
+ LEGACY_LIMIT,
+
+ // Any value starting here does *not* represent a `ProfileBufferEntry` and
+ // requires separate decoding and handling.
+
+ // Markers and their data.
+ Marker = LEGACY_LIMIT,
+
+ // Entry with "running times", such as CPU usage measurements.
+ // Optional between TimeBeforeX and X.
+ RunningTimes,
+
+ // Optional between TimeBeforeX and X.
+ UnresponsiveDurationMs,
+
+ // Collection of legacy stack entries, must follow a ThreadId and
+ // TimeBeforeCompactStack (which are not included in the CompactStack;
+ // TimeBeforeCompactStack is equivalent to Time, but indicates that a
+ // CompactStack follows shortly afterwards).
+ CompactStack,
+
+ // Indicates that this sample is identical to the previous one, must follow a
+ // ThreadId and TimeBeforeSameSample.
+ SameSample,
+
+ MODERN_LIMIT
+};
+
+enum class MarkerPayloadType : uint8_t {
+ Cpp,
+ Rust,
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferEntryKinds_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferEntrySerialization.h b/mozglue/baseprofiler/public/ProfileBufferEntrySerialization.h
new file mode 100644
index 0000000000..bdb3b54d41
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferEntrySerialization.h
@@ -0,0 +1,1184 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferEntrySerialization_h
+#define ProfileBufferEntrySerialization_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/leb128iterator.h"
+#include "mozilla/Likely.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/ProfileBufferIndex.h"
+#include "mozilla/Span.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/Unused.h"
+#include "mozilla/Variant.h"
+
+#include <string>
+#include <tuple>
+
+namespace mozilla {
+
+class ProfileBufferEntryWriter;
+
+// Iterator-like class used to read from an entry.
+// An entry may be split in two memory segments (e.g., the ends of a ring
+// buffer, or two chunks of a chunked buffer); it doesn't deal with this
+// underlying buffer, but only with one or two spans pointing at the space
+// where the entry lives.
+class ProfileBufferEntryReader {
+ public:
+ using Byte = uint8_t;
+ using Length = uint32_t;
+
+ using SpanOfConstBytes = Span<const Byte>;
+
+ // Class to be specialized for types to be read from a profile buffer entry.
+ // See common specializations at the bottom of this header.
+ // The following static functions must be provided:
+ // static void ReadInto(EntryReader aER&, T& aT)
+ // {
+ // /* Call `aER.ReadX(...)` function to deserialize into aT, be sure to
+ // read exactly `Bytes(aT)`! */
+ // }
+ // static T Read(EntryReader& aER) {
+ // /* Call `aER.ReadX(...)` function to deserialize and return a `T`, be
+ // sure to read exactly `Bytes(returned value)`! */
+ // }
+ template <typename T>
+ struct Deserializer;
+
+ ProfileBufferEntryReader() = default;
+
+ // Reader over one Span.
+ ProfileBufferEntryReader(SpanOfConstBytes aSpan,
+ ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex)
+ : mCurrentSpan(aSpan),
+ mNextSpanOrEmpty(aSpan.Last(0)),
+ mCurrentBlockIndex(aCurrentBlockIndex),
+ mNextBlockIndex(aNextBlockIndex) {
+ // 2nd internal Span points at the end of the 1st internal Span, to enforce
+ // invariants.
+ CheckInvariants();
+ }
+
+ // Reader over two Spans, the second one must not be empty.
+ ProfileBufferEntryReader(SpanOfConstBytes aSpanHead,
+ SpanOfConstBytes aSpanTail,
+ ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex)
+ : mCurrentSpan(aSpanHead),
+ mNextSpanOrEmpty(aSpanTail),
+ mCurrentBlockIndex(aCurrentBlockIndex),
+ mNextBlockIndex(aNextBlockIndex) {
+ MOZ_RELEASE_ASSERT(!mNextSpanOrEmpty.IsEmpty());
+ if (MOZ_UNLIKELY(mCurrentSpan.IsEmpty())) {
+ // First span is already empty, skip it.
+ mCurrentSpan = mNextSpanOrEmpty;
+ mNextSpanOrEmpty = mNextSpanOrEmpty.Last(0);
+ }
+ CheckInvariants();
+ }
+
+ // Allow copying, which is needed when used as an iterator in some std
+ // functions (e.g., string assignment), and to occasionally backtrack.
+ // Be aware that the main profile buffer APIs give a reference to an entry
+ // reader, and expect that reader to advance to the end of the entry, so don't
+ // just advance copies!
+ ProfileBufferEntryReader(const ProfileBufferEntryReader&) = default;
+ ProfileBufferEntryReader& operator=(const ProfileBufferEntryReader&) =
+ default;
+
+ // Don't =default moving, as it doesn't bring any benefit in this class.
+
+ [[nodiscard]] Length RemainingBytes() const {
+ return mCurrentSpan.LengthBytes() + mNextSpanOrEmpty.LengthBytes();
+ }
+
+ void SetRemainingBytes(Length aBytes) {
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ if (aBytes <= mCurrentSpan.LengthBytes()) {
+ mCurrentSpan = mCurrentSpan.First(aBytes);
+ mNextSpanOrEmpty = mCurrentSpan.Last(0);
+ } else {
+ mNextSpanOrEmpty =
+ mNextSpanOrEmpty.First(aBytes - mCurrentSpan.LengthBytes());
+ }
+ }
+
+ [[nodiscard]] ProfileBufferBlockIndex CurrentBlockIndex() const {
+ return mCurrentBlockIndex;
+ }
+
+ [[nodiscard]] ProfileBufferBlockIndex NextBlockIndex() const {
+ return mNextBlockIndex;
+ }
+
+ // Create a reader of size zero, pointing at aOffset past the current position
+ // of this Reader, so it can be used as end iterator.
+ [[nodiscard]] ProfileBufferEntryReader EmptyIteratorAtOffset(
+ Length aOffset) const {
+ MOZ_RELEASE_ASSERT(aOffset <= RemainingBytes());
+ if (MOZ_LIKELY(aOffset < mCurrentSpan.LengthBytes())) {
+ // aOffset is before the end of mCurrentSpan.
+ return ProfileBufferEntryReader(mCurrentSpan.Subspan(aOffset, 0),
+ mCurrentBlockIndex, mNextBlockIndex);
+ }
+ // aOffset is right at the end of mCurrentSpan, or inside mNextSpanOrEmpty.
+ return ProfileBufferEntryReader(
+ mNextSpanOrEmpty.Subspan(aOffset - mCurrentSpan.LengthBytes(), 0),
+ mCurrentBlockIndex, mNextBlockIndex);
+ }
+
+ // Be like a limited input iterator, with only `*`, prefix-`++`, `==`, `!=`.
+ // These definitions are expected by std functions, to recognize this as an
+ // iterator. See https://en.cppreference.com/w/cpp/iterator/iterator_traits
+ using difference_type = std::make_signed_t<Length>;
+ using value_type = Byte;
+ using pointer = const Byte*;
+ using reference = const Byte&;
+ using iterator_category = std::input_iterator_tag;
+
+ [[nodiscard]] const Byte& operator*() {
+ // Assume the caller will read from the returned reference (and not just
+ // take the address).
+ MOZ_RELEASE_ASSERT(mCurrentSpan.LengthBytes() >= 1);
+ return *(mCurrentSpan.Elements());
+ }
+
+ ProfileBufferEntryReader& operator++() {
+ MOZ_RELEASE_ASSERT(mCurrentSpan.LengthBytes() >= 1);
+ if (MOZ_LIKELY(mCurrentSpan.LengthBytes() > 1)) {
+ // More than 1 byte left in mCurrentSpan, just eat it.
+ mCurrentSpan = mCurrentSpan.From(1);
+ } else {
+ // mCurrentSpan will be empty, move mNextSpanOrEmpty to mCurrentSpan.
+ mCurrentSpan = mNextSpanOrEmpty;
+ mNextSpanOrEmpty = mNextSpanOrEmpty.Last(0);
+ }
+ CheckInvariants();
+ return *this;
+ }
+
+ ProfileBufferEntryReader& operator+=(Length aBytes) {
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ if (MOZ_LIKELY(aBytes <= mCurrentSpan.LengthBytes())) {
+ // All bytes are in mCurrentSpan.
+ // Update mCurrentSpan past the read bytes.
+ mCurrentSpan = mCurrentSpan.From(aBytes);
+ if (mCurrentSpan.IsEmpty() && !mNextSpanOrEmpty.IsEmpty()) {
+ // Don't leave mCurrentSpan empty, move non-empty mNextSpanOrEmpty into
+ // mCurrentSpan.
+ mCurrentSpan = mNextSpanOrEmpty;
+ mNextSpanOrEmpty = mNextSpanOrEmpty.Last(0);
+ }
+ } else {
+ // mCurrentSpan does not hold enough bytes.
+ // This should only happen at most once: Only for double spans, and when
+ // data crosses the gap.
+ const Length tail =
+ aBytes - static_cast<Length>(mCurrentSpan.LengthBytes());
+ // Move mNextSpanOrEmpty to mCurrentSpan, past the data. So the next call
+ // will go back to the true case above.
+ mCurrentSpan = mNextSpanOrEmpty.From(tail);
+ mNextSpanOrEmpty = mNextSpanOrEmpty.Last(0);
+ }
+ CheckInvariants();
+ return *this;
+ }
+
+ [[nodiscard]] bool operator==(const ProfileBufferEntryReader& aOther) const {
+ return mCurrentSpan.Elements() == aOther.mCurrentSpan.Elements();
+ }
+ [[nodiscard]] bool operator!=(const ProfileBufferEntryReader& aOther) const {
+ return mCurrentSpan.Elements() != aOther.mCurrentSpan.Elements();
+ }
+
+ // Read an unsigned LEB128 number and move iterator ahead.
+ template <typename T>
+ [[nodiscard]] T ReadULEB128() {
+ return ::mozilla::ReadULEB128<T>(*this);
+ }
+
+ // This struct points at a number of bytes through either one span, or two
+ // separate spans (in the rare cases when it is split between two chunks).
+ // So the possibilities are:
+ // - Totally empty: { [] [] }
+ // - First span is not empty: { [content] [] } (Most common case.)
+ // - Both spans are not empty: { [cont] [ent] }
+ // But something like { [] [content] } is not possible.
+ //
+ // Recommended usage patterns:
+ // - Call a utility function like `CopyBytesTo` if you always need to copy the
+ // data to an outside buffer, e.g., to deserialize an aligned object.
+ // - Access both spans one after the other; Note that the second one may be
+ // empty; and the fist could be empty as well if there is no data at all.
+ // - Check is the second span is empty, in which case you only need to read
+ // the first one; and since its part of a chunk, it may be directly passed
+ // as an unaligned pointer or reference, thereby saving one copy. But
+ // remember to always handle the double-span case as well.
+ //
+ // Reminder: An empty span still has a non-null pointer, so it's safe to use
+ // with functions like memcpy.
+ struct DoubleSpanOfConstBytes {
+ SpanOfConstBytes mFirstOrOnly;
+ SpanOfConstBytes mSecondOrEmpty;
+
+ void CheckInvariants() const {
+ MOZ_ASSERT(mFirstOrOnly.IsEmpty() ? mSecondOrEmpty.IsEmpty() : true,
+ "mSecondOrEmpty should not be the only span to contain data");
+ }
+
+ DoubleSpanOfConstBytes() : mFirstOrOnly(), mSecondOrEmpty() {
+ CheckInvariants();
+ }
+
+ DoubleSpanOfConstBytes(const Byte* aOnlyPointer, size_t aOnlyLength)
+ : mFirstOrOnly(aOnlyPointer, aOnlyLength), mSecondOrEmpty() {
+ CheckInvariants();
+ }
+
+ DoubleSpanOfConstBytes(const Byte* aFirstPointer, size_t aFirstLength,
+ const Byte* aSecondPointer, size_t aSecondLength)
+ : mFirstOrOnly(aFirstPointer, aFirstLength),
+ mSecondOrEmpty(aSecondPointer, aSecondLength) {
+ CheckInvariants();
+ }
+
+ // Is there no data at all?
+ [[nodiscard]] bool IsEmpty() const {
+ // We only need to check the first span, because if it's empty, the second
+ // one must be empty as well.
+ return mFirstOrOnly.IsEmpty();
+ }
+
+ // Total length (in bytes) pointed at by both spans.
+ [[nodiscard]] size_t LengthBytes() const {
+ return mFirstOrOnly.LengthBytes() + mSecondOrEmpty.LengthBytes();
+ }
+
+ // Utility functions to copy all `LengthBytes()` to a given buffer.
+ void CopyBytesTo(void* aDest) const {
+ memcpy(aDest, mFirstOrOnly.Elements(), mFirstOrOnly.LengthBytes());
+ if (MOZ_UNLIKELY(!mSecondOrEmpty.IsEmpty())) {
+ memcpy(static_cast<Byte*>(aDest) + mFirstOrOnly.LengthBytes(),
+ mSecondOrEmpty.Elements(), mSecondOrEmpty.LengthBytes());
+ }
+ }
+
+ // If the second span is empty, only the first span may point at data.
+ [[nodiscard]] bool IsSingleSpan() const { return mSecondOrEmpty.IsEmpty(); }
+ };
+
+ // Get Span(s) to a sequence of bytes, see `DoubleSpanOfConstBytes` for usage.
+ // Note that the reader location is *not* updated, do `+=` on it afterwards.
+ [[nodiscard]] DoubleSpanOfConstBytes PeekSpans(Length aBytes) const {
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ if (MOZ_LIKELY(aBytes <= mCurrentSpan.LengthBytes())) {
+ // All `aBytes` are in the current chunk, only one span is needed.
+ return DoubleSpanOfConstBytes{mCurrentSpan.Elements(), aBytes};
+ }
+ // Otherwise the first span covers then end of the current chunk, and the
+ // second span starts in the next chunk.
+ return DoubleSpanOfConstBytes{
+ mCurrentSpan.Elements(), mCurrentSpan.LengthBytes(),
+ mNextSpanOrEmpty.Elements(), aBytes - mCurrentSpan.LengthBytes()};
+ }
+
+ // Get Span(s) to a sequence of bytes, see `DoubleSpanOfConstBytes` for usage,
+ // and move the reader forward.
+ [[nodiscard]] DoubleSpanOfConstBytes ReadSpans(Length aBytes) {
+ DoubleSpanOfConstBytes spans = PeekSpans(aBytes);
+ (*this) += aBytes;
+ return spans;
+ }
+
+ // Read a sequence of bytes, like memcpy.
+ void ReadBytes(void* aDest, Length aBytes) {
+ DoubleSpanOfConstBytes spans = ReadSpans(aBytes);
+ MOZ_ASSERT(spans.LengthBytes() == aBytes);
+ spans.CopyBytesTo(aDest);
+ }
+
+ template <typename T>
+ void ReadIntoObject(T& aObject) {
+ Deserializer<T>::ReadInto(*this, aObject);
+ }
+
+ // Read into one or more objects, sequentially.
+ // `EntryReader::ReadIntoObjects()` with nothing is implicitly allowed, this
+ // could be useful for generic programming.
+ template <typename... Ts>
+ void ReadIntoObjects(Ts&... aTs) {
+ (ReadIntoObject(aTs), ...);
+ }
+
+ // Read data as an object and move iterator ahead.
+ template <typename T>
+ [[nodiscard]] T ReadObject() {
+ T ob = Deserializer<T>::Read(*this);
+ return ob;
+ }
+
+ private:
+ friend class ProfileBufferEntryWriter;
+
+ // Invariants:
+ // - mCurrentSpan cannot be empty unless mNextSpanOrEmpty is also empty. So
+ // mCurrentSpan always points at the next byte to read or the end.
+ // - If mNextSpanOrEmpty is empty, it points at the end of mCurrentSpan. So
+ // when reaching the end of mCurrentSpan, we can blindly move
+ // mNextSpanOrEmpty to mCurrentSpan and keep the invariants.
+ SpanOfConstBytes mCurrentSpan;
+ SpanOfConstBytes mNextSpanOrEmpty;
+ ProfileBufferBlockIndex mCurrentBlockIndex;
+ ProfileBufferBlockIndex mNextBlockIndex;
+
+ void CheckInvariants() const {
+ MOZ_ASSERT(!mCurrentSpan.IsEmpty() || mNextSpanOrEmpty.IsEmpty());
+ MOZ_ASSERT(!mNextSpanOrEmpty.IsEmpty() ||
+ (mNextSpanOrEmpty == mCurrentSpan.Last(0)));
+ }
+};
+
+// Iterator-like class used to write into an entry.
+// An entry may be split in two memory segments (e.g., the ends of a ring
+// buffer, or two chunks of a chunked buffer); it doesn't deal with this
+// underlying buffer, but only with one or two spans pointing at the space
+// reserved for the entry.
+class ProfileBufferEntryWriter {
+ public:
+ using Byte = uint8_t;
+ using Length = uint32_t;
+
+ using SpanOfBytes = Span<Byte>;
+
+ // Class to be specialized for types to be written in an entry.
+ // See common specializations at the bottom of this header.
+ // The following static functions must be provided:
+ // static Length Bytes(const T& aT) {
+ // /* Return number of bytes that will be written. */
+ // }
+ // static void Write(ProfileBufferEntryWriter& aEW,
+ // const T& aT) {
+ // /* Call `aEW.WriteX(...)` functions to serialize aT, be sure to write
+ // exactly `Bytes(aT)` bytes! */
+ // }
+ template <typename T>
+ struct Serializer;
+
+ ProfileBufferEntryWriter() = default;
+
+ ProfileBufferEntryWriter(SpanOfBytes aSpan,
+ ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex)
+ : mCurrentSpan(aSpan),
+ mCurrentBlockIndex(aCurrentBlockIndex),
+ mNextBlockIndex(aNextBlockIndex) {}
+
+ ProfileBufferEntryWriter(SpanOfBytes aSpanHead, SpanOfBytes aSpanTail,
+ ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex)
+ : mCurrentSpan(aSpanHead),
+ mNextSpanOrEmpty(aSpanTail),
+ mCurrentBlockIndex(aCurrentBlockIndex),
+ mNextBlockIndex(aNextBlockIndex) {
+ // Either:
+ // - mCurrentSpan is not empty, OR
+ // - mNextSpanOrEmpty is empty if mNextSpanOrEmpty is empty as well.
+ MOZ_RELEASE_ASSERT(!mCurrentSpan.IsEmpty() || mNextSpanOrEmpty.IsEmpty());
+ }
+
+ // Disable copying and moving, so we can't have multiple writing heads.
+ ProfileBufferEntryWriter(const ProfileBufferEntryWriter&) = delete;
+ ProfileBufferEntryWriter& operator=(const ProfileBufferEntryWriter&) = delete;
+ ProfileBufferEntryWriter(ProfileBufferEntryWriter&&) = delete;
+ ProfileBufferEntryWriter& operator=(ProfileBufferEntryWriter&&) = delete;
+
+ void Set() {
+ mCurrentSpan = SpanOfBytes{};
+ mNextSpanOrEmpty = SpanOfBytes{};
+ mCurrentBlockIndex = nullptr;
+ mNextBlockIndex = nullptr;
+ }
+
+ void Set(SpanOfBytes aSpan, ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex) {
+ mCurrentSpan = aSpan;
+ mNextSpanOrEmpty = SpanOfBytes{};
+ mCurrentBlockIndex = aCurrentBlockIndex;
+ mNextBlockIndex = aNextBlockIndex;
+ }
+
+ void Set(SpanOfBytes aSpan0, SpanOfBytes aSpan1,
+ ProfileBufferBlockIndex aCurrentBlockIndex,
+ ProfileBufferBlockIndex aNextBlockIndex) {
+ mCurrentSpan = aSpan0;
+ mNextSpanOrEmpty = aSpan1;
+ mCurrentBlockIndex = aCurrentBlockIndex;
+ mNextBlockIndex = aNextBlockIndex;
+ // Either:
+ // - mCurrentSpan is not empty, OR
+ // - mNextSpanOrEmpty is empty if mNextSpanOrEmpty is empty as well.
+ MOZ_RELEASE_ASSERT(!mCurrentSpan.IsEmpty() || mNextSpanOrEmpty.IsEmpty());
+ }
+
+ [[nodiscard]] Length RemainingBytes() const {
+ return mCurrentSpan.LengthBytes() + mNextSpanOrEmpty.LengthBytes();
+ }
+
+ [[nodiscard]] ProfileBufferBlockIndex CurrentBlockIndex() const {
+ return mCurrentBlockIndex;
+ }
+
+ [[nodiscard]] ProfileBufferBlockIndex NextBlockIndex() const {
+ return mNextBlockIndex;
+ }
+
+ // Be like a limited output iterator, with only `*` and prefix-`++`.
+ // These definitions are expected by std functions, to recognize this as an
+ // iterator. See https://en.cppreference.com/w/cpp/iterator/iterator_traits
+ using value_type = Byte;
+ using pointer = Byte*;
+ using reference = Byte&;
+ using iterator_category = std::output_iterator_tag;
+
+ [[nodiscard]] Byte& operator*() {
+ MOZ_RELEASE_ASSERT(RemainingBytes() >= 1);
+ return *(
+ (MOZ_LIKELY(!mCurrentSpan.IsEmpty()) ? mCurrentSpan : mNextSpanOrEmpty)
+ .Elements());
+ }
+
+ ProfileBufferEntryWriter& operator++() {
+ if (MOZ_LIKELY(mCurrentSpan.LengthBytes() >= 1)) {
+ // There is at least 1 byte in mCurrentSpan, eat it.
+ mCurrentSpan = mCurrentSpan.From(1);
+ } else {
+ // mCurrentSpan is empty, move mNextSpanOrEmpty (past the first byte) to
+ // mCurrentSpan.
+ MOZ_RELEASE_ASSERT(mNextSpanOrEmpty.LengthBytes() >= 1);
+ mCurrentSpan = mNextSpanOrEmpty.From(1);
+ mNextSpanOrEmpty = mNextSpanOrEmpty.First(0);
+ }
+ return *this;
+ }
+
+ ProfileBufferEntryWriter& operator+=(Length aBytes) {
+ // Note: This is a rare operation. The code below is a copy of `WriteBytes`
+ // but without the `memcpy`s.
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ if (MOZ_LIKELY(aBytes <= mCurrentSpan.LengthBytes())) {
+ // Data fits in mCurrentSpan.
+ // Update mCurrentSpan. It may become empty, so in case of a double span,
+ // the next call will go to the false case below.
+ mCurrentSpan = mCurrentSpan.From(aBytes);
+ } else {
+ // Data does not fully fit in mCurrentSpan.
+ // This should only happen at most once: Only for double spans, and when
+ // data crosses the gap or starts there.
+ const Length tail =
+ aBytes - static_cast<Length>(mCurrentSpan.LengthBytes());
+ // Move mNextSpanOrEmpty to mCurrentSpan, past the data. So the next call
+ // will go back to the true case above.
+ mCurrentSpan = mNextSpanOrEmpty.From(tail);
+ mNextSpanOrEmpty = mNextSpanOrEmpty.First(0);
+ }
+ return *this;
+ }
+
+ // Number of bytes needed to represent `aValue` in unsigned LEB128.
+ template <typename T>
+ [[nodiscard]] static unsigned ULEB128Size(T aValue) {
+ return ::mozilla::ULEB128Size(aValue);
+ }
+
+ // Write number as unsigned LEB128 and move iterator ahead.
+ template <typename T>
+ void WriteULEB128(T aValue) {
+ ::mozilla::WriteULEB128(aValue, *this);
+ }
+
+ // Number of bytes needed to serialize objects.
+ template <typename... Ts>
+ [[nodiscard]] static Length SumBytes(const Ts&... aTs) {
+ return (0 + ... + Serializer<Ts>::Bytes(aTs));
+ }
+
+ // Write a sequence of bytes, like memcpy.
+ void WriteBytes(const void* aSrc, Length aBytes) {
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ if (MOZ_LIKELY(aBytes <= mCurrentSpan.LengthBytes())) {
+ // Data fits in mCurrentSpan.
+ memcpy(mCurrentSpan.Elements(), aSrc, aBytes);
+ // Update mCurrentSpan. It may become empty, so in case of a double span,
+ // the next call will go to the false case below.
+ mCurrentSpan = mCurrentSpan.From(aBytes);
+ } else {
+ // Data does not fully fit in mCurrentSpan.
+ // This should only happen at most once: Only for double spans, and when
+ // data crosses the gap or starts there.
+ // Split data between the end of mCurrentSpan and the beginning of
+ // mNextSpanOrEmpty. (mCurrentSpan could be empty, it's ok to do a memcpy
+ // because Span::Elements() is never null.)
+ memcpy(mCurrentSpan.Elements(), aSrc, mCurrentSpan.LengthBytes());
+ const Length tail =
+ aBytes - static_cast<Length>(mCurrentSpan.LengthBytes());
+ memcpy(mNextSpanOrEmpty.Elements(),
+ reinterpret_cast<const Byte*>(aSrc) + mCurrentSpan.LengthBytes(),
+ tail);
+ // Move mNextSpanOrEmpty to mCurrentSpan, past the data. So the next call
+ // will go back to the true case above.
+ mCurrentSpan = mNextSpanOrEmpty.From(tail);
+ mNextSpanOrEmpty = mNextSpanOrEmpty.First(0);
+ }
+ }
+
+ void WriteFromReader(ProfileBufferEntryReader& aReader, Length aBytes) {
+ MOZ_RELEASE_ASSERT(aBytes <= RemainingBytes());
+ MOZ_RELEASE_ASSERT(aBytes <= aReader.RemainingBytes());
+ Length read0 = std::min(
+ aBytes, static_cast<Length>(aReader.mCurrentSpan.LengthBytes()));
+ if (read0 != 0) {
+ WriteBytes(aReader.mCurrentSpan.Elements(), read0);
+ }
+ Length read1 = aBytes - read0;
+ if (read1 != 0) {
+ WriteBytes(aReader.mNextSpanOrEmpty.Elements(), read1);
+ }
+ aReader += aBytes;
+ }
+
+ // Write a single object by using the appropriate Serializer.
+ template <typename T>
+ void WriteObject(const T& aObject) {
+ Serializer<T>::Write(*this, aObject);
+ }
+
+ // Write one or more objects, sequentially.
+ // Allow `EntryWrite::WriteObjects()` with nothing, this could be useful
+ // for generic programming.
+ template <typename... Ts>
+ void WriteObjects(const Ts&... aTs) {
+ (WriteObject(aTs), ...);
+ }
+
+ private:
+ // The two spans covering the memory still to be written.
+ SpanOfBytes mCurrentSpan;
+ SpanOfBytes mNextSpanOrEmpty;
+ ProfileBufferBlockIndex mCurrentBlockIndex;
+ ProfileBufferBlockIndex mNextBlockIndex;
+};
+
+// ============================================================================
+// Serializer and Deserializer ready-to-use specializations.
+
+// ----------------------------------------------------------------------------
+// Trivially-copyable types (default)
+
+// The default implementation works for all trivially-copyable types (e.g.,
+// PODs).
+//
+// Usage: `aEW.WriteObject(123);`.
+//
+// Raw pointers, though trivially-copyable, are explictly forbidden when writing
+// (to avoid unexpected leaks/UAFs), instead use one of
+// `WrapProfileBufferLiteralCStringPointer`, `WrapProfileBufferUnownedCString`,
+// or `WrapProfileBufferRawPointer` as needed.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "Serializer only works with trivially-copyable types by "
+ "default, use/add specialization for other types.");
+
+ static constexpr Length Bytes(const T&) { return sizeof(T); }
+
+ static void Write(ProfileBufferEntryWriter& aEW, const T& aT) {
+ static_assert(!std::is_pointer<T>::value,
+ "Serializer won't write raw pointers by default, use "
+ "WrapProfileBufferRawPointer or other.");
+ aEW.WriteBytes(&aT, sizeof(T));
+ }
+};
+
+// Usage: `aER.ReadObject<int>();` or `int x; aER.ReadIntoObject(x);`.
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer {
+ static_assert(std::is_trivially_copyable<T>::value,
+ "Deserializer only works with trivially-copyable types by "
+ "default, use/add specialization for other types.");
+
+ static void ReadInto(ProfileBufferEntryReader& aER, T& aT) {
+ aER.ReadBytes(&aT, sizeof(T));
+ }
+
+ static T Read(ProfileBufferEntryReader& aER) {
+ // Note that this creates a default `T` first, and then overwrites it with
+ // bytes from the buffer. Trivially-copyable types support this without UB.
+ T ob;
+ ReadInto(aER, ob);
+ return ob;
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Strip const/volatile/reference from types.
+
+// Automatically strip `const`.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<const T>
+ : public ProfileBufferEntryWriter::Serializer<T> {};
+
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<const T>
+ : public ProfileBufferEntryReader::Deserializer<T> {};
+
+// Automatically strip `volatile`.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<volatile T>
+ : public ProfileBufferEntryWriter::Serializer<T> {};
+
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<volatile T>
+ : public ProfileBufferEntryReader::Deserializer<T> {};
+
+// Automatically strip `lvalue-reference`.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<T&>
+ : public ProfileBufferEntryWriter::Serializer<T> {};
+
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<T&>
+ : public ProfileBufferEntryReader::Deserializer<T> {};
+
+// Automatically strip `rvalue-reference`.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<T&&>
+ : public ProfileBufferEntryWriter::Serializer<T> {};
+
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<T&&>
+ : public ProfileBufferEntryReader::Deserializer<T> {};
+
+// ----------------------------------------------------------------------------
+// ProfileBufferBlockIndex
+
+// ProfileBufferBlockIndex, serialized as the underlying value.
+template <>
+struct ProfileBufferEntryWriter::Serializer<ProfileBufferBlockIndex> {
+ static constexpr Length Bytes(const ProfileBufferBlockIndex& aBlockIndex) {
+ return sizeof(ProfileBufferBlockIndex);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const ProfileBufferBlockIndex& aBlockIndex) {
+ aEW.WriteBytes(&aBlockIndex, sizeof(aBlockIndex));
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<ProfileBufferBlockIndex> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ ProfileBufferBlockIndex& aBlockIndex) {
+ aER.ReadBytes(&aBlockIndex, sizeof(aBlockIndex));
+ }
+
+ static ProfileBufferBlockIndex Read(ProfileBufferEntryReader& aER) {
+ ProfileBufferBlockIndex blockIndex;
+ ReadInto(aER, blockIndex);
+ return blockIndex;
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Literal C string pointer
+
+// Wrapper around a pointer to a literal C string.
+template <size_t NonTerminalCharacters>
+struct ProfileBufferLiteralCStringPointer {
+ const char* mCString;
+};
+
+// Wrap a pointer to a literal C string.
+template <size_t CharactersIncludingTerminal>
+ProfileBufferLiteralCStringPointer<CharactersIncludingTerminal - 1>
+WrapProfileBufferLiteralCStringPointer(
+ const char (&aCString)[CharactersIncludingTerminal]) {
+ return {aCString};
+}
+
+// Literal C strings, serialized as the raw pointer because it is unique and
+// valid for the whole program lifetime.
+//
+// Usage: `aEW.WriteObject(WrapProfileBufferLiteralCStringPointer("hi"));`.
+//
+// No deserializer is provided for this type, instead it must be deserialized as
+// a raw pointer: `aER.ReadObject<const char*>();`
+template <size_t CharactersIncludingTerminal>
+struct ProfileBufferEntryReader::Deserializer<
+ ProfileBufferLiteralCStringPointer<CharactersIncludingTerminal>> {
+ static constexpr Length Bytes(
+ const ProfileBufferLiteralCStringPointer<CharactersIncludingTerminal>&) {
+ // We're only storing a pointer, its size is independent from the pointer
+ // value.
+ return sizeof(const char*);
+ }
+
+ static void Write(
+ ProfileBufferEntryWriter& aEW,
+ const ProfileBufferLiteralCStringPointer<CharactersIncludingTerminal>&
+ aWrapper) {
+ // Write the pointer *value*, not the string contents.
+ aEW.WriteBytes(aWrapper.mCString, sizeof(aWrapper.mCString));
+ }
+};
+
+// ----------------------------------------------------------------------------
+// C string contents
+
+// Wrapper around a pointer to a C string whose contents will be serialized.
+struct ProfileBufferUnownedCString {
+ const char* mCString;
+};
+
+// Wrap a pointer to a C string whose contents will be serialized.
+inline ProfileBufferUnownedCString WrapProfileBufferUnownedCString(
+ const char* aCString) {
+ return {aCString};
+}
+
+// The contents of a (probably) unowned C string are serialized as the number of
+// characters (encoded as ULEB128) and all the characters in the string. The
+// terminal '\0' is omitted.
+//
+// Usage: `aEW.WriteObject(WrapProfileBufferUnownedCString(str.c_str()))`.
+//
+// No deserializer is provided for this pointer type, instead it must be
+// deserialized as one of the other string types that manages its contents,
+// e.g.: `aER.ReadObject<std::string>();`
+template <>
+struct ProfileBufferEntryWriter::Serializer<ProfileBufferUnownedCString> {
+ static Length Bytes(const ProfileBufferUnownedCString& aS) {
+ const auto len = strlen(aS.mCString);
+ return ULEB128Size(len) + len;
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const ProfileBufferUnownedCString& aS) {
+ const auto len = strlen(aS.mCString);
+ aEW.WriteULEB128(len);
+ aEW.WriteBytes(aS.mCString, len);
+ }
+};
+
+// ----------------------------------------------------------------------------
+// Raw pointers
+
+// Wrapper around a pointer to be serialized as the raw pointer value.
+template <typename T>
+struct ProfileBufferRawPointer {
+ T* mRawPointer;
+};
+
+// Wrap a pointer to be serialized as the raw pointer value.
+template <typename T>
+ProfileBufferRawPointer<T> WrapProfileBufferRawPointer(T* aRawPointer) {
+ return {aRawPointer};
+}
+
+// Raw pointers are serialized as the raw pointer value.
+//
+// Usage: `aEW.WriteObject(WrapProfileBufferRawPointer(ptr));`
+//
+// The wrapper is compulsory when writing pointers (to avoid unexpected
+// leaks/UAFs), but reading can be done straight into a raw pointer object,
+// e.g.: `aER.ReadObject<Foo*>;`.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<ProfileBufferRawPointer<T>> {
+ template <typename U>
+ static constexpr Length Bytes(const U&) {
+ return sizeof(T*);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const ProfileBufferRawPointer<T>& aWrapper) {
+ aEW.WriteBytes(&aWrapper.mRawPointer, sizeof(aWrapper.mRawPointer));
+ }
+};
+
+// Usage: `aER.ReadObject<Foo*>;` or `Foo* p; aER.ReadIntoObject(p);`, no
+// wrapper necessary.
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<ProfileBufferRawPointer<T>> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ ProfileBufferRawPointer<T>& aPtr) {
+ aER.ReadBytes(&aPtr.mRawPointer, sizeof(aPtr));
+ }
+
+ static ProfileBufferRawPointer<T> Read(ProfileBufferEntryReader& aER) {
+ ProfileBufferRawPointer<T> rawPointer;
+ ReadInto(aER, rawPointer);
+ return rawPointer;
+ }
+};
+
+// ----------------------------------------------------------------------------
+// std::string contents
+
+// std::string contents are serialized as the number of characters (encoded as
+// ULEB128) and all the characters in the string. The terminal '\0' is omitted.
+//
+// Usage: `std::string s = ...; aEW.WriteObject(s);`
+template <typename CHAR>
+struct ProfileBufferEntryWriter::Serializer<std::basic_string<CHAR>> {
+ static Length Bytes(const std::basic_string<CHAR>& aS) {
+ const Length len = static_cast<Length>(aS.length());
+ return ULEB128Size(len) + len;
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const std::basic_string<CHAR>& aS) {
+ const Length len = static_cast<Length>(aS.length());
+ aEW.WriteULEB128(len);
+ aEW.WriteBytes(aS.c_str(), len * sizeof(CHAR));
+ }
+};
+
+// Usage: `std::string s = aEW.ReadObject<std::string>(s);` or
+// `std::string s; aER.ReadIntoObject(s);`
+template <typename CHAR>
+struct ProfileBufferEntryReader::Deserializer<std::basic_string<CHAR>> {
+ static void ReadCharsInto(ProfileBufferEntryReader& aER,
+ std::basic_string<CHAR>& aS, size_t aLength) {
+ // Assign to `aS` by using iterators.
+ // (`aER+0` so we get the same iterator type as `aER+len`.)
+ aS.assign(aER, aER.EmptyIteratorAtOffset(aLength));
+ aER += aLength;
+ }
+
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ std::basic_string<CHAR>& aS) {
+ ReadCharsInto(
+ aER, aS,
+ aER.ReadULEB128<typename std::basic_string<CHAR>::size_type>());
+ }
+
+ static std::basic_string<CHAR> ReadChars(ProfileBufferEntryReader& aER,
+ size_t aLength) {
+ // Construct a string by using iterators.
+ // (`aER+0` so we get the same iterator type as `aER+len`.)
+ std::basic_string<CHAR> s(aER, aER.EmptyIteratorAtOffset(aLength));
+ aER += aLength;
+ return s;
+ }
+
+ static std::basic_string<CHAR> Read(ProfileBufferEntryReader& aER) {
+ return ReadChars(
+ aER, aER.ReadULEB128<typename std::basic_string<CHAR>::size_type>());
+ }
+};
+
+// ----------------------------------------------------------------------------
+// mozilla::UniqueFreePtr<CHAR>
+
+// UniqueFreePtr<CHAR>, which points at a string allocated with `malloc`
+// (typically generated by `strdup()`), is serialized as the number of
+// *bytes* (encoded as ULEB128) and all the characters in the string. The
+// null terminator is omitted.
+// `CHAR` can be any type that has a specialization for
+// `std::char_traits<CHAR>::length(const CHAR*)`.
+//
+// Note: A nullptr pointer will be serialized like an empty string, so when
+// deserializing it will result in an allocated buffer only containing a
+// single null terminator.
+template <typename CHAR>
+struct ProfileBufferEntryWriter::Serializer<UniqueFreePtr<CHAR>> {
+ static Length Bytes(const UniqueFreePtr<CHAR>& aS) {
+ if (!aS) {
+ // Null pointer, store it as if it was an empty string (so: 0 bytes).
+ return ULEB128Size(0u);
+ }
+ // Note that we store the size in *bytes*, not in number of characters.
+ const auto bytes = std::char_traits<CHAR>::length(aS.get()) * sizeof(CHAR);
+ return ULEB128Size(bytes) + bytes;
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const UniqueFreePtr<CHAR>& aS) {
+ if (!aS) {
+ // Null pointer, store it as if it was an empty string (so we write a
+ // length of 0 bytes).
+ aEW.WriteULEB128(0u);
+ return;
+ }
+ // Note that we store the size in *bytes*, not in number of characters.
+ const auto bytes = std::char_traits<CHAR>::length(aS.get()) * sizeof(CHAR);
+ aEW.WriteULEB128(bytes);
+ aEW.WriteBytes(aS.get(), bytes);
+ }
+};
+
+template <typename CHAR>
+struct ProfileBufferEntryReader::Deserializer<UniqueFreePtr<CHAR>> {
+ static void ReadInto(ProfileBufferEntryReader& aER, UniqueFreePtr<CHAR>& aS) {
+ aS = Read(aER);
+ }
+
+ static UniqueFreePtr<CHAR> Read(ProfileBufferEntryReader& aER) {
+ // Read the number of *bytes* that follow.
+ const auto bytes = aER.ReadULEB128<size_t>();
+ // We need a buffer of the non-const character type.
+ using NC_CHAR = std::remove_const_t<CHAR>;
+ // We allocate the required number of bytes, plus one extra character for
+ // the null terminator.
+ NC_CHAR* buffer = static_cast<NC_CHAR*>(malloc(bytes + sizeof(NC_CHAR)));
+ // Copy the characters into the buffer.
+ aER.ReadBytes(buffer, bytes);
+ // And append a null terminator.
+ buffer[bytes / sizeof(NC_CHAR)] = NC_CHAR(0);
+ return UniqueFreePtr<CHAR>(buffer);
+ }
+};
+
+// ----------------------------------------------------------------------------
+// std::tuple
+
+// std::tuple is serialized as a sequence of each recursively-serialized item.
+//
+// This is equivalent to manually serializing each item, so reading/writing
+// tuples is equivalent to reading/writing their elements in order, e.g.:
+// ```
+// std::tuple<int, std::string> is = ...;
+// aEW.WriteObject(is); // Write the tuple, equivalent to:
+// aEW.WriteObject(/* int */ std::get<0>(is), /* string */ std::get<1>(is));
+// ...
+// // Reading back can be done directly into a tuple:
+// auto is = aER.ReadObject<std::tuple<int, std::string>>();
+// // Or each item could be read separately:
+// auto i = aER.ReadObject<int>(); auto s = aER.ReadObject<std::string>();
+// ```
+template <typename... Ts>
+struct ProfileBufferEntryWriter::Serializer<std::tuple<Ts...>> {
+ private:
+ template <size_t... Is>
+ static Length TupleBytes(const std::tuple<Ts...>& aTuple,
+ std::index_sequence<Is...>) {
+ return (0 + ... + SumBytes(std::get<Is>(aTuple)));
+ }
+
+ template <size_t... Is>
+ static void TupleWrite(ProfileBufferEntryWriter& aEW,
+ const std::tuple<Ts...>& aTuple,
+ std::index_sequence<Is...>) {
+ (aEW.WriteObject(std::get<Is>(aTuple)), ...);
+ }
+
+ public:
+ static Length Bytes(const std::tuple<Ts...>& aTuple) {
+ // Generate a 0..N-1 index pack, we'll add the sizes of each item.
+ return TupleBytes(aTuple, std::index_sequence_for<Ts...>());
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const std::tuple<Ts...>& aTuple) {
+ // Generate a 0..N-1 index pack, we'll write each item.
+ TupleWrite(aEW, aTuple, std::index_sequence_for<Ts...>());
+ }
+};
+
+template <typename... Ts>
+struct ProfileBufferEntryReader::Deserializer<std::tuple<Ts...>> {
+ template <size_t I>
+ static void TupleIReadInto(ProfileBufferEntryReader& aER,
+ std::tuple<Ts...>& aTuple) {
+ aER.ReadIntoObject(std::get<I>(aTuple));
+ }
+
+ template <size_t... Is>
+ static void TupleReadInto(ProfileBufferEntryReader& aER,
+ std::tuple<Ts...>& aTuple,
+ std::index_sequence<Is...>) {
+ (TupleIReadInto<Is>(aER, aTuple), ...);
+ }
+
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ std::tuple<Ts...>& aTuple) {
+ TupleReadInto(aER, aTuple, std::index_sequence_for<Ts...>());
+ }
+
+ static std::tuple<Ts...> Read(ProfileBufferEntryReader& aER) {
+ // Note that this creates default `Ts` first, and then overwrites them.
+ std::tuple<Ts...> ob;
+ ReadInto(aER, ob);
+ return ob;
+ }
+};
+// ----------------------------------------------------------------------------
+// mozilla::Span
+
+// Span. All elements are serialized in sequence.
+// The caller is assumed to know the number of elements (they may manually
+// write&read it before the span if needed).
+// Similar to tuples, reading/writing spans is equivalent to reading/writing
+// their elements in order.
+template <class T, size_t N>
+struct ProfileBufferEntryWriter::Serializer<Span<T, N>> {
+ static Length Bytes(const Span<T, N>& aSpan) {
+ Length bytes = 0;
+ for (const T& element : aSpan) {
+ bytes += SumBytes(element);
+ }
+ return bytes;
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW, const Span<T, N>& aSpan) {
+ for (const T& element : aSpan) {
+ aEW.WriteObject(element);
+ }
+ }
+};
+
+template <class T, size_t N>
+struct ProfileBufferEntryReader::Deserializer<Span<T, N>> {
+ // Read elements back into span pointing at a pre-allocated buffer.
+ static void ReadInto(ProfileBufferEntryReader& aER, Span<T, N>& aSpan) {
+ for (T& element : aSpan) {
+ aER.ReadIntoObject(element);
+ }
+ }
+
+ // A Span does not own its data, this would probably leak so we forbid this.
+ static Span<T, N> Read(ProfileBufferEntryReader& aER) = delete;
+};
+
+// ----------------------------------------------------------------------------
+// mozilla::Maybe
+
+// Maybe<T> is serialized as one byte containing either 'm' (Nothing),
+// or 'M' followed by the recursively-serialized `T` object.
+template <typename T>
+struct ProfileBufferEntryWriter::Serializer<Maybe<T>> {
+ static Length Bytes(const Maybe<T>& aMaybe) {
+ // 1 byte to store nothing/something flag, then object size if present.
+ return aMaybe.isNothing() ? 1 : (1 + SumBytes(aMaybe.ref()));
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW, const Maybe<T>& aMaybe) {
+ // 'm'/'M' is just an arbitrary 1-byte value to distinguish states.
+ if (aMaybe.isNothing()) {
+ aEW.WriteObject<char>('m');
+ } else {
+ aEW.WriteObject<char>('M');
+ // Use the Serializer for the contained type.
+ aEW.WriteObject(aMaybe.ref());
+ }
+ }
+};
+
+template <typename T>
+struct ProfileBufferEntryReader::Deserializer<Maybe<T>> {
+ static void ReadInto(ProfileBufferEntryReader& aER, Maybe<T>& aMaybe) {
+ char c = aER.ReadObject<char>();
+ if (c == 'm') {
+ aMaybe.reset();
+ } else {
+ MOZ_ASSERT(c == 'M');
+ // If aMaybe is empty, create a default `T` first, to be overwritten.
+ // Otherwise we'll just overwrite whatever was already there.
+ if (aMaybe.isNothing()) {
+ aMaybe.emplace();
+ }
+ // Use the Deserializer for the contained type.
+ aER.ReadIntoObject(aMaybe.ref());
+ }
+ }
+
+ static Maybe<T> Read(ProfileBufferEntryReader& aER) {
+ Maybe<T> maybe;
+ char c = aER.ReadObject<char>();
+ MOZ_ASSERT(c == 'M' || c == 'm');
+ if (c == 'M') {
+ // Note that this creates a default `T` inside the Maybe first, and then
+ // overwrites it.
+ maybe = Some(T{});
+ // Use the Deserializer for the contained type.
+ aER.ReadIntoObject(maybe.ref());
+ }
+ return maybe;
+ }
+};
+
+// ----------------------------------------------------------------------------
+// mozilla::Variant
+
+// Variant is serialized as the tag (0-based index of the stored type, encoded
+// as ULEB128), and the recursively-serialized object.
+template <typename... Ts>
+struct ProfileBufferEntryWriter::Serializer<Variant<Ts...>> {
+ public:
+ static Length Bytes(const Variant<Ts...>& aVariantTs) {
+ return aVariantTs.match([](auto aIndex, const auto& aAlternative) {
+ return ULEB128Size(aIndex) + SumBytes(aAlternative);
+ });
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const Variant<Ts...>& aVariantTs) {
+ aVariantTs.match([&aEW](auto aIndex, const auto& aAlternative) {
+ aEW.WriteULEB128(aIndex);
+ aEW.WriteObject(aAlternative);
+ });
+ }
+};
+
+template <typename... Ts>
+struct ProfileBufferEntryReader::Deserializer<Variant<Ts...>> {
+ private:
+ // Called from the fold expression in `VariantReadInto()`, only the selected
+ // variant will deserialize the object.
+ template <size_t I>
+ static void VariantIReadInto(ProfileBufferEntryReader& aER,
+ Variant<Ts...>& aVariantTs, unsigned aTag) {
+ if (I == aTag) {
+ // Ensure the variant contains the target type. Note that this may create
+ // a default object.
+ if (!aVariantTs.template is<I>()) {
+ aVariantTs = Variant<Ts...>(VariantIndex<I>{});
+ }
+ aER.ReadIntoObject(aVariantTs.template as<I>());
+ }
+ }
+
+ template <size_t... Is>
+ static void VariantReadInto(ProfileBufferEntryReader& aER,
+ Variant<Ts...>& aVariantTs,
+ std::index_sequence<Is...>) {
+ unsigned tag = aER.ReadULEB128<unsigned>();
+ (VariantIReadInto<Is>(aER, aVariantTs, tag), ...);
+ }
+
+ public:
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ Variant<Ts...>& aVariantTs) {
+ // Generate a 0..N-1 index pack, the selected variant will deserialize
+ // itself.
+ VariantReadInto(aER, aVariantTs, std::index_sequence_for<Ts...>());
+ }
+
+ static Variant<Ts...> Read(ProfileBufferEntryReader& aER) {
+ // Note that this creates a default `Variant` of the first type, and then
+ // overwrites it. Consider using `ReadInto` for more control if needed.
+ Variant<Ts...> variant(VariantIndex<0>{});
+ ReadInto(aER, variant);
+ return variant;
+ }
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferEntrySerialization_h
diff --git a/mozglue/baseprofiler/public/ProfileBufferIndex.h b/mozglue/baseprofiler/public/ProfileBufferIndex.h
new file mode 100644
index 0000000000..5cda6bd89e
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileBufferIndex.h
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileBufferIndex_h
+#define ProfileBufferIndex_h
+
+#include "mozilla/Attributes.h"
+
+#include <cstddef>
+#include <cstdint>
+
+namespace mozilla {
+
+// Generic index into a Profiler buffer, mostly for internal usage.
+// Intended to appear infinite (it should effectively never wrap).
+// 0 (zero) is reserved as nullptr-like value; it may indicate failure result,
+// or it may point at the earliest available block.
+using ProfileBufferIndex = uint64_t;
+
+// Externally-opaque class encapsulating a block index, i.e. a
+// ProfileBufferIndex that is guaranteed to point at the start of a Profile
+// buffer block (until it is destroyed, but then that index cannot be reused and
+// functions should gracefully handle expired blocks).
+// Users may get these from Profile buffer functions, to later access previous
+// blocks; they should avoid converting and operating on their value.
+class ProfileBufferBlockIndex {
+ public:
+ // Default constructor with internal 0 value, for which Profile buffers must
+ // guarantee that it is before any valid entries; All public APIs should
+ // fail gracefully, doing and/or returning Nothing.
+ ProfileBufferBlockIndex() : mBlockIndex(0) {}
+
+ // Implicit conversion from literal `nullptr` to internal 0 value, to allow
+ // convenient init/reset/comparison with 0 index.
+ MOZ_IMPLICIT ProfileBufferBlockIndex(std::nullptr_t) : mBlockIndex(0) {}
+
+ // Explicit conversion to bool, works in `if` and other tests.
+ // Only returns false for default `ProfileBufferBlockIndex{}` value.
+ explicit operator bool() const { return mBlockIndex != 0; }
+
+ // Comparison operators. Default `ProfileBufferBlockIndex{}` value is always
+ // the lowest.
+ [[nodiscard]] bool operator==(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex == aRhs.mBlockIndex;
+ }
+ [[nodiscard]] bool operator!=(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex != aRhs.mBlockIndex;
+ }
+ [[nodiscard]] bool operator<(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex < aRhs.mBlockIndex;
+ }
+ [[nodiscard]] bool operator<=(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex <= aRhs.mBlockIndex;
+ }
+ [[nodiscard]] bool operator>(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex > aRhs.mBlockIndex;
+ }
+ [[nodiscard]] bool operator>=(const ProfileBufferBlockIndex& aRhs) const {
+ return mBlockIndex >= aRhs.mBlockIndex;
+ }
+
+ // Explicit conversion to ProfileBufferIndex, mostly used by internal Profile
+ // buffer code.
+ [[nodiscard]] ProfileBufferIndex ConvertToProfileBufferIndex() const {
+ return mBlockIndex;
+ }
+
+ // Explicit creation from ProfileBufferIndex, mostly used by internal
+ // Profile buffer code.
+ [[nodiscard]] static ProfileBufferBlockIndex CreateFromProfileBufferIndex(
+ ProfileBufferIndex aIndex) {
+ return ProfileBufferBlockIndex(aIndex);
+ }
+
+ private:
+ // Private to prevent easy construction from any value. Use
+ // `CreateFromProfileBufferIndex()` instead.
+ // The main reason for this indirection is to make it harder to create these
+ // objects, because only the profiler code should need to do it. Ideally, this
+ // class should be used wherever a block index should be stored, but there is
+ // so much code that uses `uint64_t` that it would be a big task to change
+ // them all. So for now we allow conversions to/from numbers, but it's as ugly
+ // as possible to make sure it doesn't get too common; and if one day we want
+ // to tackle a global change, it should be easy to find all these locations
+ // thanks to the explicit conversion functions.
+ explicit ProfileBufferBlockIndex(ProfileBufferIndex aBlockIndex)
+ : mBlockIndex(aBlockIndex) {}
+
+ ProfileBufferIndex mBlockIndex;
+};
+
+} // namespace mozilla
+
+#endif // ProfileBufferIndex_h
diff --git a/mozglue/baseprofiler/public/ProfileChunkedBuffer.h b/mozglue/baseprofiler/public/ProfileChunkedBuffer.h
new file mode 100644
index 0000000000..ded7fbd08b
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileChunkedBuffer.h
@@ -0,0 +1,1560 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileChunkedBuffer_h
+#define ProfileChunkedBuffer_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/BaseProfilerDetail.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/ProfileBufferChunkManager.h"
+#include "mozilla/ProfileBufferChunkManagerSingle.h"
+#include "mozilla/ProfileBufferEntrySerialization.h"
+#include "mozilla/ProfileChunkedBufferDetail.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Unused.h"
+
+#include <utility>
+
+#ifdef DEBUG
+# include <cstdio>
+#endif
+
+namespace mozilla {
+
+// Thread-safe buffer that can store blocks of different sizes during defined
+// sessions, using Chunks (from a ChunkManager) as storage.
+//
+// Each *block* contains an *entry* and the entry size:
+// [ entry_size | entry ] [ entry_size | entry ] ...
+//
+// *In-session* is a period of time during which `ProfileChunkedBuffer` allows
+// reading and writing.
+// *Out-of-session*, the `ProfileChunkedBuffer` object is still valid, but
+// contains no data, and gracefully denies accesses.
+//
+// To write an entry, the buffer reserves a block of sufficient size (to contain
+// user data of predetermined size), writes the entry size, and lets the caller
+// fill the entry contents using a ProfileBufferEntryWriter. E.g.:
+// ```
+// ProfileChunkedBuffer cb(...);
+// cb.ReserveAndPut([]() { return sizeof(123); },
+// [&](Maybe<ProfileBufferEntryWriter>& aEW) {
+// if (aEW) { aEW->WriteObject(123); }
+// });
+// ```
+// Other `Put...` functions may be used as shortcuts for simple entries.
+// The objects given to the caller's callbacks should only be used inside the
+// callbacks and not stored elsewhere, because they keep their own references to
+// chunk memory and therefore should not live longer.
+// Different type of objects may be serialized into an entry, see
+// `ProfileBufferEntryWriter::Serializer` for more information.
+//
+// When reading data, the buffer iterates over blocks (it knows how to read the
+// entry size, and therefore move to the next block), and lets the caller read
+// the entry inside of each block. E.g.:
+// ```
+// cb.ReadEach([](ProfileBufferEntryReader& aER) {
+// /* Use ProfileBufferEntryReader functions to read serialized objects. */
+// int n = aER.ReadObject<int>();
+// });
+// ```
+// Different type of objects may be deserialized from an entry, see
+// `ProfileBufferEntryReader::Deserializer` for more information.
+//
+// Writers may retrieve the block index corresponding to an entry
+// (`ProfileBufferBlockIndex` is an opaque type preventing the user from easily
+// modifying it). That index may later be used with `ReadAt` to get back to the
+// entry in that particular block -- if it still exists.
+class ProfileChunkedBuffer {
+ public:
+ using Byte = ProfileBufferChunk::Byte;
+ using Length = ProfileBufferChunk::Length;
+
+ enum class ThreadSafety { WithoutMutex, WithMutex };
+
+ // Default constructor starts out-of-session (nothing to read or write).
+ explicit ProfileChunkedBuffer(ThreadSafety aThreadSafety)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex) {}
+
+ // Start in-session with external chunk manager.
+ ProfileChunkedBuffer(ThreadSafety aThreadSafety,
+ ProfileBufferChunkManager& aChunkManager)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex) {
+ SetChunkManager(aChunkManager);
+ }
+
+ // Start in-session with owned chunk manager.
+ ProfileChunkedBuffer(ThreadSafety aThreadSafety,
+ UniquePtr<ProfileBufferChunkManager>&& aChunkManager)
+ : mMutex(aThreadSafety != ThreadSafety::WithoutMutex) {
+ SetChunkManager(std::move(aChunkManager));
+ }
+
+ ~ProfileChunkedBuffer() {
+ // Do proper clean-up by resetting the chunk manager.
+ ResetChunkManager();
+ }
+
+ // This cannot change during the lifetime of this buffer, so there's no need
+ // to lock.
+ [[nodiscard]] bool IsThreadSafe() const { return mMutex.IsActivated(); }
+
+ [[nodiscard]] bool IsInSession() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return !!mChunkManager;
+ }
+
+ // Stop using the current chunk manager.
+ // If we own the current chunk manager, it will be destroyed.
+ // This will always clear currently-held chunks, if any.
+ void ResetChunkManager() {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ Unused << ResetChunkManager(lock);
+ }
+
+ // Set the current chunk manager.
+ // The caller is responsible for keeping the chunk manager alive as along as
+ // it's used here (until the next (Re)SetChunkManager, or
+ // ~ProfileChunkedBuffer).
+ void SetChunkManager(ProfileBufferChunkManager& aChunkManager) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ Unused << ResetChunkManager(lock);
+ SetChunkManager(aChunkManager, lock);
+ }
+
+ // Set the current chunk manager, and keep ownership of it.
+ void SetChunkManager(UniquePtr<ProfileBufferChunkManager>&& aChunkManager) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ Unused << ResetChunkManager(lock);
+ mOwnedChunkManager = std::move(aChunkManager);
+ if (mOwnedChunkManager) {
+ SetChunkManager(*mOwnedChunkManager, lock);
+ }
+ }
+
+ // Set the current chunk manager, except if it's already the one provided.
+ // The caller is responsible for keeping the chunk manager alive as along as
+ // it's used here (until the next (Re)SetChunkManager, or
+ // ~ProfileChunkedBuffer).
+ void SetChunkManagerIfDifferent(ProfileBufferChunkManager& aChunkManager) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (!mChunkManager || mChunkManager != &aChunkManager) {
+ Unused << ResetChunkManager(lock);
+ SetChunkManager(aChunkManager, lock);
+ }
+ }
+
+ // Clear the contents of this buffer, ready to receive new chunks.
+ // Note that memory is not freed: No chunks are destroyed, they are all
+ // receycled.
+ // Also the range doesn't reset, instead it continues at some point after the
+ // previous range. This may be useful if the caller may be keeping indexes
+ // into old chunks that have now been cleared, using these indexes will fail
+ // gracefully (instead of potentially pointing into new data).
+ void Clear() {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return;
+ }
+
+ mRangeStart = mRangeEnd = mNextChunkRangeStart;
+ mPushedBlockCount = 0;
+ mClearedBlockCount = 0;
+ mFailedPutBytes = 0;
+
+ // Recycle all released chunks as "next" chunks. This will reduce the number
+ // of future allocations. Also, when using ProfileBufferChunkManagerSingle,
+ // this retrieves the one chunk if it was released.
+ UniquePtr<ProfileBufferChunk> releasedChunks =
+ mChunkManager->GetExtantReleasedChunks();
+ if (releasedChunks) {
+ // Released chunks should be in the "Done" state, they need to be marked
+ // "recycled" before they can be reused.
+ for (ProfileBufferChunk* chunk = releasedChunks.get(); chunk;
+ chunk = chunk->GetNext()) {
+ chunk->MarkRecycled();
+ }
+ mNextChunks = ProfileBufferChunk::Join(std::move(mNextChunks),
+ std::move(releasedChunks));
+ }
+
+ if (mCurrentChunk) {
+ // We already have a current chunk (empty or in-use), mark it "done" and
+ // then "recycled", ready to be reused.
+ mCurrentChunk->MarkDone();
+ mCurrentChunk->MarkRecycled();
+ } else {
+ if (!mNextChunks) {
+ // No current chunk, and no next chunks to recycle, nothing more to do.
+ // The next "Put" operation will try to allocate a chunk as needed.
+ return;
+ }
+
+ // No current chunk, take a next chunk.
+ mCurrentChunk = std::exchange(mNextChunks, mNextChunks->ReleaseNext());
+ }
+
+ // Here, there was already a current chunk, or one has just been taken.
+ // Make sure it's ready to receive new entries.
+ InitializeCurrentChunk(lock);
+ }
+
+ // Buffer maximum length in bytes.
+ Maybe<size_t> BufferLength() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (!mChunkManager) {
+ return Nothing{};
+ }
+ return Some(mChunkManager->MaxTotalSize());
+ }
+
+ [[nodiscard]] size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return SizeOfExcludingThis(aMallocSizeOf, lock);
+ }
+
+ [[nodiscard]] size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf, lock);
+ }
+
+ // Snapshot of the buffer state.
+ struct State {
+ // Index to/before the first block.
+ ProfileBufferIndex mRangeStart = 1;
+
+ // Index past the last block. Equals mRangeStart if empty.
+ ProfileBufferIndex mRangeEnd = 1;
+
+ // Number of blocks that have been pushed into this buffer.
+ uint64_t mPushedBlockCount = 0;
+
+ // Number of blocks that have been removed from this buffer.
+ // Note: Live entries = pushed - cleared.
+ uint64_t mClearedBlockCount = 0;
+
+ // Number of bytes that could not be put into this buffer.
+ uint64_t mFailedPutBytes = 0;
+ };
+
+ // Get a snapshot of the current state.
+ // When out-of-session, mFirstReadIndex==mNextWriteIndex, and
+ // mPushedBlockCount==mClearedBlockCount==0.
+ // Note that these may change right after this thread-safe call, so they
+ // should only be used for statistical purposes.
+ [[nodiscard]] State GetState() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return {mRangeStart, mRangeEnd, mPushedBlockCount, mClearedBlockCount,
+ mFailedPutBytes};
+ }
+
+ // In in-session, return the start TimeStamp of the earliest chunk.
+ // If out-of-session, return a null TimeStamp.
+ [[nodiscard]] TimeStamp GetEarliestChunkStartTimeStamp() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return {};
+ }
+ return mChunkManager->PeekExtantReleasedChunks(
+ [&](const ProfileBufferChunk* aOldestChunk) -> TimeStamp {
+ if (aOldestChunk) {
+ return aOldestChunk->ChunkHeader().mStartTimeStamp;
+ }
+ if (mCurrentChunk) {
+ return mCurrentChunk->ChunkHeader().mStartTimeStamp;
+ }
+ return {};
+ });
+ }
+
+ [[nodiscard]] bool IsEmpty() const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return mRangeStart == mRangeEnd;
+ }
+
+ // True if this buffer is already locked on this thread.
+ // This should be used if some functions may call an already-locked buffer,
+ // e.g.: Put -> memory hook -> profiler_add_native_allocation_marker -> Put.
+ [[nodiscard]] bool IsThreadSafeAndLockedOnCurrentThread() const {
+ return mMutex.IsActivatedAndLockedOnCurrentThread();
+ }
+
+ // Lock the buffer mutex and run the provided callback.
+ // This can be useful when the caller needs to explicitly lock down this
+ // buffer, but not do anything else with it.
+ template <typename Callback>
+ auto LockAndRun(Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return std::forward<Callback>(aCallback)();
+ }
+
+ // Reserve a block that can hold an entry of the given `aCallbackEntryBytes()`
+ // size, write the entry size (ULEB128-encoded), and invoke and return
+ // `aCallback(Maybe<ProfileBufferEntryWriter>&)`.
+ // Note: `aCallbackEntryBytes` is a callback instead of a simple value, to
+ // delay this potentially-expensive computation until after we're checked that
+ // we're in-session; use `Put(Length, Callback)` below if you know the size
+ // already.
+ template <typename CallbackEntryBytes, typename Callback>
+ auto ReserveAndPut(CallbackEntryBytes&& aCallbackEntryBytes,
+ Callback&& aCallback)
+ -> decltype(std::forward<Callback>(aCallback)(
+ std::declval<Maybe<ProfileBufferEntryWriter>&>())) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+
+ // This can only be read in the 2nd lambda below after it has been written
+ // by the first lambda.
+ Length entryBytes;
+
+ return ReserveAndPutRaw(
+ [&]() {
+ entryBytes = std::forward<CallbackEntryBytes>(aCallbackEntryBytes)();
+ MOZ_ASSERT(entryBytes != 0, "Empty entries are not allowed");
+ return ULEB128Size(entryBytes) + entryBytes;
+ },
+ [&](Maybe<ProfileBufferEntryWriter>& aMaybeEntryWriter) {
+ if (aMaybeEntryWriter.isSome()) {
+ aMaybeEntryWriter->WriteULEB128(entryBytes);
+ MOZ_ASSERT(aMaybeEntryWriter->RemainingBytes() == entryBytes);
+ }
+ return std::forward<Callback>(aCallback)(aMaybeEntryWriter);
+ },
+ lock);
+ }
+
+ template <typename Callback>
+ auto Put(Length aEntryBytes, Callback&& aCallback) {
+ return ReserveAndPut([aEntryBytes]() { return aEntryBytes; },
+ std::forward<Callback>(aCallback));
+ }
+
+ // Add a new entry copied from the given buffer, return block index.
+ ProfileBufferBlockIndex PutFrom(const void* aSrc, Length aBytes) {
+ return ReserveAndPut(
+ [aBytes]() { return aBytes; },
+ [aSrc, aBytes](Maybe<ProfileBufferEntryWriter>& aMaybeEntryWriter) {
+ if (aMaybeEntryWriter.isNothing()) {
+ return ProfileBufferBlockIndex{};
+ }
+ aMaybeEntryWriter->WriteBytes(aSrc, aBytes);
+ return aMaybeEntryWriter->CurrentBlockIndex();
+ });
+ }
+
+ // Add a new single entry with *all* given object (using a Serializer for
+ // each), return block index.
+ template <typename... Ts>
+ ProfileBufferBlockIndex PutObjects(const Ts&... aTs) {
+ static_assert(sizeof...(Ts) > 0,
+ "PutObjects must be given at least one object.");
+ return ReserveAndPut(
+ [&]() { return ProfileBufferEntryWriter::SumBytes(aTs...); },
+ [&](Maybe<ProfileBufferEntryWriter>& aMaybeEntryWriter) {
+ if (aMaybeEntryWriter.isNothing()) {
+ return ProfileBufferBlockIndex{};
+ }
+ aMaybeEntryWriter->WriteObjects(aTs...);
+ return aMaybeEntryWriter->CurrentBlockIndex();
+ });
+ }
+
+ // Add a new entry copied from the given object, return block index.
+ template <typename T>
+ ProfileBufferBlockIndex PutObject(const T& aOb) {
+ return PutObjects(aOb);
+ }
+
+ // Get *all* chunks related to this buffer, including extant chunks in its
+ // ChunkManager, and yet-unused new/recycled chunks.
+ // We don't expect this buffer to be used again, though it's still possible
+ // and will allocate the first buffer when needed.
+ [[nodiscard]] UniquePtr<ProfileBufferChunk> GetAllChunks() {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return nullptr;
+ }
+ UniquePtr<ProfileBufferChunk> chunks =
+ mChunkManager->GetExtantReleasedChunks();
+ Unused << HandleRequestedChunk_IsPending(lock);
+ if (MOZ_LIKELY(!!mCurrentChunk)) {
+ mCurrentChunk->MarkDone();
+ chunks =
+ ProfileBufferChunk::Join(std::move(chunks), std::move(mCurrentChunk));
+ }
+ chunks =
+ ProfileBufferChunk::Join(std::move(chunks), std::move(mNextChunks));
+ mChunkManager->ForgetUnreleasedChunks();
+ mRangeStart = mRangeEnd = mNextChunkRangeStart;
+ return chunks;
+ }
+
+ // True if the given index points inside the current chunk (up to the last
+ // written byte).
+ // This could be used to check if an index written now would have a good
+ // chance of referring to a previous block that has not been destroyed yet.
+ // But use with extreme care: This information may become incorrect right
+ // after this function returns, because new writes could start a new chunk.
+ [[nodiscard]] bool IsIndexInCurrentChunk(ProfileBufferIndex aIndex) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager || !mCurrentChunk)) {
+ // Out-of-session, or no current chunk.
+ return false;
+ }
+ return (mCurrentChunk->RangeStart() <= aIndex) &&
+ (aIndex < (mCurrentChunk->RangeStart() +
+ mCurrentChunk->OffsetPastLastBlock()));
+ }
+
+ class Reader;
+
+ // Class that can iterate through blocks and provide
+ // `ProfileBufferEntryReader`s.
+ // Created through `Reader`, lives within a lock guard lifetime.
+ class BlockIterator {
+ public:
+#ifdef DEBUG
+ ~BlockIterator() {
+ // No BlockIterator should live outside of a mutexed call.
+ mBuffer->mMutex.AssertCurrentThreadOwns();
+ }
+#endif // DEBUG
+
+ // Comparison with other iterator, mostly used in range-for loops.
+ [[nodiscard]] bool operator==(const BlockIterator& aRhs) const {
+ MOZ_ASSERT(mBuffer == aRhs.mBuffer);
+ return mCurrentBlockIndex == aRhs.mCurrentBlockIndex;
+ }
+ [[nodiscard]] bool operator!=(const BlockIterator& aRhs) const {
+ MOZ_ASSERT(mBuffer == aRhs.mBuffer);
+ return mCurrentBlockIndex != aRhs.mCurrentBlockIndex;
+ }
+
+ // Advance to next BlockIterator.
+ BlockIterator& operator++() {
+ mBuffer->mMutex.AssertCurrentThreadOwns();
+ mCurrentBlockIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mNextBlockPointer.GlobalRangePosition());
+ mCurrentEntry =
+ mNextBlockPointer.EntryReader(mNextBlockPointer.ReadEntrySize());
+ return *this;
+ }
+
+ // Dereferencing creates a `ProfileBufferEntryReader` object for the entry
+ // inside this block.
+ // (Note: It would be possible to return a `const
+ // ProfileBufferEntryReader&`, but not useful in practice, because in most
+ // case the user will want to read, which is non-const.)
+ [[nodiscard]] ProfileBufferEntryReader operator*() const {
+ return mCurrentEntry;
+ }
+
+ // True if this iterator is just past the last entry.
+ [[nodiscard]] bool IsAtEnd() const {
+ return mCurrentEntry.RemainingBytes() == 0;
+ }
+
+ // Can be used as reference to come back to this entry with `GetEntryAt()`.
+ [[nodiscard]] ProfileBufferBlockIndex CurrentBlockIndex() const {
+ return mCurrentBlockIndex;
+ }
+
+ // Index past the end of this block, which is the start of the next block.
+ [[nodiscard]] ProfileBufferBlockIndex NextBlockIndex() const {
+ MOZ_ASSERT(!IsAtEnd());
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mNextBlockPointer.GlobalRangePosition());
+ }
+
+ // Index of the first block in the whole buffer.
+ [[nodiscard]] ProfileBufferBlockIndex BufferRangeStart() const {
+ mBuffer->mMutex.AssertCurrentThreadOwns();
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mBuffer->mRangeStart);
+ }
+
+ // Index past the last block in the whole buffer.
+ [[nodiscard]] ProfileBufferBlockIndex BufferRangeEnd() const {
+ mBuffer->mMutex.AssertCurrentThreadOwns();
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mBuffer->mRangeEnd);
+ }
+
+ private:
+ // Only a Reader can instantiate a BlockIterator.
+ friend class Reader;
+
+ BlockIterator(const ProfileChunkedBuffer& aBuffer,
+ const ProfileBufferChunk* aChunks0,
+ const ProfileBufferChunk* aChunks1,
+ ProfileBufferBlockIndex aBlockIndex)
+ : mNextBlockPointer(aChunks0, aChunks1, aBlockIndex),
+ mCurrentBlockIndex(
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mNextBlockPointer.GlobalRangePosition())),
+ mCurrentEntry(
+ mNextBlockPointer.EntryReader(mNextBlockPointer.ReadEntrySize())),
+ mBuffer(WrapNotNull(&aBuffer)) {
+ // No BlockIterator should live outside of a mutexed call.
+ mBuffer->mMutex.AssertCurrentThreadOwns();
+ }
+
+ profiler::detail::InChunkPointer mNextBlockPointer;
+
+ ProfileBufferBlockIndex mCurrentBlockIndex;
+
+ ProfileBufferEntryReader mCurrentEntry;
+
+ // Using a non-null pointer instead of a reference, to allow copying.
+ // This BlockIterator should only live inside one of the thread-safe
+ // ProfileChunkedBuffer functions, for this reference to stay valid.
+ NotNull<const ProfileChunkedBuffer*> mBuffer;
+ };
+
+ // Class that can create `BlockIterator`s (e.g., for range-for), or just
+ // iterate through entries; lives within a lock guard lifetime.
+ class MOZ_RAII Reader {
+ public:
+ Reader(const Reader&) = delete;
+ Reader& operator=(const Reader&) = delete;
+ Reader(Reader&&) = delete;
+ Reader& operator=(Reader&&) = delete;
+
+#ifdef DEBUG
+ ~Reader() {
+ // No Reader should live outside of a mutexed call.
+ mBuffer.mMutex.AssertCurrentThreadOwns();
+ }
+#endif // DEBUG
+
+ // Index of the first block in the whole buffer.
+ [[nodiscard]] ProfileBufferBlockIndex BufferRangeStart() const {
+ mBuffer.mMutex.AssertCurrentThreadOwns();
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mBuffer.mRangeStart);
+ }
+
+ // Index past the last block in the whole buffer.
+ [[nodiscard]] ProfileBufferBlockIndex BufferRangeEnd() const {
+ mBuffer.mMutex.AssertCurrentThreadOwns();
+ return ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ mBuffer.mRangeEnd);
+ }
+
+ // Iterators to the first and past-the-last blocks.
+ // Compatible with range-for (see `ForEach` below as example).
+ [[nodiscard]] BlockIterator begin() const {
+ return BlockIterator(mBuffer, mChunks0, mChunks1, nullptr);
+ }
+ // Note that a `BlockIterator` at the `end()` should not be dereferenced, as
+ // there is no actual block there!
+ [[nodiscard]] BlockIterator end() const {
+ return BlockIterator(mBuffer, nullptr, nullptr, nullptr);
+ }
+
+ // Get a `BlockIterator` at the given `ProfileBufferBlockIndex`, clamped to
+ // the stored range. Note that a `BlockIterator` at the `end()` should not
+ // be dereferenced, as there is no actual block there!
+ [[nodiscard]] BlockIterator At(ProfileBufferBlockIndex aBlockIndex) const {
+ if (aBlockIndex < BufferRangeStart()) {
+ // Anything before the range (including null ProfileBufferBlockIndex) is
+ // clamped at the beginning.
+ return begin();
+ }
+ // Otherwise we at least expect the index to be valid (pointing exactly at
+ // a live block, or just past the end.)
+ return BlockIterator(mBuffer, mChunks0, mChunks1, aBlockIndex);
+ }
+
+ // Run `aCallback(ProfileBufferEntryReader&)` on each entry from first to
+ // last. Callback should not store `ProfileBufferEntryReader`, as it may
+ // become invalid after this thread-safe call.
+ template <typename Callback>
+ void ForEach(Callback&& aCallback) const {
+ for (ProfileBufferEntryReader reader : *this) {
+ aCallback(reader);
+ }
+ }
+
+ // If this reader only points at one chunk with some data, this data will be
+ // exposed as a single entry.
+ [[nodiscard]] ProfileBufferEntryReader SingleChunkDataAsEntry() {
+ const ProfileBufferChunk* onlyNonEmptyChunk = nullptr;
+ for (const ProfileBufferChunk* chunkList : {mChunks0, mChunks1}) {
+ for (const ProfileBufferChunk* chunk = chunkList; chunk;
+ chunk = chunk->GetNext()) {
+ if (chunk->OffsetFirstBlock() != chunk->OffsetPastLastBlock()) {
+ if (onlyNonEmptyChunk) {
+ // More than one non-empty chunk.
+ return ProfileBufferEntryReader();
+ }
+ onlyNonEmptyChunk = chunk;
+ }
+ }
+ }
+ if (!onlyNonEmptyChunk) {
+ // No non-empty chunks.
+ return ProfileBufferEntryReader();
+ }
+ // Here, we have found one chunk that had some data.
+ return ProfileBufferEntryReader(
+ onlyNonEmptyChunk->BufferSpan().FromTo(
+ onlyNonEmptyChunk->OffsetFirstBlock(),
+ onlyNonEmptyChunk->OffsetPastLastBlock()),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ onlyNonEmptyChunk->RangeStart()),
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ onlyNonEmptyChunk->RangeStart() +
+ (onlyNonEmptyChunk->OffsetPastLastBlock() -
+ onlyNonEmptyChunk->OffsetFirstBlock())));
+ }
+
+ private:
+ friend class ProfileChunkedBuffer;
+
+ explicit Reader(const ProfileChunkedBuffer& aBuffer,
+ const ProfileBufferChunk* aChunks0,
+ const ProfileBufferChunk* aChunks1)
+ : mBuffer(aBuffer), mChunks0(aChunks0), mChunks1(aChunks1) {
+ // No Reader should live outside of a mutexed call.
+ mBuffer.mMutex.AssertCurrentThreadOwns();
+ }
+
+ // This Reader should only live inside one of the thread-safe
+ // ProfileChunkedBuffer functions, for this reference to stay valid.
+ const ProfileChunkedBuffer& mBuffer;
+ const ProfileBufferChunk* mChunks0;
+ const ProfileBufferChunk* mChunks1;
+ };
+
+ // In in-session, call `aCallback(ProfileChunkedBuffer::Reader&)` and return
+ // true. Callback should not store `Reader`, because it may become invalid
+ // after this call.
+ // If out-of-session, return false (callback is not invoked).
+ template <typename Callback>
+ [[nodiscard]] auto Read(Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return std::forward<Callback>(aCallback)(static_cast<Reader*>(nullptr));
+ }
+ return mChunkManager->PeekExtantReleasedChunks(
+ [&](const ProfileBufferChunk* aOldestChunk) {
+ Reader reader(*this, aOldestChunk, mCurrentChunk.get());
+ return std::forward<Callback>(aCallback)(&reader);
+ });
+ }
+
+ // Invoke `aCallback(ProfileBufferEntryReader& [, ProfileBufferBlockIndex])`
+ // on each entry, it must read or at least skip everything. Either/both chunk
+ // pointers may be null.
+ template <typename Callback>
+ static void ReadEach(const ProfileBufferChunk* aChunks0,
+ const ProfileBufferChunk* aChunks1,
+ Callback&& aCallback) {
+ static_assert(std::is_invocable_v<Callback, ProfileBufferEntryReader&> ||
+ std::is_invocable_v<Callback, ProfileBufferEntryReader&,
+ ProfileBufferBlockIndex>,
+ "ReadEach callback must take ProfileBufferEntryReader& and "
+ "optionally a ProfileBufferBlockIndex");
+ profiler::detail::InChunkPointer p{aChunks0, aChunks1};
+ while (!p.IsNull()) {
+ // The position right before an entry size *is* a block index.
+ const ProfileBufferBlockIndex blockIndex =
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ p.GlobalRangePosition());
+ Length entrySize = p.ReadEntrySize();
+ if (entrySize == 0) {
+ return;
+ }
+ ProfileBufferEntryReader entryReader = p.EntryReader(entrySize);
+ if (entryReader.RemainingBytes() == 0) {
+ return;
+ }
+ MOZ_ASSERT(entryReader.RemainingBytes() == entrySize);
+ if constexpr (std::is_invocable_v<Callback, ProfileBufferEntryReader&,
+ ProfileBufferBlockIndex>) {
+ aCallback(entryReader, blockIndex);
+ } else {
+ Unused << blockIndex;
+ aCallback(entryReader);
+ }
+ MOZ_ASSERT(entryReader.RemainingBytes() == 0);
+ }
+ }
+
+ // Invoke `aCallback(ProfileBufferEntryReader& [, ProfileBufferBlockIndex])`
+ // on each entry, it must read or at least skip everything.
+ template <typename Callback>
+ void ReadEach(Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return;
+ }
+ mChunkManager->PeekExtantReleasedChunks(
+ [&](const ProfileBufferChunk* aOldestChunk) {
+ ReadEach(aOldestChunk, mCurrentChunk.get(),
+ std::forward<Callback>(aCallback));
+ });
+ }
+
+ // Call `aCallback(Maybe<ProfileBufferEntryReader>&&)` on the entry at
+ // the given ProfileBufferBlockIndex; The `Maybe` will be `Nothing` if
+ // out-of-session, or if that entry doesn't exist anymore, or if we've reached
+ // just past the last entry. Return whatever `aCallback` returns. Callback
+ // should not store `ProfileBufferEntryReader`, because it may become invalid
+ // after this call.
+ // Either/both chunk pointers may be null.
+ template <typename Callback>
+ [[nodiscard]] static auto ReadAt(ProfileBufferBlockIndex aMinimumBlockIndex,
+ const ProfileBufferChunk* aChunks0,
+ const ProfileBufferChunk* aChunks1,
+ Callback&& aCallback) {
+ static_assert(
+ std::is_invocable_v<Callback, Maybe<ProfileBufferEntryReader>&&>,
+ "ReadAt callback must take a Maybe<ProfileBufferEntryReader>&&");
+ Maybe<ProfileBufferEntryReader> maybeEntryReader;
+ if (profiler::detail::InChunkPointer p{aChunks0, aChunks1}; !p.IsNull()) {
+ // If the pointer position is before the given position, try to advance.
+ if (p.GlobalRangePosition() >=
+ aMinimumBlockIndex.ConvertToProfileBufferIndex() ||
+ p.AdvanceToGlobalRangePosition(
+ aMinimumBlockIndex.ConvertToProfileBufferIndex())) {
+ MOZ_ASSERT(p.GlobalRangePosition() >=
+ aMinimumBlockIndex.ConvertToProfileBufferIndex());
+ // Here we're pointing at the start of a block, try to read the entry
+ // size. (Entries cannot be empty, so 0 means failure.)
+ if (Length entrySize = p.ReadEntrySize(); entrySize != 0) {
+ maybeEntryReader.emplace(p.EntryReader(entrySize));
+ if (maybeEntryReader->RemainingBytes() == 0) {
+ // An empty entry reader means there was no complete block at the
+ // given index.
+ maybeEntryReader.reset();
+ } else {
+ MOZ_ASSERT(maybeEntryReader->RemainingBytes() == entrySize);
+ }
+ }
+ }
+ }
+#ifdef DEBUG
+ auto assertAllRead = MakeScopeExit([&]() {
+ MOZ_ASSERT(!maybeEntryReader || maybeEntryReader->RemainingBytes() == 0);
+ });
+#endif // DEBUG
+ return std::forward<Callback>(aCallback)(std::move(maybeEntryReader));
+ }
+
+ // Call `aCallback(Maybe<ProfileBufferEntryReader>&&)` on the entry at
+ // the given ProfileBufferBlockIndex; The `Maybe` will be `Nothing` if
+ // out-of-session, or if that entry doesn't exist anymore, or if we've reached
+ // just past the last entry. Return whatever `aCallback` returns. Callback
+ // should not store `ProfileBufferEntryReader`, because it may become invalid
+ // after this call.
+ template <typename Callback>
+ [[nodiscard]] auto ReadAt(ProfileBufferBlockIndex aBlockIndex,
+ Callback&& aCallback) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return std::forward<Callback>(aCallback)(Nothing{});
+ }
+ return mChunkManager->PeekExtantReleasedChunks(
+ [&](const ProfileBufferChunk* aOldestChunk) {
+ return ReadAt(aBlockIndex, aOldestChunk, mCurrentChunk.get(),
+ std::forward<Callback>(aCallback));
+ });
+ }
+
+ // Append the contents of another ProfileChunkedBuffer to this one.
+ ProfileBufferBlockIndex AppendContents(const ProfileChunkedBuffer& aSrc) {
+ ProfileBufferBlockIndex firstBlockIndex;
+ // If we start failing, we'll stop writing.
+ bool failed = false;
+ aSrc.ReadEach([&](ProfileBufferEntryReader& aER) {
+ if (failed) {
+ return;
+ }
+ failed =
+ !Put(aER.RemainingBytes(), [&](Maybe<ProfileBufferEntryWriter>& aEW) {
+ if (aEW.isNothing()) {
+ return false;
+ }
+ if (!firstBlockIndex) {
+ firstBlockIndex = aEW->CurrentBlockIndex();
+ }
+ aEW->WriteFromReader(aER, aER.RemainingBytes());
+ return true;
+ });
+ });
+ return failed ? nullptr : firstBlockIndex;
+ }
+
+#ifdef DEBUG
+ void Dump(std::FILE* aFile = stdout) const {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ fprintf(aFile,
+ "ProfileChunkedBuffer[%p] State: range %u-%u pushed=%u cleared=%u "
+ "(live=%u) failed-puts=%u bytes",
+ this, unsigned(mRangeStart), unsigned(mRangeEnd),
+ unsigned(mPushedBlockCount), unsigned(mClearedBlockCount),
+ unsigned(mPushedBlockCount) - unsigned(mClearedBlockCount),
+ unsigned(mFailedPutBytes));
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ fprintf(aFile, " - Out-of-session\n");
+ return;
+ }
+ fprintf(aFile, " - chunks:\n");
+ bool hasChunks = false;
+ mChunkManager->PeekExtantReleasedChunks(
+ [&](const ProfileBufferChunk* aOldestChunk) {
+ for (const ProfileBufferChunk* chunk = aOldestChunk; chunk;
+ chunk = chunk->GetNext()) {
+ fprintf(aFile, "R ");
+ chunk->Dump(aFile);
+ hasChunks = true;
+ }
+ });
+ if (mCurrentChunk) {
+ fprintf(aFile, "C ");
+ mCurrentChunk->Dump(aFile);
+ hasChunks = true;
+ }
+ for (const ProfileBufferChunk* chunk = mNextChunks.get(); chunk;
+ chunk = chunk->GetNext()) {
+ fprintf(aFile, "N ");
+ chunk->Dump(aFile);
+ hasChunks = true;
+ }
+ switch (mRequestedChunkHolder->GetState()) {
+ case RequestedChunkRefCountedHolder::State::Unused:
+ fprintf(aFile, " - No request pending.\n");
+ break;
+ case RequestedChunkRefCountedHolder::State::Requested:
+ fprintf(aFile, " - Request pending.\n");
+ break;
+ case RequestedChunkRefCountedHolder::State::Fulfilled:
+ fprintf(aFile, " - Request fulfilled.\n");
+ break;
+ }
+ if (!hasChunks) {
+ fprintf(aFile, " No chunks.\n");
+ }
+ }
+#endif // DEBUG
+
+ private:
+ // Used to de/serialize a ProfileChunkedBuffer (e.g., containing a backtrace).
+ friend ProfileBufferEntryWriter::Serializer<ProfileChunkedBuffer>;
+ friend ProfileBufferEntryReader::Deserializer<ProfileChunkedBuffer>;
+ friend ProfileBufferEntryWriter::Serializer<UniquePtr<ProfileChunkedBuffer>>;
+ friend ProfileBufferEntryReader::Deserializer<
+ UniquePtr<ProfileChunkedBuffer>>;
+
+ [[nodiscard]] UniquePtr<ProfileBufferChunkManager> ResetChunkManager(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock&) {
+ UniquePtr<ProfileBufferChunkManager> chunkManager;
+ if (mChunkManager) {
+ mRequestedChunkHolder = nullptr;
+ mChunkManager->ForgetUnreleasedChunks();
+#ifdef DEBUG
+ mChunkManager->DeregisteredFrom(this);
+#endif
+ mChunkManager = nullptr;
+ chunkManager = std::move(mOwnedChunkManager);
+ if (mCurrentChunk) {
+ mCurrentChunk->MarkDone();
+ mCurrentChunk = nullptr;
+ }
+ mNextChunks = nullptr;
+ mNextChunkRangeStart = mRangeEnd;
+ mRangeStart = mRangeEnd;
+ mPushedBlockCount = 0;
+ mClearedBlockCount = 0;
+ mFailedPutBytes = 0;
+ }
+ return chunkManager;
+ }
+
+ void SetChunkManager(
+ ProfileBufferChunkManager& aChunkManager,
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ MOZ_ASSERT(!mChunkManager);
+ mChunkManager = &aChunkManager;
+#ifdef DEBUG
+ mChunkManager->RegisteredWith(this);
+#endif
+
+ mChunkManager->SetChunkDestroyedCallback(
+ [this](const ProfileBufferChunk& aChunk) {
+ for (;;) {
+ ProfileBufferIndex rangeStart = mRangeStart;
+ if (MOZ_LIKELY(rangeStart <= aChunk.RangeStart())) {
+ if (MOZ_LIKELY(mRangeStart.compareExchange(
+ rangeStart,
+ aChunk.RangeStart() + aChunk.BufferBytes()))) {
+ break;
+ }
+ }
+ }
+ mClearedBlockCount += aChunk.BlockCount();
+ });
+
+ // We start with one chunk right away, and request a following one now
+ // so it should be available before the current chunk is full.
+ SetAndInitializeCurrentChunk(mChunkManager->GetChunk(), aLock);
+ mRequestedChunkHolder = MakeRefPtr<RequestedChunkRefCountedHolder>();
+ RequestChunk(aLock);
+ }
+
+ [[nodiscard]] size_t SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf,
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock&) const {
+ if (MOZ_UNLIKELY(!mChunkManager)) {
+ // Out-of-session.
+ return 0;
+ }
+ size_t size = mChunkManager->SizeOfIncludingThis(aMallocSizeOf);
+ if (mCurrentChunk) {
+ size += mCurrentChunk->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ if (mNextChunks) {
+ size += mNextChunks->SizeOfIncludingThis(aMallocSizeOf);
+ }
+ return size;
+ }
+
+ void InitializeCurrentChunk(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock&) {
+ MOZ_ASSERT(!!mCurrentChunk);
+ mCurrentChunk->SetRangeStart(mNextChunkRangeStart);
+ mNextChunkRangeStart += mCurrentChunk->BufferBytes();
+ Unused << mCurrentChunk->ReserveInitialBlockAsTail(0);
+ }
+
+ void SetAndInitializeCurrentChunk(
+ UniquePtr<ProfileBufferChunk>&& aChunk,
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ mCurrentChunk = std::move(aChunk);
+ if (mCurrentChunk) {
+ InitializeCurrentChunk(aLock);
+ }
+ }
+
+ void RequestChunk(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ if (HandleRequestedChunk_IsPending(aLock)) {
+ // There is already a pending request, don't start a new one.
+ return;
+ }
+
+ // Ensure the `RequestedChunkHolder` knows we're starting a request.
+ mRequestedChunkHolder->StartRequest();
+
+ // Request a chunk, the callback carries a `RefPtr` of the
+ // `RequestedChunkHolder`, so it's guaranteed to live until it's invoked,
+ // even if this `ProfileChunkedBuffer` changes its `ChunkManager` or is
+ // destroyed.
+ mChunkManager->RequestChunk(
+ [requestedChunkHolder = RefPtr<RequestedChunkRefCountedHolder>(
+ mRequestedChunkHolder)](UniquePtr<ProfileBufferChunk> aChunk) {
+ requestedChunkHolder->AddRequestedChunk(std::move(aChunk));
+ });
+ }
+
+ [[nodiscard]] bool HandleRequestedChunk_IsPending(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ MOZ_ASSERT(!!mChunkManager);
+ MOZ_ASSERT(!!mRequestedChunkHolder);
+
+ if (mRequestedChunkHolder->GetState() ==
+ RequestedChunkRefCountedHolder::State::Unused) {
+ return false;
+ }
+
+ // A request is either in-flight or fulfilled.
+ Maybe<UniquePtr<ProfileBufferChunk>> maybeChunk =
+ mRequestedChunkHolder->GetChunkIfFulfilled();
+ if (maybeChunk.isNothing()) {
+ // Request is still pending.
+ return true;
+ }
+
+ // Since we extracted the provided chunk, the holder should now be unused.
+ MOZ_ASSERT(mRequestedChunkHolder->GetState() ==
+ RequestedChunkRefCountedHolder::State::Unused);
+
+ // Request has been fulfilled.
+ UniquePtr<ProfileBufferChunk>& chunk = *maybeChunk;
+ if (chunk) {
+ // Try to use as current chunk if needed.
+ if (!mCurrentChunk) {
+ SetAndInitializeCurrentChunk(std::move(chunk), aLock);
+ // We've just received a chunk and made it current, request a next chunk
+ // for later.
+ MOZ_ASSERT(!mNextChunks);
+ RequestChunk(aLock);
+ return true;
+ }
+
+ if (!mNextChunks) {
+ mNextChunks = std::move(chunk);
+ } else {
+ mNextChunks->InsertNext(std::move(chunk));
+ }
+ }
+
+ return false;
+ }
+
+ // Get a pointer to the next chunk available
+ [[nodiscard]] ProfileBufferChunk* GetOrCreateCurrentChunk(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ ProfileBufferChunk* current = mCurrentChunk.get();
+ if (MOZ_UNLIKELY(!current)) {
+ // No current chunk ready.
+ MOZ_ASSERT(!mNextChunks,
+ "There shouldn't be next chunks when there is no current one");
+ // See if a request has recently been fulfilled, ignore pending status.
+ Unused << HandleRequestedChunk_IsPending(aLock);
+ current = mCurrentChunk.get();
+ if (MOZ_UNLIKELY(!current)) {
+ // There was no pending chunk, try to get one right now.
+ // This may still fail, but we can't do anything else about it, the
+ // caller must handle the nullptr case.
+ // Attempt a request for later.
+ SetAndInitializeCurrentChunk(mChunkManager->GetChunk(), aLock);
+ current = mCurrentChunk.get();
+ }
+ }
+ return current;
+ }
+
+ // Get a pointer to the next chunk available
+ [[nodiscard]] ProfileBufferChunk* GetOrCreateNextChunk(
+ const baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock) {
+ MOZ_ASSERT(!!mCurrentChunk,
+ "Why ask for a next chunk when there isn't even a current one?");
+ ProfileBufferChunk* next = mNextChunks.get();
+ if (MOZ_UNLIKELY(!next)) {
+ // No next chunk ready, see if a request has recently been fulfilled,
+ // ignore pending status.
+ Unused << HandleRequestedChunk_IsPending(aLock);
+ next = mNextChunks.get();
+ if (MOZ_UNLIKELY(!next)) {
+ // There was no pending chunk, try to get one right now.
+ mNextChunks = mChunkManager->GetChunk();
+ next = mNextChunks.get();
+ // This may still fail, but we can't do anything else about it, the
+ // caller must handle the nullptr case.
+ if (MOZ_UNLIKELY(!next)) {
+ // Attempt a request for later.
+ RequestChunk(aLock);
+ }
+ }
+ }
+ return next;
+ }
+
+ // Reserve a block of `aCallbackBlockBytes()` size, and invoke and return
+ // `aCallback(Maybe<ProfileBufferEntryWriter>&)`. Note that this is the "raw"
+ // version that doesn't write the entry size at the beginning of the block.
+ // Note: `aCallbackBlockBytes` is a callback instead of a simple value, to
+ // delay this potentially-expensive computation until after we're checked that
+ // we're in-session; use `Put(Length, Callback)` below if you know the size
+ // already.
+ template <typename CallbackBlockBytes, typename Callback>
+ auto ReserveAndPutRaw(CallbackBlockBytes&& aCallbackBlockBytes,
+ Callback&& aCallback,
+ baseprofiler::detail::BaseProfilerMaybeAutoLock& aLock,
+ uint64_t aBlockCount = 1) {
+ // The entry writer that will point into one or two chunks to write
+ // into, empty by default (failure).
+ Maybe<ProfileBufferEntryWriter> maybeEntryWriter;
+
+ // The current chunk will be filled if we need to write more than its
+ // remaining space.
+ bool currentChunkFilled = false;
+
+ // If the current chunk gets filled, we may or may not initialize the next
+ // chunk!
+ bool nextChunkInitialized = false;
+
+ if (MOZ_LIKELY(mChunkManager)) {
+ // In-session.
+
+ const Length blockBytes =
+ std::forward<CallbackBlockBytes>(aCallbackBlockBytes)();
+
+ if (ProfileBufferChunk* current = GetOrCreateCurrentChunk(aLock);
+ MOZ_LIKELY(current)) {
+ if (blockBytes <= current->RemainingBytes()) {
+ // Block fits in current chunk with only one span.
+ currentChunkFilled = blockBytes == current->RemainingBytes();
+ const auto [mem0, blockIndex] = current->ReserveBlock(blockBytes);
+ MOZ_ASSERT(mem0.LengthBytes() == blockBytes);
+ maybeEntryWriter.emplace(
+ mem0, blockIndex,
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ blockIndex.ConvertToProfileBufferIndex() + blockBytes));
+ MOZ_ASSERT(maybeEntryWriter->RemainingBytes() == blockBytes);
+ mRangeEnd += blockBytes;
+ mPushedBlockCount += aBlockCount;
+ } else if (blockBytes >= current->BufferBytes()) {
+ // Currently only two buffer chunks are held at a time and it is not
+ // possible to write an object that takes up more space than this. In
+ // this scenario, silently discard this block of data if it is unable
+ // to fit into the two reserved profiler chunks.
+ mFailedPutBytes += blockBytes;
+ } else {
+ // Block doesn't fit fully in current chunk, it needs to overflow into
+ // the next one.
+ // Whether or not we can write this entry, the current chunk is now
+ // considered full, so it will be released. (Otherwise we could refuse
+ // this entry, but later accept a smaller entry into this chunk, which
+ // would be somewhat inconsistent.)
+ currentChunkFilled = true;
+ // Make sure the next chunk is available (from a previous request),
+ // otherwise create one on the spot.
+ if (ProfileBufferChunk* next = GetOrCreateNextChunk(aLock);
+ MOZ_LIKELY(next)) {
+ // Here, we know we have a current and a next chunk.
+ // Reserve head of block at the end of the current chunk.
+ const auto [mem0, blockIndex] =
+ current->ReserveBlock(current->RemainingBytes());
+ MOZ_ASSERT(mem0.LengthBytes() < blockBytes);
+ MOZ_ASSERT(current->RemainingBytes() == 0);
+ // Set the next chunk range, and reserve the needed space for the
+ // tail of the block.
+ next->SetRangeStart(mNextChunkRangeStart);
+ mNextChunkRangeStart += next->BufferBytes();
+ const auto mem1 = next->ReserveInitialBlockAsTail(
+ blockBytes - mem0.LengthBytes());
+ MOZ_ASSERT(next->RemainingBytes() != 0);
+ nextChunkInitialized = true;
+ // Block is split in two spans.
+ maybeEntryWriter.emplace(
+ mem0, mem1, blockIndex,
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ blockIndex.ConvertToProfileBufferIndex() + blockBytes));
+ MOZ_ASSERT(maybeEntryWriter->RemainingBytes() == blockBytes);
+ mRangeEnd += blockBytes;
+ mPushedBlockCount += aBlockCount;
+ } else {
+ // Cannot get a new chunk. Record put failure.
+ mFailedPutBytes += blockBytes;
+ }
+ }
+ } else {
+ // Cannot get a current chunk. Record put failure.
+ mFailedPutBytes += blockBytes;
+ }
+ } // end of `if (MOZ_LIKELY(mChunkManager))`
+
+ // Here, we either have a `Nothing` (failure), or a non-empty entry writer
+ // pointing at the start of the block.
+
+ // After we invoke the callback and return, we may need to handle the
+ // current chunk being filled.
+ auto handleFilledChunk = MakeScopeExit([&]() {
+ // If the entry writer was not already empty, the callback *must* have
+ // filled the full entry.
+ MOZ_ASSERT(!maybeEntryWriter || maybeEntryWriter->RemainingBytes() == 0);
+
+ if (currentChunkFilled) {
+ // Extract current (now filled) chunk.
+ UniquePtr<ProfileBufferChunk> filled = std::move(mCurrentChunk);
+
+ if (mNextChunks) {
+ // Cycle to the next chunk.
+ mCurrentChunk =
+ std::exchange(mNextChunks, mNextChunks->ReleaseNext());
+
+ // Make sure it is initialized (it is now the current chunk).
+ if (!nextChunkInitialized) {
+ InitializeCurrentChunk(aLock);
+ }
+ }
+
+ // And finally mark filled chunk done and release it.
+ filled->MarkDone();
+ mChunkManager->ReleaseChunk(std::move(filled));
+
+ // Request another chunk if needed.
+ // In most cases, here we should have one current chunk and no next
+ // chunk, so we want to do a request so there hopefully will be a next
+ // chunk available when the current one gets filled.
+ // But we also for a request if we don't even have a current chunk (if
+ // it's too late, it's ok because the next `ReserveAndPutRaw` wil just
+ // allocate one on the spot.)
+ // And if we already have a next chunk, there's no need for more now.
+ if (!mCurrentChunk || !mNextChunks) {
+ RequestChunk(aLock);
+ }
+ }
+ });
+
+ return std::forward<Callback>(aCallback)(maybeEntryWriter);
+ }
+
+ // Reserve a block of `aBlockBytes` size, and invoke and return
+ // `aCallback(Maybe<ProfileBufferEntryWriter>&)`. Note that this is the "raw"
+ // version that doesn't write the entry size at the beginning of the block.
+ template <typename Callback>
+ auto ReserveAndPutRaw(Length aBlockBytes, Callback&& aCallback,
+ uint64_t aBlockCount) {
+ baseprofiler::detail::BaseProfilerMaybeAutoLock lock(mMutex);
+ return ReserveAndPutRaw([aBlockBytes]() { return aBlockBytes; },
+ std::forward<Callback>(aCallback), lock,
+ aBlockCount);
+ }
+
+ // Mutex guarding the following members.
+ mutable baseprofiler::detail::BaseProfilerMaybeMutex mMutex;
+
+ // Pointer to the current Chunk Manager (or null when out-of-session.)
+ // It may be owned locally (see below) or externally.
+ ProfileBufferChunkManager* mChunkManager = nullptr;
+
+ // Only non-null when we own the current Chunk Manager.
+ UniquePtr<ProfileBufferChunkManager> mOwnedChunkManager;
+
+ UniquePtr<ProfileBufferChunk> mCurrentChunk;
+
+ UniquePtr<ProfileBufferChunk> mNextChunks;
+
+ // Class used to transfer requested chunks from a `ChunkManager` to a
+ // `ProfileChunkedBuffer`.
+ // It needs to be ref-counted because the request may be fulfilled
+ // asynchronously, and either side may be destroyed during the request.
+ // It cannot use the `ProfileChunkedBuffer` mutex, because that buffer and its
+ // mutex could be destroyed during the request.
+ class RequestedChunkRefCountedHolder {
+ public:
+ enum class State { Unused, Requested, Fulfilled };
+
+ // Get the current state. Note that it may change after the function
+ // returns, so it should be used carefully, e.g., `ProfileChunkedBuffer` can
+ // see if a request is pending or fulfilled, to avoid starting another
+ // request.
+ [[nodiscard]] State GetState() const {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ return mState;
+ }
+
+ // Must be called by `ProfileChunkedBuffer` when it requests a chunk.
+ // There cannot be more than one request in-flight.
+ void StartRequest() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ MOZ_ASSERT(mState == State::Unused, "Already requested or fulfilled");
+ mState = State::Requested;
+ }
+
+ // Must be called by the `ChunkManager` with a chunk.
+ // If the `ChunkManager` cannot provide a chunk (because of memory limits,
+ // or it gets destroyed), it must call this anyway with a nullptr.
+ void AddRequestedChunk(UniquePtr<ProfileBufferChunk>&& aChunk) {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ MOZ_ASSERT(mState == State::Requested);
+ mState = State::Fulfilled;
+ mRequestedChunk = std::move(aChunk);
+ }
+
+ // The `ProfileChunkedBuffer` can try to extract the provided chunk after a
+ // request:
+ // - Nothing -> Request is not fulfilled yet.
+ // - Some(nullptr) -> The `ChunkManager` was not able to provide a chunk.
+ // - Some(chunk) -> Requested chunk.
+ [[nodiscard]] Maybe<UniquePtr<ProfileBufferChunk>> GetChunkIfFulfilled() {
+ Maybe<UniquePtr<ProfileBufferChunk>> maybeChunk;
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ MOZ_ASSERT(mState == State::Requested || mState == State::Fulfilled);
+ if (mState == State::Fulfilled) {
+ mState = State::Unused;
+ maybeChunk.emplace(std::move(mRequestedChunk));
+ }
+ return maybeChunk;
+ }
+
+ // Ref-counting implementation. Hand-rolled, because mozilla::RefCounted
+ // logs AddRefs and Releases in xpcom, but this object could be AddRef'd
+ // by the Base Profiler before xpcom starts, then Release'd by the Gecko
+ // Profiler in xpcom, leading to apparent negative leaks.
+
+ void AddRef() {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ ++mRefCount;
+ }
+
+ void Release() {
+ {
+ baseprofiler::detail::BaseProfilerAutoLock lock(mRequestMutex);
+ if (--mRefCount > 0) {
+ return;
+ }
+ }
+ delete this;
+ }
+
+ private:
+ ~RequestedChunkRefCountedHolder() = default;
+
+ // Mutex guarding the following members.
+ mutable baseprofiler::detail::BaseProfilerMutex mRequestMutex;
+ int mRefCount = 0;
+ State mState = State::Unused;
+ UniquePtr<ProfileBufferChunk> mRequestedChunk;
+ };
+
+ // Requested-chunk holder, kept alive when in-session, but may also live
+ // longer if a request is in-flight.
+ RefPtr<RequestedChunkRefCountedHolder> mRequestedChunkHolder;
+
+ // Range start of the next chunk to become current. Starting at 1 because
+ // 0 is a reserved index similar to nullptr.
+ ProfileBufferIndex mNextChunkRangeStart = 1;
+
+ // Index to the first block.
+ // Atomic because it may be increased when a Chunk is destroyed, and the
+ // callback may be invoked from anywhere, including from inside one of our
+ // locked section, so we cannot protect it with a mutex.
+ Atomic<ProfileBufferIndex, MemoryOrdering::ReleaseAcquire> mRangeStart{1};
+
+ // Index past the last block. Equals mRangeStart if empty.
+ ProfileBufferIndex mRangeEnd = 1;
+
+ // Number of blocks that have been pushed into this buffer.
+ uint64_t mPushedBlockCount = 0;
+
+ // Number of blocks that have been removed from this buffer.
+ // Note: Live entries = pushed - cleared.
+ // Atomic because it may be updated when a Chunk is destroyed, and the
+ // callback may be invoked from anywhere, including from inside one of our
+ // locked section, so we cannot protect it with a mutex.
+ Atomic<uint64_t, MemoryOrdering::ReleaseAcquire> mClearedBlockCount{0};
+
+ // Number of bytes that could not be put into this buffer.
+ uint64_t mFailedPutBytes = 0;
+};
+
+// ----------------------------------------------------------------------------
+// ProfileChunkedBuffer serialization
+
+// A ProfileChunkedBuffer can hide another one!
+// This will be used to store marker backtraces; They can be read back into a
+// UniquePtr<ProfileChunkedBuffer>.
+// Format: len (ULEB128) | start | end | buffer (len bytes) | pushed | cleared
+// len==0 marks an out-of-session buffer, or empty buffer.
+template <>
+struct ProfileBufferEntryWriter::Serializer<ProfileChunkedBuffer> {
+ static Length Bytes(const ProfileChunkedBuffer& aBuffer) {
+ return aBuffer.Read([&](ProfileChunkedBuffer::Reader* aReader) {
+ if (!aReader) {
+ // Out-of-session, we only need 1 byte to store a length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ ProfileBufferEntryReader reader = aReader->SingleChunkDataAsEntry();
+ const ProfileBufferIndex start =
+ reader.CurrentBlockIndex().ConvertToProfileBufferIndex();
+ const ProfileBufferIndex end =
+ reader.NextBlockIndex().ConvertToProfileBufferIndex();
+ MOZ_ASSERT(end - start <= std::numeric_limits<Length>::max());
+ const Length len = static_cast<Length>(end - start);
+ if (len == 0) {
+ // In-session but empty, also store a length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ // In-session.
+ return static_cast<Length>(ULEB128Size(len) + sizeof(start) + len +
+ sizeof(aBuffer.mPushedBlockCount) +
+ sizeof(aBuffer.mClearedBlockCount));
+ });
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const ProfileChunkedBuffer& aBuffer) {
+ aBuffer.Read([&](ProfileChunkedBuffer::Reader* aReader) {
+ if (!aReader) {
+ // Out-of-session, only store a length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ ProfileBufferEntryReader reader = aReader->SingleChunkDataAsEntry();
+ const ProfileBufferIndex start =
+ reader.CurrentBlockIndex().ConvertToProfileBufferIndex();
+ const ProfileBufferIndex end =
+ reader.NextBlockIndex().ConvertToProfileBufferIndex();
+ MOZ_ASSERT(end - start <= std::numeric_limits<Length>::max());
+ const Length len = static_cast<Length>(end - start);
+ MOZ_ASSERT(len <= aEW.RemainingBytes());
+ if (len == 0) {
+ // In-session but empty, only store a length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ // In-session.
+ // Store buffer length, and start index.
+ aEW.WriteULEB128(len);
+ aEW.WriteObject(start);
+ // Write all the bytes.
+ aEW.WriteFromReader(reader, reader.RemainingBytes());
+ // And write stats.
+ aEW.WriteObject(static_cast<uint64_t>(aBuffer.mPushedBlockCount));
+ aEW.WriteObject(static_cast<uint64_t>(aBuffer.mClearedBlockCount));
+ // Note: Failed pushes are not important to serialize.
+ });
+ }
+};
+
+// A serialized ProfileChunkedBuffer can be read into an empty buffer (either
+// out-of-session, or in-session with enough room).
+template <>
+struct ProfileBufferEntryReader::Deserializer<ProfileChunkedBuffer> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ ProfileChunkedBuffer& aBuffer) {
+ // Expect an empty buffer, as we're going to overwrite it.
+ MOZ_ASSERT(aBuffer.GetState().mRangeStart == aBuffer.GetState().mRangeEnd);
+ // Read the stored buffer length.
+ const auto len = aER.ReadULEB128<ProfileChunkedBuffer::Length>();
+ if (len == 0) {
+ // 0-length means an "uninteresting" buffer, just return now.
+ return;
+ }
+ // We have a non-empty buffer to read.
+
+ // Read start and end indices.
+ const auto start = aER.ReadObject<ProfileBufferIndex>();
+ aBuffer.mRangeStart = start;
+ // For now, set the end to be the start (the buffer is still empty). It will
+ // be updated in `ReserveAndPutRaw()` below.
+ aBuffer.mRangeEnd = start;
+
+ if (aBuffer.IsInSession()) {
+ // Output buffer is in-session (i.e., it already has a memory buffer
+ // attached). Make sure the caller allocated enough space.
+ MOZ_RELEASE_ASSERT(aBuffer.BufferLength().value() >= len);
+ } else {
+ // Output buffer is out-of-session, set a new chunk manager that will
+ // provide a single chunk of just the right size.
+ aBuffer.SetChunkManager(MakeUnique<ProfileBufferChunkManagerSingle>(len));
+ MOZ_ASSERT(aBuffer.BufferLength().value() >= len);
+ }
+
+ // Copy bytes into the buffer.
+ aBuffer.ReserveAndPutRaw(
+ len,
+ [&](Maybe<ProfileBufferEntryWriter>& aEW) {
+ MOZ_RELEASE_ASSERT(aEW.isSome());
+ aEW->WriteFromReader(aER, len);
+ },
+ 0);
+ // Finally copy stats.
+ aBuffer.mPushedBlockCount = aER.ReadObject<uint64_t>();
+ aBuffer.mClearedBlockCount = aER.ReadObject<uint64_t>();
+ // Failed puts are not important to keep.
+ aBuffer.mFailedPutBytes = 0;
+ }
+
+ // We cannot output a ProfileChunkedBuffer object (not copyable), use
+ // `ReadInto()` or `aER.ReadObject<UniquePtr<BlocksRinbBuffer>>()` instead.
+ static ProfileChunkedBuffer Read(ProfileBufferEntryReader& aER) = delete;
+};
+
+// A ProfileChunkedBuffer is usually refererenced through a UniquePtr, for
+// convenience we support (de)serializing that UniquePtr directly.
+// This is compatible with the non-UniquePtr serialization above, with a null
+// pointer being treated like an out-of-session or empty buffer; and any of
+// these would be deserialized into a null pointer.
+template <>
+struct ProfileBufferEntryWriter::Serializer<UniquePtr<ProfileChunkedBuffer>> {
+ static Length Bytes(const UniquePtr<ProfileChunkedBuffer>& aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ // Otherwise write the pointed-at ProfileChunkedBuffer (which could be
+ // out-of-session or empty.)
+ return SumBytes(*aBufferUPtr);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ const UniquePtr<ProfileChunkedBuffer>& aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ // Otherwise write the pointed-at ProfileChunkedBuffer (which could be
+ // out-of-session or empty.)
+ aEW.WriteObject(*aBufferUPtr);
+ }
+};
+
+// Serialization of a raw pointer to ProfileChunkedBuffer.
+// Use Deserializer<UniquePtr<ProfileChunkedBuffer>> to read it back.
+template <>
+struct ProfileBufferEntryWriter::Serializer<ProfileChunkedBuffer*> {
+ static Length Bytes(ProfileChunkedBuffer* aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ return ULEB128Size<Length>(0);
+ }
+ // Otherwise write the pointed-at ProfileChunkedBuffer (which could be
+ // out-of-session or empty.)
+ return SumBytes(*aBufferUPtr);
+ }
+
+ static void Write(ProfileBufferEntryWriter& aEW,
+ ProfileChunkedBuffer* aBufferUPtr) {
+ if (!aBufferUPtr) {
+ // Null pointer, treat it like an empty buffer, i.e., write length of 0.
+ aEW.WriteULEB128<Length>(0);
+ return;
+ }
+ // Otherwise write the pointed-at ProfileChunkedBuffer (which could be
+ // out-of-session or empty.)
+ aEW.WriteObject(*aBufferUPtr);
+ }
+};
+
+template <>
+struct ProfileBufferEntryReader::Deserializer<UniquePtr<ProfileChunkedBuffer>> {
+ static void ReadInto(ProfileBufferEntryReader& aER,
+ UniquePtr<ProfileChunkedBuffer>& aBuffer) {
+ aBuffer = Read(aER);
+ }
+
+ static UniquePtr<ProfileChunkedBuffer> Read(ProfileBufferEntryReader& aER) {
+ UniquePtr<ProfileChunkedBuffer> bufferUPtr;
+ // Keep a copy of the reader before reading the length, so we can restart
+ // from here below.
+ ProfileBufferEntryReader readerBeforeLen = aER;
+ // Read the stored buffer length.
+ const auto len = aER.ReadULEB128<ProfileChunkedBuffer::Length>();
+ if (len == 0) {
+ // 0-length means an "uninteresting" buffer, just return nullptr.
+ return bufferUPtr;
+ }
+ // We have a non-empty buffer.
+ // allocate an empty ProfileChunkedBuffer without mutex.
+ bufferUPtr = MakeUnique<ProfileChunkedBuffer>(
+ ProfileChunkedBuffer::ThreadSafety::WithoutMutex);
+ // Rewind the reader before the length and deserialize the contents, using
+ // the non-UniquePtr Deserializer.
+ aER = readerBeforeLen;
+ aER.ReadIntoObject(*bufferUPtr);
+ return bufferUPtr;
+ }
+};
+
+} // namespace mozilla
+
+#endif // ProfileChunkedBuffer_h
diff --git a/mozglue/baseprofiler/public/ProfileChunkedBufferDetail.h b/mozglue/baseprofiler/public/ProfileChunkedBufferDetail.h
new file mode 100644
index 0000000000..9828822aaf
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProfileChunkedBufferDetail.h
@@ -0,0 +1,400 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfileChunkedBufferDetail_h
+#define ProfileChunkedBufferDetail_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Likely.h"
+#include "mozilla/ProfileBufferChunk.h"
+#include "mozilla/ProfileBufferEntrySerialization.h"
+
+namespace mozilla::profiler::detail {
+
+// Internal accessor pointing at a position inside a chunk.
+// It can handle two groups of chunks (typically the extant chunks stored in
+// the store manager, and the current chunk).
+// The main operations are:
+// - ReadEntrySize() to read an entry size, 0 means failure.
+// - operator+=(Length) to skip a number of bytes.
+// - EntryReader() creates an entry reader at the current position for a given
+// size (it may fail with an empty reader), and skips the entry.
+// Note that there is no "past-the-end" position -- as soon as InChunkPointer
+// reaches the end, it becomes effectively null.
+class InChunkPointer {
+ public:
+ using Byte = ProfileBufferChunk::Byte;
+ using Length = ProfileBufferChunk::Length;
+
+ // Nullptr-like InChunkPointer, may be used as end iterator.
+ InChunkPointer()
+ : mChunk(nullptr), mNextChunkGroup(nullptr), mOffsetInChunk(0) {}
+
+ // InChunkPointer over one or two chunk groups, pointing at the given
+ // block index (if still in range).
+ // This constructor should only be used with *trusted* block index values!
+ InChunkPointer(const ProfileBufferChunk* aChunk,
+ const ProfileBufferChunk* aNextChunkGroup,
+ ProfileBufferBlockIndex aBlockIndex)
+ : mChunk(aChunk), mNextChunkGroup(aNextChunkGroup) {
+ if (mChunk) {
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ Adjust();
+ } else if (mNextChunkGroup) {
+ mChunk = mNextChunkGroup;
+ mNextChunkGroup = nullptr;
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ Adjust();
+ } else {
+ mOffsetInChunk = 0;
+ }
+
+ // Try to advance to given position.
+ if (!AdvanceToGlobalRangePosition(aBlockIndex)) {
+ // Block does not exist anymore (or block doesn't look valid), reset the
+ // in-chunk pointer.
+ mChunk = nullptr;
+ mNextChunkGroup = nullptr;
+ }
+ }
+
+ // InChunkPointer over one or two chunk groups, will start at the first
+ // block (if any). This may be slow, so avoid using it too much.
+ InChunkPointer(const ProfileBufferChunk* aChunk,
+ const ProfileBufferChunk* aNextChunkGroup,
+ ProfileBufferIndex aIndex = ProfileBufferIndex(0))
+ : mChunk(aChunk), mNextChunkGroup(aNextChunkGroup) {
+ if (mChunk) {
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ Adjust();
+ } else if (mNextChunkGroup) {
+ mChunk = mNextChunkGroup;
+ mNextChunkGroup = nullptr;
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ Adjust();
+ } else {
+ mOffsetInChunk = 0;
+ }
+
+ // Try to advance to given position.
+ if (!AdvanceToGlobalRangePosition(aIndex)) {
+ // Block does not exist anymore, reset the in-chunk pointer.
+ mChunk = nullptr;
+ mNextChunkGroup = nullptr;
+ }
+ }
+
+ // Compute the current position in the global range.
+ // 0 if null (including if we're reached the end).
+ [[nodiscard]] ProfileBufferIndex GlobalRangePosition() const {
+ if (IsNull()) {
+ return 0;
+ }
+ return mChunk->RangeStart() + mOffsetInChunk;
+ }
+
+ // Move InChunkPointer forward to the block at the given global block
+ // position, which is assumed to be valid exactly -- but it may be obsolete.
+ // 0 stays where it is (if valid already).
+ // MOZ_ASSERTs if the index is invalid.
+ [[nodiscard]] bool AdvanceToGlobalRangePosition(
+ ProfileBufferBlockIndex aBlockIndex) {
+ if (IsNull()) {
+ // Pointer is null already. (Not asserting because it's acceptable.)
+ return false;
+ }
+ if (!aBlockIndex) {
+ // Special null position, just stay where we are.
+ return ShouldPointAtValidBlock();
+ }
+ if (aBlockIndex.ConvertToProfileBufferIndex() < GlobalRangePosition()) {
+ // Past the requested position, stay where we are (assuming the current
+ // position was valid).
+ return ShouldPointAtValidBlock();
+ }
+ for (;;) {
+ if (aBlockIndex.ConvertToProfileBufferIndex() <
+ mChunk->RangeStart() + mChunk->OffsetPastLastBlock()) {
+ // Target position is in this chunk's written space, move to it.
+ mOffsetInChunk =
+ aBlockIndex.ConvertToProfileBufferIndex() - mChunk->RangeStart();
+ return ShouldPointAtValidBlock();
+ }
+ // Position is after this chunk, try next chunk.
+ GoToNextChunk();
+ if (IsNull()) {
+ return false;
+ }
+ // Skip whatever block tail there is, we don't allow pointing in the
+ // middle of a block.
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ if (aBlockIndex.ConvertToProfileBufferIndex() < GlobalRangePosition()) {
+ // Past the requested position, meaning that the given position was in-
+ // between blocks -> Failure.
+ MOZ_ASSERT(false, "AdvanceToGlobalRangePosition - In-between blocks");
+ return false;
+ }
+ }
+ }
+
+ // Move InChunkPointer forward to the block at or after the given global
+ // range position.
+ // 0 stays where it is (if valid already).
+ [[nodiscard]] bool AdvanceToGlobalRangePosition(
+ ProfileBufferIndex aPosition) {
+ if (aPosition == 0) {
+ // Special position '0', just stay where we are.
+ // Success if this position is already valid.
+ return !IsNull();
+ }
+ for (;;) {
+ ProfileBufferIndex currentPosition = GlobalRangePosition();
+ if (currentPosition == 0) {
+ // Pointer is null.
+ return false;
+ }
+ if (aPosition <= currentPosition) {
+ // At or past the requested position, stay where we are.
+ return true;
+ }
+ if (aPosition < mChunk->RangeStart() + mChunk->OffsetPastLastBlock()) {
+ // Target position is in this chunk's written space, move to it.
+ for (;;) {
+ // Skip the current block.
+ mOffsetInChunk += ReadEntrySize();
+ if (mOffsetInChunk >= mChunk->OffsetPastLastBlock()) {
+ // Reached the end of the chunk, this can happen for the last
+ // block, let's just continue to the next chunk.
+ break;
+ }
+ if (aPosition <= mChunk->RangeStart() + mOffsetInChunk) {
+ // We're at or after the position, return at this block position.
+ return true;
+ }
+ }
+ }
+ // Position is after this chunk, try next chunk.
+ GoToNextChunk();
+ if (IsNull()) {
+ return false;
+ }
+ // Skip whatever block tail there is, we don't allow pointing in the
+ // middle of a block.
+ mOffsetInChunk = mChunk->OffsetFirstBlock();
+ }
+ }
+
+ [[nodiscard]] Byte ReadByte() {
+ MOZ_ASSERT(!IsNull());
+ MOZ_ASSERT(mOffsetInChunk < mChunk->OffsetPastLastBlock());
+ Byte byte = mChunk->ByteAt(mOffsetInChunk);
+ if (MOZ_UNLIKELY(++mOffsetInChunk == mChunk->OffsetPastLastBlock())) {
+ Adjust();
+ }
+ return byte;
+ }
+
+ // Read and skip a ULEB128-encoded size.
+ // 0 means failure (0-byte entries are not allowed.)
+ // Note that this doesn't guarantee that there are actually that many bytes
+ // available to read! (EntryReader() below may gracefully fail.)
+ [[nodiscard]] Length ReadEntrySize() {
+ ULEB128Reader<Length> reader;
+ if (IsNull()) {
+ return 0;
+ }
+ for (;;) {
+ const bool isComplete = reader.FeedByteIsComplete(ReadByte());
+ if (MOZ_UNLIKELY(IsNull())) {
+ // End of chunks, so there's no actual entry after this anyway.
+ return 0;
+ }
+ if (MOZ_LIKELY(isComplete)) {
+ if (MOZ_UNLIKELY(reader.Value() > mChunk->BufferBytes())) {
+ // Don't allow entries larger than a chunk.
+ return 0;
+ }
+ return reader.Value();
+ }
+ }
+ }
+
+ InChunkPointer& operator+=(Length aLength) {
+ MOZ_ASSERT(!IsNull());
+ mOffsetInChunk += aLength;
+ Adjust();
+ return *this;
+ }
+
+ [[nodiscard]] ProfileBufferEntryReader EntryReader(Length aLength) {
+ if (IsNull() || aLength == 0) {
+ return ProfileBufferEntryReader();
+ }
+
+ MOZ_ASSERT(mOffsetInChunk < mChunk->OffsetPastLastBlock());
+
+ // We should be pointing at the entry, past the entry size.
+ const ProfileBufferIndex entryIndex = GlobalRangePosition();
+ // Verify that there's enough space before for the size (starting at index
+ // 1 at least).
+ MOZ_ASSERT(entryIndex >= 1u + ULEB128Size(aLength));
+
+ const Length remaining = mChunk->OffsetPastLastBlock() - mOffsetInChunk;
+ Span<const Byte> mem0 = mChunk->BufferSpan();
+ mem0 = mem0.From(mOffsetInChunk);
+ if (aLength <= remaining) {
+ // Move to the end of this block, which could make this null if we have
+ // reached the end of all buffers.
+ *this += aLength;
+ return ProfileBufferEntryReader(
+ mem0.To(aLength),
+ // Block starts before the entry size.
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ entryIndex - ULEB128Size(aLength)),
+ // Block ends right after the entry (could be null for last entry).
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ GlobalRangePosition()));
+ }
+
+ // We need to go to the next chunk for the 2nd part of this block.
+ GoToNextChunk();
+ if (IsNull()) {
+ return ProfileBufferEntryReader();
+ }
+
+ Span<const Byte> mem1 = mChunk->BufferSpan();
+ const Length tail = aLength - remaining;
+ MOZ_ASSERT(tail <= mChunk->BufferBytes());
+ MOZ_ASSERT(tail == mChunk->OffsetFirstBlock());
+ // We are in the correct chunk, move the offset to the end of the block.
+ mOffsetInChunk = tail;
+ // And adjust as needed, which could make this null if we have reached the
+ // end of all buffers.
+ Adjust();
+ return ProfileBufferEntryReader(
+ mem0, mem1.To(tail),
+ // Block starts before the entry size.
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ entryIndex - ULEB128Size(aLength)),
+ // Block ends right after the entry (could be null for last entry).
+ ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
+ GlobalRangePosition()));
+ }
+
+ [[nodiscard]] bool IsNull() const { return !mChunk; }
+
+ [[nodiscard]] bool operator==(const InChunkPointer& aOther) const {
+ if (IsNull() || aOther.IsNull()) {
+ return IsNull() && aOther.IsNull();
+ }
+ return mChunk == aOther.mChunk && mOffsetInChunk == aOther.mOffsetInChunk;
+ }
+
+ [[nodiscard]] bool operator!=(const InChunkPointer& aOther) const {
+ return !(*this == aOther);
+ }
+
+ [[nodiscard]] Byte operator*() const {
+ MOZ_ASSERT(!IsNull());
+ MOZ_ASSERT(mOffsetInChunk < mChunk->OffsetPastLastBlock());
+ return mChunk->ByteAt(mOffsetInChunk);
+ }
+
+ InChunkPointer& operator++() {
+ MOZ_ASSERT(!IsNull());
+ MOZ_ASSERT(mOffsetInChunk < mChunk->OffsetPastLastBlock());
+ if (MOZ_UNLIKELY(++mOffsetInChunk == mChunk->OffsetPastLastBlock())) {
+ mOffsetInChunk = 0;
+ GoToNextChunk();
+ Adjust();
+ }
+ return *this;
+ }
+
+ private:
+ void GoToNextChunk() {
+ MOZ_ASSERT(!IsNull());
+ const ProfileBufferIndex expectedNextRangeStart =
+ mChunk->RangeStart() + mChunk->BufferBytes();
+
+ mChunk = mChunk->GetNext();
+ if (!mChunk) {
+ // Reached the end of the current chunk group, try the next one (which
+ // may be null too, especially on the 2nd try).
+ mChunk = mNextChunkGroup;
+ mNextChunkGroup = nullptr;
+ }
+
+ if (mChunk && mChunk->RangeStart() == 0) {
+ // Reached a chunk without a valid (non-null) range start, assume there
+ // are only unused chunks from here on.
+ mChunk = nullptr;
+ }
+
+ MOZ_ASSERT(!mChunk || mChunk->RangeStart() == expectedNextRangeStart,
+ "We don't handle discontinuous buffers (yet)");
+ // Non-DEBUG fallback: Stop reading past discontinuities.
+ // (They should be rare, only happening on temporary OOMs.)
+ // TODO: Handle discontinuities (by skipping over incomplete blocks).
+ if (mChunk && mChunk->RangeStart() != expectedNextRangeStart) {
+ mChunk = nullptr;
+ }
+ }
+
+ // We want `InChunkPointer` to always point at a valid byte (or be null).
+ // After some operations, `mOffsetInChunk` may point past the end of the
+ // current `mChunk`, in which case we need to adjust our position to be inside
+ // the appropriate chunk. E.g., if we're 10 bytes after the end of the current
+ // chunk, we should end up at offset 10 in the next chunk.
+ // Note that we may "fall off" the last chunk and make this `InChunkPointer`
+ // effectively null.
+ void Adjust() {
+ while (mChunk && mOffsetInChunk >= mChunk->OffsetPastLastBlock()) {
+ // TODO: Try to adjust offset between chunks relative to mRangeStart
+ // differences. But we don't handle discontinuities yet.
+ if (mOffsetInChunk < mChunk->BufferBytes()) {
+ mOffsetInChunk -= mChunk->BufferBytes();
+ } else {
+ mOffsetInChunk -= mChunk->OffsetPastLastBlock();
+ }
+ GoToNextChunk();
+ }
+ }
+
+ // Check if the current position is likely to point at a valid block.
+ // (Size should be reasonable, and block should fully fit inside buffer.)
+ // MOZ_ASSERTs on failure, to catch incorrect uses of block indices (which
+ // should only point at valid blocks if still in range). Non-asserting build
+ // fallback should still be handled.
+ [[nodiscard]] bool ShouldPointAtValidBlock() const {
+ if (IsNull()) {
+ // Pointer is null, no blocks here.
+ MOZ_ASSERT(false, "ShouldPointAtValidBlock - null pointer");
+ return false;
+ }
+ // Use a copy, so we don't modify `*this`.
+ InChunkPointer pointer = *this;
+ // Try to read the entry size.
+ Length entrySize = pointer.ReadEntrySize();
+ if (entrySize == 0) {
+ // Entry size of zero means we read 0 or a way-too-big value.
+ MOZ_ASSERT(false, "ShouldPointAtValidBlock - invalid size");
+ return false;
+ }
+ // See if the last byte of the entry is still inside the buffer.
+ pointer += entrySize - 1;
+ MOZ_ASSERT(!IsNull(), "ShouldPointAtValidBlock - past end of buffer");
+ return !IsNull();
+ }
+
+ const ProfileBufferChunk* mChunk;
+ const ProfileBufferChunk* mNextChunkGroup;
+ Length mOffsetInChunk;
+};
+
+} // namespace mozilla::profiler::detail
+
+#endif // ProfileChunkedBufferDetail_h
diff --git a/mozglue/baseprofiler/public/ProgressLogger.h b/mozglue/baseprofiler/public/ProgressLogger.h
new file mode 100644
index 0000000000..e15095faaa
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProgressLogger.h
@@ -0,0 +1,500 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProgressLogger_h
+#define ProgressLogger_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/ProportionValue.h"
+#include "mozilla/RefCounted.h"
+#include "mozilla/RefPtr.h"
+
+#include <atomic>
+
+// Uncomment to printf ProcessLogger updates.
+// #define DEBUG_PROCESSLOGGER
+
+#ifdef DEBUG_PROCESSLOGGER
+# include "mozilla/BaseProfilerUtils.h"
+# include <cstdio>
+#endif // DEBUG_PROCESSLOGGER
+
+namespace mozilla {
+
+// A `ProgressLogger` is used to update a referenced atomic `ProportionValue`,
+// and can recursively create a sub-logger corresponding to a subset of their
+// own range, but that sub-logger's updates are done in its local 0%-100% range.
+// The typical usage is for multi-level tasks, where each level can estimate its
+// own work and the work delegated to a next-level function, without knowing how
+// this local work relates to the higher-level total work. See
+// `CreateSubLoggerFromTo` for details.
+// Note that this implementation is single-threaded, it does not support logging
+// progress from multiple threads at the same time.
+class ProgressLogger {
+ public:
+ // An RefPtr'd object of this class is used as the target of all
+ // ProgressLogger updates, and it may be shared to make these updates visible
+ // from other code in any thread.
+ class SharedProgress : public external::AtomicRefCounted<SharedProgress> {
+ public:
+ MOZ_DECLARE_REFCOUNTED_TYPENAME(SharedProgress)
+
+ SharedProgress() = default;
+
+ SharedProgress(const SharedProgress&) = delete;
+ SharedProgress& operator=(const SharedProgress&) = delete;
+
+ // This constant is used to indicate that an update may change the progress
+ // value, but should not modify the previously-recorded location.
+ static constexpr const char* NO_LOCATION_UPDATE = nullptr;
+
+ // Set the current progress and location, but the previous location is not
+ // overwritten if the new one is null or empty.
+ // The location and then the progress are atomically "released", so that all
+ // preceding writes on this thread will be visible to other threads reading
+ // these values; most importantly when reaching 100% progress, the reader
+ // can be confident that the location is final and the operation being
+ // watched has completed.
+ void SetProgress(
+ ProportionValue aProgress,
+ const char* aLocationOrNullEmptyToIgnore = NO_LOCATION_UPDATE) {
+ if (aLocationOrNullEmptyToIgnore &&
+ *aLocationOrNullEmptyToIgnore != '\0') {
+ mLastLocation.store(aLocationOrNullEmptyToIgnore,
+ std::memory_order_release);
+ }
+ mProgress.store(aProgress, std::memory_order_release);
+ }
+
+ // Read the current progress value. Atomically "acquired", so that writes
+ // from the thread that stored this value are all visible to the reader
+ // here; most importantly when reaching 100%, we can be confident that the
+ // location is final and the operation being watched has completed.
+ [[nodiscard]] ProportionValue Progress() const {
+ return mProgress.load(std::memory_order_acquire);
+ }
+
+ // Read the current progress value. Atomically "acquired".
+ [[nodiscard]] const char* LastLocation() const {
+ return mLastLocation.load(std::memory_order_acquire);
+ }
+
+ private:
+ friend mozilla::detail::RefCounted<SharedProgress,
+ mozilla::detail::AtomicRefCount>;
+ ~SharedProgress() = default;
+
+ // Progress and last-known location.
+ // Beware that these two values are not strongly tied: Reading one then the
+ // other may give mismatched information; but it should be fine for
+ // informational usage.
+ // They are stored using atomic acquire-release ordering, to guarantee that
+ // when read, all writes preceding these values are visible.
+ std::atomic<ProportionValue> mProgress = ProportionValue{0.0};
+ std::atomic<const char*> mLastLocation = nullptr;
+ };
+
+ static constexpr const char* NO_LOCATION_UPDATE =
+ SharedProgress::NO_LOCATION_UPDATE;
+
+ ProgressLogger() = default;
+
+ // Construct a top-level logger, starting at 0% and expected to end at 100%.
+ explicit ProgressLogger(
+ RefPtr<SharedProgress> aGlobalProgressOrNull,
+ const char* aLocationOrNullEmptyToIgnoreAtStart = NO_LOCATION_UPDATE,
+ const char* aLocationOrNullEmptyToIgnoreAtEnd = NO_LOCATION_UPDATE)
+ : ProgressLogger{std::move(aGlobalProgressOrNull),
+ /* Start */ ProportionValue{0.0},
+ /* Multiplier */ ProportionValue{1.0},
+ aLocationOrNullEmptyToIgnoreAtStart,
+ aLocationOrNullEmptyToIgnoreAtEnd} {}
+
+ // Don't make copies, it would be confusing!
+ // TODO: Copies could one day be allowed to track multi-threaded work, but it
+ // is outside the scope of this implementation; Please update if needed.
+ ProgressLogger(const ProgressLogger&) = delete;
+ ProgressLogger& operator&(const ProgressLogger&) = delete;
+
+ // Move-construct is allowed, to return from CreateSubLoggerFromTo, and
+ // forward straight into a function. Note that moved-from ProgressLoggers must
+ // not be used anymore! Use `CreateSubLoggerFromTo` to pass a sub-logger to
+ // functions.
+ ProgressLogger(ProgressLogger&& aOther)
+ : mGlobalProgressOrNull(std::move(aOther.mGlobalProgressOrNull)),
+ mLocalStartInGlobalSpace(aOther.mLocalStartInGlobalSpace),
+ mLocalToGlobalMultiplier(aOther.mLocalToGlobalMultiplier),
+ mLocationAtDestruction(aOther.mLocationAtDestruction) {
+ aOther.MarkMovedFrom();
+#ifdef DEBUG_PROCESSLOGGER
+ if (mGlobalProgressOrNull) {
+ printf("[%d] Moved (staying globally at %.2f in [%.2f, %.2f])\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()),
+ GetGlobalProgress().ToDouble() * 100.0,
+ mLocalStartInGlobalSpace.ToDouble() * 100.0,
+ (mLocalStartInGlobalSpace + mLocalToGlobalMultiplier).ToDouble() *
+ 100.0);
+ }
+#endif // DEBUG_PROCESSLOGGER
+ }
+
+ // Move-assign. This may be useful when starting with a default (empty) logger
+ // and later assigning it a progress value to start updating.
+ ProgressLogger& operator=(ProgressLogger&& aOther) {
+ mGlobalProgressOrNull = std::move(aOther.mGlobalProgressOrNull);
+ mLocalStartInGlobalSpace = aOther.mLocalStartInGlobalSpace;
+ mLocalToGlobalMultiplier = aOther.mLocalToGlobalMultiplier;
+ mLocationAtDestruction = aOther.mLocationAtDestruction;
+ aOther.MarkMovedFrom();
+#ifdef DEBUG_PROCESSLOGGER
+ if (mGlobalProgressOrNull) {
+ printf("[%d] Re-assigned (globally at %.2f in [%.2f, %.2f])\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()),
+ GetGlobalProgress().ToDouble() * 100.0,
+ mLocalStartInGlobalSpace.ToDouble() * 100.0,
+ (mLocalStartInGlobalSpace + mLocalToGlobalMultiplier).ToDouble() *
+ 100.0);
+ }
+#endif // DEBUG_PROCESSLOGGER
+ return *this;
+ }
+
+ // Destruction sets the local update value to 100% unless empty or moved-from.
+ ~ProgressLogger() {
+ if (!IsMovedFrom()) {
+#ifdef DEBUG_PROCESSLOGGER
+ if (mGlobalProgressOrNull) {
+ printf("[%d] Destruction:\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()));
+ }
+#endif // DEBUG_PROCESSLOGGER
+ SetLocalProgress(ProportionValue{1.0}, mLocationAtDestruction);
+ }
+ }
+
+ // Retrieve the current progress in the global space. May be invalid.
+ [[nodiscard]] ProportionValue GetGlobalProgress() const {
+ return mGlobalProgressOrNull ? mGlobalProgressOrNull->Progress()
+ : ProportionValue::MakeInvalid();
+ }
+
+ // Retrieve the last known global location. May be null.
+ [[nodiscard]] const char* GetLastGlobalLocation() const {
+ return mGlobalProgressOrNull ? mGlobalProgressOrNull->LastLocation()
+ : nullptr;
+ }
+
+ // Set the current progress in the local space.
+ void SetLocalProgress(ProportionValue aLocalProgress,
+ const char* aLocationOrNullEmptyToIgnore) {
+ MOZ_ASSERT(!IsMovedFrom());
+ if (mGlobalProgressOrNull && !mLocalToGlobalMultiplier.IsExactlyZero()) {
+ mGlobalProgressOrNull->SetProgress(LocalToGlobal(aLocalProgress),
+ aLocationOrNullEmptyToIgnore);
+#ifdef DEBUG_PROCESSLOGGER
+ printf("[%d] - local %.0f%% ~ global %.2f%% \"%s\"\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()),
+ aLocalProgress.ToDouble() * 100.0,
+ LocalToGlobal(aLocalProgress).ToDouble() * 100.0,
+ aLocationOrNullEmptyToIgnore ? aLocationOrNullEmptyToIgnore
+ : "<null>");
+#endif // DEBUG_PROCESSLOGGER
+ }
+ }
+
+ // Create a sub-logger that will record progress in the given local range.
+ // E.g.: `f(pl.CreateSubLoggerFromTo(0.2, "f...", 0.4, "f done"));` expects
+ // that `f` will produce work in the local range 0.2 (when starting) to 0.4
+ // (when returning); `f` itself will update this provided logger from 0.0
+ // to 1.0 (local to that `f` function), which will effectively be converted to
+ // 0.2-0.4 (local to the calling function).
+ // This can cascade multiple levels, each deeper level affecting a smaller and
+ // smaller range in the global output.
+ [[nodiscard]] ProgressLogger CreateSubLoggerFromTo(
+ ProportionValue aSubStartInLocalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtStart,
+ ProportionValue aSubEndInLocalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtEnd = NO_LOCATION_UPDATE) {
+ MOZ_ASSERT(!IsMovedFrom());
+ if (!mGlobalProgressOrNull) {
+ return ProgressLogger{};
+ }
+ const ProportionValue subStartInGlobalSpace =
+ LocalToGlobal(aSubStartInLocalSpace);
+ const ProportionValue subEndInGlobalSpace =
+ LocalToGlobal(aSubEndInLocalSpace);
+ if (subStartInGlobalSpace.IsInvalid() || subEndInGlobalSpace.IsInvalid()) {
+ return ProgressLogger{mGlobalProgressOrNull,
+ /* Start */ ProportionValue::MakeInvalid(),
+ /* Multiplier */ ProportionValue{0.0},
+ aLocationOrNullEmptyToIgnoreAtStart,
+ aLocationOrNullEmptyToIgnoreAtEnd};
+ }
+#ifdef DEBUG_PROCESSLOGGER
+ if (mGlobalProgressOrNull) {
+ printf("[%d] * Sub: local [%.0f%%, %.0f%%] ~ global [%.2f%%, %.2f%%]\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()),
+ aSubStartInLocalSpace.ToDouble() * 100.0,
+ aSubEndInLocalSpace.ToDouble() * 100.0,
+ subStartInGlobalSpace.ToDouble() * 100.0,
+ subEndInGlobalSpace.ToDouble() * 100.0);
+ }
+#endif // DEBUG_PROCESSLOGGER
+ return ProgressLogger{
+ mGlobalProgressOrNull,
+ /* Start */ subStartInGlobalSpace,
+ /* Multipler */ subEndInGlobalSpace - subStartInGlobalSpace,
+ aLocationOrNullEmptyToIgnoreAtStart, aLocationOrNullEmptyToIgnoreAtEnd};
+ }
+
+ // Helper with no start location.
+ [[nodiscard]] ProgressLogger CreateSubLoggerFromTo(
+ ProportionValue aSubStartInLocalSpace,
+ ProportionValue aSubEndInLocalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtEnd = NO_LOCATION_UPDATE) {
+ return CreateSubLoggerFromTo(aSubStartInLocalSpace, NO_LOCATION_UPDATE,
+ aSubEndInLocalSpace,
+ aLocationOrNullEmptyToIgnoreAtEnd);
+ }
+
+ // Helper using the current progress as start.
+ [[nodiscard]] ProgressLogger CreateSubLoggerTo(
+ const char* aLocationOrNullEmptyToIgnoreAtStart,
+ ProportionValue aSubEndInLocalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtEnd = NO_LOCATION_UPDATE) {
+ MOZ_ASSERT(!IsMovedFrom());
+ if (!mGlobalProgressOrNull) {
+ return ProgressLogger{};
+ }
+ const ProportionValue subStartInGlobalSpace = GetGlobalProgress();
+ const ProportionValue subEndInGlobalSpace =
+ LocalToGlobal(aSubEndInLocalSpace);
+ if (subStartInGlobalSpace.IsInvalid() || subEndInGlobalSpace.IsInvalid()) {
+ return ProgressLogger{mGlobalProgressOrNull,
+ /* Start */ ProportionValue::MakeInvalid(),
+ /* Multiplier */ ProportionValue{0.0},
+ aLocationOrNullEmptyToIgnoreAtStart,
+ aLocationOrNullEmptyToIgnoreAtEnd};
+ }
+#ifdef DEBUG_PROCESSLOGGER
+ if (mGlobalProgressOrNull) {
+ printf("[%d] * Sub: local [(here), %.0f%%] ~ global [%.2f%%, %.2f%%]\n",
+ int(baseprofiler::profiler_current_process_id().ToNumber()),
+ aSubEndInLocalSpace.ToDouble() * 100.0,
+ subStartInGlobalSpace.ToDouble() * 100.0,
+ subEndInGlobalSpace.ToDouble() * 100.0);
+ }
+#endif // DEBUG_PROCESSLOGGER
+ return ProgressLogger{
+ mGlobalProgressOrNull,
+ /* Start */ subStartInGlobalSpace,
+ /* Multiplier */ subEndInGlobalSpace - subStartInGlobalSpace,
+ aLocationOrNullEmptyToIgnoreAtStart, aLocationOrNullEmptyToIgnoreAtEnd};
+ }
+
+ // Helper using the current progress as start, no start location.
+ [[nodiscard]] ProgressLogger CreateSubLoggerTo(
+ ProportionValue aSubEndInLocalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtEnd = NO_LOCATION_UPDATE) {
+ return CreateSubLoggerTo(NO_LOCATION_UPDATE, aSubEndInLocalSpace,
+ aLocationOrNullEmptyToIgnoreAtEnd);
+ }
+
+ class IndexAndProgressLoggerRange;
+
+ [[nodiscard]] inline IndexAndProgressLoggerRange CreateLoopSubLoggersFromTo(
+ ProportionValue aLoopStartInLocalSpace,
+ ProportionValue aLoopEndInLocalSpace, uint32_t aLoopCount,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges =
+ ProgressLogger::NO_LOCATION_UPDATE);
+ [[nodiscard]] inline IndexAndProgressLoggerRange CreateLoopSubLoggersTo(
+ ProportionValue aLoopEndInLocalSpace, uint32_t aLoopCount,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges =
+ ProgressLogger::NO_LOCATION_UPDATE);
+
+ private:
+ // All constructions start at the local 0%.
+ ProgressLogger(RefPtr<SharedProgress> aGlobalProgressOrNull,
+ ProportionValue aLocalStartInGlobalSpace,
+ ProportionValue aLocalToGlobalMultiplier,
+ const char* aLocationOrNullEmptyToIgnoreAtConstruction,
+ const char* aLocationOrNullEmptyToIgnoreAtDestruction)
+ : mGlobalProgressOrNull(std::move(aGlobalProgressOrNull)),
+ mLocalStartInGlobalSpace(aLocalStartInGlobalSpace),
+ mLocalToGlobalMultiplier(aLocalToGlobalMultiplier),
+ mLocationAtDestruction(aLocationOrNullEmptyToIgnoreAtDestruction) {
+ MOZ_ASSERT(!IsMovedFrom(), "Don't construct a moved-from object!");
+ SetLocalProgress(ProportionValue{0.0},
+ aLocationOrNullEmptyToIgnoreAtConstruction);
+ }
+
+ void MarkMovedFrom() {
+ mLocalToGlobalMultiplier = ProportionValue::MakeInvalid();
+ }
+ [[nodiscard]] bool IsMovedFrom() const {
+ return mLocalToGlobalMultiplier.IsInvalid();
+ }
+
+ [[nodiscard]] ProportionValue LocalToGlobal(
+ ProportionValue aLocalProgress) const {
+ return aLocalProgress * mLocalToGlobalMultiplier + mLocalStartInGlobalSpace;
+ }
+
+ // Global progress value to update from local changes.
+ RefPtr<SharedProgress> mGlobalProgressOrNull;
+
+ // How much to multiply and add to a local [0, 100%] value, to get the
+ // corresponding value in the global space.
+ // If mLocalToGlobalMultiplier is invalid, this ProgressLogger is moved-from,
+ // functions should not be used, and destructor won't update progress.
+ ProportionValue mLocalStartInGlobalSpace;
+ ProportionValue mLocalToGlobalMultiplier;
+
+ const char* mLocationAtDestruction = nullptr;
+};
+
+// Helper class for range-for loop, e.g., with `aProgressLogger`:
+// for (auto [index, loopProgressLogger] :
+// IndexAndProgressLoggerRange{aProgressLogger, 30_pc, 50_pc, 10,
+// "looping..."}) {
+// // This will loop 10 times.
+// // `index` is the loop index, from 0 to 9.
+// // The overall loop will start at 30% and end at 50% of aProgressLogger.
+// // `loopProgressLogger` is the progress logger for each iteration,
+// // covering 1/10th of the range, therefore: [30%,32%], then [32%,34%],
+// // etc. until [48%,50%].
+// // Progress is automatically updated before/after each loop.
+// }
+// Note that this implementation is single-threaded, it does not support logging
+// progress from parallel loops.
+class ProgressLogger::IndexAndProgressLoggerRange {
+ public:
+ struct IndexAndProgressLogger {
+ uint32_t index;
+ ProgressLogger progressLogger;
+ };
+
+ class IndexAndProgressLoggerEndIterator {
+ public:
+ explicit IndexAndProgressLoggerEndIterator(uint32_t aIndex)
+ : mIndex(aIndex) {}
+
+ [[nodiscard]] uint32_t Index() const { return mIndex; }
+
+ private:
+ uint32_t mIndex;
+ };
+
+ class IndexAndProgressLoggerIterator {
+ public:
+ IndexAndProgressLoggerIterator(
+ RefPtr<ProgressLogger::SharedProgress> aGlobalProgressOrNull,
+ ProportionValue aLoopStartInGlobalSpace,
+ ProportionValue aLoopIncrementInGlobalSpace,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges)
+ : mGlobalProgressOrNull(aGlobalProgressOrNull),
+ mLoopStartInGlobalSpace(aLoopStartInGlobalSpace),
+ mLoopIncrementInGlobalSpace(aLoopIncrementInGlobalSpace),
+ mIndex(0u),
+ mLocationOrNullEmptyToIgnoreAtEdges(
+ aLocationOrNullEmptyToIgnoreAtEdges) {
+ if (mGlobalProgressOrNull) {
+ mGlobalProgressOrNull->SetProgress(mLoopStartInGlobalSpace,
+ mLocationOrNullEmptyToIgnoreAtEdges);
+ }
+ }
+
+ [[nodiscard]] IndexAndProgressLogger operator*() {
+ return IndexAndProgressLogger{
+ mIndex,
+ mGlobalProgressOrNull
+ ? ProgressLogger{mGlobalProgressOrNull, mLoopStartInGlobalSpace,
+ mLoopIncrementInGlobalSpace,
+ ProgressLogger::NO_LOCATION_UPDATE,
+ ProgressLogger::NO_LOCATION_UPDATE}
+ : ProgressLogger{}};
+ }
+
+ [[nodiscard]] bool operator!=(
+ const IndexAndProgressLoggerEndIterator& aEnd) const {
+ return mIndex != aEnd.Index();
+ }
+
+ IndexAndProgressLoggerIterator& operator++() {
+ ++mIndex;
+ mLoopStartInGlobalSpace =
+ mLoopStartInGlobalSpace + mLoopIncrementInGlobalSpace;
+ if (mGlobalProgressOrNull) {
+ mGlobalProgressOrNull->SetProgress(mLoopStartInGlobalSpace,
+ mLocationOrNullEmptyToIgnoreAtEdges);
+ }
+ return *this;
+ }
+
+ private:
+ RefPtr<ProgressLogger::SharedProgress> mGlobalProgressOrNull;
+ ProportionValue mLoopStartInGlobalSpace;
+ ProportionValue mLoopIncrementInGlobalSpace;
+ uint32_t mIndex;
+ const char* mLocationOrNullEmptyToIgnoreAtEdges;
+ };
+
+ [[nodiscard]] IndexAndProgressLoggerIterator begin() {
+ return IndexAndProgressLoggerIterator{
+ mGlobalProgressOrNull, mLoopStartInGlobalSpace,
+ mLoopIncrementInGlobalSpace, mLocationOrNullEmptyToIgnoreAtEdges};
+ }
+
+ [[nodiscard]] IndexAndProgressLoggerEndIterator end() {
+ return IndexAndProgressLoggerEndIterator{mLoopCount};
+ }
+
+ private:
+ friend class ProgressLogger;
+ IndexAndProgressLoggerRange(ProgressLogger& aProgressLogger,
+ ProportionValue aLoopStartInGlobalSpace,
+ ProportionValue aLoopEndInGlobalSpace,
+ uint32_t aLoopCount,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges =
+ ProgressLogger::NO_LOCATION_UPDATE)
+ : mGlobalProgressOrNull(aProgressLogger.mGlobalProgressOrNull),
+ mLoopStartInGlobalSpace(aLoopStartInGlobalSpace),
+ mLoopIncrementInGlobalSpace(
+ (aLoopEndInGlobalSpace - aLoopStartInGlobalSpace) / aLoopCount),
+ mLoopCount(aLoopCount),
+ mLocationOrNullEmptyToIgnoreAtEdges(
+ aLocationOrNullEmptyToIgnoreAtEdges) {}
+
+ RefPtr<ProgressLogger::SharedProgress> mGlobalProgressOrNull;
+ ProportionValue mLoopStartInGlobalSpace;
+ ProportionValue mLoopIncrementInGlobalSpace;
+ uint32_t mLoopCount;
+ const char* mLocationOrNullEmptyToIgnoreAtEdges;
+};
+
+[[nodiscard]] ProgressLogger::IndexAndProgressLoggerRange
+ProgressLogger::CreateLoopSubLoggersFromTo(
+ ProportionValue aLoopStartInLocalSpace,
+ ProportionValue aLoopEndInLocalSpace, uint32_t aLoopCount,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges) {
+ return IndexAndProgressLoggerRange{
+ *this, LocalToGlobal(aLoopStartInLocalSpace),
+ LocalToGlobal(aLoopEndInLocalSpace), aLoopCount,
+ aLocationOrNullEmptyToIgnoreAtEdges};
+}
+
+[[nodiscard]] ProgressLogger::IndexAndProgressLoggerRange
+ProgressLogger::CreateLoopSubLoggersTo(
+ ProportionValue aLoopEndInLocalSpace, uint32_t aLoopCount,
+ const char* aLocationOrNullEmptyToIgnoreAtEdges) {
+ return IndexAndProgressLoggerRange{
+ *this, GetGlobalProgress(), LocalToGlobal(aLoopEndInLocalSpace),
+ aLoopCount, aLocationOrNullEmptyToIgnoreAtEdges};
+}
+
+} // namespace mozilla
+
+#endif // ProgressLogger_h
diff --git a/mozglue/baseprofiler/public/ProportionValue.h b/mozglue/baseprofiler/public/ProportionValue.h
new file mode 100644
index 0000000000..61eb2766ec
--- /dev/null
+++ b/mozglue/baseprofiler/public/ProportionValue.h
@@ -0,0 +1,235 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProportionValue_h
+#define ProportionValue_h
+
+#include "mozilla/Attributes.h"
+
+#include <algorithm>
+#include <limits>
+
+namespace mozilla {
+
+// Class storing a proportion value between 0 and 1, effectively 0% to 100%.
+// The public interface deals with doubles, but internally the value is encoded
+// in an integral type, so arithmetic operations are fast.
+// It also supports an invalid value: Use MakeInvalid() to construct, it infects
+// any operation, and gets converted to a signaling NaN.
+class ProportionValue {
+ public:
+ using UnderlyingType = uint32_t;
+
+ // Default-construct at 0%.
+ constexpr ProportionValue()
+ // This `noexcept` is necessary to avoid a build error when encapsulating
+ // `ProportionValue` in `std::Atomic`:
+ // "use of deleted function
+ // 'constexpr std::atomic<mozilla::ProportionValue>::atomic()"
+ // because the default `std::atomic<T>::atomic()` constructor is marked:
+ // `noexcept(std::is_nothrow_default_constructible_v<T>)`
+ // and therefore this default constructor here must be explicitly marked
+ // `noexcept` as well.
+ noexcept
+ : mIntegralValue(0u) {}
+
+ // Construct a ProportionValue with the given value, clamped to 0..1.
+ // Note that it's constexpr, so construction from literal numbers should incur
+ // no runtime costs.
+ // If `aValue` is NaN, behavior is undefined! Use `MakeInvalid()` instead.
+ constexpr explicit ProportionValue(double aValue)
+ : mIntegralValue(UnderlyingType(std::clamp(aValue, 0.0, 1.0) * scMaxD)) {}
+
+ [[nodiscard]] static constexpr ProportionValue MakeInvalid() {
+ return ProportionValue(scInvalidU, Internal{});
+ }
+
+ [[nodiscard]] constexpr double ToDouble() const {
+ return IsInvalid() ? std::numeric_limits<double>::signaling_NaN()
+ : (double(mIntegralValue) * scInvMaxD);
+ }
+
+ // Retrieve the underlying integral value, for storage or testing purposes.
+ [[nodiscard]] constexpr UnderlyingType ToUnderlyingType() const {
+ return mIntegralValue;
+ };
+
+ // Re-construct a ProportionValue from an underlying integral value.
+ [[nodiscard]] static constexpr ProportionValue FromUnderlyingType(
+ UnderlyingType aUnderlyingType) {
+ return ProportionValue(
+ (aUnderlyingType <= scMaxU) ? aUnderlyingType : scInvalidU, Internal{});
+ }
+
+ [[nodiscard]] constexpr bool IsExactlyZero() const {
+ return mIntegralValue == 0u;
+ }
+
+ [[nodiscard]] constexpr bool IsExactlyOne() const {
+ return mIntegralValue == scMaxU;
+ }
+
+ [[nodiscard]] constexpr bool IsValid() const {
+ // Compare to the maximum value, not just exactly scInvalidU, to catch any
+ // kind of invalid state.
+ return mIntegralValue <= scMaxU;
+ }
+ [[nodiscard]] constexpr bool IsInvalid() const {
+ // Compare to the maximum value, not just exactly scInvalidU, to catch any
+ // kind of invalid state.
+ return mIntegralValue > scMaxU;
+ }
+
+ // Strict comparisons based on the underlying integral value. Use
+ // `CompareWithin` instead to make fuzzy comparisons.
+ // `ProportionValue::MakeInvalid()`s are equal, and greater than anything
+ // else; Best to avoid comparisons, and first use IsInvalid() instead.
+#define OPERATOR_COMPARISON(CMP) \
+ [[nodiscard]] constexpr friend bool operator CMP( \
+ const ProportionValue& aLHS, const ProportionValue& aRHS) { \
+ return aLHS.mIntegralValue CMP aRHS.mIntegralValue; \
+ }
+ OPERATOR_COMPARISON(==)
+ OPERATOR_COMPARISON(!=)
+ OPERATOR_COMPARISON(<)
+ OPERATOR_COMPARISON(<=)
+ OPERATOR_COMPARISON(>)
+ OPERATOR_COMPARISON(>=)
+#undef OPERATOR_COMPARISON
+
+ // Arithmetic operations + - *, all working on the underlying integral values
+ // (i.e, no expensive floating-point operations are used), and always clamping
+ // to 0..1 range. Invalid values are poisonous.
+
+ [[nodiscard]] constexpr ProportionValue operator+(
+ ProportionValue aRHS) const {
+ return ProportionValue(
+ (IsInvalid() || aRHS.IsInvalid())
+ ? scInvalidU
+ // Adding fixed-point values keep the same scale, so there is no
+ // adjustment needed for that. [0,1]+[0,1]=[0,2], so we only need to
+ // ensure that the result is capped at max 1, aka scMaxU:
+ // a+b<=max <=> b<=max-a, so b is at maximum max-a.
+ : (mIntegralValue +
+ std::min(aRHS.mIntegralValue, scMaxU - mIntegralValue)),
+ Internal{});
+ }
+
+ [[nodiscard]] constexpr ProportionValue operator-(
+ ProportionValue aRHS) const {
+ return ProportionValue(
+ (IsInvalid() || aRHS.IsInvalid())
+ ? scInvalidU
+ // Subtracting fixed-point values keep the same scale, so there is
+ // no adjustment needed for that. [0,1]-[0,1]=[-1,1], so we only
+ // need to ensure that the value is positive:
+ // a-b>=0 <=> b<=a, so b is at maximum a.
+ : (mIntegralValue - std::min(aRHS.mIntegralValue, mIntegralValue)),
+ Internal{});
+ }
+
+ [[nodiscard]] constexpr ProportionValue operator*(
+ ProportionValue aRHS) const {
+ // Type to hold the full result of multiplying two maximum numbers.
+ using DoublePrecisionType = uint64_t;
+ static_assert(sizeof(DoublePrecisionType) >= 2 * sizeof(UnderlyingType));
+ return ProportionValue(
+ (IsInvalid() || aRHS.IsInvalid())
+ ? scInvalidU
+ // Multiplying fixed-point values doubles the scale (2^31 -> 2^62),
+ // so we need to adjust the result by dividing it by one scale
+ // (which is optimized into a binary right-shift).
+ : (UnderlyingType((DoublePrecisionType(mIntegralValue) *
+ DoublePrecisionType(aRHS.mIntegralValue)) /
+ DoublePrecisionType(scMaxU))),
+ Internal{});
+ }
+
+ // Explicitly forbid divisions, they make little sense, and would almost
+ // always return a clamped 100% (E.g.: 50% / 10% = 0.5 / 0.1 = 5 = 500%).
+ [[nodiscard]] constexpr ProportionValue operator/(
+ ProportionValue aRHS) const = delete;
+
+ // Division by a positive integer value, useful to split an interval in equal
+ // parts (with maybe some spare space at the end, because it is rounded down).
+ // Division by 0 produces an invalid value.
+ [[nodiscard]] constexpr ProportionValue operator/(uint32_t aDivisor) const {
+ return ProportionValue((IsInvalid() || aDivisor == 0u)
+ ? scInvalidU
+ : (mIntegralValue / aDivisor),
+ Internal{});
+ }
+
+ // Multiplication by a positive integer value, useful as inverse of the
+ // integer division above. But it may be lossy because the division is rounded
+ // down, therefore: PV - u < (PV / u) * u <= PV.
+ // Clamped to 100% max.
+ [[nodiscard]] constexpr ProportionValue operator*(
+ uint32_t aMultiplier) const {
+ return ProportionValue(IsInvalid()
+ ? scInvalidU
+ : ((aMultiplier > scMaxU / mIntegralValue)
+ ? scMaxU
+ : (mIntegralValue * aMultiplier)),
+ Internal{});
+ }
+
+ private:
+ // Tagged constructor for internal construction from the UnderlyingType, so
+ // that it is never ambiguously considered in constructions from one number.
+ struct Internal {};
+ constexpr ProportionValue(UnderlyingType aIntegralValue, Internal)
+ : mIntegralValue(aIntegralValue) {}
+
+ // Use all but 1 bit for the fractional part.
+ // Valid values can go from 0b0 (0%) up to 0b1000...00 (scMaxU aka 100%).
+ static constexpr unsigned scFractionalBits = sizeof(UnderlyingType) * 8 - 1;
+ // Maximum value corresponding to 1.0 or 100%.
+ static constexpr UnderlyingType scMaxU = UnderlyingType(1u)
+ << scFractionalBits;
+ // This maximum value corresponding to 1.0 can also be seen as the scaling
+ // factor from any [0,1] `double` value to the internal integral value.
+ static constexpr double scMaxD = double(scMaxU);
+ // The inverse can be used to convert the internal value back to [0,1].
+ static constexpr double scInvMaxD = 1.0 / scMaxD;
+
+ // Special value outside [0,max], used to construct invalid values.
+ static constexpr UnderlyingType scInvalidU = ~UnderlyingType(0u);
+
+ // Internal integral value, guaranteed to always be <= scMaxU, or scInvalidU.
+ // This is effectively a fixed-point value using 1 bit for the integer part
+ // and 31 bits for the fractional part.
+ // It is roughly equal to the `double` value [0,1] multiplied by scMaxD.
+ UnderlyingType mIntegralValue;
+};
+
+namespace literals {
+inline namespace ProportionValue_literals {
+
+// User-defined literal for integer percentages, e.g.: `10_pc`, `100_pc`
+// (equivalent to `ProportionValue{0.1}` and `ProportionValue{1.0}`).
+// Clamped to [0, 100]_pc.
+[[nodiscard]] constexpr ProportionValue operator""_pc(
+ unsigned long long int aPercentage) {
+ return ProportionValue{
+ double(std::clamp<unsigned long long int>(aPercentage, 0u, 100u)) /
+ 100.0};
+}
+
+// User-defined literal for non-integer percentages, e.g.: `12.3_pc`, `100.0_pc`
+// (equivalent to `ProportionValue{0.123}` and `ProportionValue{1.0}`).
+// Clamped to [0.0, 100.0]_pc.
+[[nodiscard]] constexpr ProportionValue operator""_pc(long double aPercentage) {
+ return ProportionValue{
+ double(std::clamp<long double>(aPercentage, 0.0, 100.0)) / 100.0};
+}
+
+} // namespace ProportionValue_literals
+} // namespace literals
+
+} // namespace mozilla
+
+#endif // ProportionValue_h
diff --git a/mozglue/baseprofiler/public/leb128iterator.h b/mozglue/baseprofiler/public/leb128iterator.h
new file mode 100644
index 0000000000..636baf916f
--- /dev/null
+++ b/mozglue/baseprofiler/public/leb128iterator.h
@@ -0,0 +1,207 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// LEB128 utilities that can read/write unsigned LEB128 numbers from/to
+// iterators.
+//
+// LEB128 = Little Endian Base 128, where small numbers take few bytes, but
+// large numbers are still allowed, which is ideal when serializing numbers that
+// are likely to be small.
+// Each byte contains 7 bits from the number, starting at the "little end", the
+// top bit is 0 for the last byte, 1 otherwise.
+// Numbers 0-127 only take 1 byte. 128-16383 take 2 bytes. Etc.
+//
+// Iterators only need to provide:
+// - `*it` to return a reference to the next byte to be read from or written to.
+// - `++it` to advance the iterator after a byte is written.
+//
+// The caller must always provide sufficient space to write any number, by:
+// - pre-allocating a large enough buffer, or
+// - allocating more space when `++it` reaches the end and/or `*it` is invoked
+// after the end, or
+// - moving the underlying pointer to an appropriate location (e.g., wrapping
+// around a circular buffer).
+// The caller must also provide enough bytes to read a full value (i.e., at
+// least one byte should have its top bit unset), and a type large enough to
+// hold the stored value.
+//
+// Note: There are insufficient checks for validity! These functions are
+// intended to be used together, i.e., the user should only `ReadULEB128()` from
+// a sufficiently-large buffer that the same user filled with `WriteULEB128()`.
+// Using with externally-sourced data (e.g., DWARF) is *not* recommended.
+//
+// https://en.wikipedia.org/wiki/LEB128
+
+#ifndef leb128iterator_h
+#define leb128iterator_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Likely.h"
+
+#include <climits>
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+
+namespace mozilla {
+
+// Number of bytes needed to represent `aValue`.
+template <typename T>
+constexpr uint_fast8_t ULEB128Size(T aValue) {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "ULEB128Size only takes unsigned types");
+ // We need one output byte per 7 bits of non-zero value. So we just remove
+ // 7 least significant bits at a time until the value becomes zero.
+ // Note the special case of 0, which still needs 1 output byte; this is done
+ // by starting the first loop before we check for 0.
+ uint_fast8_t size = 0;
+ for (;;) {
+ size += 1;
+ aValue >>= 7;
+ // Expecting small values, so it should be more likely that `aValue == 0`.
+ if (MOZ_LIKELY(aValue == 0)) {
+ return size;
+ }
+ }
+}
+
+// Maximum number of bytes needed to represent any value of type `T`.
+template <typename T>
+constexpr uint_fast8_t ULEB128MaxSize() {
+ return ULEB128Size<T>(std::numeric_limits<T>::max());
+}
+
+// Write `aValue` in LEB128 to `aIterator`.
+// The iterator will be moved past the last byte.
+template <typename T, typename It>
+void WriteULEB128(T aValue, It& aIterator) {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "WriteULEB128 only takes unsigned types");
+ using IteratorValue = std::remove_reference_t<decltype(*aIterator)>;
+ static_assert(sizeof(IteratorValue) == 1,
+ "WriteULEB128 expects an iterator to single bytes");
+ // 0. Don't test for 0 yet, as we want to output one byte for it.
+ for (;;) {
+ // 1. Extract the 7 least significant bits.
+ const uint_fast8_t byte = aValue & 0x7Fu;
+ // 2. Remove them from `aValue`.
+ aValue >>= 7;
+ // 3. Write the 7 bits, and set the 8th bit if `aValue` is not 0 yet
+ // (meaning there will be more bytes after this one.)
+ // Expecting small values, so it should be more likely that `aValue == 0`.
+ // Note: No absolute need to force-cast to IteratorValue, because we have
+ // only changed the bottom 8 bits above. However the compiler could warn
+ // about a narrowing conversion from potentially-multibyte uint_fast8_t down
+ // to whatever single-byte type `*iterator* expects, so we make it explicit.
+ *aIterator = static_cast<IteratorValue>(
+ MOZ_LIKELY(aValue == 0) ? byte : (byte | 0x80u));
+ // 4. Always advance the iterator to the next byte.
+ ++aIterator;
+ // 5. We're done if `aValue` is 0.
+ // Expecting small values, so it should be more likely that `aValue == 0`.
+ if (MOZ_LIKELY(aValue == 0)) {
+ return;
+ }
+ }
+}
+
+// Read an LEB128 value from `aIterator`.
+// The iterator will be moved past the last byte.
+template <typename T, typename It>
+T ReadULEB128(It& aIterator) {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "ReadULEB128 must return an unsigned type");
+ using IteratorValue = std::remove_reference_t<decltype(*aIterator)>;
+ static_assert(sizeof(IteratorValue) == 1,
+ "ReadULEB128 expects an iterator to single bytes");
+ // Incoming bits will be added to `result`...
+ T result = 0;
+ // ... starting with the least significant bits.
+ uint_fast8_t shift = 0;
+ for (;;) {
+ // 1. Read one byte from the iterator.
+ // `static_cast` just in case IteratorValue is not implicitly convertible to
+ // uint_fast8_t. It wouldn't matter if the sign was extended, we're only
+ // dealing with the bottom 8 bits below.
+ const uint_fast8_t byte = static_cast<uint_fast8_t>(*aIterator);
+ // 2. Always advance the iterator.
+ ++aIterator;
+ // 3. Extract the 7 bits of value, and shift them in place into `result`.
+ result |= static_cast<T>(byte & 0x7fu) << shift;
+ // 4. If the 8th bit is *not* set, this was the last byte.
+ // Expecting small values, so it should be more likely that the bit is off.
+ if (MOZ_LIKELY((byte & 0x80u) == 0)) {
+ return result;
+ }
+ // There are more bytes to read.
+ // 5. Next byte will contain more significant bits above the past 7.
+ shift += 7;
+ // Safety check that we're not going to shift by >= than the type size,
+ // which is Undefined Behavior in C++.
+ MOZ_ASSERT(shift < CHAR_BIT * sizeof(T));
+ }
+}
+
+// constexpr ULEB128 reader class.
+// Mostly useful when dealing with non-trivial byte feeds.
+template <typename T>
+class ULEB128Reader {
+ static_assert(!std::numeric_limits<T>::is_signed,
+ "ULEB128Reader must handle an unsigned type");
+
+ public:
+ constexpr ULEB128Reader() = default;
+
+ // Don't allow copy/assignment, it doesn't make sense for a stateful parser.
+ constexpr ULEB128Reader(const ULEB128Reader&) = delete;
+ constexpr ULEB128Reader& operator=(const ULEB128Reader&) = delete;
+
+ // Feed a byte into the parser.
+ // Returns true if this was the last byte.
+ [[nodiscard]] constexpr bool FeedByteIsComplete(unsigned aByte) {
+ MOZ_ASSERT(!IsComplete());
+ // Extract the 7 bits of value, and shift them in place into the value.
+ mValue |= static_cast<T>(aByte & 0x7fu) << mShift;
+ // If the 8th bit is *not* set, this was the last byte.
+ // Expecting small values, so it should be more likely that the bit is off.
+ if (MOZ_LIKELY((aByte & 0x80u) == 0)) {
+ mShift = mCompleteShift;
+ return true;
+ }
+ // There are more bytes to read.
+ // Next byte will contain more significant bits above the past 7.
+ mShift += 7;
+ // Safety check that we're not going to shift by >= than the type size,
+ // which is Undefined Behavior in C++.
+ MOZ_ASSERT(mShift < CHAR_BIT * sizeof(T));
+ return false;
+ }
+
+ constexpr void Reset() {
+ mValue = 0;
+ mShift = 0;
+ }
+
+ [[nodiscard]] constexpr bool IsComplete() const {
+ return mShift == mCompleteShift;
+ }
+
+ [[nodiscard]] constexpr T Value() const {
+ MOZ_ASSERT(IsComplete());
+ return mValue;
+ }
+
+ private:
+ // Special value of `mShift` indicating that parsing is complete.
+ constexpr static unsigned mCompleteShift = 0x10000u;
+
+ T mValue = 0;
+ unsigned mShift = 0;
+};
+
+} // namespace mozilla
+
+#endif // leb128iterator_h