From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- .../ProfileBufferChunkManagerWithLocalLimit.h | 444 +++++++++++++++++++++ 1 file changed, 444 insertions(+) create mode 100644 mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.h (limited to 'mozglue/baseprofiler/public/ProfileBufferChunkManagerWithLocalLimit.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 + +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 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)>&& + 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)> 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 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&& aChunkDestroyedCallback) + final { + baseprofiler::detail::BaseProfilerAutoLock lock(mMutex); + MOZ_ASSERT(mUser, "Not registered yet"); + mChunkDestroyedCallback = std::move(aChunkDestroyedCallback); + } + + [[nodiscard]] UniquePtr GetExtantReleasedChunks() final { + UniquePtr 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&& 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 TakeRecycledChunk( + const baseprofiler::detail::BaseProfilerAutoLock& aLock) { + UniquePtr recycled; + if (mRecycledChunks) { + recycled = std::exchange(mRecycledChunks, mRecycledChunks->ReleaseNext()); + recycled->MarkRecycled(); + } + return recycled; + } + + void DiscardOldestReleasedChunk( + const baseprofiler::detail::BaseProfilerAutoLock& aLock) { + MOZ_ASSERT(!!mReleasedChunks); + UniquePtr 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, 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& 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 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 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 mChunkDestroyedCallback; + + // Callback set from `RequestChunk()`, until it is serviced in + // `FulfillChunkRequests()`. There can only be one request in flight. + std::function)> 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 -- cgit v1.2.3