1 files changed, 295 insertions, 0 deletions
diff --git a/tools/profiler/gecko/ProfilerChild.cpp b/tools/profiler/gecko/ProfilerChild.cpp
new file mode 100644
index 0000000000..748f88ccfa
--- /dev/null
+++ b/tools/profiler/gecko/ProfilerChild.cpp
@@ -0,0 +1,295 @@
+/* -*- 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/. */
+
+#include "ProfilerChild.h"
+
+#include "GeckoProfiler.h"
+#include "platform.h"
+#include "ProfilerParent.h"
+
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+
+/* static */ DataMutexBase<ProfilerChild::ProfilerChildAndUpdate,
+                           baseprofiler::detail::BaseProfilerMutex>
+    ProfilerChild::sPendingChunkManagerUpdate{
+        "ProfilerChild::sPendingChunkManagerUpdate"};
+
+ProfilerChild::ProfilerChild()
+    : mThread(NS_GetCurrentThread()), mDestroyed(false) {
+  MOZ_COUNT_CTOR(ProfilerChild);
+}
+
+ProfilerChild::~ProfilerChild() { MOZ_COUNT_DTOR(ProfilerChild); }
+
+void ProfilerChild::ResolveChunkUpdate(
+    PProfilerChild::AwaitNextChunkManagerUpdateResolver& aResolve) {
+  MOZ_ASSERT(!!aResolve,
+             "ResolveChunkUpdate should only be called when there's a pending "
+             "resolver");
+  MOZ_ASSERT(
+      !mChunkManagerUpdate.IsNotUpdate(),
+      "ResolveChunkUpdate should only be called with a real or final update");
+  MOZ_ASSERT(
+      !mDestroyed,
+      "ResolveChunkUpdate should not be called if the actor was destroyed");
+  if (mChunkManagerUpdate.IsFinal()) {
+    // Final update, send a special "unreleased value", but don't clear the
+    // local copy so we know we got the final update.
+    std::move(aResolve)(ProfilerParent::MakeFinalUpdate());
+  } else {
+    // Optimization note: The ProfileBufferChunkManagerUpdate constructor takes
+    // the newly-released chunks nsTArray by reference-to-const, therefore
+    // constructing and then moving the array here would make a copy. So instead
+    // we first give it an empty array, and then we can write the data directly
+    // into the update's array.
+    ProfileBufferChunkManagerUpdate update{
+        mChunkManagerUpdate.UnreleasedBytes(),
+        mChunkManagerUpdate.ReleasedBytes(),
+        mChunkManagerUpdate.OldestDoneTimeStamp(),
+        {}};
+    update.newlyReleasedChunks().SetCapacity(
+        mChunkManagerUpdate.NewlyReleasedChunksRef().size());
+    for (const ProfileBufferControlledChunkManager::ChunkMetadata& chunk :
+         mChunkManagerUpdate.NewlyReleasedChunksRef()) {
+      update.newlyReleasedChunks().EmplaceBack(chunk.mDoneTimeStamp,
+                                               chunk.mBufferBytes);
+    }
+
+    std::move(aResolve)(update);
+
+    // Clear the update we just sent, so it's ready for later updates to be
+    // folded into it.
+    mChunkManagerUpdate.Clear();
+  }
+
+  // Discard the resolver, so it's empty next time there's a new request.
+  aResolve = nullptr;
+}
+
+void ProfilerChild::ProcessChunkManagerUpdate(
+    ProfileBufferControlledChunkManager::Update&& aUpdate) {
+  if (mDestroyed) {
+    return;
+  }
+  // Always store the data, it could be the final update.
+  mChunkManagerUpdate.Fold(std::move(aUpdate));
+  if (mAwaitNextChunkManagerUpdateResolver) {
+    // There is already a pending resolver, give it the info now.
+    ResolveChunkUpdate(mAwaitNextChunkManagerUpdateResolver);
+  }
+}
+
+/* static */ void ProfilerChild::ProcessPendingUpdate() {
+  auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+  if (!lockedUpdate->mProfilerChild || lockedUpdate->mUpdate.IsNotUpdate()) {
+    return;
+  }
+  lockedUpdate->mProfilerChild->mThread->Dispatch(NS_NewRunnableFunction(
+      "ProfilerChild::ProcessPendingUpdate", []() mutable {
+        auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+        if (!lockedUpdate->mProfilerChild ||
+            lockedUpdate->mUpdate.IsNotUpdate()) {
+          return;
+        }
+        lockedUpdate->mProfilerChild->ProcessChunkManagerUpdate(
+            std::move(lockedUpdate->mUpdate));
+        lockedUpdate->mUpdate.Clear();
+      }));
+}
+
+/* static */ bool ProfilerChild::IsLockedOnCurrentThread() {
+  return sPendingChunkManagerUpdate.Mutex().IsLockedOnCurrentThread();
+}
+
+void ProfilerChild::SetupChunkManager() {
+  mChunkManager = profiler_get_controlled_chunk_manager();
+  if (NS_WARN_IF(!mChunkManager)) {
+    return;
+  }
+
+  // Make sure there are no updates (from a previous run).
+  mChunkManagerUpdate.Clear();
+  {
+    auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+    lockedUpdate->mProfilerChild = this;
+    lockedUpdate->mUpdate.Clear();
+  }
+
+  mChunkManager->SetUpdateCallback(
+      [](ProfileBufferControlledChunkManager::Update&& aUpdate) {
+        // Updates from the chunk manager are stored for later processing.
+        // We avoid dispatching a task, as this could deadlock (if the queueing
+        // mutex is held elsewhere).
+        auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+        if (!lockedUpdate->mProfilerChild) {
+          return;
+        }
+        lockedUpdate->mUpdate.Fold(std::move(aUpdate));
+      });
+}
+
+void ProfilerChild::ResetChunkManager() {
+  if (!mChunkManager) {
+    return;
+  }
+
+  // We have a chunk manager, reset the callback, which will add a final
+  // pending update.
+  mChunkManager->SetUpdateCallback({});
+
+  // Clear the pending update.
+  auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+  lockedUpdate->mProfilerChild = nullptr;
+  lockedUpdate->mUpdate.Clear();
+  // And process a final update right now.
+  ProcessChunkManagerUpdate(
+      ProfileBufferControlledChunkManager::Update(nullptr));
+
+  mChunkManager = nullptr;
+  mAwaitNextChunkManagerUpdateResolver = nullptr;
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvStart(
+    const ProfilerInitParams& params) {
+  nsTArray<const char*> filterArray;
+  for (size_t i = 0; i < params.filters().Length(); ++i) {
+    filterArray.AppendElement(params.filters()[i].get());
+  }
+
+  profiler_start(PowerOfTwo32(params.entries()), params.interval(),
+                 params.features(), filterArray.Elements(),
+                 filterArray.Length(), params.activeBrowsingContextID(),
+                 params.duration());
+
+  SetupChunkManager();
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvEnsureStarted(
+    const ProfilerInitParams& params) {
+  nsTArray<const char*> filterArray;
+  for (size_t i = 0; i < params.filters().Length(); ++i) {
+    filterArray.AppendElement(params.filters()[i].get());
+  }
+
+  profiler_ensure_started(PowerOfTwo32(params.entries()), params.interval(),
+                          params.features(), filterArray.Elements(),
+                          filterArray.Length(),
+                          params.activeBrowsingContextID(), params.duration());
+
+  SetupChunkManager();
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvStop() {
+  ResetChunkManager();
+  profiler_stop();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvPause() {
+  profiler_pause();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvResume() {
+  profiler_resume();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvPauseSampling() {
+  profiler_pause_sampling();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvResumeSampling() {
+  profiler_resume_sampling();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvClearAllPages() {
+  profiler_clear_all_pages();
+  return IPC_OK();
+}
+
+static nsCString CollectProfileOrEmptyString(bool aIsShuttingDown) {
+  nsCString profileCString;
+  UniquePtr<char[]> profile =
+      profiler_get_profile(/* aSinceTime */ 0, aIsShuttingDown);
+  if (profile) {
+    size_t len = strlen(profile.get());
+    profileCString.Adopt(profile.release(), len);
+  }
+  return profileCString;
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvAwaitNextChunkManagerUpdate(
+    AwaitNextChunkManagerUpdateResolver&& aResolve) {
+  MOZ_ASSERT(!mDestroyed,
+             "Recv... should not be called if the actor was destroyed");
+  // Pick up pending updates if any.
+  {
+    auto lockedUpdate = sPendingChunkManagerUpdate.Lock();
+    if (lockedUpdate->mProfilerChild && !lockedUpdate->mUpdate.IsNotUpdate()) {
+      mChunkManagerUpdate.Fold(std::move(lockedUpdate->mUpdate));
+      lockedUpdate->mUpdate.Clear();
+    }
+  }
+  if (mChunkManagerUpdate.IsNotUpdate()) {
+    // No data yet, store the resolver for later.
+    mAwaitNextChunkManagerUpdateResolver = std::move(aResolve);
+  } else {
+    // We have data, send it now.
+    ResolveChunkUpdate(aResolve);
+  }
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvDestroyReleasedChunksAtOrBefore(
+    const TimeStamp& aTimeStamp) {
+  if (mChunkManager) {
+    mChunkManager->DestroyChunksAtOrBefore(aTimeStamp);
+  }
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult ProfilerChild::RecvGatherProfile(
+    GatherProfileResolver&& aResolve) {
+  mozilla::ipc::Shmem shmem;
+  profiler_get_profile_json_into_lazily_allocated_buffer(
+      [&](size_t allocationSize) -> char* {
+        if (AllocShmem(allocationSize,
+                       mozilla::ipc::Shmem::SharedMemory::TYPE_BASIC, &shmem)) {
+          return shmem.get<char>();
+        }
+        return nullptr;
+      },
+      /* aSinceTime */ 0,
+      /* aIsShuttingDown */ false);
+  aResolve(std::move(shmem));
+  return IPC_OK();
+}
+
+void ProfilerChild::ActorDestroy(ActorDestroyReason aActorDestroyReason) {
+  mDestroyed = true;
+}
+
+void ProfilerChild::Destroy() {
+  ResetChunkManager();
+  if (!mDestroyed) {
+    Close();
+  }
+}
+
+nsCString ProfilerChild::GrabShutdownProfile() {
+  return CollectProfileOrEmptyString(/* aIsShuttingDown */ true);
+}
+
+}  // namespace mozilla