1 files changed, 345 insertions, 0 deletions
diff --git a/gfx/layers/ipc/CanvasChild.cpp b/gfx/layers/ipc/CanvasChild.cpp
new file mode 100644
index 0000000000..2f8464402d
--- /dev/null
+++ b/gfx/layers/ipc/CanvasChild.cpp
@@ -0,0 +1,345 @@
+/* -*- 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 "CanvasChild.h"
+
+#include "MainThreadUtils.h"
+#include "mozilla/gfx/DrawTargetRecording.h"
+#include "mozilla/gfx/Tools.h"
+#include "mozilla/gfx/Rect.h"
+#include "mozilla/gfx/Point.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/ipc/ProcessChild.h"
+#include "mozilla/layers/CanvasDrawEventRecorder.h"
+#include "nsIObserverService.h"
+#include "RecordedCanvasEventImpl.h"
+
+namespace mozilla {
+namespace layers {
+
+class RingBufferWriterServices final
+    : public CanvasEventRingBuffer::WriterServices {
+ public:
+  explicit RingBufferWriterServices(RefPtr<CanvasChild> aCanvasChild)
+      : mCanvasChild(std::move(aCanvasChild)) {}
+
+  ~RingBufferWriterServices() final = default;
+
+  bool ReaderClosed() final {
+    return !mCanvasChild->GetIPCChannel()->CanSend() ||
+           ipc::ProcessChild::ExpectingShutdown();
+  }
+
+  void ResumeReader() final { mCanvasChild->ResumeTranslation(); }
+
+ private:
+  RefPtr<CanvasChild> mCanvasChild;
+};
+
+class SourceSurfaceCanvasRecording final : public gfx::SourceSurface {
+ public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SourceSurfaceCanvasRecording, final)
+
+  SourceSurfaceCanvasRecording(
+      const RefPtr<gfx::SourceSurface>& aRecordedSuface,
+      CanvasChild* aCanvasChild,
+      const RefPtr<CanvasDrawEventRecorder>& aRecorder)
+      : mRecordedSurface(aRecordedSuface),
+        mCanvasChild(aCanvasChild),
+        mRecorder(aRecorder) {
+    // It's important that AddStoredObject is called first because that will
+    // run any pending processing required by recorded objects that have been
+    // deleted off the main thread.
+    mRecorder->AddStoredObject(this);
+    mRecorder->RecordEvent(RecordedAddSurfaceAlias(this, aRecordedSuface));
+  }
+
+  ~SourceSurfaceCanvasRecording() {
+    ReferencePtr surfaceAlias = this;
+    if (NS_IsMainThread()) {
+      ReleaseOnMainThread(std::move(mRecorder), surfaceAlias,
+                          std::move(mRecordedSurface), std::move(mCanvasChild));
+      return;
+    }
+
+    mRecorder->AddPendingDeletion(
+        [recorder = std::move(mRecorder), surfaceAlias,
+         aliasedSurface = std::move(mRecordedSurface),
+         canvasChild = std::move(mCanvasChild)]() mutable -> void {
+          ReleaseOnMainThread(std::move(recorder), surfaceAlias,
+                              std::move(aliasedSurface),
+                              std::move(canvasChild));
+        });
+  }
+
+  gfx::SurfaceType GetType() const final { return mRecordedSurface->GetType(); }
+
+  gfx::IntSize GetSize() const final { return mRecordedSurface->GetSize(); }
+
+  gfx::SurfaceFormat GetFormat() const final {
+    return mRecordedSurface->GetFormat();
+  }
+
+  already_AddRefed<gfx::DataSourceSurface> GetDataSurface() final {
+    EnsureDataSurfaceOnMainThread();
+    return do_AddRef(mDataSourceSurface);
+  }
+
+ private:
+  void EnsureDataSurfaceOnMainThread() {
+    // The data can only be retrieved on the main thread.
+    if (!mDataSourceSurface && NS_IsMainThread()) {
+      mDataSourceSurface = mCanvasChild->GetDataSurface(mRecordedSurface);
+    }
+  }
+
+  // Used to ensure that clean-up that requires it is done on the main thread.
+  static void ReleaseOnMainThread(RefPtr<CanvasDrawEventRecorder> aRecorder,
+                                  ReferencePtr aSurfaceAlias,
+                                  RefPtr<gfx::SourceSurface> aAliasedSurface,
+                                  RefPtr<CanvasChild> aCanvasChild) {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    aRecorder->RemoveStoredObject(aSurfaceAlias);
+    aRecorder->RecordEvent(RecordedRemoveSurfaceAlias(aSurfaceAlias));
+    aAliasedSurface = nullptr;
+    aCanvasChild = nullptr;
+    aRecorder = nullptr;
+  }
+
+  RefPtr<gfx::SourceSurface> mRecordedSurface;
+  RefPtr<CanvasChild> mCanvasChild;
+  RefPtr<CanvasDrawEventRecorder> mRecorder;
+  RefPtr<gfx::DataSourceSurface> mDataSourceSurface;
+};
+
+CanvasChild::CanvasChild(Endpoint<PCanvasChild>&& aEndpoint) {
+  aEndpoint.Bind(this);
+}
+
+CanvasChild::~CanvasChild() = default;
+
+static void NotifyCanvasDeviceReset() {
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    obs->NotifyObservers(nullptr, "canvas-device-reset", nullptr);
+  }
+}
+
+ipc::IPCResult CanvasChild::RecvNotifyDeviceChanged() {
+  NotifyCanvasDeviceReset();
+  mRecorder->RecordEvent(RecordedDeviceChangeAcknowledged());
+  return IPC_OK();
+}
+
+/* static */ bool CanvasChild::mDeactivated = false;
+
+ipc::IPCResult CanvasChild::RecvDeactivate() {
+  mDeactivated = true;
+  NotifyCanvasDeviceReset();
+  return IPC_OK();
+}
+
+void CanvasChild::EnsureRecorder(TextureType aTextureType) {
+  if (!mRecorder) {
+    MOZ_ASSERT(mTextureType == TextureType::Unknown);
+    mTextureType = aTextureType;
+    mRecorder = MakeAndAddRef<CanvasDrawEventRecorder>();
+    SharedMemoryBasic::Handle handle;
+    CrossProcessSemaphoreHandle readerSem;
+    CrossProcessSemaphoreHandle writerSem;
+    if (!mRecorder->Init(OtherPid(), &handle, &readerSem, &writerSem,
+                         MakeUnique<RingBufferWriterServices>(this))) {
+      mRecorder = nullptr;
+      return;
+    }
+
+    if (CanSend()) {
+      Unused << SendInitTranslator(mTextureType, std::move(handle),
+                                   std::move(readerSem), std::move(writerSem));
+    }
+  }
+
+  MOZ_RELEASE_ASSERT(mTextureType == aTextureType,
+                     "We only support one remote TextureType currently.");
+}
+
+void CanvasChild::ActorDestroy(ActorDestroyReason aWhy) {
+  // Explicitly drop our reference to the recorder, because it holds a reference
+  // to us via the ResumeTranslation callback.
+  mRecorder = nullptr;
+}
+
+void CanvasChild::ResumeTranslation() {
+  if (CanSend()) {
+    SendResumeTranslation();
+  }
+}
+
+void CanvasChild::Destroy() {
+  if (CanSend()) {
+    Close();
+  }
+}
+
+void CanvasChild::OnTextureWriteLock() {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return;
+  }
+
+  mHasOutstandingWriteLock = true;
+  mLastWriteLockCheckpoint = mRecorder->CreateCheckpoint();
+}
+
+void CanvasChild::OnTextureForwarded() {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return;
+  }
+
+  if (mHasOutstandingWriteLock) {
+    mRecorder->RecordEvent(RecordedCanvasFlush());
+    if (!mRecorder->WaitForCheckpoint(mLastWriteLockCheckpoint)) {
+      gfxWarning() << "Timed out waiting for last write lock to be processed.";
+    }
+
+    mHasOutstandingWriteLock = false;
+  }
+
+  // We hold onto the last transaction's external surfaces until we have waited
+  // for the write locks in this transaction. This means we know that the
+  // surfaces have been picked up in the canvas threads and there is no race
+  // with them being removed from SharedSurfacesParent. Note this releases the
+  // current contents of mLastTransactionExternalSurfaces.
+  mRecorder->TakeExternalSurfaces(mLastTransactionExternalSurfaces);
+}
+
+void CanvasChild::EnsureBeginTransaction() {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return;
+  }
+
+  if (!mIsInTransaction) {
+    mRecorder->RecordEvent(RecordedCanvasBeginTransaction());
+    mIsInTransaction = true;
+  }
+}
+
+void CanvasChild::EndTransaction() {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return;
+  }
+
+  if (mIsInTransaction) {
+    mRecorder->RecordEvent(RecordedCanvasEndTransaction());
+    mIsInTransaction = false;
+    mLastNonEmptyTransaction = TimeStamp::NowLoRes();
+  }
+
+  ++mTransactionsSinceGetDataSurface;
+}
+
+bool CanvasChild::ShouldBeCleanedUp() const {
+  // Always return true if we've been deactivated.
+  if (Deactivated()) {
+    return true;
+  }
+
+  // We can only be cleaned up if nothing else references our recorder.
+  if (mRecorder && !mRecorder->hasOneRef()) {
+    return false;
+  }
+
+  static const TimeDuration kCleanUpCanvasThreshold =
+      TimeDuration::FromSeconds(10);
+  return TimeStamp::NowLoRes() - mLastNonEmptyTransaction >
+         kCleanUpCanvasThreshold;
+}
+
+already_AddRefed<gfx::DrawTarget> CanvasChild::CreateDrawTarget(
+    gfx::IntSize aSize, gfx::SurfaceFormat aFormat) {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return nullptr;
+  }
+
+  RefPtr<gfx::DrawTarget> dummyDt = gfx::Factory::CreateDrawTarget(
+      gfx::BackendType::SKIA, gfx::IntSize(1, 1), aFormat);
+  RefPtr<gfx::DrawTarget> dt = MakeAndAddRef<gfx::DrawTargetRecording>(
+      mRecorder, dummyDt, gfx::IntRect(gfx::IntPoint(0, 0), aSize));
+  return dt.forget();
+}
+
+void CanvasChild::RecordEvent(const gfx::RecordedEvent& aEvent) {
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return;
+  }
+
+  mRecorder->RecordEvent(aEvent);
+}
+
+already_AddRefed<gfx::DataSourceSurface> CanvasChild::GetDataSurface(
+    const gfx::SourceSurface* aSurface) {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aSurface);
+
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return nullptr;
+  }
+
+  // mTransactionsSinceGetDataSurface is used to determine if we want to prepare
+  // a DataSourceSurface in the GPU process up front at the end of the
+  // transaction, but that only makes sense if the canvas JS is requesting data
+  // in between transactions.
+  if (!mIsInTransaction) {
+    mTransactionsSinceGetDataSurface = 0;
+  }
+  EnsureBeginTransaction();
+  mRecorder->RecordEvent(RecordedPrepareDataForSurface(aSurface));
+  uint32_t checkpoint = mRecorder->CreateCheckpoint();
+
+  gfx::IntSize ssSize = aSurface->GetSize();
+  gfx::SurfaceFormat ssFormat = aSurface->GetFormat();
+  size_t dataFormatWidth = ssSize.width * BytesPerPixel(ssFormat);
+  RefPtr<gfx::DataSourceSurface> dataSurface =
+      gfx::Factory::CreateDataSourceSurfaceWithStride(ssSize, ssFormat,
+                                                      dataFormatWidth);
+  if (!dataSurface) {
+    gfxWarning() << "Failed to create DataSourceSurface.";
+    return nullptr;
+  }
+  gfx::DataSourceSurface::ScopedMap map(dataSurface,
+                                        gfx::DataSourceSurface::READ_WRITE);
+  char* dest = reinterpret_cast<char*>(map.GetData());
+  if (!mRecorder->WaitForCheckpoint(checkpoint)) {
+    gfxWarning() << "Timed out preparing data for DataSourceSurface.";
+    return dataSurface.forget();
+  }
+
+  mRecorder->RecordEvent(RecordedGetDataForSurface(aSurface));
+  mRecorder->ReturnRead(dest, ssSize.height * dataFormatWidth);
+
+  return dataSurface.forget();
+}
+
+already_AddRefed<gfx::SourceSurface> CanvasChild::WrapSurface(
+    const RefPtr<gfx::SourceSurface>& aSurface) {
+  MOZ_ASSERT(aSurface);
+  // We drop mRecorder in ActorDestroy to break the reference cycle.
+  if (!mRecorder) {
+    return nullptr;
+  }
+
+  return MakeAndAddRef<SourceSurfaceCanvasRecording>(aSurface, this, mRecorder);
+}
+
+}  // namespace layers
+}  // namespace mozilla