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/* -*- 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 */
#ifndef mozilla_layers_CanvasChild_h
#define mozilla_layers_CanvasChild_h
#include "mozilla/gfx/RecordedEvent.h"
#include "mozilla/ipc/CrossProcessSemaphore.h"
#include "mozilla/layers/PCanvasChild.h"
#include "mozilla/layers/SourceSurfaceSharedData.h"
#include "mozilla/WeakPtr.h"
namespace mozilla {
namespace dom {
class ThreadSafeWorkerRef;
namespace gfx {
class DrawTargetRecording;
class SourceSurface;
namespace layers {
class CanvasDrawEventRecorder;
struct RemoteTextureOwnerId;
class CanvasChild final : public PCanvasChild, public SupportsWeakPtr {
explicit CanvasChild(dom::ThreadSafeWorkerRef* aWorkerRef);
* @returns true if remote canvas has been deactivated due to failure.
static bool Deactivated() { return mDeactivated; }
* Release resources until they are next required.
void ClearCachedResources();
ipc::IPCResult RecvNotifyDeviceChanged();
ipc::IPCResult RecvDeactivate();
ipc::IPCResult RecvBlockCanvas();
ipc::IPCResult RecvNotifyRequiresRefresh(int64_t aTextureId);
ipc::IPCResult RecvSnapshotShmem(int64_t aTextureId, Handle&& aShmemHandle,
uint32_t aShmemSize,
SnapshotShmemResolver&& aResolve);
* Ensures that the DrawEventRecorder has been created.
* @params aTextureType the TextureType to create in the CanvasTranslator.
void EnsureRecorder(gfx::IntSize aSize, gfx::SurfaceFormat aFormat,
TextureType aTextureType, TextureType aWebglTextureType);
* Clean up IPDL actor.
void Destroy();
* @returns true if we should be caching data surfaces in the GPU process.
bool ShouldCacheDataSurface() const {
return mTransactionsSinceGetDataSurface < kCacheDataSurfaceThreshold;
* Ensures that we have sent a begin transaction event, since the last
* end transaction.
* @returns false on failure to begin transaction
bool EnsureBeginTransaction();
* Send an end transaction event to indicate the end of events for this frame.
void EndTransaction();
* @returns true if the canvas IPC classes have not been used for some time
* and can be cleaned up.
bool ShouldBeCleanedUp() const;
* Create a DrawTargetRecording for a canvas texture.
* @param aTextureId the id of the new texture
* @param aSize size for the DrawTarget
* @param aFormat SurfaceFormat for the DrawTarget
* @returns newly created DrawTargetRecording
already_AddRefed<gfx::DrawTargetRecording> CreateDrawTarget(
int64_t aTextureId, const RemoteTextureOwnerId& aTextureOwnerId,
gfx::IntSize aSize, gfx::SurfaceFormat aFormat);
* Record an event for processing by the CanvasParent's CanvasTranslator.
* @param aEvent the event to record
void RecordEvent(const gfx::RecordedEvent& aEvent);
int64_t CreateCheckpoint();
* Wrap the given surface, so that we can provide a DataSourceSurface if
* required.
* @param aSurface the SourceSurface to wrap
* @param aTextureId the texture id of the source TextureData
* @returns a SourceSurface that can provide a DataSourceSurface if required
already_AddRefed<gfx::SourceSurface> WrapSurface(
const RefPtr<gfx::SourceSurface>& aSurface, int64_t aTextureId);
* The DrawTargetRecording backing the surface has not been modified since the
* previous use, so it is safe to reattach the snapshot for readback.
void AttachSurface(const RefPtr<gfx::SourceSurface>& aSurface);
* The DrawTargetRecording is about to change, so detach the old snapshot.
void DetachSurface(const RefPtr<gfx::SourceSurface>& aSurface);
* Get DataSourceSurface from the translated equivalent version of aSurface in
* the GPU process.
* @param aTextureId the source TextureData to read from
* @param aSurface the SourceSurface in this process for which we need a
* DataSourceSurface
* @param aDetached whether the surface is old
* @returns a DataSourceSurface created from data for aSurface retrieve from
* GPU process
already_AddRefed<gfx::DataSourceSurface> GetDataSurface(
int64_t aTextureId, const gfx::SourceSurface* aSurface, bool aDetached);
bool RequiresRefresh(int64_t aTextureId) const;
void CleanupTexture(int64_t aTextureId);
void ActorDestroy(ActorDestroyReason aWhy) final;
~CanvasChild() final;
bool EnsureDataSurfaceShmem(gfx::IntSize aSize, gfx::SurfaceFormat aFormat);
void ReturnDataSurfaceShmem(
already_AddRefed<ipc::SharedMemoryBasic> aDataSurfaceShmem);
struct DataShmemHolder {
RefPtr<ipc::SharedMemoryBasic> shmem;
RefPtr<CanvasChild> canvasChild;
static void ReleaseDataShmemHolder(void* aClosure);
void DropFreeBuffersWhenDormant();
static const uint32_t kCacheDataSurfaceThreshold = 10;
static bool mDeactivated;
RefPtr<dom::ThreadSafeWorkerRef> mWorkerRef;
RefPtr<CanvasDrawEventRecorder> mRecorder;
RefPtr<ipc::SharedMemoryBasic> mDataSurfaceShmem;
bool mDataSurfaceShmemAvailable = false;
int64_t mLastWriteLockCheckpoint = 0;
uint32_t mTransactionsSinceGetDataSurface = kCacheDataSurfaceThreshold;
struct TextureInfo {
RefPtr<mozilla::ipc::SharedMemoryBasic> mSnapshotShmem;
bool mRequiresRefresh = false;
std::unordered_map<int64_t, TextureInfo> mTextureInfo;
bool mIsInTransaction = false;
bool mDormant = false;
bool mBlocked = false;
} // namespace layers
} // namespace mozilla
#endif // mozilla_layers_CanvasChild_h