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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_CanvasThread_h
#define mozilla_layers_CanvasThread_h
#include "mozilla/layers/CompositorThread.h"
#include "mozilla/DataMutex.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/TaskQueue.h"
#include "nsIThreadPool.h"
namespace mozilla {
namespace layers {
* The CanvasThreadHolder is used to manage the lifetime of the canvas
* thread (IPC) and workers and also provides methods for using them.
class CanvasThreadHolder final {
// We only AddRef/Release on the Compositor thread.
* Ensures that the canvas thread and workers are created.
* This must be called on the compositor thread.
* @return a CanvasThreadHolder
static already_AddRefed<CanvasThreadHolder> EnsureCanvasThread();
* Used to release CanvasThreadHolder references, which must be released on
* the compositor thread.
* @param aCanvasThreadHolder the reference to release
static void ReleaseOnCompositorThread(
already_AddRefed<CanvasThreadHolder> aCanvasThreadHolder);
* @return true if in the canvas thread
static bool IsInCanvasThread();
* @return true if in a canvas worker thread
static bool IsInCanvasWorker();
* @return true if in the canvas thread or worker
static bool IsInCanvasThreadOrWorker();
* Static method to dispatch a runnable to the canvas thread. If there is no
* canvas thread this will just release aRunnable.
* @param aRunnable the runnable to dispatch
static void MaybeDispatchToCanvasThread(
already_AddRefed<nsIRunnable> aRunnable);
* Dispatch a runnable to the canvas thread.
* @param aRunnable the runnable to dispatch
void DispatchToCanvasThread(already_AddRefed<nsIRunnable> aRunnable);
* Create a TaskQueue for the canvas worker threads. This must be shutdown
* before the reference to CanvasThreadHolder is dropped.
* @return a TaskQueue that dispatches to the canvas worker threads
already_AddRefed<TaskQueue> CreateWorkerTaskQueue();
static StaticDataMutex<StaticRefPtr<CanvasThreadHolder>> sCanvasThreadHolder;
CanvasThreadHolder(already_AddRefed<nsISerialEventTarget> aCanvasThread,
already_AddRefed<nsIThreadPool> aCanvasWorkers);
nsCOMPtr<nsISerialEventTarget> mCanvasThread;
RefPtr<nsIThreadPool> mCanvasWorkers;
// Hold a reference to prevent the compositor thread ending.
RefPtr<CompositorThreadHolder> mCompositorThreadKeepAlive;
} // namespace layers
} // namespace mozilla
#endif // mozilla_layers_CanvasThread_h