1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/MediaTaskQueue.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,94 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef MediaTaskQueue_h_
1.11 +#define MediaTaskQueue_h_
1.12 +
1.13 +#include <queue>
1.14 +#include "mozilla/RefPtr.h"
1.15 +#include "mozilla/Monitor.h"
1.16 +#include "nsThreadUtils.h"
1.17 +
1.18 +class nsIRunnable;
1.19 +
1.20 +namespace mozilla {
1.21 +
1.22 +class SharedThreadPool;
1.23 +
1.24 +// Abstracts executing runnables in order in a thread pool. The runnables
1.25 +// dispatched to the MediaTaskQueue will be executed in the order in which
1.26 +// they're received, and are guaranteed to not be executed concurrently.
1.27 +// They may be executed on different threads, and a memory barrier is used
1.28 +// to make this threadsafe for objects that aren't already threadsafe.
1.29 +class MediaTaskQueue MOZ_FINAL {
1.30 + ~MediaTaskQueue();
1.31 +
1.32 +public:
1.33 + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaTaskQueue)
1.34 +
1.35 + MediaTaskQueue(TemporaryRef<SharedThreadPool> aPool);
1.36 +
1.37 + nsresult Dispatch(TemporaryRef<nsIRunnable> aRunnable);
1.38 +
1.39 + // Removes all pending tasks from the task queue, and blocks until
1.40 + // the currently running task (if any) finishes.
1.41 + void Flush();
1.42 +
1.43 + // Blocks until all tasks finish executing, then shuts down the task queue
1.44 + // and exits.
1.45 + void Shutdown();
1.46 +
1.47 + // Blocks until all task finish executing.
1.48 + void AwaitIdle();
1.49 +
1.50 + bool IsEmpty();
1.51 +
1.52 + // Returns true if the current thread is currently running a Runnable in
1.53 + // the task queue. This is for debugging/validation purposes only.
1.54 + bool IsCurrentThreadIn();
1.55 +
1.56 +private:
1.57 +
1.58 + // Blocks until all task finish executing. Called internally by methods
1.59 + // that need to wait until the task queue is idle.
1.60 + // mQueueMonitor must be held.
1.61 + void AwaitIdleLocked();
1.62 +
1.63 + RefPtr<SharedThreadPool> mPool;
1.64 +
1.65 + // Monitor that protects the queue and mIsRunning;
1.66 + Monitor mQueueMonitor;
1.67 +
1.68 + // Queue of tasks to run.
1.69 + std::queue<RefPtr<nsIRunnable>> mTasks;
1.70 +
1.71 + // The thread currently running the task queue. We store a reference
1.72 + // to this so that IsCurrentThreadIn() can tell if the current thread
1.73 + // is the thread currently running in the task queue.
1.74 + RefPtr<nsIThread> mRunningThread;
1.75 +
1.76 + // True if we've dispatched an event to the pool to execute events from
1.77 + // the queue.
1.78 + bool mIsRunning;
1.79 +
1.80 + // True if we've started our shutdown process.
1.81 + bool mIsShutdown;
1.82 +
1.83 + class Runner : public nsRunnable {
1.84 + public:
1.85 + Runner(MediaTaskQueue* aQueue)
1.86 + : mQueue(aQueue)
1.87 + {
1.88 + }
1.89 + NS_METHOD Run() MOZ_OVERRIDE;
1.90 + private:
1.91 + RefPtr<MediaTaskQueue> mQueue;
1.92 + };
1.93 +};
1.94 +
1.95 +} // namespace mozilla
1.96 +
1.97 +#endif // MediaTaskQueue_h_
