blob: c3797bc93ef702642b2e883b1f70dad2ddedb403 [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_CHILD_WORKER_TASK_RUNNER_H_
#define CONTENT_CHILD_WORKER_TASK_RUNNER_H_
#include <map>
#include "base/callback_forward.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/threading/platform_thread.h"
#include "base/threading/thread_local.h"
#include "content/common/content_export.h"
namespace base {
class TaskRunner;
}
namespace content {
class CONTENT_EXPORT WorkerTaskRunner {
public:
WorkerTaskRunner();
bool PostTask(int id, const base::Closure& task);
int PostTaskToAllThreads(const base::Closure& task);
int CurrentWorkerId();
static WorkerTaskRunner* Instance();
class CONTENT_EXPORT Observer {
public:
virtual ~Observer() {}
virtual void OnWorkerRunLoopStopped() = 0;
};
// Add/Remove an observer that will get notified when the current worker run
// loop is stopping. This observer will not get notified when other threads
// are stopping. It's only valid to call these on a worker thread.
void AddStopObserver(Observer* observer);
void RemoveStopObserver(Observer* observer);
void OnWorkerRunLoopStarted();
void OnWorkerRunLoopStopped();
base::TaskRunner* GetTaskRunnerFor(int worker_id);
private:
friend class WorkerTaskRunnerTest;
using IDToTaskRunnerMap = std::map<base::PlatformThreadId, base::TaskRunner*>;
~WorkerTaskRunner();
// It is possible for an IPC message to arrive for a worker thread that has
// already gone away. In such cases, it is still necessary to provide a
// task-runner for that particular thread, because otherwise the message will
// end up being handled as per usual in the main-thread, causing incorrect
// results. |task_runner_for_dead_worker_| is used to handle such messages,
// which silently discards all the tasks it receives.
scoped_refptr<base::TaskRunner> task_runner_for_dead_worker_;
struct ThreadLocalState;
base::ThreadLocalPointer<ThreadLocalState> current_tls_;
IDToTaskRunnerMap task_runner_map_;
base::Lock task_runner_map_lock_;
};
} // namespace content
#endif // CONTENT_CHILD_WORKER_TASK_RUNNER_H_