blob: 488373d5633a4cb110f80c2bfd1b58d4d3905c24 [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.
#include <set>
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/time/time.h"
namespace base {
class SingleThreadTaskRunner;
namespace chromecast {
namespace media {
class BalancedMediaTaskRunner;
class MediaTaskRunner;
// BalancedMediaTaskRunnerFactory -
// Create media tasks runners that are loosely synchronized between each other.
// For two tasks T1 and T2 with timestamps ts1 and ts2, the scheduler ensures
// T2 is not scheduled before T1 if ts2 > ts1 + |max_delta|.
class BalancedMediaTaskRunnerFactory
: public base::RefCountedThreadSafe<BalancedMediaTaskRunnerFactory> {
explicit BalancedMediaTaskRunnerFactory(base::TimeDelta max_delta);
// Creates a media task runner using |task_runner| as the underlying
// regular task runner.
// Restriction on the returned media task runner:
// - can only schedule only one media task at a time.
// - timestamps of tasks posted on that task runner must be increasing.
scoped_refptr<MediaTaskRunner> CreateMediaTaskRunner(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
typedef std::set<scoped_refptr<BalancedMediaTaskRunner> > MediaTaskRunnerSet;
friend class base::RefCountedThreadSafe<BalancedMediaTaskRunnerFactory>;
virtual ~BalancedMediaTaskRunnerFactory();
// Invoked when one of the registered media task runners received a new media
// task.
void OnNewTask();
// Unregister a media task runner.
void UnregisterMediaTaskRunner(
const scoped_refptr<BalancedMediaTaskRunner>& media_task_runner);
// Maximum timestamp deviation between tasks from the registered task runners.
const base::TimeDelta max_delta_;
// Task runners created by the factory that have not been unregistered yet.
base::Lock lock_;
MediaTaskRunnerSet task_runners_;
} // namespace media
} // namespace chromecast