blob: 9f4eac285111787071191ee23fca789c1e46769a [file] [log] [blame]
// Copyright (c) 2012 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 "media/audio/scoped_task_runner_observer.h"
#include "base/bind.h"
#include "base/synchronization/waitable_event.h"
namespace media {
ScopedTaskRunnerObserver::ScopedTaskRunnerObserver(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
: task_runner_(task_runner) {
ObserveLoopDestruction(true, NULL);
}
ScopedTaskRunnerObserver::~ScopedTaskRunnerObserver() {
ObserveLoopDestruction(false, NULL);
}
void ScopedTaskRunnerObserver::ObserveLoopDestruction(
bool enable,
base::WaitableEvent* done) {
// Note: |done| may be NULL.
if (task_runner_->BelongsToCurrentThread()) {
base::MessageLoop* loop = base::MessageLoop::current();
if (enable) {
loop->AddDestructionObserver(this);
} else {
loop->RemoveDestructionObserver(this);
}
} else {
base::WaitableEvent event(false, false);
if (task_runner_->PostTask(FROM_HERE,
base::Bind(&ScopedTaskRunnerObserver::ObserveLoopDestruction,
base::Unretained(this), enable, &event))) {
event.Wait();
} else {
// The message loop's thread has already terminated, so no need to wait.
}
}
if (done)
done->Signal();
}
} // namespace media.