Moved the fake input stream's processing onto the audio worker thread.

media/audio/fake_audio_worker.cc

 // Copyright (c) 2013 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/fake_audio_consumer.h"
+#include "media/audio/fake_audio_worker.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/cancelable_callback.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "media/audio/audio_parameters.h"
-#include "media/base/audio_bus.h"
 
 namespace media {
 
-class FakeAudioConsumer::Worker
-    : public base::RefCountedThreadSafe<FakeAudioConsumer::Worker> {
+class FakeAudioWorker::Worker
+    : public base::RefCountedThreadSafe<FakeAudioWorker::Worker> {
  public:
   Worker(const scoped_refptr<base::SingleThreadTaskRunner>& worker_task_runner,
          const AudioParameters& params);
 
   bool IsStopped();
-  void Start(const ReadCB& read_cb);
+  void Start(const base::Closure& worker_cb);
   void Stop();
 
  private:
   friend class base::RefCountedThreadSafe<Worker>;
   ~Worker();
 
   // Initialize and start regular calls to DoRead() on the worker thread.
   void DoStart();
 
   // Cancel any delayed callbacks to DoRead() in the worker loop's queue.
   void DoCancel();
 
-  // Task that regularly calls |read_cb_| according to the playback rate as
+  // Task that regularly calls |worker_cb_| according to the playback rate as
   // determined by the audio parameters given during construction.  Runs on
   // the worker loop.
   void DoRead();
 
   const scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner_;
-  const scoped_ptr<AudioBus> audio_bus_;
   const base::TimeDelta buffer_duration_;
 
-  base::Lock read_cb_lock_;  // Held while mutating or running |read_cb_|.
-  ReadCB read_cb_;
+  base::Lock worker_cb_lock_;  // Held while mutating or running |worker_cb_|.
+  base::Closure worker_cb_;
   base::TimeTicks next_read_time_;
 
   // Used to cancel any delayed tasks still inside the worker loop's queue.
-  base::CancelableClosure read_task_cb_;
+  base::CancelableClosure worker_task_cb_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(Worker);
 };
 
-FakeAudioConsumer::FakeAudioConsumer(
+FakeAudioWorker::FakeAudioWorker(
     const scoped_refptr<base::SingleThreadTaskRunner>& worker_task_runner,
     const AudioParameters& params)
     : worker_(new Worker(worker_task_runner, params)) {
 }
 
-FakeAudioConsumer::~FakeAudioConsumer() {
+FakeAudioWorker::~FakeAudioWorker() {
   DCHECK(worker_->IsStopped());
 }
 
-void FakeAudioConsumer::Start(const ReadCB& read_cb) {
+void FakeAudioWorker::Start(const base::Closure& worker_cb) {
   DCHECK(worker_->IsStopped());
-  worker_->Start(read_cb);
+  worker_->Start(worker_cb);
 }
 
-void FakeAudioConsumer::Stop() {
+void FakeAudioWorker::Stop() {
   worker_->Stop();
 }
 
-FakeAudioConsumer::Worker::Worker(
+FakeAudioWorker::Worker::Worker(
     const scoped_refptr<base::SingleThreadTaskRunner>& worker_task_runner,
     const AudioParameters& params)
     : worker_task_runner_(worker_task_runner),
-      audio_bus_(AudioBus::Create(params)),
       buffer_duration_(base::TimeDelta::FromMicroseconds(
           params.frames_per_buffer() * base::Time::kMicrosecondsPerSecond /
           static_cast<float>(params.sample_rate()))) {
-  audio_bus_->Zero();
-
   // Worker can be constructed on any thread, but will DCHECK that its
   // Start/Stop methods are called from the same thread.
   thread_checker_.DetachFromThread();
 }
 
-FakeAudioConsumer::Worker::~Worker() {
-  DCHECK(read_cb_.is_null());
+FakeAudioWorker::Worker::~Worker() {
+  DCHECK(worker_cb_.is_null());
 }
 
-bool FakeAudioConsumer::Worker::IsStopped() {
-  base::AutoLock scoped_lock(read_cb_lock_);
-  return read_cb_.is_null();
+bool FakeAudioWorker::Worker::IsStopped() {
+  base::AutoLock scoped_lock(worker_cb_lock_);
+  return worker_cb_.is_null();
 }
 
-void FakeAudioConsumer::Worker::Start(const ReadCB& read_cb)  {
+void FakeAudioWorker::Worker::Start(const base::Closure& worker_cb)  {
   DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!read_cb.is_null());
+  DCHECK(!worker_cb.is_null());
   {
-    base::AutoLock scoped_lock(read_cb_lock_);
-    DCHECK(read_cb_.is_null());
-    read_cb_ = read_cb;
+    base::AutoLock scoped_lock(worker_cb_lock_);
+    DCHECK(worker_cb_.is_null());
+    worker_cb_ = worker_cb;
   }
   worker_task_runner_->PostTask(FROM_HERE, base::Bind(&Worker::DoStart, this));
 }
 
-void FakeAudioConsumer::Worker::DoStart() {
+void FakeAudioWorker::Worker::DoStart() {
   DCHECK(worker_task_runner_->BelongsToCurrentThread());
   next_read_time_ = base::TimeTicks::Now();
-  read_task_cb_.Reset(base::Bind(&Worker::DoRead, this));
-  read_task_cb_.callback().Run();
+  worker_task_cb_.Reset(base::Bind(&Worker::DoRead, this));
+  worker_task_cb_.callback().Run();
 }
 
-void FakeAudioConsumer::Worker::Stop() {
+void FakeAudioWorker::Worker::Stop() {
   DCHECK(thread_checker_.CalledOnValidThread());
   {
-    base::AutoLock scoped_lock(read_cb_lock_);
-    if (read_cb_.is_null())
+    base::AutoLock scoped_lock(worker_cb_lock_);
+    if (worker_cb_.is_null())
       return;
-    read_cb_.Reset();
+    worker_cb_.Reset();
   }
   worker_task_runner_->PostTask(FROM_HERE, base::Bind(&Worker::DoCancel, this));
 }
 
-void FakeAudioConsumer::Worker::DoCancel() {
+void FakeAudioWorker::Worker::DoCancel() {
   DCHECK(worker_task_runner_->BelongsToCurrentThread());
-  read_task_cb_.Cancel();
+  worker_task_cb_.Cancel();
 }
 
-void FakeAudioConsumer::Worker::DoRead() {
+void FakeAudioWorker::Worker::DoRead() {
   DCHECK(worker_task_runner_->BelongsToCurrentThread());
 
   {
-    base::AutoLock scoped_lock(read_cb_lock_);
-    if (!read_cb_.is_null())
-      read_cb_.Run(audio_bus_.get());
+    base::AutoLock scoped_lock(worker_cb_lock_);
+    if (!worker_cb_.is_null())
+      worker_cb_.Run();
   }
 
-  // Need to account for time spent here due to the cost of |read_cb_| as well
+  // Need to account for time spent here due to the cost of |worker_cb| as well
   // as the imprecision of PostDelayedTask().
   const base::TimeTicks now = base::TimeTicks::Now();
   base::TimeDelta delay = next_read_time_ + buffer_duration_ - now;
 
   // If we're behind, find the next nearest ontime interval.
   if (delay < base::TimeDelta())
     delay += buffer_duration_ * (-delay / buffer_duration_ + 1);
   next_read_time_ = now + delay;
 
   worker_task_runner_->PostDelayedTask(
-      FROM_HERE, read_task_cb_.callback(), delay);
+      FROM_HERE, worker_task_cb_.callback(), delay);
 }
 
 }  // namespace media