Move OnDecoderInitDone() from decoder to pipeline thread.

media/audio/null_audio_sink.cc

 // 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/null_audio_sink.h"
 
 #include "base/bind.h"
 #include "base/stringprintf.h"
 #include "base/sys_byteorder.h"
 #include "base/threading/platform_thread.h"
@@ skipping 27 matching lines @@
 
 void NullAudioSink::Start() {
   if (!thread_.Start())
     return;
 
   thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &NullAudioSink::FillBufferTask, this));
 }
 
 void NullAudioSink::Stop() {
-  SetPlaying(false);
+  playing_ = false;
   thread_.Stop();
 }
 
 void NullAudioSink::Play() {
-  SetPlaying(true);
+  playing_ = true;
 }
 
 void NullAudioSink::Pause(bool /* flush */) {
-  SetPlaying(false);
+  playing_ = false;
 }
 
 bool NullAudioSink::SetVolume(double volume) {
   // Audio is always muted.
   return volume == 0.0;
 }
 
-void NullAudioSink::SetPlaying(bool is_playing) {
-  base::AutoLock auto_lock(lock_);
-  playing_ = is_playing;
-}
-
 NullAudioSink::~NullAudioSink() {
   DCHECK(!thread_.IsRunning());
 }
 
 void NullAudioSink::FillBufferTask() {
-  base::AutoLock auto_lock(lock_);
-
   base::TimeDelta delay;
   // Only consume buffers when actually playing.
   if (playing_)  {

[Ami GONE FROM CHROMIUM, 2012/11/01 19:57:01]

This variable is set on the pipeline thread but is being read on the
NullAudioThread, with no locking.  What's up with that?

[DaleCurtis, 2012/11/01 22:02:59]

Normally we don't want to lock on the audio thread for a simple play check (a
value which could change afterward anyways); for NullAudioSink it doesn't
matter, so I'll just revert this chunk since you're opposed.

     int frames_received = callback_->Render(audio_bus_.get(), 0);
     int frames_per_millisecond =
         params_.sample_rate() / base::Time::kMillisecondsPerSecond;
 
     if (hash_audio_for_testing_ && frames_received > 0) {
       DCHECK_EQ(sizeof(float), sizeof(uint32));
       int channels = audio_bus_->channels();
       for (int channel_idx = 0; channel_idx < channels; ++channel_idx) {
         float* channel = audio_bus_->channel(channel_idx);
         for (int frame_idx = 0; frame_idx < frames_received; frame_idx++) {
@@ skipping 45 matching lines @@
     base::MD5Final(&digest, &md5_channel_contexts_[i]);
     base::MD5Update(&md5_channel_contexts_[0], base::StringPiece(
         reinterpret_cast<char*>(&digest), sizeof(base::MD5Digest)));
   }
 
   base::MD5Final(&digest, &md5_channel_contexts_[0]);
   return base::MD5DigestToBase16(digest);
 }
 
 }  // namespace media