Fix start/stop of html5 audio stream and race condition when pausing.

content/renderer/media/audio_device.h

 // Copyright (c) 2011 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.
 //
 // Low-latency audio rendering unit utilizing audio output stream provided
 // by browser process through IPC.
 //
 // Relationship of classes.
 //
 //  AudioOutputController                AudioDevice
@@ skipping 63 matching lines @@
 #include "content/renderer/media/audio_message_filter.h"
 #include "media/audio/audio_parameters.h"
 
 class CONTENT_EXPORT AudioDevice
     : public AudioMessageFilter::Delegate,
       public base::DelegateSimpleThread::Delegate,
       public base::RefCountedThreadSafe<AudioDevice> {
  public:
   class CONTENT_EXPORT RenderCallback {
    public:
-    virtual void Render(const std::vector<float*>& audio_data,
-                        size_t number_of_frames,
-                        size_t audio_delay_milliseconds) = 0;
+    // Fills entire buffer, returns actual number of frames it got from source.
+    virtual size_t Render(const std::vector<float*>& audio_data,

[Chris Rogers, 2011/12/14 20:48:35]

probably should add comment about the return value

[enal1, 2011/12/14 22:14:54]

Made existing comment more clear.

+                          size_t number_of_frames,
+                          size_t audio_delay_milliseconds) = 0;
    protected:
     virtual ~RenderCallback() {}
   };
 
   // Methods called on main render thread -------------------------------------
 
   // Minimal constructor where Initialize() must be called later.
   AudioDevice();
 
   AudioDevice(size_t buffer_size,
@@ skipping 58 matching lines @@
   void PlayOnIOThread();
   void PauseOnIOThread(bool flush);
   void ShutDownOnIOThread(base::WaitableEvent* completion);
   void SetVolumeOnIOThread(double volume);
 
   void Send(IPC::Message* message);
 
   // Method called on the audio thread (+ one call on the IO thread) ----------
   // Calls the client's callback for rendering audio. There will also be one
   // initial call on the IO thread before the audio thread has been created.
-  void FireRenderCallback(int16* data);
+  // Returns actual number of filled frames.
+  size_t FireRenderCallback(int16* data);

[Chris Rogers, 2011/12/14 20:48:35]

comment about return value

[enal1, 2011/12/14 22:14:54]

Done.

 
   // DelegateSimpleThread::Delegate implementation.
   virtual void Run() OVERRIDE;
 
   // Closes socket and joins with the audio thread.
   void ShutDownAudioThread();
 
   // Format
   size_t buffer_size_;  // in sample-frames
   int channels_;
@@ skipping 42 matching lines @@
 
   // Protects lifetime of:
   // socket_handle_
   // audio_thread_
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDevice);
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_H_