A patch making the pulseaudio working with the threaded mainloop.

media/audio/linux/pulse_output.h

Index: media/audio/linux/pulse_output.h
===================================================================
--- media/audio/linux/pulse_output.h	(revision 108881)
+++ media/audio/linux/pulse_output.h	(working copy)
@@ -12,13 +12,12 @@
 // on the same thread that created the object.
 //
 // WARNING: This object blocks on internal PulseAudio calls in Open() while
-// waiting for PulseAudio's context structure to be ready.  It also blocks in
-// inside PulseAudio in Start() and repeated during playback, waiting for
-// PulseAudio write callbacks to occur.
+// waiting for PulseAudio's context structure to be ready.
 
 #ifndef MEDIA_AUDIO_LINUX_PULSE_OUTPUT_H_
 #define MEDIA_AUDIO_LINUX_PULSE_OUTPUT_H_
 
+#include <pulse/glib-mainloop.h>
 #include <pulse/pulseaudio.h>
 
 #include "base/memory/scoped_ptr.h"
@@ -53,54 +52,41 @@
 
  private:
   // PulseAudio Callbacks.
-  static void ContextStateCallback(pa_context* context, void* state_addr);
+  static void ContextStateCallback(pa_context* context, void* p_this);

[tommi (sloooow) - chröme, 2011/11/08 10:51:36]

p_this -> this_ptr

Actually, the documentation for this callback says that the name of the last
argument is |user_data|. Can we just use that?

[no longer working on chromium, 2011/11/09 12:57:33]

Done.

   static void WriteRequestCallback(pa_stream* playback_handle, size_t length,
-                                   void* stream_addr);
+                                   void* p_this);

[tommi (sloooow) - chröme, 2011/11/08 10:51:36]

same here

[no longer working on chromium, 2011/11/09 12:57:33]

Done.

 
-  // Iterate the PulseAudio mainloop to get write requests.
-  void WaitForWriteRequest();
-
-  // Get another packet from the data source and write it to the client buffer.
-  bool BufferPacketFromSource();
-
-  // Fulfill a write request from the write request callback.  If the write
+  // Fulfills a write request from the write request callback.  If the write
   // can't be finished a first, post a new attempt to the message loop.
   void FulfillWriteRequest(size_t requested_bytes);
 
-  // Write data from the client buffer to the PulseAudio stream.
-  void WriteToStream(size_t bytes_to_write, size_t* bytes_written);
-
-  // API for Proxying calls to the AudioSourceCallback provided during Start().
-  uint32 RunDataCallback(uint8* dest, uint32 max_size,
-                         AudioBuffersState buffers_state);
-
   // Close() helper function to free internal structs.
   void Reset();
 
   // Configuration constants from the constructor.  Referencable by all threads
   // since they are constants.
-  const ChannelLayout channel_layout_;
-  const uint32 channel_count_;
+  const uint32 channels_;
   const pa_sample_format_t sample_format_;
   const uint32 sample_rate_;
   const uint32 bytes_per_frame_;
+  const uint32 packet_size_;
+  const uint32 frames_per_packet_;
 
   // Audio manager that created us.  Used to report that we've closed.
   AudioManagerLinux* manager_;
 
   // PulseAudio API structs.
   pa_context* pa_context_;
-  pa_mainloop* pa_mainloop_;
+  pa_glib_mainloop* pa_glib_mainloop_;
 
   // Handle to the actual PulseAudio playback stream.
   pa_stream* playback_handle_;
 
   // Device configuration data.  Populated after Open() completes.
-  uint32 packet_size_;
-  uint32 frames_per_packet_;
+  uint32 pa_buffer_size_;
 
   // Client side audio buffer feeding pulse audio's server side buffer.
-  scoped_ptr<media::SeekableBuffer> client_buffer_;
+  scoped_ptr<media::SeekableBuffer> buffer_;
 
   // Float representation of volume from 0.0 to 1.0.
   float volume_;
@@ -110,9 +96,8 @@
   // entered an unrecoverable error state, or the Close() has executed.
   bool stream_stopped_;
 
-  // Whether or not PulseAudio has called the WriteCallback for the most recent
-  // set of pa_mainloop iterations.
-  bool write_callback_handled_;
+  // Flag indicating the state of the context has been changed.
+  bool context_state_changed_;
 
   // Message loop used to post WaitForWriteTasks.  Used to prevent blocking on
   // the audio thread while waiting for PulseAudio write callbacks.