Decouple 'give me more data' and 'rendered end of stream' audio callbacks.

content/renderer/media/audio_renderer_impl.cc

Index: content/renderer/media/audio_renderer_impl.cc
===================================================================
--- content/renderer/media/audio_renderer_impl.cc	(revision 121128)
+++ content/renderer/media/audio_renderer_impl.cc	(working copy)
@@ -16,6 +16,8 @@
 #include "media/audio/audio_util.h"
 #include "media/base/filter_host.h"
 
+using base::subtle::AtomicWord;
+
 // We define GetBufferSizeForSampleRate() instead of using
 // GetAudioHardwareBufferSize() in audio_util because we're using
 // the AUDIO_PCM_LINEAR flag, instead of AUDIO_PCM_LOW_LATENCY,
@@ -41,7 +43,10 @@
       bytes_per_second_(0),
       stopped_(false),
       sink_(sink),
-      is_initialized_(false) {
+      is_initialized_(false),
+      ended_event_scheduled_(false),
+      io_message_loop_proxy_(ChildProcess::current()->io_message_loop_proxy()),
+      stream_id_(0) {
 }
 
 AudioRendererImpl::~AudioRendererImpl() {
@@ -66,9 +71,9 @@
           static_cast<int64>(ceil(predicted_play_time.InMicroseconds() *
                                   playback_rate)));
     }
-    earliest_end_time_ =
+    set_earliest_end_time(
         std::max(earliest_end_time_,
-                 time_now + request_delay + predicted_play_time);
+                 time_now + request_delay + predicted_play_time));
   }
 }
 
@@ -173,18 +178,22 @@
 }
 
 void AudioRendererImpl::DoPlay() {
-  earliest_end_time_ = base::Time::Now();
+  set_earliest_end_time(base::Time::Now());
+  ended_event_scheduled_ = false;
   DCHECK(sink_.get());
   sink_->Play();
 }
 
 void AudioRendererImpl::DoPause() {
+  ++stream_id_;
   DCHECK(sink_.get());
   sink_->Pause(false);
 }
 
 void AudioRendererImpl::DoSeek() {
-  earliest_end_time_ = base::Time::Now();
+  set_earliest_end_time(base::Time::Now());
+  ended_event_scheduled_ = false;
+  ++stream_id_;
 
   // Pause and flush the stream when we seek to a new location.
   DCHECK(sink_.get());
@@ -197,7 +206,7 @@
   if (stopped_ || GetPlaybackRate() == 0.0f) {
     // Output silence if stopped.
     for (size_t i = 0; i < audio_data.size(); ++i)
-      memset(audio_data[i], 0, sizeof(float) * number_of_frames);
+      memset(audio_data[i], 0, sizeof(audio_data[i][0]) * number_of_frames);
     return 0;
   }
 
@@ -239,7 +248,7 @@
       int frames_to_zero = number_of_frames - filled_frames;
       memset(audio_data[channel_index] + filled_frames,
              0,
-             sizeof(float) * frames_to_zero);
+             sizeof(audio_data[channel_index][0]) * frames_to_zero);
     }
   }
   return filled_frames;
@@ -249,8 +258,28 @@
   host()->DisableAudioRenderer();
 }
 
+int64 AudioRendererImpl::OnRenderEndOfStreamDelay() {
+  return (earliest_end_time() - base::Time::Now()).InMilliseconds();
+}
+
 void AudioRendererImpl::OnRenderEndOfStream() {
-  // TODO(enal): schedule callback instead of polling.
-  if (base::Time::Now() >= earliest_end_time_)
+  if (!ended_event_scheduled_) {
+    ended_event_scheduled_ = true;
+    int64 delay_ms = OnRenderEndOfStreamDelay();
+    if (delay_ms <= 0) {
+      DoSignalEndOfStream(stream_id_);
+    } else {
+      io_message_loop_proxy_->PostDelayedTask(
+          FROM_HERE,
+          base::Bind(&AudioRendererImpl::DoSignalEndOfStream, this, stream_id_),
+          delay_ms);
+    }
+  }
+}
+
+void AudioRendererImpl::DoSignalEndOfStream(AtomicWord stream_id) {
+  // There is no way to cancel delayed task if we paused or seeked after task
+  // was scheduled, use stream id to catch such case.
+  if (stream_id == stream_id_)
     SignalEndOfStream();
 }