Implement low-latency audio on Pepper.

BUG=28292
TEST=none

Review URL: http://codereview.chromium.org/577019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38392 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 138 insertions, 12 deletions

diff --git a/chrome/renderer/audio_message_filter.cc b/chrome/renderer/audio_message_filter.cc
index 31c1df4..de209d9 100644
--- a/chrome/renderer/audio_message_filter.cc
+++ b/chrome/renderer/audio_message_filter.cc
@@ -35,6 +35,8 @@ bool AudioMessageFilter::OnMessageReceived(const IPC::Message& message) {
   IPC_BEGIN_MESSAGE_MAP(AudioMessageFilter, message)
     IPC_MESSAGE_HANDLER(ViewMsg_RequestAudioPacket, OnRequestPacket)
     IPC_MESSAGE_HANDLER(ViewMsg_NotifyAudioStreamCreated, OnStreamCreated)
+    IPC_MESSAGE_HANDLER(ViewMsg_NotifyLowLatencyAudioStreamCreated,
+                        OnLowLatencyStreamCreated)
     IPC_MESSAGE_HANDLER(ViewMsg_NotifyAudioStreamStateChanged,
                         OnStreamStateChanged)
     IPC_MESSAGE_HANDLER(ViewMsg_NotifyAudioStreamVolume, OnStreamVolume)
@@ -84,6 +86,27 @@ void AudioMessageFilter::OnStreamCreated(int stream_id,
   delegate->OnCreated(handle, length);
 }
 
+void AudioMessageFilter::OnLowLatencyStreamCreated(
+    int stream_id,
+    base::SharedMemoryHandle handle,
+#if defined(OS_WIN)
+    base::SyncSocket::Handle socket_handle,
+#else
+    base::FileDescriptor socket_descriptor,
+#endif
+    uint32 length) {
+  Delegate* delegate = delegates_.Lookup(stream_id);
+  if (!delegate) {
+    DLOG(WARNING) << "Got audio stream event for a non-existent or removed"
+        " audio renderer.";
+    return;
+  }
+#if !defined(OS_WIN)
+  base::SyncSocket::Handle socket_handle = socket_descriptor.fd;
+#endif
+  delegate->OnLowLatencyCreated(handle, socket_handle, length);
+}
+
 void AudioMessageFilter::OnStreamStateChanged(
     int stream_id,
     const ViewMsg_AudioStreamState_Params& state) {
diff --git a/chrome/renderer/audio_message_filter.h b/chrome/renderer/audio_message_filter.h
index 3dfacdc..6b4f736 100644
--- a/chrome/renderer/audio_message_filter.h
+++ b/chrome/renderer/audio_message_filter.h
@@ -12,6 +12,7 @@
 
 #include "base/id_map.h"
 #include "base/shared_memory.h"
+#include "base/sync_socket.h"
 #include "base/time.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
@@ -33,6 +34,12 @@ class AudioMessageFilter : public IPC::ChannelProxy::MessageFilter {
     // Called when an audio stream has been created in the browser process.
     virtual void OnCreated(base::SharedMemoryHandle handle, uint32 length) = 0;
 
+    // Called when a low-latency audio stream has been created in the browser
+    // process.
+    virtual void OnLowLatencyCreated(base::SharedMemoryHandle handle,
+                                     base::SyncSocket::Handle socket_handle,
+                                     uint32 length) = 0;
+
     // Called when notification of stream volume is received from the browser
     // process.
     virtual void OnVolume(double volume) = 0;
@@ -76,6 +83,17 @@ class AudioMessageFilter : public IPC::ChannelProxy::MessageFilter {
   void OnStreamCreated(int stream_id, base::SharedMemoryHandle handle,
                        uint32 length);
 
+  // Received when browser process has created an audio output stream of low
+  // latency.
+  void OnLowLatencyStreamCreated(int stream_id, base::SharedMemoryHandle handle,
+#if defined(OS_WIN)
+                                 base::SyncSocket::Handle socket_handle,
+#else
+                                 base::FileDescriptor socket_descriptor,
+#endif
+                                 uint32 length);
+
+
   // Received when internal state of browser process' audio output device has
   // changed.
   void OnStreamStateChanged(int stream_id,
diff --git a/chrome/renderer/audio_message_filter_unittest.cc b/chrome/renderer/audio_message_filter_unittest.cc
index 3dce864..e4be68c 100644
--- a/chrome/renderer/audio_message_filter_unittest.cc
+++ b/chrome/renderer/audio_message_filter_unittest.cc
@@ -34,6 +34,11 @@ class MockAudioDelegate : public AudioMessageFilter::Delegate {
     length_ = length;
   }
 
+  virtual void OnLowLatencyCreated(base::SharedMemoryHandle handle,
+                                   base::SyncSocket::Handle,
+                                   uint32 length) {
+  }
+
   virtual void OnVolume(double volume) {
     volume_received_ = true;
     volume_ = volume;
diff --git a/chrome/renderer/media/audio_renderer_impl.cc b/chrome/renderer/media/audio_renderer_impl.cc
index 3aba1c1..b03ba9e 100644
--- a/chrome/renderer/media/audio_renderer_impl.cc
+++ b/chrome/renderer/media/audio_renderer_impl.cc
@@ -174,6 +174,12 @@ void AudioRendererImpl::OnCreated(base::SharedMemoryHandle handle,
   shared_memory_size_ = length;
 }
 
+void AudioRendererImpl::OnLowLatencyCreated(base::SharedMemoryHandle,
+                                            base::SyncSocket::Handle, uint32) {
+  // AudioRenderer should not have a low-latency audio channel.
+  NOTREACHED();
+}
+
 void AudioRendererImpl::OnRequestPacket(uint32 bytes_in_buffer,
                                         const base::Time& message_timestamp) {
   DCHECK(MessageLoop::current() == io_loop_);
diff --git a/chrome/renderer/media/audio_renderer_impl.h b/chrome/renderer/media/audio_renderer_impl.h
index 2c4d990..2e714ee 100644
--- a/chrome/renderer/media/audio_renderer_impl.h
+++ b/chrome/renderer/media/audio_renderer_impl.h
@@ -122,6 +122,9 @@ class AudioRendererImpl : public media::AudioRendererBase,
                        const base::Time& message_timestamp);
   void OnStateChanged(const ViewMsg_AudioStreamState_Params& state);
   void OnCreated(base::SharedMemoryHandle handle, uint32 length);
+  void OnLowLatencyCreated(base::SharedMemoryHandle handle,
+                           base::SyncSocket::Handle socket_handle,
+                           uint32 length);
   void OnVolume(double volume);
 
   // Methods called on pipeline thread ----------------------------------------
diff --git a/chrome/renderer/pepper_devices.cc b/chrome/renderer/pepper_devices.cc
index 3b14d16..4a831f4 100644
--- a/chrome/renderer/pepper_devices.cc
+++ b/chrome/renderer/pepper_devices.cc
@@ -98,14 +98,18 @@ AudioDeviceContext::~AudioDeviceContext() {
   }
 }
 
-NPError AudioDeviceContext::Initialize(
-        AudioMessageFilter* filter, const NPDeviceContextAudioConfig* config,
-        NPDeviceContextAudio* context) {
-  filter_ = filter;
-  context_= context;
+NPError AudioDeviceContext::Initialize(AudioMessageFilter* filter,
+                                       const NPDeviceContextAudioConfig* config,
+                                       NPDeviceContextAudio* context) {
+  DCHECK(filter);
   // Make sure we don't call init more than once.
   DCHECK_EQ(0, stream_id_);
-  stream_id_ = filter_->AddDelegate(this);
+
+  if (!config || !context) {
+    return NPERR_INVALID_PARAM;
+  }
+  filter_ = filter;
+  context_= context;
 
   ViewHostMsg_Audio_CreateStream_Params params;
   params.format = AudioManager::AUDIO_PCM_LINEAR;
@@ -133,6 +137,7 @@ NPError AudioDeviceContext::Initialize(
       config->sampleFrameCount << "Hz, " << params.bits_per_sample <<
       " bits, " << config->outputChannelMap << "channels";
 
+  stream_id_ = filter_->AddDelegate(this);
   filter->Send(new ViewHostMsg_CreateAudioStream(0, stream_id_, params));
   return NPERR_NO_ERROR;
 }
@@ -143,13 +148,17 @@ void AudioDeviceContext::OnDestroy() {
   filter_->RemoveDelegate(stream_id_);
   filter_->Send(new ViewHostMsg_CloseAudioStream(0, stream_id_));
   stream_id_ = 0;
+  if (audio_thread_.get()) {
+    socket_->Close();
+    audio_thread_->Join();
+  }
 }
 
 void AudioDeviceContext::OnRequestPacket(
     uint32 bytes_in_buffer, const base::Time& message_timestamp) {
-  context_->config.callback(context_);
+  FireAudioCallback();
   filter_->Send(new ViewHostMsg_NotifyAudioPacketReady(0, stream_id_,
-                                                        shared_memory_size_));
+                                                       shared_memory_size_));
 }
 
 void AudioDeviceContext::OnStateChanged(
@@ -158,15 +167,60 @@ void AudioDeviceContext::OnStateChanged(
 
 void AudioDeviceContext::OnCreated(
     base::SharedMemoryHandle handle, uint32 length) {
+#if defined(OS_WIN)
+  DCHECK(handle);
+#else
+  DCHECK_NE(-1, handle.fd);
+#endif
+  DCHECK(length);
+  DCHECK(context_);
+
+  shared_memory_.reset(new base::SharedMemory(handle, false));
+  shared_memory_->Map(length);
+  shared_memory_size_ = length;
+
+  context_->outBuffer = shared_memory_->memory();
+  FireAudioCallback();
+  filter_->Send(new ViewHostMsg_PlayAudioStream(0, stream_id_));
+}
+
+void AudioDeviceContext::OnLowLatencyCreated(
+    base::SharedMemoryHandle handle, base::SyncSocket::Handle socket_handle,
+    uint32 length) {
+#if defined(OS_WIN)
+  DCHECK(handle);
+  DCHECK(socket_handle);
+#else
+  DCHECK_NE(-1, handle.fd);
+  DCHECK_NE(-1, socket_handle);
+#endif
+  DCHECK(length);
+  DCHECK(context_);
+  DCHECK(!audio_thread_.get());
   shared_memory_.reset(new base::SharedMemory(handle, false));
   shared_memory_->Map(length);
   shared_memory_size_ = length;
 
   context_->outBuffer = shared_memory_->memory();
-  // TODO(neb): call play after prefilling
+  socket_.reset(new base::SyncSocket(socket_handle));
+  if (context_->config.callback) {
+    FireAudioCallback();
+    audio_thread_.reset(
+        new base::DelegateSimpleThread(this, "plugin_audio_thread"));
+    audio_thread_->Start();
+  }
   filter_->Send(new ViewHostMsg_PlayAudioStream(0, stream_id_));
 }
 
 void AudioDeviceContext::OnVolume(double volume) {
 }
 
+void AudioDeviceContext::Run() {
+  int pending_data;
+  while (sizeof(pending_data) == socket_->Receive(&pending_data,
+                                                  sizeof(pending_data)) &&
+      pending_data >= 0) {
+    FireAudioCallback();
+  }
+}
+
diff --git a/chrome/renderer/pepper_devices.h b/chrome/renderer/pepper_devices.h
index 31a2d11..2aa0b54 100644
--- a/chrome/renderer/pepper_devices.h
+++ b/chrome/renderer/pepper_devices.h
@@ -9,6 +9,7 @@
 
 #include "base/scoped_ptr.h"
 #include "base/shared_memory.h"
+#include "base/simple_thread.h"
 #include "base/gfx/rect.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/transport_dib.h"
@@ -46,7 +47,8 @@ class Graphics2DDeviceContext {
 // Each instance of AudioDeviceContext corresponds to one host stream (and one
 // audio context). NPDeviceContextAudio contains the id of the context's
 // stream in the privatePtr member.
-class AudioDeviceContext : public AudioMessageFilter::Delegate {
+class AudioDeviceContext : public AudioMessageFilter::Delegate,
+                           public base::DelegateSimpleThread::Delegate {
  public:
   // TODO(neb): if plugin_delegate parameter is indeed unused, remove it
   explicit AudioDeviceContext() : stream_id_(0) {
@@ -57,24 +59,39 @@ class AudioDeviceContext : public AudioMessageFilter::Delegate {
                      const NPDeviceContextAudioConfig* config,
                      NPDeviceContextAudio* context);
 
+  base::SharedMemory* shared_memory() { return shared_memory_.get(); }
+
+ private:
+
   // AudioMessageFilter::Delegate implementation
   virtual void OnRequestPacket(uint32 bytes_in_buffer,
                                const base::Time& message_timestamp);
   virtual void OnStateChanged(const ViewMsg_AudioStreamState_Params& state);
   virtual void OnCreated(base::SharedMemoryHandle handle, uint32 length);
+  virtual void OnLowLatencyCreated(base::SharedMemoryHandle handle,
+                                   base::SyncSocket::Handle socket_handle,
+                                   uint32 length);
   virtual void OnVolume(double volume);
   // End of AudioMessageFilter::Delegate implementation
 
-  base::SharedMemory* shared_memory() { return shared_memory_.get(); }
+  // DelegateSimpleThread::Delegate implementation
+  virtual void Run();
+  // End of DelegateSimpleThread::Delegate implementation
 
- private:
   void OnDestroy();
+  void FireAudioCallback() {
+    if (context_ && context_->config.callback) {
+      context_->config.callback(context_);
+    }
+  }
 
   NPDeviceContextAudio* context_;
   scoped_refptr<AudioMessageFilter> filter_;
   int32 stream_id_;
   scoped_ptr<base::SharedMemory> shared_memory_;
   uint32 shared_memory_size_;
+  scoped_ptr<base::SyncSocket> socket_;
+  scoped_ptr<base::DelegateSimpleThread> audio_thread_;
 };
 
 #endif  // CHROME_RENDERER_PEPPER_DEVICES_H_