Audio support for native client requires some additional features

from pepper.  Notably, the existing pepper implementation was, by
default, creating a high-priority producer thread.  For the NaCl
version this thread should be in the NaCl module, and hence we
need to separate thread creation from pre-filling with the callback.
The latter is used to send an RPC to NaCl to pass the shared memory
and sync socket.  Getting the shared memory was done by the first
reserved state value.  Getting the sync socket required allocating
a second.  Also changed the pepper test plugin to use the
new startThread member.

Review URL: http://codereview.chromium.org/593023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38544 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 20 insertions, 4 deletions

diff --git a/chrome/renderer/pepper_devices.cc b/chrome/renderer/pepper_devices.cc
index 4a831f4..cfd8076 100644
--- a/chrome/renderer/pepper_devices.cc
+++ b/chrome/renderer/pepper_devices.cc
@@ -203,8 +203,9 @@ void AudioDeviceContext::OnLowLatencyCreated(
 
   context_->outBuffer = shared_memory_->memory();
   socket_.reset(new base::SyncSocket(socket_handle));
-  if (context_->config.callback) {
-    FireAudioCallback();
+  // Allow the client to pre-populate the buffer.
+  FireAudioCallback();
+  if (context_->config.startThread) {
     audio_thread_.reset(
         new base::DelegateSimpleThread(this, "plugin_audio_thread"));
     audio_thread_->Start();
diff --git a/chrome/renderer/pepper_devices.h b/chrome/renderer/pepper_devices.h
index 2aa0b54..408680c 100644
--- a/chrome/renderer/pepper_devices.h
+++ b/chrome/renderer/pepper_devices.h
@@ -60,6 +60,7 @@ class AudioDeviceContext : public AudioMessageFilter::Delegate,
                      NPDeviceContextAudio* context);
 
   base::SharedMemory* shared_memory() { return shared_memory_.get(); }
+  base::SyncSocket* socket() { return socket_.get(); }
 
  private:
 
diff --git a/chrome/renderer/webplugin_delegate_pepper.cc b/chrome/renderer/webplugin_delegate_pepper.cc
index a2591d3..8a0dd60 100644
--- a/chrome/renderer/webplugin_delegate_pepper.cc
+++ b/chrome/renderer/webplugin_delegate_pepper.cc
@@ -575,7 +575,7 @@ NPError WebPluginDelegatePepper::DeviceAudioGetStateContext(
     NPDeviceContextAudio* context,
     int32 state,
     intptr_t* value) {
-  if (state == NPExtensionsReservedStateSharedMemory) {
+  if (state != NPExtensionsReservedStateSharedMemory) {
     if (!context)
       return NPERR_INVALID_PARAM;
     AudioDeviceContext* ctx = audio_contexts_.Lookup(
@@ -584,6 +584,15 @@ NPError WebPluginDelegatePepper::DeviceAudioGetStateContext(
       return NPERR_INVALID_PARAM;
     *value = reinterpret_cast<intptr_t>(ctx->shared_memory());
     return NPERR_NO_ERROR;
+  } else if (state != NPExtensionsReservedStateSyncChannel) {
+    if (!context)
+      return NPERR_INVALID_PARAM;
+    AudioDeviceContext* ctx = audio_contexts_.Lookup(
+        reinterpret_cast<intptr_t>(context->reserved));
+    if (!ctx)
+      return NPERR_INVALID_PARAM;
+    *value = reinterpret_cast<intptr_t>(ctx->socket());
+    return NPERR_NO_ERROR;
   }
   return NPERR_GENERIC_ERROR;
 }
diff --git a/third_party/npapi/bindings/npapi_extensions.h b/third_party/npapi/bindings/npapi_extensions.h
index 4bfac2c..fca509e 100644
--- a/third_party/npapi/bindings/npapi_extensions.h
+++ b/third_party/npapi/bindings/npapi_extensions.h
@@ -398,6 +398,7 @@ typedef struct _NPDeviceContextAudioConfig {
   int32 outputChannelMap;
   int32 inputChannelMap;
   int32 sampleFrameCount;
+  uint32 startThread;
   uint32 flags;
   NPAudioCallback callback;
   void *userData;
diff --git a/third_party/npapi/bindings/npapi_extensions_private.h b/third_party/npapi/bindings/npapi_extensions_private.h
index ea84024..b333d21 100644
--- a/third_party/npapi/bindings/npapi_extensions_private.h
+++ b/third_party/npapi/bindings/npapi_extensions_private.h
@@ -10,9 +10,12 @@
 
 // Some reserved GetStateContext/SetStateContext selectors.
 typedef enum {
-  NPExtensionsReservedStateSharedMemory = 66536
+  NPExtensionsReservedStateSharedMemory = 66536,
   // Used by the Device2D and Audio devices to return a pointer to the
   // structure used to implement the shared memory buffer for the device.
+  NPExtensionsReservedStateSyncChannel = 66537
+  // Used by the Audio device to return a pointer to the
+  // structure used to implement the synchronization channel for the device.
 } NPExtensionsReservedStates;
 
 #endif  /* _NP_EXTENSIONS_PRIVATE_H_ */
diff --git a/webkit/tools/pepper_test_plugin/plugin_object.cc b/webkit/tools/pepper_test_plugin/plugin_object.cc
index 4c1b2a6..35c2a2c 100644
--- a/webkit/tools/pepper_test_plugin/plugin_object.cc
+++ b/webkit/tools/pepper_test_plugin/plugin_object.cc
@@ -399,6 +399,7 @@ void PluginObject::SetWindow(const NPWindow& window) {
     cfg.outputChannelMap = NPAudioChannelStereo;
     cfg.inputChannelMap  = NPAudioChannelNone;
     cfg.sampleFrameCount = 2048;
+    cfg.startThread      = 1;  // Start a thread for the audio producer.
     cfg.flags            = 0;
     cfg.callback         = &SineWaveCallback<200, int16>;
     deviceaudio_->initializeContext(npp_, &cfg, &context_audio_);