Bug 856361. Part 6: Make MediaStreamAudioSourceNode keep its DOMMediaStream alive, and make the DOMMediaStream keep the MediaStreamAudioSourceNode alive. r=ehsan

--HG--
extra : rebase_source : b7172f79fbf0cacaaf10f812444444ba17ad00e9

content/media/DOMMediaStream.cpp

@@ -28,11 +28,13 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMMediaStream)
   tmp->Destroy();
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindow)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mTracks)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mConsumersToKeepAlive)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMMediaStream)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindow)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTracks)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mConsumersToKeepAlive)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(DOMMediaStream)
@@ -285,6 +287,16 @@ DOMMediaStream::NotifyMediaStreamGraphShutdown()
   // to prevent leaks.
   mNotifiedOfMediaStreamGraphShutdown = true;
   mRunOnTracksAvailable.Clear();
+
+  mConsumersToKeepAlive.Clear();
+}
+
+void
+DOMMediaStream::NotifyStreamStateChanged()
+{
+  if (IsFinished()) {
+    mConsumersToKeepAlive.Clear();
+  }
 }
 
 void

content/media/DOMMediaStream.h

@@ -95,6 +95,10 @@ public:
    * will only be called during a forced shutdown due to application exit.
    */
   void NotifyMediaStreamGraphShutdown();
+  /**
+   * Called when the main-thread state of the MediaStream changed.
+   */
+  void NotifyStreamStateChanged();
 
   // Indicate what track types we eventually expect to add to this stream
   enum {
@@ -147,6 +151,17 @@ public:
   // Takes ownership of aCallback.
   void OnTracksAvailable(OnTracksAvailableCallback* aCallback);
 
+  /**
+   * Add an nsISupports object that this stream will keep alive as long as
+   * the stream is not finished.
+   */
+  void AddConsumerToKeepAlive(nsISupports* aConsumer)
+  {
+    if (!IsFinished() && !mNotifiedOfMediaStreamGraphShutdown) {
+      mConsumersToKeepAlive.AppendElement(aConsumer);
+    }
+  }
+
 protected:
   void Destroy();
   void InitSourceStream(nsIDOMWindow* aWindow, TrackTypeHints aHintContents);
@@ -175,6 +190,9 @@ protected:
 
   nsTArray<nsAutoPtr<OnTracksAvailableCallback> > mRunOnTracksAvailable;
 
+  // Keep these alive until the stream finishes
+  nsTArray<nsCOMPtr<nsISupports> > mConsumersToKeepAlive;
+
   // Indicate what track types we eventually expect to add to this stream
   uint8_t mHintContents;
   // Indicate what track types have been added to this stream

content/media/MediaStreamGraph.cpp

@@ -1220,6 +1220,9 @@ MediaStreamGraphImpl::ApplyStreamUpdate(StreamUpdate* aUpdate)
   stream->mMainThreadCurrentTime = aUpdate->mNextMainThreadCurrentTime;
   stream->mMainThreadFinished = aUpdate->mNextMainThreadFinished;
 
+  if (stream->mWrapper) {
+    stream->mWrapper->NotifyStreamStateChanged();
+  }
   for (int32_t i = stream->mMainThreadListeners.Length() - 1; i >= 0; --i) {
     stream->mMainThreadListeners[i]->NotifyMainThreadStateChanged();
   }

content/media/webaudio/AudioContext.cpp

@@ -255,7 +255,7 @@ AudioContext::CreateAnalyser()
 }
 
 already_AddRefed<MediaStreamAudioSourceNode>
-AudioContext::CreateMediaStreamSource(const DOMMediaStream& aMediaStream,
+AudioContext::CreateMediaStreamSource(DOMMediaStream& aMediaStream,
                                       ErrorResult& aRv)
 {
   if (mIsOffline) {

content/media/webaudio/AudioContext.h

@@ -163,7 +163,7 @@ public:
   }
 
   already_AddRefed<MediaStreamAudioSourceNode>
-  CreateMediaStreamSource(const DOMMediaStream& aMediaStream, ErrorResult& aRv);
+  CreateMediaStreamSource(DOMMediaStream& aMediaStream, ErrorResult& aRv);
 
   already_AddRefed<DelayNode>
   CreateDelay(double aMaxDelayTime, ErrorResult& aRv);

content/media/webaudio/MediaStreamAudioSourceNode.cpp

@@ -13,18 +13,38 @@
 namespace mozilla {
 namespace dom {
 
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaStreamAudioSourceNode)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mInputStream)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(AudioNode)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaStreamAudioSourceNode, AudioNode)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInputStream)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MediaStreamAudioSourceNode)
+NS_INTERFACE_MAP_END_INHERITING(MediaStreamAudioSourceNode)
+
+NS_IMPL_ADDREF_INHERITED(MediaStreamAudioSourceNode, AudioNode)
+NS_IMPL_RELEASE_INHERITED(MediaStreamAudioSourceNode, AudioNode)
+
 MediaStreamAudioSourceNode::MediaStreamAudioSourceNode(AudioContext* aContext,
-                                                       const DOMMediaStream* aMediaStream)
+                                                       DOMMediaStream* aMediaStream)
   : AudioNode(aContext,
               2,
               ChannelCountMode::Max,
-              ChannelInterpretation::Speakers)
+              ChannelInterpretation::Speakers),
+    mInputStream(aMediaStream)
 {
   AudioNodeEngine* engine = new AudioNodeEngine(this);
   mStream = aContext->Graph()->CreateAudioNodeExternalInputStream(engine);
   ProcessedMediaStream* outputStream = static_cast<ProcessedMediaStream*>(mStream.get());
   mInputPort = outputStream->AllocateInputPort(aMediaStream->GetStream(),
                                                MediaInputPort::FLAG_BLOCK_INPUT);
+  mInputStream->AddConsumerToKeepAlive(this);
+}
+
+MediaStreamAudioSourceNode::~MediaStreamAudioSourceNode()
+{
 }
 
 void

content/media/webaudio/MediaStreamAudioSourceNode.h

@@ -10,12 +10,20 @@
 #include "AudioNode.h"
 
 namespace mozilla {
+
+class DOMMediaStream;
+
 namespace dom {
 
 class MediaStreamAudioSourceNode : public AudioNode
 {
 public:
-  MediaStreamAudioSourceNode(AudioContext* aContext, const DOMMediaStream* aMediaStream);
+  MediaStreamAudioSourceNode(AudioContext* aContext, DOMMediaStream* aMediaStream);
+  // Define consturctor out-of-line so we can forward-declare DOMMediaStream
+  virtual ~MediaStreamAudioSourceNode();
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaStreamAudioSourceNode, AudioNode)
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
 
@@ -25,10 +33,10 @@ public:
 
 private:
   nsRefPtr<MediaInputPort> mInputPort;
+  nsRefPtr<DOMMediaStream> mInputStream;
 };
 
 }
 }
 
 #endif
-