Bug 881512 - Don't mix refcounting with auto ptr use. Rather than try to hang on to the reader, punch the appropriate holes through via the state machine class. r=cajbir

content/media/MediaDecoderStateMachine.h

@@ -120,7 +120,6 @@ public:
   MediaDecoderStateMachine(MediaDecoder* aDecoder,
                                MediaDecoderReader* aReader,
                                bool aRealTime = false);
-  ~MediaDecoderStateMachine();
 
   nsresult Init(MediaDecoderStateMachine* aCloneDonor);
 
@@ -359,10 +358,10 @@ public:
   void SetMinimizePrerollUntilPlaybackStarts();
 
 protected:
+  virtual ~MediaDecoderStateMachine();
 
   void AssertCurrentThreadInMonitor() const { mDecoder->GetReentrantMonitor().AssertCurrentThreadIn(); }
 
-private:
   class WakeDecoderRunnable : public nsRunnable {
   public:
     WakeDecoderRunnable(MediaDecoderStateMachine* aSM)

content/media/mediasource/MediaSourceDecoder.cpp

@@ -47,8 +47,6 @@ public:
   {
   }
 
-  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaSourceReader)
-
   nsresult Init(MediaDecoderReader* aCloneDonor) MOZ_OVERRIDE
   {
     // Although we technically don't implement anything here, we return NS_OK
@@ -148,6 +146,8 @@ public:
   already_AddRefed<SubBufferDecoder> CreateSubDecoder(const nsACString& aType,
                                                       MediaSourceDecoder* aParentDecoder);
 
+  void CallDecoderInitialization();
+
 private:
   bool SwitchVideoReaders(int64_t aTimeThreshold) {
     MOZ_ASSERT(mActiveVideoReader != -1);
@@ -173,7 +173,6 @@ private:
 
   bool EnsureWorkQueueInitialized();
   nsresult EnqueueDecoderInitialization();
-  void CallDecoderInitialization();
   void WaitForPendingDecoders();
 
   nsTArray<nsRefPtr<SubBufferDecoder>> mPendingDecoders;
@@ -187,6 +186,26 @@ private:
   nsCOMPtr<nsIThread> mWorkQueue;
 };
 
+class MediaSourceStateMachine : public MediaDecoderStateMachine
+{
+public:
+  MediaSourceStateMachine(MediaDecoder* aDecoder,
+                          MediaDecoderReader* aReader,
+                          bool aRealTime = false)
+    : MediaDecoderStateMachine(aDecoder, aReader, aRealTime)
+  {
+  }
+
+  already_AddRefed<SubBufferDecoder> CreateSubDecoder(const nsACString& aType,
+                                                      MediaSourceDecoder* aParentDecoder) {
+    return static_cast<MediaSourceReader*>(mReader.get())->CreateSubDecoder(aType, aParentDecoder);
+  }
+
+  void CallDecoderInitialization() {
+    return static_cast<MediaSourceReader*>(mReader.get())->CallDecoderInitialization();
+  }
+};
+
 MediaSourceDecoder::MediaSourceDecoder(dom::HTMLMediaElement* aElement)
   : mMediaSource(nullptr)
 {
@@ -203,9 +222,7 @@ MediaSourceDecoder::Clone()
 MediaDecoderStateMachine*
 MediaSourceDecoder::CreateStateMachine()
 {
-  // XXX: Find a cleaner way to retain a reference to our reader.
-  mReader = new MediaSourceReader(this);
-  return new MediaDecoderStateMachine(this, mReader);
+  return new MediaSourceStateMachine(this, new MediaSourceReader(this));
 }
 
 nsresult
@@ -260,7 +277,13 @@ MediaSourceDecoder::DetachMediaSource()
 already_AddRefed<SubBufferDecoder>
 MediaSourceDecoder::CreateSubDecoder(const nsACString& aType)
 {
-  return mReader->CreateSubDecoder(aType, this);
+  return static_cast<MediaSourceStateMachine*>(mDecoderStateMachine.get())->CreateSubDecoder(aType, this);
+}
+
+void
+MediaSourceDecoder::CallDecoderInitialization()
+{
+  return static_cast<MediaSourceStateMachine*>(mDecoderStateMachine.get())->CallDecoderInitialization();
 }
 
 bool
@@ -284,7 +307,9 @@ MediaSourceReader::EnqueueDecoderInitialization()
   if (!EnsureWorkQueueInitialized()) {
     return NS_ERROR_FAILURE;
   }
-  return mWorkQueue->Dispatch(NS_NewRunnableMethod(this, &MediaSourceReader::CallDecoderInitialization), NS_DISPATCH_NORMAL);
+  return mWorkQueue->Dispatch(NS_NewRunnableMethod(static_cast<MediaSourceDecoder*>(mDecoder),
+                                                   &MediaSourceDecoder::CallDecoderInitialization),
+                              NS_DISPATCH_NORMAL);
 }
 
 void
@@ -345,6 +370,7 @@ MediaSourceReader::WaitForPendingDecoders()
 already_AddRefed<SubBufferDecoder>
 MediaSourceReader::CreateSubDecoder(const nsACString& aType, MediaSourceDecoder* aParentDecoder)
 {
+  // XXX: Why/when is mDecoder null here, since it should be equal to aParentDecoder?!
   nsRefPtr<SubBufferDecoder> decoder =
     new SubBufferDecoder(new SourceBufferResource(nullptr, aType), aParentDecoder);
   nsAutoPtr<MediaDecoderReader> reader(DecoderTraits::CreateReader(aType, decoder));
@@ -352,7 +378,7 @@ MediaSourceReader::CreateSubDecoder(const nsACString& aType, MediaSourceDecoder*
     return nullptr;
   }
   reader->Init(nullptr);
-  ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
+  ReentrantMonitorAutoEnter mon(aParentDecoder->GetReentrantMonitor());
   MSE_DEBUG("Registered subdecoder %p subreader %p", decoder.get(), reader.get());
   decoder->SetReader(reader.forget());
   mPendingDecoders.AppendElement(decoder);
@@ -366,8 +392,12 @@ MediaSourceReader::ReadMetadata(MediaInfo* aInfo, MetadataTags** aTags)
   mDecoder->SetMediaSeekable(true);
   mDecoder->SetTransportSeekable(false);
 
+  MSE_DEBUG("%p: MSR::ReadMetadata pending=%u", this, mPendingDecoders.Length());
+
   WaitForPendingDecoders();
 
+  MSE_DEBUG("%p: MSR::ReadMetadata decoders=%u", this, mDecoders.Length());
+
   // XXX: Make subdecoder setup async, so that use cases like bug 989888 can
   // work.  This will require teaching the state machine about dynamic track
   // changes (and multiple tracks).
@@ -388,12 +418,14 @@ MediaSourceReader::ReadMetadata(MediaInfo* aInfo, MetadataTags** aTags)
       mActiveVideoReader = i;
       mInfo.mVideo = mi.mVideo;
       maxDuration = std::max(maxDuration, mDecoders[i]->GetMediaDuration());
+      MSE_DEBUG("%p: MSR::ReadMetadata video decoder=%u maxDuration=%lld", this, i, maxDuration);
     }
     if (mi.HasAudio() && !mInfo.HasAudio()) {
       MOZ_ASSERT(mActiveAudioReader == -1);
       mActiveAudioReader = i;
       mInfo.mAudio = mi.mAudio;
       maxDuration = std::max(maxDuration, mDecoders[i]->GetMediaDuration());
+      MSE_DEBUG("%p: MSR::ReadMetadata audio decoder=%u maxDuration=%lld", this, i, maxDuration);
     }
   }
   *aInfo = mInfo;

content/media/mediasource/MediaSourceDecoder.h

@@ -50,12 +50,13 @@ public:
 
   already_AddRefed<SubBufferDecoder> CreateSubDecoder(const nsACString& aType);
 
+  void CallDecoderInitialization();
+
 private:
   // The owning MediaSource holds a strong reference to this decoder, and
   // calls Attach/DetachMediaSource on this decoder to set and clear
   // mMediaSource.
   dom::MediaSource* mMediaSource;
-  nsRefPtr<MediaSourceReader> mReader;
 };
 
 } // namespace mozilla