Bug 1040563 - Move WaitForData/NotifyGotData from MediaSource to MediaSourceDecoder, which is off-main-thread friendly. r=cajbir

Also remove mMediaSource from MediaSourceReader and rejig SetMediaSourceDuration to go via MediaSourceDecoder and handle mMediaSource being null.

content/media/mediasource/MediaSource.cpp

@@ -377,7 +377,6 @@ MediaSource::MediaSource(nsPIDOMWindow* aWindow)
   , mDuration(UnspecifiedNaN<double>())
   , mDecoder(nullptr)
   , mReadyState(MediaSourceReadyState::Closed)
-  , mWaitForDataMonitor("MediaSource.WaitForData.Monitor")
 {
   MOZ_ASSERT(NS_IsMainThread());
   mSourceBuffers = new SourceBufferList(this);
@@ -465,22 +464,6 @@ MediaSource::NotifyEvicted(double aStart, double aEnd)
   mSourceBuffers->Evict(aStart, aEnd);
 }
 
-void
-MediaSource::WaitForData()
-{
-  MSE_DEBUG("MediaSource(%p)::WaitForData()", this);
-  MonitorAutoLock mon(mWaitForDataMonitor);
-  mon.Wait();
-}
-
-void
-MediaSource::NotifyGotData()
-{
-  MSE_DEBUG("MediaSource(%p)::NotifyGotData()", this);
-  MonitorAutoLock mon(mWaitForDataMonitor);
-  mon.NotifyAll();
-}
-
 nsPIDOMWindow*
 MediaSource::GetParentObject() const
 {

content/media/mediasource/MediaSource.h

@@ -13,7 +13,6 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/DOMEventTargetHelper.h"
 #include "mozilla/dom/MediaSourceBinding.h"
-#include "mozilla/Monitor.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionNoteChild.h"
 #include "nsCycleCollectionParticipant.h"
@@ -91,12 +90,6 @@ public:
   // that were evicted are provided.
   void NotifyEvicted(double aStart, double aEnd);
 
-  // Block thread waiting for data to be appended to a SourceBuffer.
-  void WaitForData();
-
-  // Unblock threads waiting for data to be appended to a SourceBuffer.
-  void NotifyGotData();
-
 private:
   ~MediaSource();
 
@@ -116,10 +109,6 @@ private:
   nsRefPtr<MediaSourceDecoder> mDecoder;
 
   MediaSourceReadyState mReadyState;
-
-  // Monitor for waiting for when new data is appended to
-  // a Source Buffer.
-  Monitor mWaitForDataMonitor;
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(MediaSource, MOZILLA_DOM_MEDIASOURCE_IMPLEMENTATION_IID)

content/media/mediasource/MediaSourceDecoder.cpp

@@ -47,7 +47,7 @@ MediaSourceDecoder::Clone()
 MediaDecoderStateMachine*
 MediaSourceDecoder::CreateStateMachine()
 {
-  mReader = new MediaSourceReader(this, mMediaSource);
+  mReader = new MediaSourceReader(this);
   return new MediaDecoderStateMachine(this, mReader);
 }
 
@@ -72,6 +72,10 @@ MediaSourceDecoder::Load(nsIStreamListener**, MediaDecoder*)
 nsresult
 MediaSourceDecoder::GetSeekable(dom::TimeRanges* aSeekable)
 {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!mMediaSource) {
+    return NS_ERROR_FAILURE;
+  }
   double duration = mMediaSource->Duration();
   if (IsNaN(duration)) {
     // Return empty range.
@@ -86,6 +90,16 @@ MediaSourceDecoder::GetSeekable(dom::TimeRanges* aSeekable)
   return NS_OK;
 }
 
+void
+MediaSourceDecoder::Shutdown()
+{
+  MediaDecoder::Shutdown();
+
+  // Kick WaitForData out of its slumber.
+  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
+  mon.NotifyAll();
+}
+
 /*static*/
 already_AddRefed<MediaResource>
 MediaSourceDecoder::CreateResource()
@@ -96,13 +110,14 @@ MediaSourceDecoder::CreateResource()
 void
 MediaSourceDecoder::AttachMediaSource(dom::MediaSource* aMediaSource)
 {
-  MOZ_ASSERT(!mMediaSource && !mDecoderStateMachine);
+  MOZ_ASSERT(!mMediaSource && !mDecoderStateMachine && NS_IsMainThread());
   mMediaSource = aMediaSource;
 }
 
 void
 MediaSourceDecoder::DetachMediaSource()
 {
+  MOZ_ASSERT(mMediaSource && NS_IsMainThread());
   mMediaSource = nullptr;
 }
 
@@ -113,4 +128,31 @@ MediaSourceDecoder::CreateSubDecoder(const nsACString& aType)
   return mReader->CreateSubDecoder(aType);
 }
 
+void
+MediaSourceDecoder::SetMediaSourceDuration(double aDuration)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!mMediaSource) {
+    return;
+  }
+  ErrorResult dummy;
+  mMediaSource->SetDuration(aDuration, dummy);
+}
+
+void
+MediaSourceDecoder::WaitForData()
+{
+  MSE_DEBUG("MediaSourceDecoder(%p)::WaitForData()", this);
+  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
+  mon.Wait();
+}
+
+void
+MediaSourceDecoder::NotifyGotData()
+{
+  MSE_DEBUG("MediaSourceDecoder(%p)::NotifyGotData()", this);
+  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
+  mon.NotifyAll();
+}
+
 } // namespace mozilla

content/media/mediasource/MediaSourceDecoder.h

@@ -38,6 +38,8 @@ public:
   virtual nsresult Load(nsIStreamListener**, MediaDecoder*) MOZ_OVERRIDE;
   virtual nsresult GetSeekable(dom::TimeRanges* aSeekable) MOZ_OVERRIDE;
 
+  virtual void Shutdown() MOZ_OVERRIDE;
+
   static already_AddRefed<MediaResource> CreateResource();
 
   void AttachMediaSource(dom::MediaSource* aMediaSource);
@@ -45,6 +47,14 @@ public:
 
   already_AddRefed<SourceBufferDecoder> CreateSubDecoder(const nsACString& aType);
 
+  void SetMediaSourceDuration(double aDuration);
+
+  // Provide a mechanism for MediaSourceReader to block waiting on data from a SourceBuffer.
+  void WaitForData();
+
+  // Called whenever a SourceBuffer has new data appended.
+  void NotifyGotData();
+
 private:
   // The owning MediaSource holds a strong reference to this decoder, and
   // calls Attach/DetachMediaSource on this decoder to set and clear

content/media/mediasource/MediaSourceReader.cpp

@@ -35,12 +35,11 @@ extern PRLogModuleInfo* GetMediaSourceAPILog();
 
 namespace mozilla {
 
-MediaSourceReader::MediaSourceReader(MediaSourceDecoder* aDecoder, dom::MediaSource* aSource)
+MediaSourceReader::MediaSourceReader(MediaSourceDecoder* aDecoder)
   : MediaDecoderReader(aDecoder)
   , mTimeThreshold(-1)
   , mDropAudioBeforeThreshold(false)
   , mDropVideoBeforeThreshold(false)
-  , mMediaSource(aSource)
 {
 }
 
@@ -249,14 +248,6 @@ MediaSourceReader::SwitchReaders(SwitchType aType)
   return didSwitch;
 }
 
-void
-MediaSourceReader::SetMediaSourceDuration(double aDuration)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  ErrorResult dummy;
-  mMediaSource->SetDuration(aDuration, dummy);
-}
-
 class ReleaseDecodersTask : public nsRunnable {
 public:
   ReleaseDecodersTask(nsTArray<nsRefPtr<SourceBufferDecoder>>& aDecoders)
@@ -423,7 +414,7 @@ MediaSourceReader::Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime,
   // we'll remove this for an async approach based on that in bug XXXXXXX.
   while (!DecodersContainTime(target) && !IsShutdown()) {
     MSE_DEBUG("MediaSourceReader(%p)::Seek waiting for target=%f", this, target);
-    mMediaSource->WaitForData();
+    static_cast<MediaSourceDecoder*>(mDecoder)->WaitForData();
     SwitchReaders(SWITCH_FORCED);
   }
 
@@ -491,7 +482,8 @@ MediaSourceReader::ReadMetadata(MediaInfo* aInfo, MetadataTags** aTags)
     ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
     mDecoder->SetMediaDuration(maxDuration);
     nsRefPtr<nsIRunnable> task (
-      NS_NewRunnableMethodWithArg<double>(this, &MediaSourceReader::SetMediaSourceDuration,
+      NS_NewRunnableMethodWithArg<double>(static_cast<MediaSourceDecoder*>(mDecoder),
+                                          &MediaSourceDecoder::SetMediaSourceDuration,
                                           static_cast<double>(maxDuration) / USECS_PER_S));
     NS_DispatchToMainThread(task);
   }

content/media/mediasource/MediaSourceReader.h

@@ -29,7 +29,7 @@ class MediaSource;
 class MediaSourceReader : public MediaDecoderReader
 {
 public:
-  MediaSourceReader(MediaSourceDecoder* aDecoder, dom::MediaSource* aSource);
+  MediaSourceReader(MediaSourceDecoder* aDecoder);
 
   nsresult Init(MediaDecoderReader* aCloneDonor) MOZ_OVERRIDE
   {
@@ -98,8 +98,6 @@ private:
   bool SwitchAudioReader(MediaDecoderReader* aTargetReader);
   bool SwitchVideoReader(MediaDecoderReader* aTargetReader);
 
-  void SetMediaSourceDuration(double aDuration) ;
-
   // These are read and written on the decode task queue threads.
   int64_t mTimeThreshold;
   bool mDropAudioBeforeThreshold;
@@ -110,8 +108,6 @@ private:
 
   nsRefPtr<MediaDecoderReader> mAudioReader;
   nsRefPtr<MediaDecoderReader> mVideoReader;
-
-  dom::MediaSource* mMediaSource;
 };
 
 } // namespace mozilla

content/media/mediasource/SourceBuffer.cpp

@@ -499,7 +499,7 @@ SourceBuffer::AppendData(const uint8_t* aData, uint32_t aLength, ErrorResult& aR
   // if required when data is appended.
   mMediaSource->GetDecoder()->ScheduleStateMachineThread();
 
-  mMediaSource->NotifyGotData();
+  mMediaSource->GetDecoder()->NotifyGotData();
 }
 
 double