Bug 1426061. P2 - offload MediaCacheStream::Close() to another thread. r=bechen,gerald

So we won't take the cache lock on the main thread.

MozReview-Commit-ID: KYSB0vonOZ2

--HG--
extra : rebase_source : 142884bb450a5469b2634a676ce2d4f3c1790954
extra : intermediate-source : 0911c55511374cd19719743531c136fc122e4ab0
extra : source : 2f46a7eddea484fc5dec773d9d57896e524e014d

dom/media/MediaCache.cpp

@@ -2377,8 +2377,19 @@ MediaCacheStream::Close()
   if (!mMediaCache) {
     return;
   }
+  OwnerThread()->Dispatch(NS_NewRunnableFunction(
+    "MediaCacheStream::Close",
+    [ this, client = RefPtr<ChannelMediaResource>(mClient) ]() {
+      AutoLock lock(mMediaCache->Monitor());
+      CloseInternal(lock);
+    }));
+}
+
+void
+MediaCacheStream::CloseInternal(AutoLock& aLock)
+{
+  MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
 
-  AutoLock lock(mMediaCache->Monitor());
   if (mClosed) {
     return;
   }
@@ -2386,17 +2397,15 @@ MediaCacheStream::Close()
   // Closing a stream will change the return value of
   // MediaCacheStream::AreAllStreamsForResourceSuspended as well as
   // ChannelMediaResource::IsSuspendedByCache. Let's notify it.
-  mMediaCache->QueueSuspendedStatusUpdate(lock, mResourceID);
+  mMediaCache->QueueSuspendedStatusUpdate(aLock, mResourceID);
 
   mClosed = true;
-  mMediaCache->ReleaseStreamBlocks(lock, this);
+  mMediaCache->ReleaseStreamBlocks(aLock, this);
   // Wake up any blocked readers
-  lock.NotifyAll();
+  aLock.NotifyAll();
 
-  // Queue an Update since we may have created more free space. Don't do
-  // it from CloseInternal since that gets called by Update() itself
-  // sometimes, and we try to not to queue updates from Update().
-  mMediaCache->QueueUpdate(lock);
+  // Queue an Update since we may have created more free space.
+  mMediaCache->QueueUpdate(aLock);
 }
 
 void

dom/media/MediaCache.h

@@ -465,6 +465,8 @@ private:
 
   void UpdateDownloadStatistics(AutoLock&);
 
+  void CloseInternal(AutoLock&);
+
   // Instance of MediaCache to use with this MediaCacheStream.
   RefPtr<MediaCache> mMediaCache;