Bug 1213897 - Extract DelayedScheduler out of MDSM to a common class. r=jwwang

--HG--
extra : rebase_source : 5408c282a678fe060d24138eccbe34cf99c8c929

dom/media/MediaDecoderStateMachine.cpp

@@ -204,7 +204,7 @@ MediaDecoderStateMachine::MediaDecoderStateMachine(MediaDecoder* aDecoder,
   mProducerID(ImageContainer::AllocateProducerID()),
   mRealTime(aRealTime),
   mDispatchedStateMachine(false),
-  mDelayedScheduler(this),
+  mDelayedScheduler(mTaskQueue),
   mState(DECODER_STATE_DECODING_NONE, "MediaDecoderStateMachine::mState"),
   mCurrentFrameID(0),
   mObservedDuration(TimeUnit(), "MediaDecoderStateMachine::mObservedDuration"),
@@ -2855,7 +2855,13 @@ MediaDecoderStateMachine::ScheduleStateMachineIn(int64_t aMicroseconds)
   TimeStamp target = now + TimeDuration::FromMicroseconds(aMicroseconds);
 
   SAMPLE_LOG("Scheduling state machine for %lf ms from now", (target - now).ToMilliseconds());
-  mDelayedScheduler.Ensure(target);
+
+  nsRefPtr<MediaDecoderStateMachine> self = this;
+  mDelayedScheduler.Ensure(target, [self] () {
+    self->OnDelayedSchedule();
+  }, [self] () {
+    self->NotReached();
+  });
 }
 
 bool MediaDecoderStateMachine::OnTaskQueue() const

dom/media/MediaDecoderStateMachine.h

@@ -679,51 +679,8 @@ private:
   // yet to run.
   bool mDispatchedStateMachine;
 
-  // Class for managing delayed dispatches of the state machine.
-  class DelayedScheduler {
-  public:
-    explicit DelayedScheduler(MediaDecoderStateMachine* aSelf)
-      : mSelf(aSelf), mMediaTimer(new MediaTimer()) {}
-
-    bool IsScheduled() const { return !mTarget.IsNull(); }
-
-    void Reset()
-    {
-      MOZ_ASSERT(mSelf->OnTaskQueue(), "Must be on state machine queue to disconnect");
-      if (IsScheduled()) {
-        mRequest.Disconnect();
-        mTarget = TimeStamp();
-      }
-    }
-
-    void Ensure(mozilla::TimeStamp& aTarget)
-    {
-      MOZ_ASSERT(mSelf->OnTaskQueue());
-      if (IsScheduled() && mTarget <= aTarget) {
-        return;
-      }
-      Reset();
-      mTarget = aTarget;
-      mRequest.Begin(mMediaTimer->WaitUntil(mTarget, __func__)->Then(
-        mSelf->OwnerThread(), __func__, mSelf,
-        &MediaDecoderStateMachine::OnDelayedSchedule,
-        &MediaDecoderStateMachine::NotReached));
-    }
-
-    void CompleteRequest()
-    {
-      MOZ_ASSERT(mSelf->OnTaskQueue());
-      mRequest.Complete();
-      mTarget = TimeStamp();
-    }
-
-  private:
-    MediaDecoderStateMachine* mSelf;
-    nsRefPtr<MediaTimer> mMediaTimer;
-    MozPromiseRequestHolder<mozilla::MediaTimerPromise> mRequest;
-    TimeStamp mTarget;
-
-  } mDelayedScheduler;
+  // Used to dispatch another round schedule with specific target time.
+  DelayedScheduler mDelayedScheduler;
 
   // StartTimeRendezvous is a helper class that quarantines the first sample
   // until it gets a sample from both channels, such that we can be guaranteed

dom/media/MediaTimer.h

@@ -113,6 +113,58 @@ private:
   bool mUpdateScheduled;
 };
 
+// Class for managing delayed dispatches on target thread.
+class DelayedScheduler {
+public:
+  explicit DelayedScheduler(AbstractThread* aTargetThread)
+    : mTargetThread(aTargetThread), mMediaTimer(new MediaTimer())
+  {
+    MOZ_ASSERT(mTargetThread);
+  }
+
+  bool IsScheduled() const { return !mTarget.IsNull(); }
+
+  void Reset()
+  {
+    MOZ_ASSERT(mTargetThread->IsCurrentThreadIn(),
+      "Must be on target thread to disconnect");
+    if (IsScheduled()) {
+      mRequest.Disconnect();
+      mTarget = TimeStamp();
+    }
+  }
+
+  template <typename ResolveFunc, typename RejectFunc>
+  void Ensure(mozilla::TimeStamp& aTarget,
+              ResolveFunc&& aResolver,
+              RejectFunc&& aRejector)
+  {
+    MOZ_ASSERT(mTargetThread->IsCurrentThreadIn());
+    if (IsScheduled() && mTarget <= aTarget) {
+      return;
+    }
+    Reset();
+    mTarget = aTarget;
+    mRequest.Begin(mMediaTimer->WaitUntil(mTarget, __func__)->Then(
+      mTargetThread, __func__,
+      Forward<ResolveFunc>(aResolver),
+      Forward<RejectFunc>(aRejector)));
+  }
+
+  void CompleteRequest()
+  {
+    MOZ_ASSERT(mTargetThread->IsCurrentThreadIn());
+    mRequest.Complete();
+    mTarget = TimeStamp();
+  }
+
+private:
+  nsRefPtr<AbstractThread> mTargetThread;
+  nsRefPtr<MediaTimer> mMediaTimer;
+  MozPromiseRequestHolder<mozilla::MediaTimerPromise> mRequest;
+  TimeStamp mTarget;
+};
+
 } // namespace mozilla
 
 #endif