Bug 1003006: Move b2g camera rotation checks to MainThread r=mikeh

content/media/webrtc/MediaEngineWebRTC.h

@@ -170,6 +170,7 @@ public:
   NS_DECL_ISUPPORTS_INHERITED
 
   void OnHardwareStateChange(HardwareState aState);
+  void GetRotation();
   bool OnNewPreviewFrame(layers::Image* aImage, uint32_t aWidth, uint32_t aHeight);
   void OnUserError(UserContext aContext, nsresult aError);
   void OnTakePictureComplete(uint8_t* aData, uint32_t aLength, const nsAString& aMimeType);
@@ -212,9 +213,12 @@ private:
 
   // Engine variables.
 #ifdef MOZ_B2G_CAMERA
-  nsRefPtr<ICameraControl> mCameraControl;
   mozilla::ReentrantMonitor mCallbackMonitor; // Monitor for camera callback handling
+  // This is only modified on MainThread (AllocImpl and DeallocImpl)
+  nsRefPtr<ICameraControl> mCameraControl;
   nsRefPtr<nsIDOMFile> mLastCapture;
+
+  // These are protected by mMonitor below
   int mRotation;
   int mCameraAngle; // See dom/base/ScreenOrientation.h
   bool mBackCamera;

content/media/webrtc/MediaEngineWebRTCVideo.cpp

@@ -415,7 +415,7 @@ MediaEngineWebRTCVideoSource::Allocate(const VideoTrackConstraintsN &aConstraint
   ReentrantMonitorAutoEnter sync(mCallbackMonitor);
   if (mState == kReleased && mInitDone) {
     ChooseCapability(aConstraints, aPrefs);
-    NS_DispatchToMainThread(WrapRunnable(this,
+    NS_DispatchToMainThread(WrapRunnable(nsRefPtr<MediaEngineWebRTCVideoSource>(this),
                                          &MediaEngineWebRTCVideoSource::AllocImpl));
     mCallbackMonitor.Wait();
     if (mState != kAllocated) {
@@ -459,7 +459,7 @@ MediaEngineWebRTCVideoSource::Deallocate()
 #ifdef MOZ_B2G_CAMERA
     // We do not register success callback here
 
-    NS_DispatchToMainThread(WrapRunnable(this,
+    NS_DispatchToMainThread(WrapRunnable(nsRefPtr<MediaEngineWebRTCVideoSource>(this),
                                          &MediaEngineWebRTCVideoSource::DeallocImpl));
     mCallbackMonitor.Wait();
     if (mState != kReleased) {
@@ -519,7 +519,7 @@ MediaEngineWebRTCVideoSource::Start(SourceMediaStream* aStream, TrackID aID)
   mImageContainer = layers::LayerManager::CreateImageContainer();
 
 #ifdef MOZ_B2G_CAMERA
-  NS_DispatchToMainThread(WrapRunnable(this,
+  NS_DispatchToMainThread(WrapRunnable(nsRefPtr<MediaEngineWebRTCVideoSource>(this),
                                        &MediaEngineWebRTCVideoSource::StartImpl,
                                        mCapability));
   mCallbackMonitor.Wait();
@@ -573,7 +573,7 @@ MediaEngineWebRTCVideoSource::Stop(SourceMediaStream *aSource, TrackID aID)
     mImage = nullptr;
   }
 #ifdef MOZ_B2G_CAMERA
-  NS_DispatchToMainThread(WrapRunnable(this,
+  NS_DispatchToMainThread(WrapRunnable(nsRefPtr<MediaEngineWebRTCVideoSource>(this),
                                        &MediaEngineWebRTCVideoSource::StopImpl));
 #else
   mViERender->StopRender(mCaptureIndex);
@@ -789,26 +789,37 @@ MediaEngineWebRTCVideoSource::OnHardwareStateChange(HardwareState aState)
       mCallbackMonitor.Notify();
     }
   } else {
-    mCameraControl->Get(CAMERA_PARAM_SENSORANGLE, mCameraAngle);
-    MOZ_ASSERT(mCameraAngle == 0 || mCameraAngle == 90 || mCameraAngle == 180 ||
-               mCameraAngle == 270);
-    hal::ScreenConfiguration aConfig;
-    hal::GetCurrentScreenConfiguration(&aConfig);
-
-    nsCString deviceName;
-    ICameraControl::GetCameraName(mCaptureIndex, deviceName);
-    if (deviceName.EqualsASCII("back")) {
-      mBackCamera = true;
-    }
-
-    mRotation = GetRotateAmount(aConfig.orientation(), mCameraAngle, mBackCamera);
-    LOG(("*** Initial orientation: %d (Camera %d Back %d MountAngle: %d)",
-         mRotation, mCaptureIndex, mBackCamera, mCameraAngle));
+    // Can't read this except on MainThread (ugh)
+    NS_DispatchToMainThread(WrapRunnable(nsRefPtr<MediaEngineWebRTCVideoSource>(this),
+                                         &MediaEngineWebRTCVideoSource::GetRotation));
     mState = kStarted;
     mCallbackMonitor.Notify();
   }
 }
 
+void
+MediaEngineWebRTCVideoSource::GetRotation()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MonitorAutoLock enter(mMonitor);
+
+  mCameraControl->Get(CAMERA_PARAM_SENSORANGLE, mCameraAngle);
+  MOZ_ASSERT(mCameraAngle == 0 || mCameraAngle == 90 || mCameraAngle == 180 ||
+             mCameraAngle == 270);
+  hal::ScreenConfiguration config;
+  hal::GetCurrentScreenConfiguration(&config);
+
+  nsCString deviceName;
+  ICameraControl::GetCameraName(mCaptureIndex, deviceName);
+  if (deviceName.EqualsASCII("back")) {
+    mBackCamera = true;
+  }
+
+  mRotation = GetRotateAmount(config.orientation(), mCameraAngle, mBackCamera);
+  LOG(("*** Initial orientation: %d (Camera %d Back %d MountAngle: %d)",
+       mRotation, mCaptureIndex, mBackCamera, mCameraAngle));
+}
+
 void
 MediaEngineWebRTCVideoSource::OnUserError(UserContext aContext, nsresult aError)
 {