Fix crash when deleting Compositor parent, and change RPC calls to sync calls..

gfx/layers/ipc/CompositorChild.cpp

@@ -66,28 +66,27 @@ CompositorChild::~CompositorChild()
 void
 CompositorChild::Destroy()
 {
-  CallStop();
+  SendStop();
 }
 
 CompositorChild*
-CompositorChild::CreateCompositor(LayerManager *aLayerManager)
+CompositorChild::CreateCompositor(LayerManager *aLayerManager,
+                                  CompositorParent *aCompositorParent)
 {
   Thread* compositorThread = new Thread("CompositorThread");
   if (compositorThread->Start()) {
     MessageLoop *parentMessageLoop = MessageLoop::current();
     MessageLoop *childMessageLoop = compositorThread->message_loop();
-    CompositorParent* compositorParent = new CompositorParent();
     CompositorChild *compositorChild = new CompositorChild(compositorThread, aLayerManager);
     mozilla::ipc::AsyncChannel *parentChannel =
-      compositorParent->GetIPCChannel();
+      aCompositorParent->GetIPCChannel();
     mozilla::ipc::AsyncChannel *childChannel =
       compositorChild->GetIPCChannel();
     mozilla::ipc::AsyncChannel::Side childSide =
       mozilla::ipc::AsyncChannel::Child;
 
     compositorChild->Open(parentChannel, childMessageLoop, childSide);
-    compositorChild->CallInit();
-    compositorChild->mCompositorParent = compositorParent;
+    compositorChild->SendInit();
 
     return compositorChild;
   }

gfx/layers/ipc/CompositorChild.h

@@ -62,7 +62,8 @@ public:
 
   void Destroy();
 
-  static CompositorChild* CreateCompositor(LayerManager *aLayerManager);
+  static CompositorChild* CreateCompositor(LayerManager *aLayerManager,
+                                           CompositorParent *aCompositorParent);
 
 protected:
   CompositorChild(Thread* aCompositorThread, LayerManager *aLayerManager);

gfx/layers/ipc/CompositorParent.cpp

@@ -54,12 +54,11 @@ CompositorParent::CompositorParent()
 CompositorParent::~CompositorParent()
 {
   printf("delete parent\n");
-  delete mLayerManager;
   MOZ_COUNT_DTOR(CompositorParent);
 }
 
 bool
-CompositorParent::AnswerInit()
+CompositorParent::RecvInit()
 {
   CancelableTask *composeTask = NewRunnableMethod(this, &CompositorParent::Composite);
   MessageLoop::current()->PostTask(FROM_HERE, composeTask);
@@ -67,12 +66,8 @@ CompositorParent::AnswerInit()
 }
 
 bool
-CompositorParent::AnswerStop()
+CompositorParent::RecvStop()
 {
-  if (mLayerManager) {
-    delete mLayerManager;
-    mLayerManager = NULL;
-  }
   return true;
 }
 

gfx/layers/ipc/CompositorParent.h

@@ -57,8 +57,8 @@ public:
   CompositorParent();
   virtual ~CompositorParent();
 
-  bool AnswerInit();
-  bool AnswerStop();
+  bool RecvInit();
+  bool RecvStop();
 
   void RequestComposition();
 
@@ -73,7 +73,7 @@ protected:
 private:
   void Composite();
 
-  LayerManager *mLayerManager;
+  nsRefPtr<LayerManager> mLayerManager;
 
   DISALLOW_EVIL_CONSTRUCTORS(CompositorParent);
 };

gfx/layers/ipc/PCompositor.ipdl

@@ -74,8 +74,8 @@ rpc protocol PCompositor
 
 parent:  
 
-  rpc Init();
-  rpc Stop();
+  sync Init();
+  sync Stop();
 
   async PLayers(LayersBackend backend, WidgetDescriptor widgetDescriptor);
 

widget/src/xpwidgets/nsBaseWidget.cpp

@@ -39,6 +39,7 @@
 #include "mozilla/Util.h"
 
 #include "mozilla/layers/CompositorChild.h"
+#include "mozilla/layers/CompositorParent.h"
 #include "nsBaseWidget.h"
 #include "nsDeviceContext.h"
 #include "nsCOMPtr.h"
@@ -141,15 +142,16 @@ nsBaseWidget::~nsBaseWidget()
     static_cast<BasicLayerManager*>(mLayerManager.get())->ClearRetainerWidget();
   }
 
-  if (mCompositor) {
-    mCompositor->Destroy();
-  }
 
   if (mLayerManager) {
     mLayerManager->Destroy();
     mLayerManager = NULL;
   }
 
+  if (mCompositor) {
+    mCompositor->Destroy();
+  }
+
 #ifdef NOISY_WIDGET_LEAKS
   gNumWidgets--;
   printf("WIDGETS- = %d\n", gNumWidgets);
@@ -836,7 +838,8 @@ LayerManager* nsBaseWidget::GetLayerManager(PLayersChild* aShadowManager,
         Preferences::GetBool("layers.offmainthreadcomposition.enabled", false);
       if (useCompositor) {
         LayerManager* lm = CreateBasicLayerManager();
-        mCompositor = CompositorChild::CreateCompositor(lm);
+        mCompositorParent = new CompositorParent();
+        mCompositor = CompositorChild::CreateCompositor(lm, mCompositorParent);
 
         if (mCompositor) {
           // e10s uses the parameter to pass in the shadow manager from the TabChild

widget/src/xpwidgets/nsBaseWidget.h

@@ -54,10 +54,12 @@ class gfxContext;
 namespace mozilla {
 namespace layers {
 class CompositorChild;
+class CompositorParent;
 }
 }
 
 using mozilla::layers::CompositorChild;
+using mozilla::layers::CompositorParent;
 
 /**
  * Common widget implementation used as base class for native
@@ -277,6 +279,7 @@ protected:
   nsRefPtr<LayerManager> mLayerManager;
   nsRefPtr<LayerManager> mBasicLayerManager;
   nsRefPtr<CompositorChild> mCompositor;
+  nsRefPtr<CompositorParent> mCompositorParent;
   nscolor           mBackground;
   nscolor           mForeground;
   nsCursor          mCursor;