Bug 885580 - Make sure that Compositor::GetBackend is only used [Cfrom the compositor thread. r=nical

gfx/layers/Compositor.cpp

@@ -5,6 +5,7 @@
 
 #include "mozilla/layers/Compositor.h"
 #include "mozilla/layers/Effects.h"
+#include "mozilla/layers/CompositorParent.h"
 
 namespace mozilla {
 namespace layers {
@@ -13,6 +14,9 @@ namespace layers {
 /* static */ LayersBackend
 Compositor::GetBackend()
 {
+  MOZ_ASSERT(CompositorParent::CompositorLoop() ==
+             MessageLoop::current(),
+             "Can only call this from the compositor thread!");
   return sBackend;
 }
 

gfx/layers/Compositor.h

@@ -391,6 +391,8 @@ public:
    * thread at the same time. The backend type in use can be checked with this
    * static method. We need this for creating texture clients/hosts etc. when we
    * don't have a reference to a Compositor.
+   *
+   * This can only be used from the compositor thread!
    */
   static LayersBackend GetBackend();
 

gfx/layers/client/ClientLayerManager.cpp

@@ -383,7 +383,7 @@ ClientLayerManager::ClearLayer(Layer* aLayer)
 void
 ClientLayerManager::GetBackendName(nsAString& aName)
 {
-  switch (Compositor::GetBackend()) {
+  switch (GetCompositorBackendType()) {
     case LAYERS_BASIC: aName.AssignLiteral("Basic"); return;
     case LAYERS_OPENGL: aName.AssignLiteral("OpenGL"); return;
     case LAYERS_D3D9: aName.AssignLiteral("Direct3D 9"); return;

gfx/layers/client/ClientLayerManager.h

@@ -55,7 +55,7 @@ public:
 
   virtual void FlushRendering() MOZ_OVERRIDE;
 
-  virtual bool NeedsWidgetInvalidation() MOZ_OVERRIDE { return Compositor::GetBackend() == LAYERS_BASIC; }
+  virtual bool NeedsWidgetInvalidation() MOZ_OVERRIDE { return GetCompositorBackendType() == LAYERS_BASIC; }
 
   ShadowableLayer* Hold(Layer* aLayer);
 

widget/cocoa/nsChildView.mm

@@ -1387,7 +1387,7 @@ NS_IMETHODIMP nsChildView::Invalidate(const nsIntRect &aRect)
     return NS_OK;
 
   NS_ASSERTION(GetLayerManager()->GetBackendType() != LAYERS_CLIENT ||
-               Compositor::GetBackend() == LAYERS_BASIC,
+               static_cast<ClientLayerManager*>(GetLayerManager())->GetCompositorBackendType() == LAYERS_BASIC,
                "Shouldn't need to invalidate with accelerated OMTC layers!");
 
   if ([NSView focusView]) {
@@ -1821,8 +1821,8 @@ nsChildView::CreateCompositor()
       compositor::GetLayerManager(mCompositorParent);
     Compositor *compositor = manager->GetCompositor();
 
-    LayersBackend backend = compositor->GetBackend();
-    if (backend == LAYERS_OPENGL) {
+    ClientLayerManager *clientManager = static_cast<ClientLayerManager*>(GetLayerManager());
+    if (clientManager->GetCompositorBackendType() == LAYERS_OPENGL) {
       CompositorOGL *compositorOGL = static_cast<CompositorOGL*>(compositor);
 
       NSOpenGLContext *glContext = (NSOpenGLContext *)compositorOGL->gl()->GetNativeData(GLContext::NativeGLContext);
@@ -3073,8 +3073,8 @@ NSEvent* gLastDragMouseDownEvent = nil;
     painted = mGeckoChild->PaintWindow(region);
   } else if (mGeckoChild->GetLayerManager()->GetBackendType() == LAYERS_CLIENT) {
     // We only need this so that we actually get DidPaintWindow fired
-    if (Compositor::GetBackend() == LAYERS_BASIC) {
-      ClientLayerManager *manager = static_cast<ClientLayerManager*>(mGeckoChild->GetLayerManager());
+    ClientLayerManager *manager = static_cast<ClientLayerManager*>(mGeckoChild->GetLayerManager());
+    if (manager->GetCompositorBackendType() == LAYERS_BASIC) {
       manager->SetShadowTarget(targetContext);
     }
     painted = mGeckoChild->PaintWindow(region);

widget/gtk2/nsWindow.cpp

@@ -2124,13 +2124,14 @@ nsWindow::OnExposeEvent(cairo_t *cr)
         return TRUE;
     }
     // If this widget uses OMTC...
-    if (GetLayerManager()->AsShadowForwarder() && GetLayerManager()->AsShadowForwarder()->HasShadowManager() &&
-        Compositor::GetBackend() != LAYERS_BASIC) {
-        listener->DidPaintWindow();
-
-        g_free(rects);
-        return TRUE;
+    if (GetLayerManager()->GetBackendType() == LAYERS_CLIENT) {
+        ClientLayerManager *manager = static_cast<ClientLayerManager*>(GetLayerManager());
+        if (manager->GetCompositorBackendType() != LAYERS_BASIC) {
+            listener->DidPaintWindow();
 
+            g_free(rects);
+            return TRUE;
+        }
     } else if (GetLayerManager()->GetBackendType() == mozilla::layers::LAYERS_OPENGL) {
         LayerManagerOGL *manager = static_cast<LayerManagerOGL*>(GetLayerManager());
         manager->SetClippingRegion(region);