Bug 1491442 - Add CompositorWidget::DoCompositorCleanup() to give the widget a chance to clean up any state from PreRender/PostRender on the correct thread. r=mattwoodrow

Differential Revision: https://phabricator.services.mozilla.com/D40514

--HG--
extra : moz-landing-system : lando

gfx/layers/Compositor.cpp

@@ -76,6 +76,9 @@ Compositor::Compositor(widget::CompositorWidget* aWidget,
 
 Compositor::~Compositor() { ReadUnlockTextures(); }
 
+// Called just before DetachWidget.
+void Compositor::DoWidgetCleanup() { mWidget->DoCompositorCleanup(); }
+
 void Compositor::Destroy() {
   TextureSourceProvider::Destroy();
   mIsDestroyed = true;

gfx/layers/Compositor.h

@@ -190,6 +190,7 @@ class Compositor : public TextureSourceProvider {
   void Destroy() override;
   bool IsDestroyed() const { return mIsDestroyed; }
 
+  virtual void DoWidgetCleanup();
   virtual void DetachWidget() { mWidget = nullptr; }
 
   /**

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -499,6 +499,7 @@ void CompositorBridgeParent::StopAndClearResources() {
   }
 
   if (mCompositor) {
+    mCompositor->DoWidgetCleanup();
     mCompositor->DetachWidget();
     mCompositor->Destroy();
     mCompositor = nullptr;

gfx/webrender_bindings/RendererOGL.cpp

@@ -68,6 +68,7 @@ RendererOGL::~RendererOGL() {
     // Leak resources!
     return;
   }
+  mCompositor->GetWidget()->DoCompositorCleanup();
   wr_renderer_delete(mRenderer);
 }
 

widget/CompositorWidget.h

@@ -116,6 +116,13 @@ class CompositorWidget {
    */
   virtual void PostRender(WidgetRenderingContext* aContext) {}
 
+  /**
+   * Called on the same thread as PreRender/PostRender during destruction.
+   * This method gives the widget a chance to do any cleanup for state that it
+   * created during PreRender / PostRender.
+   */
+  virtual void DoCompositorCleanup() {}
+
   /**
    * Called before the LayerManager draws the layer tree.
    *

widget/InProcessCompositorWidget.cpp

@@ -44,6 +44,10 @@ void InProcessCompositorWidget::PostRender(WidgetRenderingContext* aContext) {
   mWidget->PostRender(aContext);
 }
 
+void InProcessCompositorWidget::DoCompositorCleanup() {
+  mWidget->DoCompositorCleanup();
+}
+
 void InProcessCompositorWidget::DrawWindowUnderlay(
     WidgetRenderingContext* aContext, LayoutDeviceIntRect aRect) {
   mWidget->DrawWindowUnderlay(aContext, aRect);

widget/InProcessCompositorWidget.h

@@ -19,6 +19,7 @@ class InProcessCompositorWidget : public CompositorWidget {
 
   virtual bool PreRender(WidgetRenderingContext* aManager) override;
   virtual void PostRender(WidgetRenderingContext* aManager) override;
+  virtual void DoCompositorCleanup() override;
   virtual void DrawWindowUnderlay(WidgetRenderingContext* aContext,
                                   LayoutDeviceIntRect aRect) override;
   virtual void DrawWindowOverlay(WidgetRenderingContext* aContext,

widget/nsBaseWidget.h

@@ -448,6 +448,7 @@ class nsBaseWidget : public nsIWidget, public nsSupportsWeakReference {
     return true;
   }
   virtual void PostRender(mozilla::widget::WidgetRenderingContext* aContext) {}
+  virtual void DoCompositorCleanup() {}
   virtual void DrawWindowUnderlay(
       mozilla::widget::WidgetRenderingContext* aContext,
       LayoutDeviceIntRect aRect) {}