Prevent WebView from crashing when detached from the window

Bug #6365056

WebView enqueues a functor in the hardware renderer to handle
animations and this functor is called at a later time by the
hardware renderer. However, the functor was not removed from
the queue when WebView was removed from the window. This could
cause the hardware renderer to attempt to execute an invalid
functor and lead to a crash.

Change-Id: I9d38e80f3fdc5e29d4d0cdfa1e893c251a954508

1 files changed, 43 insertions, 2 deletions

diff --git a/core/java/android/view/HardwareRenderer.java b/core/java/android/view/HardwareRenderer.java
index 1ec754a1dde1..b9295c368493 100644
--- a/core/java/android/view/HardwareRenderer.java
+++ b/core/java/android/view/HardwareRenderer.java
@@ -437,6 +437,27 @@ public abstract class HardwareRenderer {
     abstract void setSurfaceTexture(HardwareLayer layer, SurfaceTexture surfaceTexture);
 
     /**
+     * Detaches the specified functor from the current functor execution queue.
+     * 
+     * @param functor The native functor to remove from the execution queue.
+     *                
+     * @see HardwareCanvas#callDrawGLFunction(int) 
+     * @see #attachFunctor(android.view.View.AttachInfo, int) 
+     */
+    abstract void detachFunctor(int functor);
+
+    /**
+     * Schedules the specified functor in the functors execution queue.
+     *
+     * @param attachInfo AttachInfo tied to this renderer.
+     * @param functor The native functor to insert in the execution queue.
+     *
+     * @see HardwareCanvas#callDrawGLFunction(int)
+     * @see #detachFunctor(int) 
+     */
+    abstract void attachFunctor(View.AttachInfo attachInfo, int functor);
+
+    /**
      * Initializes the hardware renderer for the specified surface and setup the
      * renderer for drawing, if needed. This is invoked when the ViewAncestor has
      * potentially lost the hardware renderer. The hardware renderer should be
@@ -1202,13 +1223,33 @@ public abstract class HardwareRenderer {
             }
 
             if ((status & DisplayList.STATUS_INVOKE) != 0) {
-                attachInfo.mHandler.removeCallbacks(mFunctorsRunnable);
-                mFunctorsRunnable.attachInfo = attachInfo;
+                scheduleFunctors(attachInfo);
+            }
+        }
+
+        private void scheduleFunctors(View.AttachInfo attachInfo) {
+            mFunctorsRunnable.attachInfo = attachInfo;
+            if (!attachInfo.mHandler.hasCallbacks(mFunctorsRunnable)) {
                 // delay the functor callback by a few ms so it isn't polled constantly
                 attachInfo.mHandler.postDelayed(mFunctorsRunnable, FUNCTOR_PROCESS_DELAY);
             }
         }
 
+        @Override
+        void detachFunctor(int functor) {
+            if (mCanvas != null) {
+                mCanvas.detachFunctor(functor);
+            }
+        }
+
+        @Override
+        void attachFunctor(View.AttachInfo attachInfo, int functor) {
+            if (mCanvas != null) {
+                mCanvas.attachFunctor(functor);
+                scheduleFunctors(attachInfo);
+            }
+        }
+
         /**
          * Ensures the current EGL context is the one we expect.
          *