Fix texture corruption

When memory gets low on a device, activities flush everything they can.
Hardware-accelerated activites, such as Launcher, flush GL resources and destroy
the GL context. However, some resources were still hanging around, due to deferred
destruction policies (we don't delete layers until the DisplayLists they are in
are finalized, to ensure we don't deref deleted objects). This meant that we were
referring to obsolete GL data in these objects. in particular, it meant that we might
come around later, after a new GL context was created, and delete a texture object
that was incorrect. We use the layer's "texture id" to refer to the texture underlying the
layer. But if there's a new GL context, then this texture ID is no longer valid, and
we may be deleting the texture that a different object (layer, icon, whatever) is referring
to, because the driver may return that same ID under the new GL context.

The fix is to more aggressively delete things that we know will not be used again
when the GL context is destroyed. In particular, we delete all resources being used
by all DisplayLists at GL context destruction time.

Issue #7195815 Textures corruption on all devices, in many apps

Change-Id: I52d2d208173690dbb794a83402d38f14ea4c6c22

4 files changed, 24 insertions, 0 deletions

diff --git a/core/java/android/view/DisplayList.java b/core/java/android/view/DisplayList.java
index a42e156..5e34a36 100644
--- a/core/java/android/view/DisplayList.java
+++ b/core/java/android/view/DisplayList.java
@@ -332,4 +332,11 @@ public abstract class DisplayList {
      * @see View#offsetTopAndBottom(int)
      */
     public abstract void offsetTopBottom(int offset);
+
+    /**
+     * Reset native resources. This is called when cleaning up the state of DisplayLists
+     * during destruction of hardware resources, to ensure that we do not hold onto
+     * obsolete resources after related resources are gone.
+     */
+    public abstract void reset();
 }
diff --git a/core/java/android/view/GLES20DisplayList.java b/core/java/android/view/GLES20DisplayList.java
index 3bdd5c0..e9bd0c4 100644
--- a/core/java/android/view/GLES20DisplayList.java
+++ b/core/java/android/view/GLES20DisplayList.java
@@ -87,6 +87,13 @@ class GLES20DisplayList extends DisplayList {
     }
 
     @Override
+    public void reset() {
+        if (hasNativeDisplayList()) {
+            nReset(mFinalizer.mNativeDisplayList);
+        }
+    }
+
+    @Override
     public boolean isValid() {
         return mValid;
     }
@@ -294,6 +301,7 @@ class GLES20DisplayList extends DisplayList {
         }
     }
 
+    private static native void nReset(int displayList);
     private static native void nOffsetTopBottom(int displayList, int offset);
     private static native void nOffsetLeftRight(int displayList, int offset);
     private static native void nSetLeftTopRightBottom(int displayList, int left, int top,
diff --git a/core/java/android/view/HardwareRenderer.java b/core/java/android/view/HardwareRenderer.java
index 28763b3..99987bf 100644
--- a/core/java/android/view/HardwareRenderer.java
+++ b/core/java/android/view/HardwareRenderer.java
@@ -1508,6 +1508,9 @@ public abstract class HardwareRenderer {
         @Override
         void destroyLayers(View view) {
             if (view != null && isEnabled() && checkCurrent() != SURFACE_STATE_ERROR) {
+                if (mCanvas != null) {
+                    mCanvas.clearLayerUpdates();
+                }
                 destroyHardwareLayer(view);
                 GLES20Canvas.flushCaches(GLES20Canvas.FLUSH_CACHES_LAYERS);
             }
@@ -1556,6 +1559,9 @@ public abstract class HardwareRenderer {
                 safelyRun(new Runnable() {
                     @Override
                     public void run() {
+                        if (mCanvas != null) {
+                            mCanvas.clearLayerUpdates();
+                        }
                         destroyResources(view);
                         GLES20Canvas.flushCaches(GLES20Canvas.FLUSH_CACHES_LAYERS);
                     }
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 6eca8fd..4b6f4ea 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -12394,6 +12394,9 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
                 mHardwareLayer.destroy();
                 mHardwareLayer = null;
 
+                if (mDisplayList != null) {
+                    mDisplayList.reset();
+                }
                 invalidate(true);
                 invalidateParentCaches();
             }