am adb52ef7: Merge "Implement finalizer for RS contexts."

* commit 'adb52ef7034d4d3e0eee58cedae2a343d29771b9':
  Implement finalizer for RS contexts.

rs/java/android/renderscript/RenderScript.java

@@ -938,6 +938,8 @@ public class RenderScript {
 
     long     mDev;
     long     mContext;
+    private boolean mDestroyed = false;
+
     @SuppressWarnings({"FieldCanBeLocal"})
     MessageThread mMessageThread;
 
@@ -1382,14 +1384,16 @@ public class RenderScript {
         nContextFinish();
     }
 
-    /**
+    private void helpDestroy() {
-     * Destroys this RenderScript context.  Once this function is called,
+        boolean shouldDestroy = false;
-     * using this context or any objects belonging to this context is
+        synchronized(this) {
-     * illegal.
+            if (!mDestroyed) {
-     *
+                shouldDestroy = true;
-     */
+                mDestroyed = true;
-    public void destroy() {
+            }
-        validate();
+        }
+
+        if (shouldDestroy) {
             nContextFinish();
 
             nContextDeinitToClient(mContext);
@@ -1404,6 +1408,24 @@ public class RenderScript {
             nDeviceDestroy(mDev);
             mDev = 0;
         }
+    }
+
+    protected void finalize() throws Throwable {
+        helpDestroy();
+        super.finalize();
+    }
+
+
+    /**
+     * Destroys this RenderScript context.  Once this function is called,
+     * using this context or any objects belonging to this context is
+     * illegal.
+     *
+     */
+    public void destroy() {
+        validate();
+        helpDestroy();
+    }
 
     boolean isAlive() {
         return mContext != 0;