Fix potential synchronization issues with framelisteners in EglRenderer.

webrtc/api/androidtests/src/org/webrtc/EglRendererTest.java

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 11 matching lines @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 // EmptyActivity is needed for the surface.
 public class EglRendererTest extends InstrumentationTestCase {
   final static String TAG = "EglRendererTest";
   final static int RENDER_WAIT_MS = 1000;
   final static int SURFACE_WAIT_MS = 1000;
   final static int TEST_FRAME_WIDTH = 4;
   final static int TEST_FRAME_HEIGHT = 4;
+  final static int REMOVE_FRAME_LISTENER_RACY_NUM_TESTS = 10;
   // Some arbitrary frames.
   final static ByteBuffer[][] TEST_FRAMES = {
       {
           ByteBuffer.wrap(new byte[] {
               11, -12, 13, -14, -15, 16, -17, 18, 19, -110, 111, -112, -113, 114, -115, 116}),
           ByteBuffer.wrap(new byte[] {117, 118, 119, 120}),
           ByteBuffer.wrap(new byte[] {121, 122, 123, 124}),
       },
       {
           ByteBuffer.wrap(new byte[] {-11, -12, -13, -14, -15, -16, -17, -18, -19, -110, -111, -112,
@@ skipping 215 matching lines @@
   @SmallTest
   public void testAddFrameListenerBitmapScale() throws Exception {
     for (int i = 0; i < 3; ++i) {
       float scale = i * 0.5f + 0.5f;
       eglRenderer.addFrameListener(testFrameListener, scale);
       feedFrame(i);
       assertTrue(testFrameListener.waitForBitmap(RENDER_WAIT_MS));
       checkBitmap(testFrameListener.resetAndGetBitmap(), scale);
     }
   }
+
+  /**
+   * Checks that the frame listener will not be called with a frame that was delivered before the
+   * frame listener was added.
+   */
+  @SmallTest
+  public void testFrameListenerNotCalledWithOldFrames() throws Exception {
+    feedFrame(0);
+    eglRenderer.addFrameListener(testFrameListener, 0f);
+    // Check the old frame does not trigger frame listener.
+    assertFalse(testFrameListener.waitForBitmap(RENDER_WAIT_MS));
+  }
+
+  /** Checks that the frame listener will not be called after it is removed. */
+  @SmallTest
+  public void testRemoveFrameListenerNotRacy() throws Exception {
+    for (int i = 0; i < REMOVE_FRAME_LISTENER_RACY_NUM_TESTS; i++) {
+      feedFrame(0);
+      eglRenderer.addFrameListener(testFrameListener, 0f);
+      eglRenderer.removeFrameListener(testFrameListener);
+      feedFrame(1);
+    }
+    // Check the frame listener hasn't triggered.
+    assertFalse(testFrameListener.waitForBitmap(RENDER_WAIT_MS));
+  }
 }