Don't process pending prefetch events if we fail to create video decoder job

media/base/android/media_source_player_unittest.cc

Index: media/base/android/media_source_player_unittest.cc
diff --git a/media/base/android/media_source_player_unittest.cc b/media/base/android/media_source_player_unittest.cc
index c07210be432eda55c6b2edcf118daeae1dcbb8ef..9983628f147e3fce35637b125226bd34a9c70369 100644
--- a/media/base/android/media_source_player_unittest.cc
+++ b/media/base/android/media_source_player_unittest.cc
@@ -886,6 +886,32 @@ TEST_F(MediaSourcePlayerTest, ChangeMultipleSurfaceWhileDecoding) {
   EXPECT_EQ(1, demuxer_->num_seek_requests());
 }
 
+TEST_F(MediaSourcePlayerTest, SetEmptySurfaceWhileDecoding) {
+  SKIP_TEST_IF_MEDIA_CODEC_BRIDGE_IS_NOT_AVAILABLE();
+
+  // Test player pauses if an empty surface is passed.
+  CreateNextTextureAndSetVideoSurface();
+  StartVideoDecoderJob(true);
+
+  // Send the first input chunk.
+  player_.OnDemuxerDataAvailable(CreateReadFromDemuxerAckForVideo());
+
+  // While the decoder is decoding, pass an empty surface.
+  gfx::ScopedJavaSurface empty_surface;
+  player_.SetVideoSurface(empty_surface.Pass());

[wolenetz, 2014/02/20 20:52:11]

Is this where the NPE previously occurred prior to this patch? Shouldn't the
player already have entered PREFETCH_DONE_EVENT_PENDING in
StartVideoDecoderJob(true), above? Then, OnPrefetchDone() is invoked by
OnDemuxerDataAvailable(), above, and PREFETCH_DONE_EVENT_PENDING is cleared and
VDJ->Decode() is invoked on the prefetched data. So at this point, no event is
pending, IIUC.

Is perhaps there some race between OnPrefetchDone()'s calling of
DecodeMoreVideo() (which could NPE if VDJ is null) and resetting the VDJ? If so,
I'm not sure this patch fixes that issue.

In general, the early ProcessPendingEvents() return condition added by the patch
looks good, but I'm not sure that it solves the problem (or how this test tests
the problem's existence and solution).

[qinmin, 2014/02/20 22:36:05]

Added a TriggerPlayerStarvation() call to let the player to have a
PREFETCH_DONE_EVENT_PENDING status after setting the empty surface.

On 2014/02/20 20:52:11, wolenetz wrote:

+
+  // Wait for the decoder job to finish decoding and be reset.
+  while (GetMediaDecoderJob(false))
+    message_loop_.RunUntilIdle();
+
+  // No seek request should have been received since the surface is empty.
+  EXPECT_EQ(0, demuxer_->num_browser_seek_requests());
+
+  // Playback resumes once a non-empty surface is passed.
+  CreateNextTextureAndSetVideoSurface();
+  EXPECT_EQ(1, demuxer_->num_browser_seek_requests());
+}
+
 TEST_F(MediaSourcePlayerTest, AudioOnlyStartAfterSeekFinish) {
   SKIP_TEST_IF_MEDIA_CODEC_BRIDGE_IS_NOT_AVAILABLE();