Initialization of audio manager for Android is now done on the audio thread

media/audio/android/audio_android_unittest.cc

Index: media/audio/android/audio_android_unittest.cc
diff --git a/media/audio/android/audio_android_unittest.cc b/media/audio/android/audio_android_unittest.cc
index 688a940bfbc11d0dc13390ac0bde8ec295f688d3..8fdc7d00b7fa1c702f25afbc7b6c5d4d77cbe9d9 100644
--- a/media/audio/android/audio_android_unittest.cc
+++ b/media/audio/android/audio_android_unittest.cc
@@ -508,9 +508,13 @@ std::vector<bool> RunAudioRecordInputPathTests() {
 class AudioAndroidInputTest : public AudioAndroidOutputTest,
                               public testing::WithParamInterface<bool> {
  public:
-  AudioAndroidInputTest() {}
+  AudioAndroidInputTest()
+      : event_(false, false),
+        audio_input_stream_(NULL) {}
 
  protected:
+  AudioInputStream* audio_input_stream() { return audio_input_stream_; }
+
   AudioParameters GetInputStreamParameters() {
     AudioParameters input_params = audio_manager()->GetInputStreamParameters(
         AudioManagerBase::kDefaultDeviceId);
@@ -567,8 +571,26 @@ class AudioAndroidInputTest : public AudioAndroidOutputTest,
               1.30 * expected_time_between_callbacks_ms);
   }
 
+  void CreateAndCloseAISOnAudioThread(const AudioParameters& params) {
+    if (!audio_manager()->GetTaskRunner()->BelongsToCurrentThread()) {
+      audio_manager()->GetTaskRunner()->PostTask(
+          FROM_HERE,
+          base::Bind(&AudioAndroidInputTest::CreateAndCloseAISOnAudioThread,
+                     base::Unretained(this),
+                     params));
+      event_.Wait();
+    } else {
+      audio_input_stream_ = audio_manager()->MakeAudioInputStream(
+          params, AudioManagerBase::kDefaultDeviceId);
+      EXPECT_TRUE(audio_input_stream_);
+      audio_input_stream_->Close();
+      event_.Signal();
+    }
+  }
 
  private:
+  base::WaitableEvent event_;

[tommi (sloooow) - chröme, 2014/01/30 15:26:04]

This pattern is racy and could throw TSAN off.
CreateAndCloseAISOnAudioThread is now touching this variable on two different
threads (at least) and there's no DCHECK inside the |if
(!audio_manager()->GetTaskRunner()->BelongsToCurrentThread())| check that we're
always on the same thread there, so we're open to even more threads being in the
picture and that's a bug.

I realize that this is test code with very specific intentions but the bug is
not obvious so it's possible that the assumptions that are in here (and not
documented) go by unnoticed and someone copies this pattern into production
code.

[henrika (OOO until Aug 14), 2014/01/30 17:20:23]

Uploaded new and improved version after offline discussion with you. Please
check proposal of new pattern in next patch. Thanks.

+  AudioInputStream* audio_input_stream_;
   DISALLOW_COPY_AND_ASSIGN(AudioAndroidInputTest);
 };
 
@@ -619,10 +641,7 @@ TEST_F(AudioAndroidOutputTest, GetAudioOutputDeviceNames) {
 // Ensure that a default input stream can be created and closed.
 TEST_P(AudioAndroidInputTest, CreateAndCloseInputStream) {
   AudioParameters params = GetInputStreamParameters();
-  AudioInputStream* ais = audio_manager()->MakeAudioInputStream(
-      params, AudioManagerBase::kDefaultDeviceId);
-  EXPECT_TRUE(ais);
-  ais->Close();
+  CreateAndCloseAISOnAudioThread(params);
 }
 
 // Ensure that a default output stream can be created and closed.