Adding audio unit tests for Android

media/audio/android/opensles_output.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
 #define MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
 
 #include <SLES/OpenSLES.h>
 #include <SLES/OpenSLES_Android.h>
 
 #include "base/compiler_specific.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/thread_checker.h"
 #include "media/audio/android/opensles_util.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
 namespace media {
 
 class AudioManagerAndroid;
 
 // Implements PCM audio output support for Android using the OpenSLES API.
+// This class is created and lives on the Audio Manager thread but recorded
+// audio buffers are given to us from an internal OpenSLES audio thread.
+// All public methods should be called on the Audio Manager thread.
 class OpenSLESOutputStream : public AudioOutputStream {
  public:
-  static const int kNumOfQueuesInBuffer = 2;
+  static const int kMaxNumOfBuffersInQueue = 2;
 
   OpenSLESOutputStream(AudioManagerAndroid* manager,
                        const AudioParameters& params);
 
   virtual ~OpenSLESOutputStream();
 
   // Implementation of AudioOutputStream.
   virtual bool Open() OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual void Start(AudioSourceCallback* callback) OVERRIDE;
   virtual void Stop() OVERRIDE;
   virtual void SetVolume(double volume) OVERRIDE;
   virtual void GetVolume(double* volume) OVERRIDE;
 
  private:
   bool CreatePlayer();
 
+  // Called from OpenSLES specific audio worker thread.
   static void SimpleBufferQueueCallback(
-      SLAndroidSimpleBufferQueueItf buffer_queue, void* instance);
+      SLAndroidSimpleBufferQueueItf buffer_queue,
+      void* instance);
 
+  // Fills up one buffer by asking the registered source for data.
+  // Called from OpenSLES specific audio worker thread.
   void FillBufferQueue();
 
+  // Called from the audio manager thread.
+  void FillBufferQueueNoLock();
+
   // Called in Open();
   void SetupAudioBuffer();
 
   // Called in Close();
   void ReleaseAudioBuffer();
 
   // If OpenSLES reports an error this function handles it and passes it to
   // the attached AudioOutputCallback::OnError().
   void HandleError(SLresult error);
 
+  base::ThreadChecker thread_checker_;
+
+  // Protects |callback_|, |active_buffer_index_|, |audio_data_|,
+  // |buffer_size_bytes_| and |simple_buffer_queue_|.
+  base::Lock lock_;
+
   AudioManagerAndroid* audio_manager_;
 
   AudioSourceCallback* callback_;
 
   // Shared engine interfaces for the app.
   media::ScopedSLObjectItf engine_object_;
   media::ScopedSLObjectItf player_object_;
   media::ScopedSLObjectItf output_mixer_;
 
   SLPlayItf player_;
 
   // Buffer queue recorder interface.
   SLAndroidSimpleBufferQueueItf simple_buffer_queue_;
 
   SLDataFormat_PCM format_;
 
-  // Audio buffer arrays that are allocated in the constructor.
-  uint8* audio_data_[kNumOfQueuesInBuffer];
+  // Audio buffers that are allocated in the constructor based on
+  // info from audio parameters.
+  uint8* audio_data_[kMaxNumOfBuffersInQueue];
 
-  int active_queue_;
+  int active_buffer_index_;
   size_t buffer_size_bytes_;
 
   bool started_;
 
   // Volume level from 0 to 1.
   float volume_;
 
   // Container for retrieving data from AudioSourceCallback::OnMoreData().
   scoped_ptr<AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(OpenSLESOutputStream);
 };
 
 }  // namespace media
 
-#endif  // MEDIA_AUDIO_ANDROID_OPENSLES_INPUT_H_
+#endif  // MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_