Cast: Removed unnecessary ref counters.

media/cast/audio_receiver/audio_decoder.h

 // Copyright 2013 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_CAST_AUDIO_RECEIVER_AUDIO_DECODER_H_
 #define MEDIA_CAST_AUDIO_RECEIVER_AUDIO_DECODER_H_
 
+#include "base/atomicops.h"
 #include "base/callback.h"
-#include "base/memory/ref_counted.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/rtp_common/rtp_defines.h"
 
 namespace webrtc {
 class AudioCodingModule;
 }
 
 namespace media {
 namespace cast {
 
 // Thread safe class.
-class AudioDecoder : public base::RefCountedThreadSafe<AudioDecoder> {
+class AudioDecoder {
  public:
   explicit AudioDecoder(const AudioReceiverConfig& audio_config);
+  virtual ~AudioDecoder();
 
   // Extract a raw audio frame from the decoder.
   // Set the number of desired 10ms blocks and frequency.
   // Should be called from the cast audio decoder thread; however that is not
   // required.
   bool GetRawAudioFrame(int number_of_10ms_blocks,
                         int desired_frequency,
                         PcmAudioFrame* audio_frame,
                         uint32* rtp_timestamp);
 
   // Insert an RTP packet to the decoder.
   // Should be called from the main cast thread; however that is not required.
   void IncomingParsedRtpPacket(const uint8* payload_data,
                                size_t payload_size,
                                const RtpCastHeader& rtp_header);
 
- protected:
-  virtual ~AudioDecoder();
-
  private:
-  friend class base::RefCountedThreadSafe<AudioDecoder>;
-
+  // The webrtc AudioCodingModule is threadsafe.
   scoped_ptr<webrtc::AudioCodingModule> audio_decoder_;
-  bool have_received_packets_;
+  // TODO(pwestin): Refactor to avoid this. Call IncomingParsedRtpPacket from
+  // audio decoder thread that way this class does not have to be thread safe.
+  base::subtle::Atomic32 have_received_packets_;

[Alpha Left Google, 2013/11/18 22:01:14]

Is there a difference in terms of performance using lock or atomicops? I would
prefer using locks to atomicops.

[pwestin, 2013/11/22 19:16:29]

I doubt there is a measurable difference for this use case.
Changed to Lock 

 
   DISALLOW_COPY_AND_ASSIGN(AudioDecoder);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_AUDIO_RECEIVER_AUDIO_DECODER_H_