Lock scheme #8: Introduced the new locking scheme

webrtc/modules/audio_processing/echo_control_mobile_impl.h

 /*
  *  Copyright (c) 2012 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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CONTROL_MOBILE_IMPL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CONTROL_MOBILE_IMPL_H_
 
+#include "webrtc/base/criticalsection.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/common_audio/swap_queue.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/audio_processing/processing_component.h"
 
 namespace webrtc {
 
 class AudioBuffer;
-class CriticalSectionWrapper;
 
 class EchoControlMobileImpl : public EchoControlMobile,
                               public ProcessingComponent {
  public:
   EchoControlMobileImpl(const AudioProcessing* apm,
-                        CriticalSectionWrapper* crit);
+                        rtc::CriticalSection* crit_render,
+                        rtc::CriticalSection* crit_capture);
+
   virtual ~EchoControlMobileImpl();
 
   int ProcessRenderAudio(const AudioBuffer* audio);
   int ProcessCaptureAudio(AudioBuffer* audio);
 
   // EchoControlMobile implementation.
   bool is_enabled() const override;
   RoutingMode routing_mode() const override;
   bool is_comfort_noise_enabled() const override;
 
   // ProcessingComponent implementation.
   int Initialize() override;
 
   // Reads render side data that has been queued on the render call.
   void ReadQueuedRenderData();
 
  private:
   // EchoControlMobile implementation.
   int Enable(bool enable) override;
   int set_routing_mode(RoutingMode mode) override;
   int enable_comfort_noise(bool enable) override;
   int SetEchoPath(const void* echo_path, size_t size_bytes) override;
   int GetEchoPath(void* echo_path, size_t size_bytes) const override;
 
   // ProcessingComponent implementation.
+  // Called holding both the render and capture locks.
   void* CreateHandle() const override;
   int InitializeHandle(void* handle) const override;
   int ConfigureHandle(void* handle) const override;
   void DestroyHandle(void* handle) const override;
   int num_handles_required() const override;
   int GetHandleError(void* handle) const override;
 
   void AllocateRenderQueue();
 
+  // Not guarded as its public API is thread safe.
   const AudioProcessing* apm_;
-  CriticalSectionWrapper* crit_;
-  RoutingMode routing_mode_;
-  bool comfort_noise_enabled_;
-  unsigned char* external_echo_path_;
 
-  size_t render_queue_element_max_size_;
-  std::vector<int16_t> render_queue_buffer_;
-  std::vector<int16_t> capture_queue_buffer_;
+  rtc::CriticalSection* const crit_render_ ACQUIRED_BEFORE(crit_capture_);
+  rtc::CriticalSection* const crit_capture_;
+
+  RoutingMode routing_mode_ GUARDED_BY(crit_capture_);
+  bool comfort_noise_enabled_ GUARDED_BY(crit_capture_);
+  unsigned char* external_echo_path_ GUARDED_BY(crit_render_)
+      GUARDED_BY(crit_capture_);
+
+  size_t render_queue_element_max_size_ GUARDED_BY(crit_render_)
+      GUARDED_BY(crit_capture_);
+
+  std::vector<int16_t> render_queue_buffer_ GUARDED_BY(crit_render_);
+  std::vector<int16_t> capture_queue_buffer_ GUARDED_BY(crit_capture_);
+
+  // Lock protection not needed.
   rtc::scoped_ptr<
       SwapQueue<std::vector<int16_t>, RenderQueueItemVerifier<int16_t>>>
       render_signal_queue_;
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CONTROL_MOBILE_IMPL_H_