Lock scheme #8: Introduced the new locking scheme

webrtc/modules/audio_processing/echo_control_mobile_impl.h

Index: webrtc/modules/audio_processing/echo_control_mobile_impl.h
diff --git a/webrtc/modules/audio_processing/echo_control_mobile_impl.h b/webrtc/modules/audio_processing/echo_control_mobile_impl.h
index 8bfa1d73d11c5ba2ec4cc6d64f465a8ae8c18a7d..3b5dbf3be144b7dd13bc22fd39fe377954322e20 100644
--- a/webrtc/modules/audio_processing/echo_control_mobile_impl.h
+++ b/webrtc/modules/audio_processing/echo_control_mobile_impl.h
@@ -11,6 +11,7 @@
 #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"
@@ -19,13 +20,14 @@
 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);
@@ -51,6 +53,7 @@ class EchoControlMobileImpl : public EchoControlMobile,
   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;
@@ -60,15 +63,24 @@ class EchoControlMobileImpl : public EchoControlMobile,
 
   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_;