Lock scheme #8: Introduced the new locking scheme

webrtc/modules/audio_processing/echo_cancellation_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_CANCELLATION_IMPL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CANCELLATION_IMPL_H_
 
 #include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread_annotations.h"

[hlundin-webrtc, 2015/11/05 16:11:22]

You're not using any of this, right?

[peah-webrtc, 2015/11/06 09:54:32]

Done.

 #include "webrtc/base/thread_checker.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 {
 
 namespace {
 // Functor to use when supplying a verifier function for the queue item
 // verifcation.
 class AecRenderQueueItemVerifier {
  public:
   explicit AecRenderQueueItemVerifier(size_t minimum_capacity)
       : minimum_capacity_(minimum_capacity) {}
 
   bool operator()(const std::vector<float>& v) const {
     return v.capacity() >= minimum_capacity_;
   }
 
  private:
   size_t minimum_capacity_;
 };
 
 }  // namespace anonymous
 
 class AudioBuffer;
-class CriticalSectionWrapper;
 
 class EchoCancellationImpl : public EchoCancellation,
                              public ProcessingComponent {
  public:
+  // Called holding both the capture and render locks.
   EchoCancellationImpl(const AudioProcessing* apm,
-                       CriticalSectionWrapper* crit,
+                       rtc::CriticalSection* crit_render,
+                       rtc::CriticalSection* crit_capture,
                        rtc::ThreadChecker* render_thread_checker);
+
   virtual ~EchoCancellationImpl();
 
-  int ProcessRenderAudio(const AudioBuffer* audio);
-  int ProcessCaptureAudio(AudioBuffer* audio);
+  int ProcessRenderAudio(
+      const AudioBuffer* audio);  // Called holding the render lock.

[hlundin-webrtc, 2015/11/05 16:11:22]

+1 for adding the comments.
-1 for the ugly line breaks. Please, add the comments to the line above each
method and restore the original format. Here and in all places below.

[peah-webrtc, 2015/11/06 09:54:32]

Sorry!!!
Done.

+  int ProcessCaptureAudio(
+      AudioBuffer* audio);  // Called holding the capture lock.
 
   // EchoCancellation implementation.
-  bool is_enabled() const override;
-  int stream_drift_samples() const override;
-  SuppressionLevel suppression_level() const override;
-  bool is_drift_compensation_enabled() const override;
+  bool is_enabled()
+      const override;  // Aquires both the render and capture locks.
+  int stream_drift_samples() const override;  // Aquires the capture lock.
+  SuppressionLevel suppression_level()
+      const override;  // Aquires the capture lock.
+  bool is_drift_compensation_enabled()
+      const override;  // Aquires the capture lock.
 
   // ProcessingComponent implementation.
-  int Initialize() override;
-  void SetExtraOptions(const Config& config) override;
+  int Initialize()
+      override;  // Called holding both the capture and render locks.
+  void SetExtraOptions(const Config& config)
+      override;  // Conditionally acquires the capture lock.
 
-  bool is_delay_agnostic_enabled() const;
-  bool is_extended_filter_enabled() const;
+  bool is_delay_agnostic_enabled()
+      const;  // Only called from APM. No lock required.
+  bool is_extended_filter_enabled()
+      const;  // Only called from APM. No lock required.
 
   // Reads render side data that has been queued on the render call.
-  void ReadQueuedRenderData();
+  void ReadQueuedRenderData();  // Called holding the capture lock.
 
  private:
   static const size_t kAllowedValuesOfSamplesPerFrame1 = 80;
   static const size_t kAllowedValuesOfSamplesPerFrame2 = 160;
   // TODO(peah): Decrease this once we properly handle hugely unbalanced
   // reverse and forward call numbers.
   static const size_t kMaxNumFramesToBuffer = 100;
 
   // EchoCancellation implementation.
-  int Enable(bool enable) override;
-  int enable_drift_compensation(bool enable) override;
-  void set_stream_drift_samples(int drift) override;
-  int set_suppression_level(SuppressionLevel level) override;
-  int enable_metrics(bool enable) override;
-  bool are_metrics_enabled() const override;
-  bool stream_has_echo() const override;
-  int GetMetrics(Metrics* metrics) override;
-  int enable_delay_logging(bool enable) override;
-  bool is_delay_logging_enabled() const override;
-  int GetDelayMetrics(int* median, int* std) override;
+  int Enable(
+      bool enable) override;  // Aquires both the render and capture locks.
+  int enable_drift_compensation(
+      bool enable) override;  // Aquires the capture lock.
+  void set_stream_drift_samples(
+      int drift) override;  // Aquires the capture lock.
+  int set_suppression_level(
+      SuppressionLevel level) override;       // Aquires the capture lock.
+  int enable_metrics(bool enable) override;   // Aquires the capture lock.
+  bool are_metrics_enabled() const override;  // Aquires the capture lock.
+  bool stream_has_echo()
+      const override;  // Conditionally acquires the capture lock.
+  int GetMetrics(Metrics* metrics) override;       // Aquires the capture lock.
+  int enable_delay_logging(bool enable) override;  // Aquires the capture lock.
+  bool is_delay_logging_enabled()
+      const override;  // Only called from APM. No lock required.
   int GetDelayMetrics(int* median,
-                      int* std,
-                      float* fraction_poor_delays) override;
-  struct AecCore* aec_core() const override;
+                      int* std) override;  // Aquires the capture lock.
+  int GetDelayMetrics(
+      int* median,
+      int* std,
+      float* fraction_poor_delays) override;  // Aquires the capture lock.
+  struct AecCore* aec_core()
+      const override;  // Only called from APM. No lock required.
 
   // ProcessingComponent implementation.
-  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* CreateHandle()
+      const override;  // Called holding both the render and capture locks.
+  int InitializeHandle(void* handle)
+      const override;  // Called holding both the render and capture locks.
+  int ConfigureHandle(void* handle)
+      const override;  // Called holding both the render and capture locks.
+  void DestroyHandle(void* handle)
+      const override;  // Called holding both the render and capture locks.
+  int num_handles_required()
+      const override;  // Called holding both the render and capture locks.
+  int GetHandleError(void* handle)
+      const override;  // Called holding both the render and capture locks.
 
-  void AllocateRenderQueue();
+  void
+  AllocateRenderQueue();  // Called holding both the render and capture locks.
 
   const AudioProcessing* apm_;
-  CriticalSectionWrapper* crit_;
+  rtc::CriticalSection* const crit_render_;
+  rtc::CriticalSection* const crit_capture_;
   const rtc::ThreadChecker* const render_thread_checker_;
 
   bool drift_compensation_enabled_;
   bool metrics_enabled_;
   SuppressionLevel suppression_level_;
   int stream_drift_samples_;
   bool was_stream_drift_set_;
   bool stream_has_echo_;
   bool delay_logging_enabled_;
   bool extended_filter_enabled_;
   bool delay_agnostic_enabled_;
 
   size_t render_queue_element_max_size_;
   std::vector<float> render_queue_buffer_;
   std::vector<float> capture_queue_buffer_;
-  rtc::scoped_ptr<SwapQueue<std::vector<float>, AecRenderQueueItemVerifier>>
-      render_signal_queue_;
+  rtc::scoped_ptr<SwapQueue<std::vector<float>, AecRenderQueueItemVerifier> >
+      render_signal_queue_;  // Lock protection not needed.
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_ECHO_CANCELLATION_IMPL_H_