Lock scheme #8: Introduced the new locking scheme

webrtc/modules/audio_processing/level_estimator_impl.cc

 /*
  *  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.
  */
 
 #include "webrtc/modules/audio_processing/level_estimator_impl.h"
 
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/audio_processing/rms_level.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 
 namespace webrtc {
 
-LevelEstimatorImpl::LevelEstimatorImpl(const AudioProcessing* apm,
-                                       CriticalSectionWrapper* crit)
-    : ProcessingComponent(),
-      crit_(crit) {}
+LevelEstimatorImpl::LevelEstimatorImpl(const AudioProcessing* apm)
+    : ProcessingComponent() {}
 
 LevelEstimatorImpl::~LevelEstimatorImpl() {}
 
 int LevelEstimatorImpl::ProcessStream(AudioBuffer* audio) {
+  // Only called from within APM so no locking needed.
   if (!is_component_enabled()) {
     return AudioProcessing::kNoError;
   }
 
   RMSLevel* rms_level = static_cast<RMSLevel*>(handle(0));
   for (int i = 0; i < audio->num_channels(); ++i) {
     rms_level->Process(audio->channels_const()[i],
                        audio->num_frames());
   }
 
   return AudioProcessing::kNoError;
 }
 
 int LevelEstimatorImpl::Enable(bool enable) {
-  CriticalSectionScoped crit_scoped(crit_);
   return EnableComponent(enable);
 }
 
 bool LevelEstimatorImpl::is_enabled() const {
+  // Only called from within APM so no locking needed.
   return is_component_enabled();
 }
 
 int LevelEstimatorImpl::RMS() {
+  // Only called from within APM so no locking needed.
   if (!is_component_enabled()) {
     return AudioProcessing::kNotEnabledError;
   }
 
   RMSLevel* rms_level = static_cast<RMSLevel*>(handle(0));
   return rms_level->RMS();
 }
 
 // The ProcessingComponent implementation is pretty weird in this class since
 // we have only a single instance of the trivial underlying component.
@@ skipping 16 matching lines @@
 
 int LevelEstimatorImpl::num_handles_required() const {
   return 1;
 }
 
 int LevelEstimatorImpl::GetHandleError(void* /*handle*/) const {
   return AudioProcessing::kUnspecifiedError;
 }
 
 }  // namespace webrtc