Preparational work for an upcoming addition of a threadchecking scheme for APM

webrtc/modules/audio_processing/echo_cancellation_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.
  */
 
@@ skipping 44 matching lines @@
 }
 
 // Maximum length that a frame of samples can have.
 static const size_t kMaxAllowedValuesOfSamplesPerFrame = 160;
 // Maximum number of frames to buffer in the render queue.
 // TODO(peah): Decrease this once we properly handle hugely unbalanced
 // reverse and forward call numbers.
 static const size_t kMaxNumFramesToBuffer = 100;
 }  // namespace
 
-EchoCancellationImpl::EchoCancellationImpl(const AudioProcessing* apm,
-                                           CriticalSectionWrapper* crit)
+EchoCancellationImpl::EchoCancellationImpl(
+    const AudioProcessing* apm,
+    CriticalSectionWrapper* crit,
+    const rtc::ThreadChecker* render_thread_checker)
     : ProcessingComponent(),
       apm_(apm),
       crit_(crit),
+      render_thread_checker_(render_thread_checker),
       drift_compensation_enabled_(false),
       metrics_enabled_(false),
       suppression_level_(kModerateSuppression),
       stream_drift_samples_(0),
       was_stream_drift_set_(false),
       stream_has_echo_(false),
       delay_logging_enabled_(false),
       extended_filter_enabled_(false),
       delay_agnostic_enabled_(false),
       render_queue_element_max_size_(0) {}
 
 EchoCancellationImpl::~EchoCancellationImpl() {}
 
 int EchoCancellationImpl::ProcessRenderAudio(const AudioBuffer* audio) {
+  RTC_DCHECK(render_thread_checker_->CalledOnValidThread());
   if (!is_component_enabled()) {
     return apm_->kNoError;
   }
 
   assert(audio->num_frames_per_band() <= 160);
   assert(audio->num_channels() == apm_->num_reverse_channels());
 
   int err = apm_->kNoError;
 
   // The ordering convention must be followed to pass to the correct AEC.
@@ skipping 50 matching lines @@
         WebRtcAec_BufferFarend(my_handle, &capture_queue_buffer_[buffer_index],
                                num_frames_per_band);
 
         buffer_index += num_frames_per_band;
         handle_index++;
       }
     }
   }
 }
 
 int EchoCancellationImpl::ProcessCaptureAudio(AudioBuffer* audio) {

[the sun, 2015/11/23 12:46:21]

Why no check on the capture_thread_checker here, like you do in gain control?

[peah-webrtc, 2015/11/23 13:49:40]

You are definitely correct in that. The history behind it is that with the
initial thread-checker scheme, it was not possible. But due to the changes done
in response to the very good feedback on that scheme, it would now be possible.

As the access to these submodules will at some point in the not-so-far future be
redirected via the APM API, it was, together with the the reviewer, decided not
to add the threadcheckers in the submodules in the scope of this work.

   if (!is_component_enabled()) {
     return apm_->kNoError;
   }
 
   if (!apm_->was_stream_delay_set()) {
     return apm_->kStreamParameterNotSetError;
   }
 
   if (drift_compensation_enabled_ && !was_stream_drift_set_) {
     return apm_->kStreamParameterNotSetError;
@@ skipping 269 matching lines @@
                        48000);
 }
 
 int EchoCancellationImpl::ConfigureHandle(void* handle) const {
   assert(handle != NULL);
   AecConfig config;
   config.metricsMode = metrics_enabled_;
   config.nlpMode = MapSetting(suppression_level_);
   config.skewMode = drift_compensation_enabled_;
   config.delay_logging = delay_logging_enabled_;
-
   WebRtcAec_enable_extended_filter(
       WebRtcAec_aec_core(static_cast<Handle*>(handle)),
       extended_filter_enabled_ ? 1 : 0);
   WebRtcAec_enable_delay_agnostic(
       WebRtcAec_aec_core(static_cast<Handle*>(handle)),
       delay_agnostic_enabled_ ? 1 : 0);
   return WebRtcAec_set_config(static_cast<Handle*>(handle), config);
 }
 
 int EchoCancellationImpl::num_handles_required() const {
   return apm_->num_output_channels() *
          apm_->num_reverse_channels();
 }
 
 int EchoCancellationImpl::GetHandleError(void* handle) const {
   assert(handle != NULL);
   return AudioProcessing::kUnspecifiedError;
 }
 }  // namespace webrtc