Simplify CongestionController.

webrtc/call/congestion_controller.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/call/congestion_controller.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/socket.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
 #include "webrtc/modules/pacing/paced_sender.h"
 #include "webrtc/modules/pacing/packet_router.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/send_time_history.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy.h"
 #include "webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h"
 #include "webrtc/modules/utility/include/process_thread.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
-#include "webrtc/video/call_stats.h"
 #include "webrtc/video/payload_router.h"
 
 namespace webrtc {
 namespace {
 
 static const uint32_t kTimeOffsetSwitchThreshold = 30;
 
 class WrappingBitrateEstimator : public RemoteBitrateEstimator {
  public:
   WrappingBitrateEstimator(RemoteBitrateObserver* observer, Clock* clock)
@@ skipping 92 matching lines @@
   uint32_t packets_since_absolute_send_time_;
   int min_bitrate_bps_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(WrappingBitrateEstimator);
 };
 
 }  // namespace
 
 CongestionController::CongestionController(
     Clock* clock,
-    ProcessThread* process_thread,
-    CallStats* call_stats,
     BitrateObserver* bitrate_observer,
     RemoteBitrateObserver* remote_bitrate_observer)
     : clock_(clock),
       packet_router_(new PacketRouter()),
       pacer_(new PacedSender(clock_,
                              packet_router_.get(),
                              BitrateController::kDefaultStartBitrateKbps,
                              PacedSender::kDefaultPaceMultiplier *
                                  BitrateController::kDefaultStartBitrateKbps,
                              0)),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
       remote_estimator_proxy_(
           new RemoteEstimatorProxy(clock_, packet_router_.get())),
-      process_thread_(process_thread),
-      call_stats_(call_stats),
       pacer_thread_(ProcessThread::Create("PacerThread")),
       // Constructed last as this object calls the provided callback on
       // construction.
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, bitrate_observer)),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {
-  call_stats_->RegisterStatsObserver(remote_bitrate_estimator_.get());
-
   pacer_thread_->RegisterModule(pacer_.get());
   pacer_thread_->RegisterModule(remote_estimator_proxy_.get());
   pacer_thread_->Start();
-
-  process_thread_->RegisterModule(remote_bitrate_estimator_.get());
-  process_thread_->RegisterModule(bitrate_controller_.get());
 }
 
 CongestionController::~CongestionController() {
   pacer_thread_->Stop();
   pacer_thread_->DeRegisterModule(pacer_.get());
   pacer_thread_->DeRegisterModule(remote_estimator_proxy_.get());
-  process_thread_->DeRegisterModule(bitrate_controller_.get());
-  process_thread_->DeRegisterModule(remote_bitrate_estimator_.get());
-  call_stats_->DeregisterStatsObserver(remote_bitrate_estimator_.get());
-  if (transport_feedback_adapter_.get())
-    call_stats_->DeregisterStatsObserver(transport_feedback_adapter_.get());
 }
 
 
 void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                           int start_bitrate_bps,
                                           int max_bitrate_bps) {
+  RTC_DCHECK(config_thread_checker_.CalledOnValidThread());
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
   const int kMinBitrateBps = 10000;
   if (min_bitrate_bps < kMinBitrateBps)
     min_bitrate_bps = kMinBitrateBps;
   if (max_bitrate_bps > 0)
     max_bitrate_bps = std::max(min_bitrate_bps, max_bitrate_bps);
   if (start_bitrate_bps > 0) {
     start_bitrate_bps = std::max(min_bitrate_bps, start_bitrate_bps);
     bitrate_controller_->SetStartBitrate(start_bitrate_bps);
   }
   bitrate_controller_->SetMinMaxBitrate(min_bitrate_bps, max_bitrate_bps);
-  if (remote_bitrate_estimator_.get())
+  if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
-  if (transport_feedback_adapter_.get())
+  min_bitrate_bps_ = min_bitrate_bps;
+
+  rtc::CritScope lock(&crit_);
+  if (transport_feedback_adapter_)
     transport_feedback_adapter_->GetBitrateEstimator()->SetMinBitrate(
         min_bitrate_bps);
-  min_bitrate_bps_ = min_bitrate_bps;
 }
 
 BitrateController* CongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
 }
 
 RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
     bool send_side_bwe) const {
-
   if (send_side_bwe)
     return remote_estimator_proxy_.get();
   else
     return remote_bitrate_estimator_.get();
 }
 
 TransportFeedbackObserver*

[the sun, 2016/02/17 12:47:26]

So, you may return a pointer to the TFA on one thread here, while the CC dtor
just started executing on a different thread.

Can you instead always set up the TFA in the ctor? Does it matter a lot that the
object is unused by receive streams? Then you could get rid of the lock.

[stefan-webrtc, 2016/02/17 13:32:48]

Yes, it turned out to be fairly easy to make that change.

Done.

 CongestionController::GetTransportFeedbackObserver() {
+  RTC_DCHECK(config_thread_checker_.CalledOnValidThread());
+  rtc::CritScope lock(&crit_);
   if (transport_feedback_adapter_.get() == nullptr) {

[pbos-webrtc, 2016/02/17 12:17:12]

!transport_feedback_adapter_

[stefan-webrtc, 2016/02/17 13:32:48]

Done.

-    transport_feedback_adapter_.reset(new TransportFeedbackAdapter(
-        bitrate_controller_.get(), clock_, process_thread_));
+    transport_feedback_adapter_.reset(
+        new TransportFeedbackAdapter(bitrate_controller_.get(), clock_));
     transport_feedback_adapter_->SetBitrateEstimator(
         new RemoteBitrateEstimatorAbsSendTime(transport_feedback_adapter_.get(),
                                               clock_));
     transport_feedback_adapter_->GetBitrateEstimator()->SetMinBitrate(
         min_bitrate_bps_);
-    call_stats_->RegisterStatsObserver(transport_feedback_adapter_.get());
   }
   return transport_feedback_adapter_.get();
 }
 
 void CongestionController::UpdatePacerBitrate(int bitrate_kbps,
                                               int max_bitrate_kbps,
                                               int min_bitrate_kbps) {
   pacer_->UpdateBitrate(bitrate_kbps, max_bitrate_kbps, min_bitrate_kbps);
 }
 
 int64_t CongestionController::GetPacerQueuingDelayMs() const {
   return pacer_->QueueInMs();
 }
 
 void CongestionController::SignalNetworkState(NetworkState state) {
   if (state == kNetworkUp) {
     pacer_->Resume();
   } else {
     pacer_->Pause();
   }
 }
 
 void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
+  rtc::CritScope lock(&crit_);
   if (transport_feedback_adapter_) {
     transport_feedback_adapter_->OnSentPacket(sent_packet.packet_id,
                                               sent_packet.send_time_ms);
   }
 }
+
+void CongestionController::OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) {
+  remote_bitrate_estimator_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
+
+  rtc::CritScope lock(&crit_);
+  if (transport_feedback_adapter_)
+    transport_feedback_adapter_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
+}
+
+int64_t CongestionController::TimeUntilNextProcess() {
+  int64_t time_until_process =
+      std::min(bitrate_controller_->TimeUntilNextProcess(),
+               remote_bitrate_estimator_->TimeUntilNextProcess());
+  rtc::CritScope lock(&crit_);
+  if (transport_feedback_adapter_) {
+    time_until_process =
+        std::min(transport_feedback_adapter_->GetBitrateEstimator()
+                     ->TimeUntilNextProcess(),
+                 time_until_process);
+  }
+  return time_until_process;
+}
+
+int32_t CongestionController::Process() {
+  bitrate_controller_->Process();
+  remote_bitrate_estimator_->Process();
+  rtc::CritScope lock(&crit_);
+  if (transport_feedback_adapter_)
+    transport_feedback_adapter_->GetBitrateEstimator()->Process();
+  return 0;
+}
+
 }  // namespace webrtc