Potential race-condition resolution in CongestionController::min_bitrate_bps_

webrtc/modules/congestion_controller/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.
  */
 
@@ skipping 153 matching lines @@
       packet_router_(packet_router),
       pacer_(std::move(pacer)),
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       probe_controller_(new ProbeController(pacer_.get(), clock_)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_bitrate_estimator_(remote_bitrate_observer, clock_),
       remote_estimator_proxy_(clock_, packet_router_),
       transport_feedback_adapter_(clock_),
-      min_bitrate_bps_(congestion_controller::GetMinBitrateBps()),
-      max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp),
+      min_bitrate_bps_(congestion_controller::GetMinBitrateBps()),
       delay_based_bwe_(new DelayBasedBwe(event_log_, clock_)) {
   delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   worker_thread_checker_.DetachFromThread();
 }
 
 CongestionController::~CongestionController() {}
 
 void CongestionController::OnReceivedPacket(int64_t arrival_time_ms,
                                             size_t payload_size,
                                             const RTPHeader& header) {
@@ skipping 11 matching lines @@
 void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                           int start_bitrate_bps,
                                           int max_bitrate_bps) {
   ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   bitrate_controller_->SetBitrates(start_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
 
   probe_controller_->SetBitrates(min_bitrate_bps, start_bitrate_bps,
                                  max_bitrate_bps);
-  max_bitrate_bps_ = max_bitrate_bps;
 
   remote_bitrate_estimator_.SetMinBitrate(min_bitrate_bps);
-  min_bitrate_bps_ = min_bitrate_bps;
   {
     rtc::CritScope cs(&bwe_lock_);
     if (start_bitrate_bps > 0)
       delay_based_bwe_->SetStartBitrate(start_bitrate_bps);
+    min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   }
   MaybeTriggerOnNetworkChanged();
 }
 
 // TODO(holmer): Split this up and use SetBweBitrates in combination with
 // OnNetworkRouteChanged.
 void CongestionController::OnNetworkRouteChanged(
     const rtc::NetworkRoute& network_route,
     int bitrate_bps,
     int min_bitrate_bps,
     int max_bitrate_bps) {
   ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   // TODO(honghaiz): Recreate this object once the bitrate controller is
   // no longer exposed outside CongestionController.
   bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
                                      max_bitrate_bps);
-  min_bitrate_bps_ = min_bitrate_bps;
-  max_bitrate_bps_ = max_bitrate_bps;
   // TODO(honghaiz): Recreate this object once the remote bitrate estimator is
   // no longer exposed outside CongestionController.
   remote_bitrate_estimator_.SetMinBitrate(min_bitrate_bps);
 
   transport_feedback_adapter_.SetNetworkIds(network_route.local_network_id,
                                             network_route.remote_network_id);
   {
     rtc::CritScope cs(&bwe_lock_);
+    min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_.reset(new DelayBasedBwe(event_log_, clock_));
     delay_based_bwe_->SetStartBitrate(bitrate_bps);
-    delay_based_bwe_->SetMinBitrate(min_bitrate_bps);
+    delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   }
 
   probe_controller_->Reset();
   probe_controller_->SetBitrates(min_bitrate_bps, bitrate_bps, max_bitrate_bps);
 
   MaybeTriggerOnNetworkChanged();
 }
 
 BitrateController* CongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
@@ skipping 156 matching lines @@
 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&network_state_lock_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc