CongestionController::SetBweBitrates may now trigger probing.

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 @@
       pacer_(new PacedSender(clock_, packet_router_.get())),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
+      max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp) {
   Init();
 }
 
 CongestionController::CongestionController(
     Clock* clock,
     Observer* observer,
     RemoteBitrateObserver* remote_bitrate_observer,
     RtcEventLog* event_log,
     std::unique_ptr<PacketRouter> packet_router,
     std::unique_ptr<PacedSender> pacer)
     : clock_(clock),
       observer_(observer),
       packet_router_(std::move(packet_router)),
       pacer_(std::move(pacer)),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
       // Constructed last as this object calls the provided callback on
       // construction.
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
+      max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp) {
   Init();
 }
 
 CongestionController::~CongestionController() {}
 
 void CongestionController::Init() {
   transport_feedback_adapter_.SetBitrateEstimator(
       new DelayBasedBwe(&transport_feedback_adapter_, clock_));
   transport_feedback_adapter_.GetBitrateEstimator()->SetMinBitrate(
       min_bitrate_bps_);
 }
 
 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);
 
+  {
+    rtc::CritScope cs(&critsect_);
+    if (last_reported_bitrate_bps_ != 0 &&

[stefan-webrtc, 2016/08/16 11:48:39]

Add comment to explain why we don't do this if no bitrate has been reported and
why the max bitrate must have been increased.

[philipel, 2016/08/16 13:04:31]

Done.

+        last_reported_bitrate_bps_ < static_cast<uint32_t>(max_bitrate_bps) &&
+        max_bitrate_bps_ < max_bitrate_bps) {

[stefan-webrtc, 2016/08/16 11:48:39]

I think it's easier to read if we do max_bitrate_bps > max_bitrate_bps_, but
maybe I'm just odd. :)

[philipel, 2016/08/16 13:04:31]

Done.

+      pacer_->ProbeAtBitrate(max_bitrate_bps, 5);
+    }
+  }
+  max_bitrate_bps_ = max_bitrate_bps;
+
   if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
   transport_feedback_adapter_.GetBitrateEstimator()->SetMinBitrate(
       min_bitrate_bps_);
   MaybeTriggerOnNetworkChanged();
 }
 
 void CongestionController::ResetBweAndBitrates(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.
   if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
 
   RemoteBitrateEstimator* rbe = new DelayBasedBwe(
       &transport_feedback_adapter_, clock_);
   transport_feedback_adapter_.SetBitrateEstimator(rbe);
   rbe->SetMinBitrate(min_bitrate_bps);
   // TODO(holmer): Trigger a new probe once mid-call probing is implemented.
@@ skipping 113 matching lines @@
 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&critsect_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc