Simplify CongestionController.

webrtc/call/congestion_controller.cc

Index: webrtc/call/congestion_controller.cc
diff --git a/webrtc/call/congestion_controller.cc b/webrtc/call/congestion_controller.cc
index 59713d30576cec2b98ed55752e6e457b0d92f2d9..aa279a8e428fdede14378a075323375b51a4012c 100644
--- a/webrtc/call/congestion_controller.cc
+++ b/webrtc/call/congestion_controller.cc
@@ -27,7 +27,6 @@
 #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 {
@@ -140,8 +139,6 @@ class WrappingBitrateEstimator : public RemoteBitrateEstimator {
 
 CongestionController::CongestionController(
     Clock* clock,
-    ProcessThread* process_thread,
-    CallStats* call_stats,
     BitrateObserver* bitrate_observer,
     RemoteBitrateObserver* remote_bitrate_observer)
     : clock_(clock),
@@ -156,39 +153,28 @@ CongestionController::CongestionController(
           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.
@@ -202,12 +188,14 @@ void CongestionController::SetBweBitrates(int min_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 {
@@ -216,7 +204,6 @@ BitrateController* CongestionController::GetBitrateController() const {
 
 RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
     bool send_side_bwe) const {
-
   if (send_side_bwe)
     return remote_estimator_proxy_.get();
   else
@@ -225,15 +212,16 @@ RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
 
 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();
 }
@@ -257,9 +245,42 @@ void CongestionController::SignalNetworkState(NetworkState state) {
 }
 
 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