Add ability to control TaskQueuePacedSender holdback window.
Holdback window can be specified as absolute time and in terms of packet
send times. Example:
WebRTC-TaskQueuePacer/Enabled,holdback_window:20ms,holdback_packet:3/
If current conditions have us running with 2000kbps pacing rate and
1250byte (10kbit) packets, each packet send time is 5ms.
The holdback window would then be min(20ms, 3*5ms) = 15ms.
The default is like before 1ms and packets no take into account when
TQ pacer is used, parameters have no effect with legacy process thread
pacer.
Bug: webrtc:10809
Change-Id: I800de05107e2d4df461eabaaf1ca04fb4c5de51e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/233421
Commit-Queue: Erik Språng <sprang@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35266}
diff --git a/call/rtp_transport_controller_send.cc b/call/rtp_transport_controller_send.cc
index 9d27b33..8825df2 100644
--- a/call/rtp_transport_controller_send.cc
+++ b/call/rtp_transport_controller_send.cc
@@ -75,6 +75,15 @@
} // namespace
+RtpTransportControllerSend::PacerSettings::PacerSettings(
+ const WebRtcKeyValueConfig* trials)
+ : tq_disabled("Disabled"),
+ holdback_window("holdback_window", PacingController::kMinSleepTime),
+ holdback_packets("holdback_packets", -1) {
+ ParseFieldTrial({&tq_disabled, &holdback_window, &holdback_packets},
+ trials->Lookup("WebRTC-TaskQueuePacer"));
+}
+
RtpTransportControllerSend::RtpTransportControllerSend(
Clock* clock,
webrtc::RtcEventLog* event_log,
@@ -89,8 +98,8 @@
bitrate_configurator_(bitrate_config),
pacer_started_(false),
process_thread_(std::move(process_thread)),
- use_task_queue_pacer_(!IsDisabled(trials, "WebRTC-TaskQueuePacer")),
- process_thread_pacer_(use_task_queue_pacer_
+ pacer_settings_(trials),
+ process_thread_pacer_(pacer_settings_.use_task_queue_pacer()
? nullptr
: new PacedSender(clock,
&packet_router_,
@@ -98,14 +107,14 @@
trials,
process_thread_.get())),
task_queue_pacer_(
- use_task_queue_pacer_
- ? new TaskQueuePacedSender(
- clock,
- &packet_router_,
- event_log,
- trials,
- task_queue_factory,
- /*hold_back_window = */ PacingController::kMinSleepTime)
+ pacer_settings_.use_task_queue_pacer()
+ ? new TaskQueuePacedSender(clock,
+ &packet_router_,
+ event_log,
+ trials,
+ task_queue_factory,
+ pacer_settings_.holdback_window.Get(),
+ pacer_settings_.holdback_packets.Get())
: nullptr),
observer_(nullptr),
controller_factory_override_(controller_factory),
@@ -194,14 +203,14 @@
}
RtpPacketPacer* RtpTransportControllerSend::pacer() {
- if (use_task_queue_pacer_) {
+ if (pacer_settings_.use_task_queue_pacer()) {
return task_queue_pacer_.get();
}
return process_thread_pacer_.get();
}
const RtpPacketPacer* RtpTransportControllerSend::pacer() const {
- if (use_task_queue_pacer_) {
+ if (pacer_settings_.use_task_queue_pacer()) {
return task_queue_pacer_.get();
}
return process_thread_pacer_.get();
@@ -226,7 +235,7 @@
}
RtpPacketSender* RtpTransportControllerSend::packet_sender() {
- if (use_task_queue_pacer_) {
+ if (pacer_settings_.use_task_queue_pacer()) {
return task_queue_pacer_.get();
}
return process_thread_pacer_.get();
@@ -503,7 +512,7 @@
void RtpTransportControllerSend::EnsureStarted() {
if (!pacer_started_) {
pacer_started_ = true;
- if (use_task_queue_pacer_) {
+ if (pacer_settings_.use_task_queue_pacer()) {
task_queue_pacer_->EnsureStarted();
} else {
process_thread_->Start();
diff --git a/call/rtp_transport_controller_send.h b/call/rtp_transport_controller_send.h
index f1b90c7..ac4213d 100644
--- a/call/rtp_transport_controller_send.h
+++ b/call/rtp_transport_controller_send.h
@@ -128,6 +128,16 @@
void OnRemoteNetworkEstimate(NetworkStateEstimate estimate) override;
private:
+ struct PacerSettings {
+ explicit PacerSettings(const WebRtcKeyValueConfig* trials);
+
+ bool use_task_queue_pacer() const { return !tq_disabled.Get(); }
+
+ FieldTrialFlag tq_disabled; // Kill-switch not normally used.
+ FieldTrialParameter<TimeDelta> holdback_window;
+ FieldTrialParameter<int> holdback_packets;
+ };
+
void MaybeCreateControllers() RTC_RUN_ON(task_queue_);
void UpdateInitialConstraints(TargetRateConstraints new_contraints)
RTC_RUN_ON(task_queue_);
@@ -158,7 +168,7 @@
std::map<std::string, rtc::NetworkRoute> network_routes_;
bool pacer_started_;
const std::unique_ptr<ProcessThread> process_thread_;
- const bool use_task_queue_pacer_;
+ const PacerSettings pacer_settings_;
std::unique_ptr<PacedSender> process_thread_pacer_;
std::unique_ptr<TaskQueuePacedSender> task_queue_pacer_;
