Move CheckBandwidthGrowth in QUIC from Bbr2Startup to Bbr2NetworkModel. No functional change.
PiperOrigin-RevId: 347472199
Change-Id: I3737c5bce0d42f084b4297b92d5af3fa342c26e1
diff --git a/quic/core/congestion_control/bbr2_misc.cc b/quic/core/congestion_control/bbr2_misc.cc
index 700995f..0be3253 100644
--- a/quic/core/congestion_control/bbr2_misc.cc
+++ b/quic/core/congestion_control/bbr2_misc.cc
@@ -311,4 +311,38 @@
return inflight_hi_ > headroom ? inflight_hi_ - headroom : 0;
}
+bool Bbr2NetworkModel::CheckBandwidthGrowth(
+ const Bbr2CongestionEvent& congestion_event) {
+ DCHECK(!full_bandwidth_reached_);
+ DCHECK(congestion_event.end_of_round_trip);
+ if (congestion_event.last_sample_is_app_limited) {
+ // Return true such that when Params().always_exit_startup_on_excess_loss is
+ // false, we'll not check excess loss, which is the behavior of QUIC BBRv1.
+ return true;
+ }
+
+ QuicBandwidth threshold =
+ full_bandwidth_baseline_ * Params().startup_full_bw_threshold;
+
+ if (MaxBandwidth() >= threshold) {
+ QUIC_DVLOG(3) << " CheckBandwidthGrowth at end of round. max_bandwidth:"
+ << MaxBandwidth() << ", threshold:" << threshold
+ << " (Still growing) @ " << congestion_event.event_time;
+ full_bandwidth_baseline_ = MaxBandwidth();
+ rounds_without_bandwidth_growth_ = 0;
+ return true;
+ }
+
+ ++rounds_without_bandwidth_growth_;
+ full_bandwidth_reached_ =
+ rounds_without_bandwidth_growth_ >= Params().startup_full_bw_rounds;
+ QUIC_DVLOG(3) << " CheckBandwidthGrowth at end of round. max_bandwidth:"
+ << MaxBandwidth() << ", threshold:" << threshold
+ << " rounds_without_growth:" << rounds_without_bandwidth_growth_
+ << " full_bw_reached:" << full_bandwidth_reached_ << " @ "
+ << congestion_event.event_time;
+
+ return false;
+}
+
} // namespace quic
diff --git a/quic/core/congestion_control/bbr2_misc.h b/quic/core/congestion_control/bbr2_misc.h
index f81d3cd..c26d2f9 100644
--- a/quic/core/congestion_control/bbr2_misc.h
+++ b/quic/core/congestion_control/bbr2_misc.h
@@ -409,6 +409,13 @@
bool IsInflightTooHigh(const Bbr2CongestionEvent& congestion_event,
int64_t max_loss_events) const;
+ // Check bandwidth growth in the past round. Must be called at the end of a
+ // round.
+ // Return true if the bandwidth growed as expected.
+ // Return false otherwise, if enough rounds have elapsed without expected
+ // growth, also sets |full_bandwidth_reached_| to true.
+ bool CheckBandwidthGrowth(const Bbr2CongestionEvent& congestion_event);
+
QuicPacketNumber last_sent_packet() const {
return round_trip_counter_.last_sent_packet();
}
@@ -465,6 +472,15 @@
float pacing_gain() const { return pacing_gain_; }
void set_pacing_gain(float pacing_gain) { pacing_gain_ = pacing_gain; }
+ bool full_bandwidth_reached() const { return full_bandwidth_reached_; }
+ void set_full_bandwidth_reached() { full_bandwidth_reached_ = true; }
+ QuicBandwidth full_bandwidth_baseline() const {
+ return full_bandwidth_baseline_;
+ }
+ QuicRoundTripCount rounds_without_bandwidth_growth() const {
+ return rounds_without_bandwidth_growth_;
+ }
+
private:
const Bbr2Params& Params() const { return *params_; }
const Bbr2Params* const params_;
@@ -502,6 +518,11 @@
float cwnd_gain_;
float pacing_gain_;
+
+ // STARTUP-centric fields which experimentally used by PROBE_UP.
+ bool full_bandwidth_reached_ = false;
+ QuicBandwidth full_bandwidth_baseline_ = QuicBandwidth::Zero();
+ QuicRoundTripCount rounds_without_bandwidth_growth_ = 0;
};
enum class Bbr2Mode : uint8_t {
diff --git a/quic/core/congestion_control/bbr2_sender.cc b/quic/core/congestion_control/bbr2_sender.cc
index a71dbdf..c12c4e2 100644
--- a/quic/core/congestion_control/bbr2_sender.cc
+++ b/quic/core/congestion_control/bbr2_sender.cc
@@ -303,7 +303,7 @@
}
QuicBandwidth target_rate = model_.pacing_gain() * model_.BandwidthEstimate();
- if (startup_.FullBandwidthReached()) {
+ if (model_.full_bandwidth_reached()) {
pacing_rate_ = target_rate;
return;
}
@@ -317,7 +317,7 @@
QuicByteCount target_cwnd = GetTargetCongestionWindow(model_.cwnd_gain());
const QuicByteCount prior_cwnd = cwnd_;
- if (startup_.FullBandwidthReached()) {
+ if (model_.full_bandwidth_reached()) {
target_cwnd += model_.MaxAckHeight();
cwnd_ = std::min(prior_cwnd + bytes_acked, target_cwnd);
} else if (prior_cwnd < target_cwnd || prior_cwnd < 2 * initial_cwnd_) {
@@ -332,7 +332,7 @@
QUIC_DVLOG(3) << this << " Updating CWND. target_cwnd:" << target_cwnd
<< ", max_ack_height:" << model_.MaxAckHeight()
- << ", full_bw:" << startup_.FullBandwidthReached()
+ << ", full_bw:" << model_.full_bandwidth_reached()
<< ", bytes_acked:" << bytes_acked
<< ", inflight_lo:" << model_.inflight_lo()
<< ", inflight_hi:" << model_.inflight_hi() << ". (prior_cwnd) "
diff --git a/quic/core/congestion_control/bbr2_startup.cc b/quic/core/congestion_control/bbr2_startup.cc
index 479c66b..5d02de7 100644
--- a/quic/core/congestion_control/bbr2_startup.cc
+++ b/quic/core/congestion_control/bbr2_startup.cc
@@ -15,10 +15,7 @@
Bbr2StartupMode::Bbr2StartupMode(const Bbr2Sender* sender,
Bbr2NetworkModel* model,
QuicTime now)
- : Bbr2ModeBase(sender, model),
- full_bandwidth_reached_(false),
- full_bandwidth_baseline_(QuicBandwidth::Zero()),
- rounds_without_bandwidth_growth_(0) {
+ : Bbr2ModeBase(sender, model) {
// Clear some startup stats if |sender_->connection_stats_| has been used by
// another sender, which happens e.g. when QuicConnection switch send
// algorithms.
@@ -43,10 +40,10 @@
const AckedPacketVector& /*acked_packets*/,
const LostPacketVector& /*lost_packets*/,
const Bbr2CongestionEvent& congestion_event) {
- if (!full_bandwidth_reached_ && congestion_event.end_of_round_trip) {
+ if (!model_->full_bandwidth_reached() && congestion_event.end_of_round_trip) {
// TCP BBR always exits upon excessive losses. QUIC BBRv1 does not exits
// upon excessive losses, if enough bandwidth growth is observed.
- bool has_enough_bw_growth = CheckBandwidthGrowth(congestion_event);
+ bool has_enough_bw_growth = model_->CheckBandwidthGrowth(congestion_event);
if (Params().always_exit_startup_on_excess_loss || !has_enough_bw_growth) {
CheckExcessiveLosses(congestion_event);
@@ -57,50 +54,14 @@
model_->set_cwnd_gain(Params().startup_cwnd_gain);
// TODO(wub): Maybe implement STARTUP => PROBE_RTT.
- return full_bandwidth_reached_ ? Bbr2Mode::DRAIN : Bbr2Mode::STARTUP;
-}
-
-bool Bbr2StartupMode::CheckBandwidthGrowth(
- const Bbr2CongestionEvent& congestion_event) {
- DCHECK(!full_bandwidth_reached_);
- DCHECK(congestion_event.end_of_round_trip);
- if (congestion_event.last_sample_is_app_limited) {
- // Return true such that when Params().always_exit_startup_on_excess_loss is
- // false, we'll not check excess loss, which is the behavior of QUIC BBRv1.
- return true;
- }
-
- QuicBandwidth threshold =
- full_bandwidth_baseline_ * Params().startup_full_bw_threshold;
-
- if (model_->MaxBandwidth() >= threshold) {
- QUIC_DVLOG(3) << sender_
- << " CheckBandwidthGrowth at end of round. max_bandwidth:"
- << model_->MaxBandwidth() << ", threshold:" << threshold
- << " (Still growing) @ " << congestion_event.event_time;
- full_bandwidth_baseline_ = model_->MaxBandwidth();
- rounds_without_bandwidth_growth_ = 0;
- return true;
- }
-
- ++rounds_without_bandwidth_growth_;
- full_bandwidth_reached_ =
- rounds_without_bandwidth_growth_ >= Params().startup_full_bw_rounds;
- QUIC_DVLOG(3) << sender_
- << " CheckBandwidthGrowth at end of round. max_bandwidth:"
- << model_->MaxBandwidth() << ", threshold:" << threshold
- << " rounds_without_growth:" << rounds_without_bandwidth_growth_
- << " full_bw_reached:" << full_bandwidth_reached_ << " @ "
- << congestion_event.event_time;
-
- return false;
+ return model_->full_bandwidth_reached() ? Bbr2Mode::DRAIN : Bbr2Mode::STARTUP;
}
void Bbr2StartupMode::CheckExcessiveLosses(
const Bbr2CongestionEvent& congestion_event) {
DCHECK(congestion_event.end_of_round_trip);
- if (full_bandwidth_reached_) {
+ if (model_->full_bandwidth_reached()) {
return;
}
@@ -117,17 +78,17 @@
<< new_inflight_hi;
// TODO(ianswett): Add a shared method to set inflight_hi in the model.
model_->set_inflight_hi(new_inflight_hi);
-
- full_bandwidth_reached_ = true;
+ model_->set_full_bandwidth_reached();
sender_->connection_stats_->bbr_exit_startup_due_to_loss = true;
}
}
Bbr2StartupMode::DebugState Bbr2StartupMode::ExportDebugState() const {
DebugState s;
- s.full_bandwidth_reached = full_bandwidth_reached_;
- s.full_bandwidth_baseline = full_bandwidth_baseline_;
- s.round_trips_without_bandwidth_growth = rounds_without_bandwidth_growth_;
+ s.full_bandwidth_reached = model_->full_bandwidth_reached();
+ s.full_bandwidth_baseline = model_->full_bandwidth_baseline();
+ s.round_trips_without_bandwidth_growth =
+ model_->rounds_without_bandwidth_growth();
return s;
}
diff --git a/quic/core/congestion_control/bbr2_startup.h b/quic/core/congestion_control/bbr2_startup.h
index 75ec71e..f753a1e 100644
--- a/quic/core/congestion_control/bbr2_startup.h
+++ b/quic/core/congestion_control/bbr2_startup.h
@@ -45,8 +45,6 @@
return Bbr2Mode::STARTUP;
}
- bool FullBandwidthReached() const { return full_bandwidth_reached_; }
-
struct QUIC_EXPORT_PRIVATE DebugState {
bool full_bandwidth_reached;
QuicBandwidth full_bandwidth_baseline = QuicBandwidth::Zero();
@@ -58,18 +56,7 @@
private:
const Bbr2Params& Params() const;
- // Check bandwidth growth in the past round. Must be called at the end of a
- // round.
- // Return true if the bandwidth growed as expected.
- // Return false otherwise, if enough rounds have elapsed without expected
- // growth, also sets |full_bandwidth_reached_| to true.
- bool CheckBandwidthGrowth(const Bbr2CongestionEvent& congestion_event);
-
void CheckExcessiveLosses(const Bbr2CongestionEvent& congestion_event);
-
- bool full_bandwidth_reached_;
- QuicBandwidth full_bandwidth_baseline_;
- QuicRoundTripCount rounds_without_bandwidth_growth_;
};
QUIC_EXPORT_PRIVATE std::ostream& operator<<(
