gfe-relnote: In QUIC, add a connection option to use 2 * rttvar when calculating PTO timeout. Protected by existing gfe2_reloadable_flag_quic_enable_pto.
PiperOrigin-RevId: 278451908
Change-Id: I5f68cad58734bd52e70efce51eefd84646050cac
diff --git a/quic/core/crypto/crypto_protocol.h b/quic/core/crypto/crypto_protocol.h
index f09c595..9707fb5 100644
--- a/quic/core/crypto/crypto_protocol.h
+++ b/quic/core/crypto/crypto_protocol.h
@@ -207,6 +207,8 @@
// since 1st PTO.
const QuicTag kPEB2 = TAG('P', 'E', 'B', '2'); // Start exponential backoff
// since 2nd PTO.
+const QuicTag kPVS1 = TAG('P', 'V', 'S', '1'); // Use 2 * rttvar when
+ // calculating PTO timeout.
// Optional support of truncated Connection IDs. If sent by a peer, the value
// is the minimum number of bytes allowed for the connection ID sent to the
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 06f1ebb..443ecbc 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -444,11 +444,11 @@
}
if (config.HasClientSentConnectionOption(k7PTO, perspective_)) {
max_consecutive_ptos_ = 6;
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 3, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 3, 8);
}
if (config.HasClientSentConnectionOption(k8PTO, perspective_)) {
max_consecutive_ptos_ = 7;
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 4, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 4, 8);
}
}
if (config.HasClientSentConnectionOption(kNSTP, perspective_)) {
diff --git a/quic/core/quic_sent_packet_manager.cc b/quic/core/quic_sent_packet_manager.cc
index f9ec1c0..deec82f 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -105,6 +105,7 @@
skip_packet_number_for_pto_(false),
always_include_max_ack_delay_for_pto_timeout_(true),
pto_exponential_backoff_start_point_(0),
+ pto_rttvar_multiplier_(4),
neuter_handshake_packets_once_(
GetQuicReloadableFlag(quic_neuter_handshake_packets_once)) {
SetSendAlgorithm(congestion_control_type);
@@ -151,12 +152,12 @@
if (GetQuicReloadableFlag(quic_enable_pto)) {
if (config.HasClientSentConnectionOption(k2PTO, perspective)) {
pto_enabled_ = true;
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 2, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 2, 8);
}
if (config.HasClientSentConnectionOption(k1PTO, perspective)) {
pto_enabled_ = true;
max_probe_packets_per_pto_ = 1;
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 1, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 1, 8);
}
}
@@ -174,17 +175,21 @@
if (pto_enabled_) {
if (config.HasClientSentConnectionOption(kPTOA, perspective)) {
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 5, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 5, 8);
always_include_max_ack_delay_for_pto_timeout_ = false;
}
if (config.HasClientSentConnectionOption(kPEB1, perspective)) {
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 6, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 6, 8);
StartExponentialBackoffAfterNthPto(1);
}
if (config.HasClientSentConnectionOption(kPEB2, perspective)) {
- QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 7, 7);
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 7, 8);
StartExponentialBackoffAfterNthPto(2);
}
+ if (config.HasClientSentConnectionOption(kPVS1, perspective)) {
+ QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 8, 8);
+ pto_rttvar_multiplier_ = 2;
+ }
}
// Configure congestion control.
@@ -1045,7 +1050,7 @@
}
const QuicTime::Delta pto_delay =
rtt_stats_.smoothed_rtt() +
- std::max(4 * rtt_stats_.mean_deviation(),
+ std::max(pto_rttvar_multiplier_ * rtt_stats_.mean_deviation(),
QuicTime::Delta::FromMilliseconds(1)) +
(ShouldAddMaxAckDelay() ? peer_max_ack_delay_ : QuicTime::Delta::Zero());
return pto_delay * (1 << (consecutive_pto_count_ -
diff --git a/quic/core/quic_sent_packet_manager.h b/quic/core/quic_sent_packet_manager.h
index 5d362f4..2c3cf99 100644
--- a/quic/core/quic_sent_packet_manager.h
+++ b/quic/core/quic_sent_packet_manager.h
@@ -641,6 +641,9 @@
// since nth PTO.
size_t pto_exponential_backoff_start_point_;
+ // The multiplier of rttvar when calculating PTO timeout.
+ int pto_rttvar_multiplier_;
+
// Latched value of quic_neuter_handshake_packets_once.
const bool neuter_handshake_packets_once_;
};
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index b7ca395..539ce97 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -3026,6 +3026,35 @@
manager_.GetRetransmissionTime());
}
+TEST_F(QuicSentPacketManagerTest, PtoTimeoutRttVarMultiple) {
+ EnablePto(k1PTO);
+ // Use 2 * rttvar
+ QuicConfig config;
+ QuicTagVector options;
+ options.push_back(kPVS1);
+ QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
+ EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+ EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
+ manager_.SetFromConfig(config);
+
+ EXPECT_CALL(*send_algorithm_, PacingRate(_))
+ .WillRepeatedly(Return(QuicBandwidth::Zero()));
+ EXPECT_CALL(*send_algorithm_, GetCongestionWindow())
+ .WillRepeatedly(Return(10 * kDefaultTCPMSS));
+ RttStats* rtt_stats = const_cast<RttStats*>(manager_.GetRttStats());
+ rtt_stats->UpdateRtt(QuicTime::Delta::FromMilliseconds(100),
+ QuicTime::Delta::Zero(), QuicTime::Zero());
+ QuicTime::Delta srtt = rtt_stats->smoothed_rtt();
+
+ SendDataPacket(1, ENCRYPTION_FORWARD_SECURE);
+ // Verify PTO is correctly set based on 2 times rtt var.
+ QuicTime::Delta expected_pto_delay =
+ srtt + 2 * rtt_stats->mean_deviation() +
+ QuicTime::Delta::FromMilliseconds(kDefaultDelayedAckTimeMs);
+ EXPECT_EQ(clock_.Now() + expected_pto_delay,
+ manager_.GetRetransmissionTime());
+}
+
} // namespace
} // namespace test
} // namespace quic
diff --git a/quic/core/quic_time.h b/quic/core/quic_time.h
index 9a5ae7d..d4429e3 100644
--- a/quic/core/quic_time.h
+++ b/quic/core/quic_time.h
@@ -210,6 +210,9 @@
inline bool operator>=(QuicTime::Delta lhs, QuicTime::Delta rhs) {
return !(lhs < rhs);
}
+inline QuicTime::Delta operator<<(QuicTime::Delta lhs, size_t rhs) {
+ return QuicTime::Delta(lhs.time_offset_ << rhs);
+}
inline QuicTime::Delta operator>>(QuicTime::Delta lhs, size_t rhs) {
return QuicTime::Delta(lhs.time_offset_ >> rhs);
}
