gfe-relnote: only respect TLPR when there is pending non-crypto stream data. Flag protected by quic_ignore_tlpr_if_no_pending_stream_data and session_decides_what_to_write.
When calculating the tail loss probe delay and TLPR option is enabled, only use half tail loss probe when session has pending stream data. Otherwise, ignore TLPR.
PiperOrigin-RevId: 253286073
Change-Id: I9321c9d0608f68bb4ec0f7f4fbba1e470e4a0a3c
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index a0746fe..1e8302f 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -267,6 +267,14 @@
return packet;
}
+ SerializedPacket CreatePingPacket(uint64_t packet_number) {
+ SerializedPacket packet(QuicPacketNumber(packet_number),
+ PACKET_4BYTE_PACKET_NUMBER, nullptr, kDefaultLength,
+ false, false);
+ packet.retransmittable_frames.push_back(QuicFrame(QuicPingFrame()));
+ return packet;
+ }
+
void SendDataPacket(uint64_t packet_number) {
SendDataPacket(packet_number, ENCRYPTION_INITIAL);
}
@@ -282,6 +290,17 @@
NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA);
}
+ void SendPingPacket(uint64_t packet_number,
+ EncryptionLevel encryption_level) {
+ EXPECT_CALL(*send_algorithm_,
+ OnPacketSent(_, BytesInFlight(),
+ QuicPacketNumber(packet_number), _, _));
+ SerializedPacket packet(CreatePingPacket(packet_number));
+ packet.encryption_level = encryption_level;
+ manager_.OnPacketSent(&packet, QuicPacketNumber(), clock_.Now(),
+ NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA);
+ }
+
void SendCryptoPacket(uint64_t packet_number) {
EXPECT_CALL(
*send_algorithm_,
@@ -1761,6 +1780,118 @@
EXPECT_EQ(expected_time, manager_.GetRetransmissionTime());
}
+TEST_P(QuicSentPacketManagerTest, TLPRWithPendingStreamData) {
+ if (!manager_.session_decides_what_to_write()) {
+ return;
+ }
+
+ QuicConfig config;
+ QuicTagVector options;
+
+ options.push_back(kTLPR);
+ QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
+ EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
+ EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+ EXPECT_CALL(*send_algorithm_, PacingRate(_))
+ .WillRepeatedly(Return(QuicBandwidth::Zero()));
+ EXPECT_CALL(*send_algorithm_, GetCongestionWindow())
+ .WillOnce(Return(10 * kDefaultTCPMSS));
+ manager_.SetFromConfig(config);
+ EXPECT_TRUE(
+ QuicSentPacketManagerPeer::GetEnableHalfRttTailLossProbe(&manager_));
+
+ QuicSentPacketManagerPeer::SetMaxTailLossProbes(&manager_, 2);
+
+ SendDataPacket(1);
+ SendDataPacket(2);
+
+ // Test with a standard smoothed RTT.
+ RttStats* rtt_stats = const_cast<RttStats*>(manager_.GetRttStats());
+ rtt_stats->set_initial_rtt(QuicTime::Delta::FromMilliseconds(100));
+ QuicTime::Delta srtt = rtt_stats->initial_rtt();
+ // With pending stream data, TLPR is used.
+ QuicTime::Delta expected_tlp_delay = 0.5 * srtt;
+ EXPECT_CALL(notifier_, HasUnackedStreamData()).WillRepeatedly(Return(true));
+
+ EXPECT_EQ(expected_tlp_delay,
+ manager_.GetRetransmissionTime() - clock_.Now());
+
+ // Retransmit the packet by invoking the retransmission timeout.
+ clock_.AdvanceTime(expected_tlp_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_FALSE(manager_.HasPendingRetransmissions());
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .WillOnce(WithArgs<1>(Invoke(
+ [this](TransmissionType type) { RetransmitDataPacket(3, type); })));
+ EXPECT_TRUE(manager_.MaybeRetransmitTailLossProbe());
+
+ EXPECT_CALL(*send_algorithm_, CanSend(_)).WillOnce(Return(false));
+ EXPECT_EQ(QuicTime::Delta::Infinite(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_FALSE(manager_.HasPendingRetransmissions());
+
+ // 2nd TLP.
+ expected_tlp_delay = 2 * srtt;
+ EXPECT_EQ(expected_tlp_delay,
+ manager_.GetRetransmissionTime() - clock_.Now());
+}
+
+TEST_P(QuicSentPacketManagerTest, TLPRWithoutPendingStreamData) {
+ if (!manager_.session_decides_what_to_write()) {
+ return;
+ }
+
+ QuicConfig config;
+ QuicTagVector options;
+
+ options.push_back(kTLPR);
+ QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
+ EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
+ EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+ EXPECT_CALL(*send_algorithm_, PacingRate(_))
+ .WillRepeatedly(Return(QuicBandwidth::Zero()));
+ EXPECT_CALL(*send_algorithm_, GetCongestionWindow())
+ .WillOnce(Return(10 * kDefaultTCPMSS));
+ manager_.SetFromConfig(config);
+ EXPECT_TRUE(
+ QuicSentPacketManagerPeer::GetEnableHalfRttTailLossProbe(&manager_));
+ QuicSentPacketManagerPeer::SetMaxTailLossProbes(&manager_, 2);
+
+ SendPingPacket(1, ENCRYPTION_INITIAL);
+ SendPingPacket(2, ENCRYPTION_INITIAL);
+
+ // Test with a standard smoothed RTT.
+ RttStats* rtt_stats = const_cast<RttStats*>(manager_.GetRttStats());
+ rtt_stats->set_initial_rtt(QuicTime::Delta::FromMilliseconds(100));
+ QuicTime::Delta srtt = rtt_stats->initial_rtt();
+ QuicTime::Delta expected_tlp_delay = 0.5 * srtt;
+ if (GetQuicReloadableFlag(quic_ignore_tlpr_if_no_pending_stream_data)) {
+ // With no pending stream data, TLPR is ignored.
+ expected_tlp_delay = 2 * srtt;
+ }
+ EXPECT_CALL(notifier_, HasUnackedStreamData()).WillRepeatedly(Return(false));
+ EXPECT_EQ(expected_tlp_delay,
+ manager_.GetRetransmissionTime() - clock_.Now());
+
+ // Retransmit the packet by invoking the retransmission timeout.
+ clock_.AdvanceTime(expected_tlp_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_FALSE(manager_.HasPendingRetransmissions());
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .WillOnce(WithArgs<1>(Invoke(
+ [this](TransmissionType type) { RetransmitDataPacket(3, type); })));
+ EXPECT_TRUE(manager_.MaybeRetransmitTailLossProbe());
+ EXPECT_CALL(*send_algorithm_, CanSend(_)).WillOnce(Return(false));
+ EXPECT_EQ(QuicTime::Delta::Infinite(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_FALSE(manager_.HasPendingRetransmissions());
+
+ // 2nd TLP.
+ expected_tlp_delay = 2 * srtt;
+ EXPECT_EQ(expected_tlp_delay,
+ manager_.GetRetransmissionTime() - clock_.Now());
+}
+
TEST_P(QuicSentPacketManagerTest, GetTransmissionTimeSpuriousRTO) {
RttStats* rtt_stats = const_cast<RttStats*>(manager_.GetRttStats());
rtt_stats->UpdateRtt(QuicTime::Delta::FromMilliseconds(100),
