gfe-relnote: In QUIC, add 2 connection options to set the start point of exponential backoff when calculating PTO timeout. Protected by exisiting gfe2_reloadable_flag_quic_enable_pto.
PiperOrigin-RevId: 278370348
Change-Id: I3bbafdc9789b4a38f2fa7175febf86cb8f419a29
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index f2a72e0..c9d70b9 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -2882,6 +2882,121 @@
manager_.GetRetransmissionTime());
}
+TEST_F(QuicSentPacketManagerTest, StartExponentialBackoffSince2ndPto) {
+ EnablePto(k2PTO);
+ QuicConfig config;
+ QuicTagVector options;
+ options.push_back(kPEB2);
+ 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.
+ QuicTime::Delta expected_pto_delay =
+ srtt + 4 * rtt_stats->mean_deviation() +
+ QuicTime::Delta::FromMilliseconds(kDefaultDelayedAckTimeMs);
+ EXPECT_EQ(clock_.Now() + expected_pto_delay,
+ manager_.GetRetransmissionTime());
+
+ clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
+ SendDataPacket(2, ENCRYPTION_FORWARD_SECURE);
+ // Verify PTO is correctly set based on sent time of packet 2.
+ EXPECT_EQ(clock_.Now() + expected_pto_delay,
+ manager_.GetRetransmissionTime());
+ EXPECT_EQ(0u, stats_.pto_count);
+
+ // Invoke PTO.
+ clock_.AdvanceTime(expected_pto_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_EQ(1u, stats_.pto_count);
+
+ // Verify two probe packets get sent.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .Times(2)
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(3, type, ENCRYPTION_FORWARD_SECURE);
+ })))
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(4, type, ENCRYPTION_FORWARD_SECURE);
+ })));
+ manager_.MaybeSendProbePackets();
+ // Verify no exponential backoff.
+ EXPECT_EQ(clock_.Now() + expected_pto_delay,
+ manager_.GetRetransmissionTime());
+
+ // Invoke 2nd PTO.
+ clock_.AdvanceTime(expected_pto_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_EQ(2u, stats_.pto_count);
+
+ // Verify two probe packets get sent.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .Times(2)
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(5, type, ENCRYPTION_FORWARD_SECURE);
+ })))
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(6, type, ENCRYPTION_FORWARD_SECURE);
+ })));
+ manager_.MaybeSendProbePackets();
+ // Verify still no exponential backoff.
+ EXPECT_EQ(clock_.Now() + expected_pto_delay,
+ manager_.GetRetransmissionTime());
+
+ // Invoke 3rd PTO.
+ clock_.AdvanceTime(expected_pto_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_EQ(3u, stats_.pto_count);
+
+ // Verify two probe packets get sent.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .Times(2)
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(7, type, ENCRYPTION_FORWARD_SECURE);
+ })))
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(8, type, ENCRYPTION_FORWARD_SECURE);
+ })));
+ manager_.MaybeSendProbePackets();
+ // Verify exponential backoff starts.
+ EXPECT_EQ(clock_.Now() + expected_pto_delay * 2,
+ manager_.GetRetransmissionTime());
+
+ // Invoke 4th PTO.
+ clock_.AdvanceTime(expected_pto_delay * 2);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+ EXPECT_EQ(4u, stats_.pto_count);
+
+ // Verify two probe packets get sent.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .Times(2)
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(9, type, ENCRYPTION_FORWARD_SECURE);
+ })))
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(10, type, ENCRYPTION_FORWARD_SECURE);
+ })));
+ manager_.MaybeSendProbePackets();
+ // Verify exponential backoff continues.
+ EXPECT_EQ(clock_.Now() + expected_pto_delay * 4,
+ manager_.GetRetransmissionTime());
+}
+
} // namespace
} // namespace test
} // namespace quic
