In quic, clear last_inflight_packets_sent_time_ of a packet number space if there is no bytes in flight. protected by gfe2_reloadable_flag_quic_fix_last_inflight_packets_sent_time.
PiperOrigin-RevId: 312363743
Change-Id: Ie497ea4cd11d68595993f7597b039d4101d2f011
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index d479c68..7125986 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -4003,6 +4003,68 @@
manager_.MaybeSendProbePackets();
}
+// Regression test for b/156487311
+TEST_F(QuicSentPacketManagerTest, ClearLastInflightPacketsSentTime) {
+ manager_.EnableMultiplePacketNumberSpacesSupport();
+ EXPECT_CALL(*send_algorithm_, PacingRate(_))
+ .WillRepeatedly(Return(QuicBandwidth::Zero()));
+ EXPECT_CALL(*send_algorithm_, GetCongestionWindow())
+ .WillRepeatedly(Return(10 * kDefaultTCPMSS));
+
+ // Send INITIAL 1.
+ SendDataPacket(1, ENCRYPTION_INITIAL);
+ const QuicTime packet1_sent_time = clock_.Now();
+ // Send HANDSHAKE 2.
+ clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
+ SendDataPacket(2, ENCRYPTION_HANDSHAKE);
+ SendDataPacket(3, ENCRYPTION_HANDSHAKE);
+ SendDataPacket(4, ENCRYPTION_HANDSHAKE);
+ const QuicTime packet2_sent_time = clock_.Now();
+
+ // Send half RTT 5.
+ clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
+ SendDataPacket(5, ENCRYPTION_FORWARD_SECURE);
+
+ // Received ACK for INITIAL 1.
+ ExpectAck(1);
+ clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(90));
+ manager_.OnAckFrameStart(QuicPacketNumber(1), QuicTime::Delta::Infinite(),
+ clock_.Now());
+ manager_.OnAckRange(QuicPacketNumber(1), QuicPacketNumber(2));
+ EXPECT_EQ(PACKETS_NEWLY_ACKED,
+ manager_.OnAckFrameEnd(clock_.Now(), QuicPacketNumber(1),
+ ENCRYPTION_INITIAL));
+ RttStats* rtt_stats = const_cast<RttStats*>(manager_.GetRttStats());
+ int pto_rttvar_multiplier =
+ GetQuicReloadableFlag(quic_default_on_pto) ? 2 : 4;
+ const QuicTime::Delta pto_delay =
+ rtt_stats->smoothed_rtt() +
+ pto_rttvar_multiplier * rtt_stats->mean_deviation() +
+ QuicTime::Delta::FromMilliseconds(kDefaultDelayedAckTimeMs);
+ if (GetQuicReloadableFlag(quic_fix_last_inflight_packets_sent_time)) {
+ // Verify PTO is armed based on handshake data.
+ EXPECT_EQ(packet2_sent_time + pto_delay, manager_.GetRetransmissionTime());
+ } else {
+ // Problematic: PTO is still armed based on initial data.
+ EXPECT_EQ(packet1_sent_time + pto_delay, manager_.GetRetransmissionTime());
+ clock_.AdvanceTime(pto_delay);
+ manager_.OnRetransmissionTimeout();
+ // Nothing to retransmit in INITIAL space.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _)).Times(0);
+ manager_.MaybeSendProbePackets();
+ // PING packet gets sent.
+ SendPingPacket(6, ENCRYPTION_INITIAL);
+
+ // Verify PTO is armed based on packet 2.
+ EXPECT_EQ(packet2_sent_time + pto_delay * 2,
+ manager_.GetRetransmissionTime());
+ clock_.AdvanceTime(pto_delay * 2);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _)).Times(testing::AtLeast(1));
+ manager_.MaybeSendProbePackets();
+ }
+}
+
} // namespace
} // namespace test
} // namespace quic
