gfe-relnote: In QUIC, add probe timeout mode, which unifies TLP and RTO. Protected by gfe2_reloadable_flag_quic_enable_pto.
PTO mode is enabled on client side if gfe2_reloadable_flag_quic_enable_pto is true and client sends 1PTO or 2PTO. PTO mode is enabled on server side if gfe2_reloadable_flag_quic_enable_pto is true and server receives 1PTO or 2PTO from client.
Connection is closed after 7 or 8 PTO depending on connection option 7PTO or 8PTO, respectively.
PiperOrigin-RevId: 263574963
Change-Id: Id952a3e4640146c3fe72e3d6745cbac5ee16dcdc
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index 56c3d8a..ae5722b 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -357,6 +357,20 @@
pending.transmission_type, HAS_RETRANSMITTABLE_DATA);
}
+ void EnablePto(QuicTag tag) {
+ SetQuicReloadableFlag(quic_fix_rto_retransmission3, true);
+ manager_.SetSessionDecideWhatToWrite(true);
+ SetQuicReloadableFlag(quic_enable_pto, true);
+ QuicConfig config;
+ QuicTagVector options;
+ options.push_back(tag);
+ QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
+ EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+ EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
+ manager_.SetFromConfig(config);
+ EXPECT_TRUE(manager_.enable_pto());
+ }
+
QuicSentPacketManager manager_;
MockClock clock_;
QuicConnectionStats stats_;
@@ -2980,6 +2994,107 @@
}
}
+TEST_P(QuicSentPacketManagerTest, ComputingProbeTimeout) {
+ EnablePto(k2PTO);
+ 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 PTO period gets set to twice the current value.
+ QuicTime sent_time = clock_.Now();
+ EXPECT_EQ(sent_time + expected_pto_delay * 2,
+ manager_.GetRetransmissionTime());
+
+ // Received ACK for packets 1 and 2.
+ uint64_t acked[] = {1, 2};
+ ExpectAcksAndLosses(true, acked, QUIC_ARRAYSIZE(acked), nullptr, 0);
+ manager_.OnAckFrameStart(QuicPacketNumber(2), QuicTime::Delta::Infinite(),
+ clock_.Now());
+ manager_.OnAckRange(QuicPacketNumber(1), QuicPacketNumber(3));
+ EXPECT_EQ(PACKETS_NEWLY_ACKED,
+ manager_.OnAckFrameEnd(clock_.Now(), QuicPacketNumber(1),
+ ENCRYPTION_FORWARD_SECURE));
+ expected_pto_delay =
+ rtt_stats->SmoothedOrInitialRtt() +
+ std::max(4 * rtt_stats->mean_deviation(),
+ QuicTime::Delta::FromMilliseconds(1)) +
+ QuicTime::Delta::FromMilliseconds(kDefaultDelayedAckTimeMs);
+
+ // Verify PTO is correctly re-armed based on sent time of packet 4.
+ EXPECT_EQ(sent_time + expected_pto_delay, manager_.GetRetransmissionTime());
+}
+
+TEST_P(QuicSentPacketManagerTest, SendOneProbePacket) {
+ EnablePto(k1PTO);
+ EXPECT_CALL(*send_algorithm_, PacingRate(_))
+ .WillRepeatedly(Return(QuicBandwidth::Zero()));
+ EXPECT_CALL(*send_algorithm_, GetCongestionWindow())
+ .WillRepeatedly(Return(10 * kDefaultTCPMSS));
+
+ SendDataPacket(1, ENCRYPTION_FORWARD_SECURE);
+ clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
+ SendDataPacket(2, ENCRYPTION_FORWARD_SECURE);
+
+ 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();
+ // Verify PTO period 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());
+
+ // Invoke PTO.
+ clock_.AdvanceTime(expected_pto_delay);
+ manager_.OnRetransmissionTimeout();
+ EXPECT_EQ(QuicTime::Delta::Zero(), manager_.TimeUntilSend(clock_.Now()));
+
+ // Verify one probe packet gets sent.
+ EXPECT_CALL(notifier_, RetransmitFrames(_, _))
+ .WillOnce(WithArgs<1>(Invoke([this](TransmissionType type) {
+ RetransmitDataPacket(3, type, ENCRYPTION_FORWARD_SECURE);
+ })));
+ manager_.MaybeSendProbePackets();
+}
+
} // namespace
} // namespace test
} // namespace quic
