- Remove all experiments that tunes blackhole detection delay or path degrading delay, and
- Ensure network blackhole delay is at least path degrading delay plus 2 PTOs.
This is to avoid issues like https://bugs.chromium.org/p/chromium/issues/detail?id=1334029.
Protected by FLAGS_quic_reloadable_flag_quic_remove_blackhole_detection_experiments.
PiperOrigin-RevId: 454883575
diff --git a/quiche/quic/core/quic_connection.cc b/quiche/quic/core/quic_connection.cc
index 2645c58..3c9034f 100644
--- a/quiche/quic/core/quic_connection.cc
+++ b/quiche/quic/core/quic_connection.cc
@@ -563,21 +563,23 @@
if (config.HasClientSentConnectionOption(kNBHD, perspective_)) {
blackhole_detection_disabled_ = true;
}
- if (config.HasClientSentConnectionOption(k2RTO, perspective_)) {
- QUIC_CODE_COUNT(quic_2rto_blackhole_detection);
- num_rtos_for_blackhole_detection_ = 2;
- }
- if (config.HasClientSentConnectionOption(k3RTO, perspective_)) {
- QUIC_CODE_COUNT(quic_3rto_blackhole_detection);
- num_rtos_for_blackhole_detection_ = 3;
- }
- if (config.HasClientSentConnectionOption(k4RTO, perspective_)) {
- QUIC_CODE_COUNT(quic_4rto_blackhole_detection);
- num_rtos_for_blackhole_detection_ = 4;
- }
- if (config.HasClientSentConnectionOption(k6RTO, perspective_)) {
- QUIC_CODE_COUNT(quic_6rto_blackhole_detection);
- num_rtos_for_blackhole_detection_ = 6;
+ if (!sent_packet_manager_.remove_blackhole_detection_experiments()) {
+ if (config.HasClientSentConnectionOption(k2RTO, perspective_)) {
+ QUIC_CODE_COUNT(quic_2rto_blackhole_detection);
+ num_rtos_for_blackhole_detection_ = 2;
+ }
+ if (config.HasClientSentConnectionOption(k3RTO, perspective_)) {
+ QUIC_CODE_COUNT(quic_3rto_blackhole_detection);
+ num_rtos_for_blackhole_detection_ = 3;
+ }
+ if (config.HasClientSentConnectionOption(k4RTO, perspective_)) {
+ QUIC_CODE_COUNT(quic_4rto_blackhole_detection);
+ num_rtos_for_blackhole_detection_ = 4;
+ }
+ if (config.HasClientSentConnectionOption(k6RTO, perspective_)) {
+ QUIC_CODE_COUNT(quic_6rto_blackhole_detection);
+ num_rtos_for_blackhole_detection_ = 6;
+ }
}
}
@@ -6439,11 +6441,35 @@
return QuicTime::Zero();
}
QUICHE_DCHECK_LT(0u, num_rtos_for_blackhole_detection_);
+ if (sent_packet_manager_.remove_blackhole_detection_experiments()) {
+ QUIC_RELOADABLE_FLAG_COUNT(quic_remove_blackhole_detection_experiments);
+ const QuicTime::Delta blackhole_delay =
+ sent_packet_manager_.GetNetworkBlackholeDelay(
+ num_rtos_for_blackhole_detection_);
+ if (!ShouldDetectPathDegrading()) {
+ return clock_->ApproximateNow() + blackhole_delay;
+ }
+ return clock_->ApproximateNow() +
+ CalculateNetworkBlackholeDelay(
+ blackhole_delay, sent_packet_manager_.GetPathDegradingDelay(),
+ sent_packet_manager_.GetPtoDelay());
+ }
return clock_->ApproximateNow() +
sent_packet_manager_.GetNetworkBlackholeDelay(
num_rtos_for_blackhole_detection_);
}
+// static
+QuicTime::Delta QuicConnection::CalculateNetworkBlackholeDelay(
+ QuicTime::Delta blackhole_delay, QuicTime::Delta path_degrading_delay,
+ QuicTime::Delta pto_delay) {
+ const QuicTime::Delta min_delay = path_degrading_delay + pto_delay * 2;
+ if (blackhole_delay < min_delay) {
+ QUIC_CODE_COUNT(quic_extending_short_blackhole_delay);
+ }
+ return std::max(min_delay, blackhole_delay);
+}
+
bool QuicConnection::ShouldDetectBlackhole() const {
if (!connected_ || blackhole_detection_disabled_) {
return false;
diff --git a/quiche/quic/core/quic_connection.h b/quiche/quic/core/quic_connection.h
index aab56b7..87f9c14 100644
--- a/quiche/quic/core/quic_connection.h
+++ b/quiche/quic/core/quic_connection.h
@@ -1230,6 +1230,11 @@
return quic_bug_10511_43_error_detail_;
}
+ // Ensures the network blackhole delay is longer than path degrading delay.
+ static QuicTime::Delta CalculateNetworkBlackholeDelay(
+ QuicTime::Delta blackhole_delay, QuicTime::Delta path_degrading_delay,
+ QuicTime::Delta pto_delay);
+
protected:
// Calls cancel() on all the alarms owned by this connection.
void CancelAllAlarms();
diff --git a/quiche/quic/core/quic_connection_test.cc b/quiche/quic/core/quic_connection_test.cc
index b3c01d5..2a89850 100644
--- a/quiche/quic/core/quic_connection_test.cc
+++ b/quiche/quic/core/quic_connection_test.cc
@@ -10643,7 +10643,8 @@
}
TEST_P(QuicConnectionTest, 2RtoBlackholeDetection) {
- if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2)) {
+ if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2) ||
+ GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
return;
}
QuicConfig config;
@@ -10670,7 +10671,8 @@
}
TEST_P(QuicConnectionTest, 3RtoBlackholeDetection) {
- if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2)) {
+ if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2) ||
+ GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
return;
}
QuicConfig config;
@@ -10697,7 +10699,8 @@
}
TEST_P(QuicConnectionTest, 4RtoBlackholeDetection) {
- if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2)) {
+ if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2) ||
+ GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
return;
}
QuicConfig config;
@@ -10724,7 +10727,8 @@
}
TEST_P(QuicConnectionTest, 6RtoBlackholeDetection) {
- if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2)) {
+ if (!GetQuicReloadableFlag(quic_default_enable_5rto_blackhole_detection2) ||
+ GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
return;
}
QuicConfig config;
@@ -15405,6 +15409,26 @@
EXPECT_FALSE(connection_.GetRetransmissionAlarm()->IsSet());
}
+TEST_P(QuicConnectionTest, CalculateNetworkBlackholeDelay) {
+ if (!IsDefaultTestConfiguration()) {
+ return;
+ }
+
+ const QuicTime::Delta kOneSec = QuicTime::Delta::FromSeconds(1);
+ const QuicTime::Delta kTwoSec = QuicTime::Delta::FromSeconds(2);
+ const QuicTime::Delta kFourSec = QuicTime::Delta::FromSeconds(4);
+
+ // Normal case: blackhole_delay longer than path_degrading_delay +
+ // 2*pto_delay.
+ EXPECT_EQ(QuicConnection::CalculateNetworkBlackholeDelay(kFourSec, kOneSec,
+ kOneSec),
+ kFourSec);
+
+ EXPECT_EQ(QuicConnection::CalculateNetworkBlackholeDelay(kFourSec, kOneSec,
+ kTwoSec),
+ QuicTime::Delta::FromSeconds(5));
+}
+
} // namespace
} // namespace test
} // namespace quic
diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index e17b850..938446d 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -17,6 +17,8 @@
QUIC_FLAG(quic_restart_flag_quic_testonly_default_true, true)
// If bytes in flight has dipped below 1.25*MaxBW in the last round, do not exit PROBE_UP due to excess queue buildup.
QUIC_FLAG(quic_reloadable_flag_quic_bbr2_no_probe_up_exit_if_no_queue, true)
+// If true, 1) remove all experiments that tunes blackhole detection delay or path degrading delay, and 2) ensure network blackhole delay is at least path degrading delay plus 2 PTOs.
+QUIC_FLAG(quic_reloadable_flag_quic_remove_blackhole_detection_experiments, true)
// If true, QUIC Legacy Version Encapsulation will be disabled.
QUIC_FLAG(quic_restart_flag_quic_disable_legacy_version_encapsulation, false)
// If true, QUIC will default enable MTU discovery at server, with a target of 1450 bytes.
diff --git a/quiche/quic/core/quic_sent_packet_manager.cc b/quiche/quic/core/quic_sent_packet_manager.cc
index 1083583..0725631 100644
--- a/quiche/quic/core/quic_sent_packet_manager.cc
+++ b/quiche/quic/core/quic_sent_packet_manager.cc
@@ -131,17 +131,19 @@
ignore_ack_delay_ = true;
}
- if (config.HasClientRequestedIndependentOption(kPDP1, perspective)) {
- num_ptos_for_path_degrading_ = 1;
- }
- if (config.HasClientRequestedIndependentOption(kPDP2, perspective)) {
- num_ptos_for_path_degrading_ = 2;
- }
- if (config.HasClientRequestedIndependentOption(kPDP3, perspective)) {
- num_ptos_for_path_degrading_ = 3;
- }
- if (config.HasClientRequestedIndependentOption(kPDP5, perspective)) {
- num_ptos_for_path_degrading_ = 5;
+ if (!remove_blackhole_detection_experiments_) {
+ if (config.HasClientRequestedIndependentOption(kPDP1, perspective)) {
+ num_ptos_for_path_degrading_ = 1;
+ }
+ if (config.HasClientRequestedIndependentOption(kPDP2, perspective)) {
+ num_ptos_for_path_degrading_ = 2;
+ }
+ if (config.HasClientRequestedIndependentOption(kPDP3, perspective)) {
+ num_ptos_for_path_degrading_ = 3;
+ }
+ if (config.HasClientRequestedIndependentOption(kPDP5, perspective)) {
+ num_ptos_for_path_degrading_ = 5;
+ }
}
// Configure congestion control.
diff --git a/quiche/quic/core/quic_sent_packet_manager.h b/quiche/quic/core/quic_sent_packet_manager.h
index f0a6bc6..731bd3d 100644
--- a/quiche/quic/core/quic_sent_packet_manager.h
+++ b/quiche/quic/core/quic_sent_packet_manager.h
@@ -26,6 +26,7 @@
#include "quiche/quic/core/quic_types.h"
#include "quiche/quic/core/quic_unacked_packet_map.h"
#include "quiche/quic/platform/api/quic_export.h"
+#include "quiche/quic/platform/api/quic_flags.h"
#include "quiche/common/quiche_circular_deque.h"
namespace quic {
@@ -464,6 +465,11 @@
// kMinUntrustedInitialRoundTripTimeUs if not |trusted|.
void SetInitialRtt(QuicTime::Delta rtt, bool trusted);
+ // Latched value of --quic_remove_blackhole_detection_experiments.
+ bool remove_blackhole_detection_experiments() const {
+ return remove_blackhole_detection_experiments_;
+ }
+
private:
friend class test::QuicConnectionPeer;
friend class test::QuicSentPacketManagerPeer;
@@ -668,6 +674,9 @@
// Whether to ignore the ack_delay in received ACKs.
bool ignore_ack_delay_;
+
+ const bool remove_blackhole_detection_experiments_ =
+ GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments);
};
} // namespace quic
diff --git a/quiche/quic/core/quic_sent_packet_manager_test.cc b/quiche/quic/core/quic_sent_packet_manager_test.cc
index 8c8076b..67605e4 100644
--- a/quiche/quic/core/quic_sent_packet_manager_test.cc
+++ b/quiche/quic/core/quic_sent_packet_manager_test.cc
@@ -2499,6 +2499,9 @@
}
TEST_F(QuicSentPacketManagerTest, GetPathDegradingDelayUsing2PTO) {
+ if (GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
+ return;
+ }
QuicConfig client_config;
QuicTagVector client_options;
client_options.push_back(kPDP2);
@@ -2512,6 +2515,9 @@
}
TEST_F(QuicSentPacketManagerTest, GetPathDegradingDelayUsing1PTO) {
+ if (GetQuicReloadableFlag(quic_remove_blackhole_detection_experiments)) {
+ return;
+ }
QuicConfig client_config;
QuicTagVector client_options;
client_options.push_back(kPDP1);
