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| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "net/quic/congestion_control/tcp_cubic_sender_packets.h" | |
| 6 | |
| 7 #include <algorithm> | |
| 8 #include <memory> | |
| 9 | |
| 10 #include "base/logging.h" | |
| 11 #include "net/quic/congestion_control/rtt_stats.h" | |
| 12 #include "net/quic/crypto/crypto_protocol.h" | |
| 13 #include "net/quic/proto/cached_network_parameters.pb.h" | |
| 14 #include "net/quic/quic_flags.h" | |
| 15 #include "net/quic/quic_protocol.h" | |
| 16 #include "net/quic/quic_utils.h" | |
| 17 #include "net/quic/test_tools/mock_clock.h" | |
| 18 #include "net/quic/test_tools/quic_config_peer.h" | |
| 19 #include "net/quic/test_tools/quic_test_utils.h" | |
| 20 #include "testing/gtest/include/gtest/gtest.h" | |
| 21 | |
| 22 using std::min; | |
| 23 | |
| 24 namespace net { | |
| 25 namespace test { | |
| 26 | |
| 27 // TODO(ianswett): A number of theses tests were written with the assumption of | |
| 28 // an initial CWND of 10. They have carefully calculated values which should be | |
| 29 // updated to be based on kInitialCongestionWindow. | |
| 30 const uint32_t kInitialCongestionWindowPackets = 10; | |
| 31 const uint32_t kMaxCongestionWindowPackets = 200; | |
| 32 const uint32_t kDefaultWindowTCP = | |
| 33 kInitialCongestionWindowPackets * kDefaultTCPMSS; | |
| 34 const float kRenoBeta = 0.7f; // Reno backoff factor. | |
| 35 | |
| 36 class TcpCubicSenderPacketsPeer : public TcpCubicSenderPackets { | |
| 37 public: | |
| 38 TcpCubicSenderPacketsPeer(const QuicClock* clock, | |
| 39 bool reno, | |
| 40 QuicPacketCount max_tcp_congestion_window) | |
| 41 : TcpCubicSenderPackets(clock, | |
| 42 &rtt_stats_, | |
| 43 reno, | |
| 44 kInitialCongestionWindowPackets, | |
| 45 max_tcp_congestion_window, | |
| 46 &stats_) {} | |
| 47 | |
| 48 QuicPacketCount congestion_window() { return congestion_window_; } | |
| 49 | |
| 50 QuicPacketCount max_congestion_window() { return max_tcp_congestion_window_; } | |
| 51 | |
| 52 QuicPacketCount slowstart_threshold() { return slowstart_threshold_; } | |
| 53 | |
| 54 const HybridSlowStart& hybrid_slow_start() const { | |
| 55 return hybrid_slow_start_; | |
| 56 } | |
| 57 | |
| 58 float GetRenoBeta() const { return RenoBeta(); } | |
| 59 | |
| 60 RttStats rtt_stats_; | |
| 61 QuicConnectionStats stats_; | |
| 62 }; | |
| 63 | |
| 64 class TcpCubicSenderPacketsTest : public ::testing::Test { | |
| 65 protected: | |
| 66 TcpCubicSenderPacketsTest() | |
| 67 : one_ms_(QuicTime::Delta::FromMilliseconds(1)), | |
| 68 sender_(new TcpCubicSenderPacketsPeer(&clock_, | |
| 69 true, | |
| 70 kMaxCongestionWindowPackets)), | |
| 71 packet_number_(1), | |
| 72 acked_packet_number_(0), | |
| 73 bytes_in_flight_(0) {} | |
| 74 | |
| 75 int SendAvailableSendWindow() { | |
| 76 return SendAvailableSendWindow(kDefaultTCPMSS); | |
| 77 } | |
| 78 | |
| 79 int SendAvailableSendWindow(QuicPacketLength packet_length) { | |
| 80 // Send as long as TimeUntilSend returns Zero. | |
| 81 int packets_sent = 0; | |
| 82 bool can_send = | |
| 83 sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero(); | |
| 84 while (can_send) { | |
| 85 sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, packet_number_++, | |
| 86 kDefaultTCPMSS, HAS_RETRANSMITTABLE_DATA); | |
| 87 ++packets_sent; | |
| 88 bytes_in_flight_ += kDefaultTCPMSS; | |
| 89 can_send = | |
| 90 sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero(); | |
| 91 } | |
| 92 return packets_sent; | |
| 93 } | |
| 94 | |
| 95 // Normal is that TCP acks every other segment. | |
| 96 void AckNPackets(int n) { | |
| 97 sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(60), | |
| 98 QuicTime::Delta::Zero(), clock_.Now()); | |
| 99 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 100 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 101 for (int i = 0; i < n; ++i) { | |
| 102 ++acked_packet_number_; | |
| 103 acked_packets.push_back( | |
| 104 std::make_pair(acked_packet_number_, kDefaultTCPMSS)); | |
| 105 } | |
| 106 sender_->OnCongestionEvent(true, bytes_in_flight_, acked_packets, | |
| 107 lost_packets); | |
| 108 bytes_in_flight_ -= n * kDefaultTCPMSS; | |
| 109 clock_.AdvanceTime(one_ms_); | |
| 110 } | |
| 111 | |
| 112 void LoseNPackets(int n) { LoseNPackets(n, kDefaultTCPMSS); } | |
| 113 | |
| 114 void LoseNPackets(int n, QuicPacketLength packet_length) { | |
| 115 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 116 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 117 for (int i = 0; i < n; ++i) { | |
| 118 ++acked_packet_number_; | |
| 119 lost_packets.push_back( | |
| 120 std::make_pair(acked_packet_number_, packet_length)); | |
| 121 } | |
| 122 sender_->OnCongestionEvent(false, bytes_in_flight_, acked_packets, | |
| 123 lost_packets); | |
| 124 bytes_in_flight_ -= n * packet_length; | |
| 125 } | |
| 126 | |
| 127 // Does not increment acked_packet_number_. | |
| 128 void LosePacket(QuicPacketNumber packet_number) { | |
| 129 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 130 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 131 lost_packets.push_back(std::make_pair(packet_number, kDefaultTCPMSS)); | |
| 132 sender_->OnCongestionEvent(false, bytes_in_flight_, acked_packets, | |
| 133 lost_packets); | |
| 134 bytes_in_flight_ -= kDefaultTCPMSS; | |
| 135 } | |
| 136 | |
| 137 const QuicTime::Delta one_ms_; | |
| 138 MockClock clock_; | |
| 139 std::unique_ptr<TcpCubicSenderPacketsPeer> sender_; | |
| 140 QuicPacketNumber packet_number_; | |
| 141 QuicPacketNumber acked_packet_number_; | |
| 142 QuicByteCount bytes_in_flight_; | |
| 143 }; | |
| 144 | |
| 145 TEST_F(TcpCubicSenderPacketsTest, SimpleSender) { | |
| 146 // At startup make sure we are at the default. | |
| 147 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 148 // At startup make sure we can send. | |
| 149 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 150 // Make sure we can send. | |
| 151 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 152 // And that window is un-affected. | |
| 153 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 154 | |
| 155 // Fill the send window with data, then verify that we can't send. | |
| 156 SendAvailableSendWindow(); | |
| 157 EXPECT_FALSE( | |
| 158 sender_->TimeUntilSend(clock_.Now(), sender_->GetCongestionWindow()) | |
| 159 .IsZero()); | |
| 160 } | |
| 161 | |
| 162 TEST_F(TcpCubicSenderPacketsTest, ApplicationLimitedSlowStart) { | |
| 163 // Send exactly 10 packets and ensure the CWND ends at 14 packets. | |
| 164 const int kNumberOfAcks = 5; | |
| 165 // At startup make sure we can send. | |
| 166 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 167 // Make sure we can send. | |
| 168 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 169 | |
| 170 SendAvailableSendWindow(); | |
| 171 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 172 AckNPackets(2); | |
| 173 } | |
| 174 QuicByteCount bytes_to_send = sender_->GetCongestionWindow(); | |
| 175 // It's expected 2 acks will arrive when the bytes_in_flight are greater than | |
| 176 // half the CWND. | |
| 177 EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * 2, bytes_to_send); | |
| 178 } | |
| 179 | |
| 180 TEST_F(TcpCubicSenderPacketsTest, ExponentialSlowStart) { | |
| 181 const int kNumberOfAcks = 20; | |
| 182 // At startup make sure we can send. | |
| 183 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 184 EXPECT_EQ(QuicBandwidth::Zero(), sender_->BandwidthEstimate()); | |
| 185 // Make sure we can send. | |
| 186 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero()); | |
| 187 | |
| 188 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 189 // Send our full send window. | |
| 190 SendAvailableSendWindow(); | |
| 191 AckNPackets(2); | |
| 192 } | |
| 193 const QuicByteCount cwnd = sender_->GetCongestionWindow(); | |
| 194 EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * kNumberOfAcks, cwnd); | |
| 195 EXPECT_EQ(QuicBandwidth::FromBytesAndTimeDelta( | |
| 196 cwnd, sender_->rtt_stats_.smoothed_rtt()), | |
| 197 sender_->BandwidthEstimate()); | |
| 198 } | |
| 199 | |
| 200 TEST_F(TcpCubicSenderPacketsTest, SlowStartPacketLoss) { | |
| 201 sender_->SetNumEmulatedConnections(1); | |
| 202 const int kNumberOfAcks = 10; | |
| 203 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 204 // Send our full send window. | |
| 205 SendAvailableSendWindow(); | |
| 206 AckNPackets(2); | |
| 207 } | |
| 208 SendAvailableSendWindow(); | |
| 209 QuicByteCount expected_send_window = | |
| 210 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 211 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 212 | |
| 213 // Lose a packet to exit slow start. | |
| 214 LoseNPackets(1); | |
| 215 size_t packets_in_recovery_window = expected_send_window / kDefaultTCPMSS; | |
| 216 | |
| 217 // We should now have fallen out of slow start with a reduced window. | |
| 218 expected_send_window *= kRenoBeta; | |
| 219 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 220 | |
| 221 // Recovery phase. We need to ack every packet in the recovery window before | |
| 222 // we exit recovery. | |
| 223 size_t number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; | |
| 224 DVLOG(1) << "number_packets: " << number_of_packets_in_window; | |
| 225 AckNPackets(packets_in_recovery_window); | |
| 226 SendAvailableSendWindow(); | |
| 227 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 228 | |
| 229 // We need to ack an entire window before we increase CWND by 1. | |
| 230 AckNPackets(number_of_packets_in_window - 2); | |
| 231 SendAvailableSendWindow(); | |
| 232 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 233 | |
| 234 // Next ack should increase cwnd by 1. | |
| 235 AckNPackets(1); | |
| 236 expected_send_window += kDefaultTCPMSS; | |
| 237 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 238 | |
| 239 // Now RTO and ensure slow start gets reset. | |
| 240 EXPECT_TRUE(sender_->hybrid_slow_start().started()); | |
| 241 sender_->OnRetransmissionTimeout(true); | |
| 242 EXPECT_FALSE(sender_->hybrid_slow_start().started()); | |
| 243 } | |
| 244 | |
| 245 TEST_F(TcpCubicSenderPacketsTest, SlowStartPacketLossWithLargeReduction) { | |
| 246 QuicConfig config; | |
| 247 QuicTagVector options; | |
| 248 options.push_back(kSSLR); | |
| 249 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 250 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 251 | |
| 252 sender_->SetNumEmulatedConnections(1); | |
| 253 const int kNumberOfAcks = (kDefaultWindowTCP / (2 * kDefaultTCPMSS)) - 1; | |
| 254 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 255 // Send our full send window. | |
| 256 SendAvailableSendWindow(); | |
| 257 AckNPackets(2); | |
| 258 } | |
| 259 SendAvailableSendWindow(); | |
| 260 QuicByteCount expected_send_window = | |
| 261 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 262 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 263 | |
| 264 // Lose a packet to exit slow start. We should now have fallen out of | |
| 265 // slow start with a window reduced by 1. | |
| 266 LoseNPackets(1); | |
| 267 expected_send_window -= kDefaultTCPMSS; | |
| 268 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 269 | |
| 270 // Lose 5 packets in recovery and verify that congestion window is reduced | |
| 271 // further. | |
| 272 LoseNPackets(5); | |
| 273 expected_send_window -= 5 * kDefaultTCPMSS; | |
| 274 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 275 // Lose another 10 packets and ensure it reduces below half the peak CWND, | |
| 276 // because we never acked the full IW. | |
| 277 LoseNPackets(10); | |
| 278 expected_send_window -= 10 * kDefaultTCPMSS; | |
| 279 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 280 | |
| 281 size_t packets_in_recovery_window = expected_send_window / kDefaultTCPMSS; | |
| 282 | |
| 283 // Recovery phase. We need to ack every packet in the recovery window before | |
| 284 // we exit recovery. | |
| 285 size_t number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; | |
| 286 DVLOG(1) << "number_packets: " << number_of_packets_in_window; | |
| 287 AckNPackets(packets_in_recovery_window); | |
| 288 SendAvailableSendWindow(); | |
| 289 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 290 | |
| 291 // We need to ack the rest of the window before cwnd increases by 1. | |
| 292 AckNPackets(number_of_packets_in_window - 1); | |
| 293 SendAvailableSendWindow(); | |
| 294 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 295 | |
| 296 // Next ack should increase cwnd by 1. | |
| 297 AckNPackets(1); | |
| 298 expected_send_window += kDefaultTCPMSS; | |
| 299 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 300 | |
| 301 // Now RTO and ensure slow start gets reset. | |
| 302 EXPECT_TRUE(sender_->hybrid_slow_start().started()); | |
| 303 sender_->OnRetransmissionTimeout(true); | |
| 304 EXPECT_FALSE(sender_->hybrid_slow_start().started()); | |
| 305 } | |
| 306 | |
| 307 TEST_F(TcpCubicSenderPacketsTest, SlowStartHalfPacketLossWithLargeReduction) { | |
| 308 QuicConfig config; | |
| 309 QuicTagVector options; | |
| 310 options.push_back(kSSLR); | |
| 311 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 312 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 313 | |
| 314 sender_->SetNumEmulatedConnections(1); | |
| 315 const int kNumberOfAcks = 10; | |
| 316 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 317 // Send our full send window in half sized packets. | |
| 318 SendAvailableSendWindow(kDefaultTCPMSS / 2); | |
| 319 AckNPackets(2); | |
| 320 } | |
| 321 SendAvailableSendWindow(kDefaultTCPMSS / 2); | |
| 322 QuicByteCount expected_send_window = | |
| 323 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 324 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 325 | |
| 326 // Lose a packet to exit slow start. We should now have fallen out of | |
| 327 // slow start with a window reduced by 1. | |
| 328 LoseNPackets(1); | |
| 329 expected_send_window -= kDefaultTCPMSS; | |
| 330 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 331 | |
| 332 // Lose 10 packets in recovery and verify that congestion window is reduced | |
| 333 // by 5 packets. | |
| 334 LoseNPackets(10, kDefaultTCPMSS / 2); | |
| 335 expected_send_window -= 5 * kDefaultTCPMSS; | |
| 336 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 337 } | |
| 338 | |
| 339 TEST_F(TcpCubicSenderPacketsTest, SlowStartPacketLossWithMaxHalfReduction) { | |
| 340 QuicConfig config; | |
| 341 QuicTagVector options; | |
| 342 options.push_back(kSSLR); | |
| 343 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 344 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 345 | |
| 346 sender_->SetNumEmulatedConnections(1); | |
| 347 const int kNumberOfAcks = kInitialCongestionWindowPackets / 2; | |
| 348 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 349 // Send our full send window. | |
| 350 SendAvailableSendWindow(); | |
| 351 AckNPackets(2); | |
| 352 } | |
| 353 SendAvailableSendWindow(); | |
| 354 QuicByteCount expected_send_window = | |
| 355 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 356 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 357 | |
| 358 // Lose a packet to exit slow start. We should now have fallen out of | |
| 359 // slow start with a window reduced by 1. | |
| 360 LoseNPackets(1); | |
| 361 expected_send_window -= kDefaultTCPMSS; | |
| 362 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 363 | |
| 364 // Lose half the outstanding packets in recovery and verify the congestion | |
| 365 // window is only reduced by a max of half. | |
| 366 LoseNPackets(kNumberOfAcks * 2); | |
| 367 expected_send_window -= (kNumberOfAcks * 2 - 1) * kDefaultTCPMSS; | |
| 368 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 369 LoseNPackets(5); | |
| 370 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 371 } | |
| 372 | |
| 373 TEST_F(TcpCubicSenderPacketsTest, NoPRRWhenLessThanOnePacketInFlight) { | |
| 374 SendAvailableSendWindow(); | |
| 375 LoseNPackets(kInitialCongestionWindowPackets - 1); | |
| 376 AckNPackets(1); | |
| 377 // PRR will allow 2 packets for every ack during recovery. | |
| 378 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 379 // Simulate abandoning all packets by supplying a bytes_in_flight of 0. | |
| 380 // PRR should now allow a packet to be sent, even though prr's state | |
| 381 // variables believe it has sent enough packets. | |
| 382 EXPECT_EQ(QuicTime::Delta::Zero(), sender_->TimeUntilSend(clock_.Now(), 0)); | |
| 383 } | |
| 384 | |
| 385 TEST_F(TcpCubicSenderPacketsTest, SlowStartPacketLossPRR) { | |
| 386 sender_->SetNumEmulatedConnections(1); | |
| 387 // Test based on the first example in RFC6937. | |
| 388 // Ack 10 packets in 5 acks to raise the CWND to 20, as in the example. | |
| 389 const int kNumberOfAcks = 5; | |
| 390 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 391 // Send our full send window. | |
| 392 SendAvailableSendWindow(); | |
| 393 AckNPackets(2); | |
| 394 } | |
| 395 SendAvailableSendWindow(); | |
| 396 QuicByteCount expected_send_window = | |
| 397 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 398 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 399 | |
| 400 LoseNPackets(1); | |
| 401 | |
| 402 // We should now have fallen out of slow start with a reduced window. | |
| 403 size_t send_window_before_loss = expected_send_window; | |
| 404 expected_send_window *= kRenoBeta; | |
| 405 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 406 | |
| 407 // Testing TCP proportional rate reduction. | |
| 408 // We should send packets paced over the received acks for the remaining | |
| 409 // outstanding packets. The number of packets before we exit recovery is the | |
| 410 // original CWND minus the packet that has been lost and the one which | |
| 411 // triggered the loss. | |
| 412 size_t remaining_packets_in_recovery = | |
| 413 send_window_before_loss / kDefaultTCPMSS - 2; | |
| 414 | |
| 415 for (size_t i = 0; i < remaining_packets_in_recovery; ++i) { | |
| 416 AckNPackets(1); | |
| 417 SendAvailableSendWindow(); | |
| 418 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 419 } | |
| 420 | |
| 421 // We need to ack another window before we increase CWND by 1. | |
| 422 size_t number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; | |
| 423 for (size_t i = 0; i < number_of_packets_in_window; ++i) { | |
| 424 AckNPackets(1); | |
| 425 EXPECT_EQ(1, SendAvailableSendWindow()); | |
| 426 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 427 } | |
| 428 | |
| 429 AckNPackets(1); | |
| 430 expected_send_window += kDefaultTCPMSS; | |
| 431 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 432 } | |
| 433 | |
| 434 TEST_F(TcpCubicSenderPacketsTest, SlowStartBurstPacketLossPRR) { | |
| 435 sender_->SetNumEmulatedConnections(1); | |
| 436 // Test based on the second example in RFC6937, though we also implement | |
| 437 // forward acknowledgements, so the first two incoming acks will trigger | |
| 438 // PRR immediately. | |
| 439 // Ack 20 packets in 10 acks to raise the CWND to 30. | |
| 440 const int kNumberOfAcks = 10; | |
| 441 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 442 // Send our full send window. | |
| 443 SendAvailableSendWindow(); | |
| 444 AckNPackets(2); | |
| 445 } | |
| 446 SendAvailableSendWindow(); | |
| 447 QuicByteCount expected_send_window = | |
| 448 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 449 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 450 | |
| 451 // Lose one more than the congestion window reduction, so that after loss, | |
| 452 // bytes_in_flight is lesser than the congestion window. | |
| 453 size_t send_window_after_loss = kRenoBeta * expected_send_window; | |
| 454 size_t num_packets_to_lose = | |
| 455 (expected_send_window - send_window_after_loss) / kDefaultTCPMSS + 1; | |
| 456 LoseNPackets(num_packets_to_lose); | |
| 457 // Immediately after the loss, ensure at least one packet can be sent. | |
| 458 // Losses without subsequent acks can occur with timer based loss detection. | |
| 459 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero()); | |
| 460 AckNPackets(1); | |
| 461 | |
| 462 // We should now have fallen out of slow start with a reduced window. | |
| 463 expected_send_window *= kRenoBeta; | |
| 464 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 465 | |
| 466 // Only 2 packets should be allowed to be sent, per PRR-SSRB | |
| 467 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 468 | |
| 469 // Ack the next packet, which triggers another loss. | |
| 470 LoseNPackets(1); | |
| 471 AckNPackets(1); | |
| 472 | |
| 473 // Send 2 packets to simulate PRR-SSRB. | |
| 474 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 475 | |
| 476 // Ack the next packet, which triggers another loss. | |
| 477 LoseNPackets(1); | |
| 478 AckNPackets(1); | |
| 479 | |
| 480 // Send 2 packets to simulate PRR-SSRB. | |
| 481 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 482 | |
| 483 // Exit recovery and return to sending at the new rate. | |
| 484 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 485 AckNPackets(1); | |
| 486 EXPECT_EQ(1, SendAvailableSendWindow()); | |
| 487 } | |
| 488 } | |
| 489 | |
| 490 TEST_F(TcpCubicSenderPacketsTest, RTOCongestionWindow) { | |
| 491 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 492 EXPECT_EQ(kMaxCongestionWindowPackets, sender_->slowstart_threshold()); | |
| 493 | |
| 494 // Expect the window to decrease to the minimum once the RTO fires | |
| 495 // and slow start threshold to be set to 1/2 of the CWND. | |
| 496 sender_->OnRetransmissionTimeout(true); | |
| 497 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 498 EXPECT_EQ(5u, sender_->slowstart_threshold()); | |
| 499 } | |
| 500 | |
| 501 TEST_F(TcpCubicSenderPacketsTest, RTOCongestionWindowNoRetransmission) { | |
| 502 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 503 | |
| 504 // Expect the window to remain unchanged if the RTO fires but no | |
| 505 // packets are retransmitted. | |
| 506 sender_->OnRetransmissionTimeout(false); | |
| 507 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 508 } | |
| 509 | |
| 510 TEST_F(TcpCubicSenderPacketsTest, RetransmissionDelay) { | |
| 511 const int64_t kRttMs = 10; | |
| 512 const int64_t kDeviationMs = 3; | |
| 513 EXPECT_EQ(QuicTime::Delta::Zero(), sender_->RetransmissionDelay()); | |
| 514 | |
| 515 sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(kRttMs), | |
| 516 QuicTime::Delta::Zero(), clock_.Now()); | |
| 517 | |
| 518 // Initial value is to set the median deviation to half of the initial | |
| 519 // rtt, the median in then multiplied by a factor of 4 and finally the | |
| 520 // smoothed rtt is added which is the initial rtt. | |
| 521 QuicTime::Delta expected_delay = | |
| 522 QuicTime::Delta::FromMilliseconds(kRttMs + kRttMs / 2 * 4); | |
| 523 EXPECT_EQ(expected_delay, sender_->RetransmissionDelay()); | |
| 524 | |
| 525 for (int i = 0; i < 100; ++i) { | |
| 526 // Run to make sure that we converge. | |
| 527 sender_->rtt_stats_.UpdateRtt( | |
| 528 QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs), | |
| 529 QuicTime::Delta::Zero(), clock_.Now()); | |
| 530 sender_->rtt_stats_.UpdateRtt( | |
| 531 QuicTime::Delta::FromMilliseconds(kRttMs - kDeviationMs), | |
| 532 QuicTime::Delta::Zero(), clock_.Now()); | |
| 533 } | |
| 534 expected_delay = QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs * 4); | |
| 535 | |
| 536 EXPECT_NEAR(kRttMs, sender_->rtt_stats_.smoothed_rtt().ToMilliseconds(), 1); | |
| 537 EXPECT_NEAR(expected_delay.ToMilliseconds(), | |
| 538 sender_->RetransmissionDelay().ToMilliseconds(), 1); | |
| 539 EXPECT_EQ(static_cast<int64_t>( | |
| 540 sender_->GetCongestionWindow() * kNumMicrosPerSecond / | |
| 541 sender_->rtt_stats_.smoothed_rtt().ToMicroseconds()), | |
| 542 sender_->BandwidthEstimate().ToBytesPerSecond()); | |
| 543 } | |
| 544 | |
| 545 TEST_F(TcpCubicSenderPacketsTest, SlowStartMaxSendWindow) { | |
| 546 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 547 const int kNumberOfAcks = 100; | |
| 548 sender_.reset( | |
| 549 new TcpCubicSenderPacketsPeer(&clock_, false, kMaxCongestionWindowTCP)); | |
| 550 | |
| 551 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 552 // Send our full send window. | |
| 553 SendAvailableSendWindow(); | |
| 554 AckNPackets(2); | |
| 555 } | |
| 556 QuicByteCount expected_send_window = kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 557 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 558 } | |
| 559 | |
| 560 TEST_F(TcpCubicSenderPacketsTest, TcpRenoMaxCongestionWindow) { | |
| 561 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 562 const int kNumberOfAcks = 1000; | |
| 563 sender_.reset( | |
| 564 new TcpCubicSenderPacketsPeer(&clock_, true, kMaxCongestionWindowTCP)); | |
| 565 | |
| 566 SendAvailableSendWindow(); | |
| 567 AckNPackets(2); | |
| 568 // Make sure we fall out of slow start. | |
| 569 LoseNPackets(1); | |
| 570 | |
| 571 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 572 // Send our full send window. | |
| 573 SendAvailableSendWindow(); | |
| 574 AckNPackets(2); | |
| 575 } | |
| 576 | |
| 577 QuicByteCount expected_send_window = kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 578 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 579 } | |
| 580 | |
| 581 TEST_F(TcpCubicSenderPacketsTest, TcpCubicMaxCongestionWindow) { | |
| 582 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 583 // Set to 10000 to compensate for small cubic alpha. | |
| 584 const int kNumberOfAcks = 10000; | |
| 585 | |
| 586 sender_.reset( | |
| 587 new TcpCubicSenderPacketsPeer(&clock_, false, kMaxCongestionWindowTCP)); | |
| 588 | |
| 589 SendAvailableSendWindow(); | |
| 590 AckNPackets(2); | |
| 591 // Make sure we fall out of slow start. | |
| 592 LoseNPackets(1); | |
| 593 | |
| 594 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 595 // Send our full send window. | |
| 596 SendAvailableSendWindow(); | |
| 597 AckNPackets(2); | |
| 598 } | |
| 599 | |
| 600 QuicByteCount expected_send_window = kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 601 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 602 } | |
| 603 | |
| 604 TEST_F(TcpCubicSenderPacketsTest, TcpCubicResetEpochOnQuiescence) { | |
| 605 const int kMaxCongestionWindow = 50; | |
| 606 const QuicByteCount kMaxCongestionWindowBytes = | |
| 607 kMaxCongestionWindow * kDefaultTCPMSS; | |
| 608 sender_.reset( | |
| 609 new TcpCubicSenderPacketsPeer(&clock_, false, kMaxCongestionWindow)); | |
| 610 | |
| 611 int num_sent = SendAvailableSendWindow(); | |
| 612 | |
| 613 // Make sure we fall out of slow start. | |
| 614 QuicByteCount saved_cwnd = sender_->GetCongestionWindow(); | |
| 615 LoseNPackets(1); | |
| 616 EXPECT_GT(saved_cwnd, sender_->GetCongestionWindow()); | |
| 617 | |
| 618 // Ack the rest of the outstanding packets to get out of recovery. | |
| 619 for (int i = 1; i < num_sent; ++i) { | |
| 620 AckNPackets(1); | |
| 621 } | |
| 622 EXPECT_EQ(0u, bytes_in_flight_); | |
| 623 | |
| 624 // Send a new window of data and ack all; cubic growth should occur. | |
| 625 saved_cwnd = sender_->GetCongestionWindow(); | |
| 626 num_sent = SendAvailableSendWindow(); | |
| 627 for (int i = 0; i < num_sent; ++i) { | |
| 628 AckNPackets(1); | |
| 629 } | |
| 630 EXPECT_LT(saved_cwnd, sender_->GetCongestionWindow()); | |
| 631 EXPECT_GT(kMaxCongestionWindowBytes, sender_->GetCongestionWindow()); | |
| 632 EXPECT_EQ(0u, bytes_in_flight_); | |
| 633 | |
| 634 // Quiescent time of 100 seconds | |
| 635 clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(100000)); | |
| 636 | |
| 637 // Send new window of data and ack one packet. Cubic epoch should have | |
| 638 // been reset; ensure cwnd increase is not dramatic. | |
| 639 saved_cwnd = sender_->GetCongestionWindow(); | |
| 640 SendAvailableSendWindow(); | |
| 641 AckNPackets(1); | |
| 642 EXPECT_NEAR(saved_cwnd, sender_->GetCongestionWindow(), kDefaultTCPMSS); | |
| 643 EXPECT_GT(kMaxCongestionWindowBytes, sender_->GetCongestionWindow()); | |
| 644 } | |
| 645 | |
| 646 TEST_F(TcpCubicSenderPacketsTest, TcpCubicShiftedEpochOnQuiescence) { | |
| 647 ValueRestore<bool> old_flag(&FLAGS_shift_quic_cubic_epoch_when_app_limited, | |
| 648 true); | |
| 649 const int kMaxCongestionWindow = 50; | |
| 650 const QuicByteCount kMaxCongestionWindowBytes = | |
| 651 kMaxCongestionWindow * kDefaultTCPMSS; | |
| 652 sender_.reset( | |
| 653 new TcpCubicSenderPacketsPeer(&clock_, false, kMaxCongestionWindow)); | |
| 654 | |
| 655 int num_sent = SendAvailableSendWindow(); | |
| 656 | |
| 657 // Make sure we fall out of slow start. | |
| 658 QuicByteCount saved_cwnd = sender_->GetCongestionWindow(); | |
| 659 LoseNPackets(1); | |
| 660 EXPECT_GT(saved_cwnd, sender_->GetCongestionWindow()); | |
| 661 | |
| 662 // Ack the rest of the outstanding packets to get out of recovery. | |
| 663 for (int i = 1; i < num_sent; ++i) { | |
| 664 AckNPackets(1); | |
| 665 } | |
| 666 EXPECT_EQ(0u, bytes_in_flight_); | |
| 667 | |
| 668 // Send a new window of data and ack all; cubic growth should occur. | |
| 669 saved_cwnd = sender_->GetCongestionWindow(); | |
| 670 num_sent = SendAvailableSendWindow(); | |
| 671 for (int i = 0; i < num_sent; ++i) { | |
| 672 AckNPackets(1); | |
| 673 } | |
| 674 EXPECT_LT(saved_cwnd, sender_->GetCongestionWindow()); | |
| 675 EXPECT_GT(kMaxCongestionWindowBytes, sender_->GetCongestionWindow()); | |
| 676 EXPECT_EQ(0u, bytes_in_flight_); | |
| 677 | |
| 678 // Quiescent time of 100 seconds | |
| 679 clock_.AdvanceTime(QuicTime::Delta::FromSeconds(100)); | |
| 680 | |
| 681 // Send new window of data and ack one packet. Cubic epoch should have | |
| 682 // been reset; ensure cwnd increase is not dramatic. | |
| 683 saved_cwnd = sender_->GetCongestionWindow(); | |
| 684 SendAvailableSendWindow(); | |
| 685 AckNPackets(1); | |
| 686 EXPECT_NEAR(saved_cwnd, sender_->GetCongestionWindow(), kDefaultTCPMSS); | |
| 687 EXPECT_GT(kMaxCongestionWindowBytes, sender_->GetCongestionWindow()); | |
| 688 } | |
| 689 | |
| 690 TEST_F(TcpCubicSenderPacketsTest, MultipleLossesInOneWindow) { | |
| 691 SendAvailableSendWindow(); | |
| 692 const QuicByteCount initial_window = sender_->GetCongestionWindow(); | |
| 693 LosePacket(acked_packet_number_ + 1); | |
| 694 const QuicByteCount post_loss_window = sender_->GetCongestionWindow(); | |
| 695 EXPECT_GT(initial_window, post_loss_window); | |
| 696 LosePacket(acked_packet_number_ + 3); | |
| 697 EXPECT_EQ(post_loss_window, sender_->GetCongestionWindow()); | |
| 698 LosePacket(packet_number_ - 1); | |
| 699 EXPECT_EQ(post_loss_window, sender_->GetCongestionWindow()); | |
| 700 | |
| 701 // Lose a later packet and ensure the window decreases. | |
| 702 LosePacket(packet_number_); | |
| 703 EXPECT_GT(post_loss_window, sender_->GetCongestionWindow()); | |
| 704 } | |
| 705 | |
| 706 TEST_F(TcpCubicSenderPacketsTest, DontTrackAckPackets) { | |
| 707 // Send a packet with no retransmittable data, and ensure it's not tracked. | |
| 708 EXPECT_FALSE(sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, | |
| 709 packet_number_++, kDefaultTCPMSS, | |
| 710 NO_RETRANSMITTABLE_DATA)); | |
| 711 | |
| 712 // Send a data packet with retransmittable data, and ensure it is tracked. | |
| 713 EXPECT_TRUE(sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, | |
| 714 packet_number_++, kDefaultTCPMSS, | |
| 715 HAS_RETRANSMITTABLE_DATA)); | |
| 716 } | |
| 717 | |
| 718 TEST_F(TcpCubicSenderPacketsTest, ConfigureInitialWindow) { | |
| 719 QuicConfig config; | |
| 720 | |
| 721 QuicTagVector options; | |
| 722 options.push_back(kIW03); | |
| 723 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 724 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 725 EXPECT_EQ(3u, sender_->congestion_window()); | |
| 726 | |
| 727 options.clear(); | |
| 728 options.push_back(kIW10); | |
| 729 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 730 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 731 EXPECT_EQ(10u, sender_->congestion_window()); | |
| 732 | |
| 733 options.clear(); | |
| 734 options.push_back(kIW20); | |
| 735 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 736 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 737 EXPECT_EQ(20u, sender_->congestion_window()); | |
| 738 | |
| 739 options.clear(); | |
| 740 options.push_back(kIW50); | |
| 741 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 742 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 743 EXPECT_EQ(50u, sender_->congestion_window()); | |
| 744 } | |
| 745 | |
| 746 TEST_F(TcpCubicSenderPacketsTest, ConfigureMinimumWindow) { | |
| 747 QuicConfig config; | |
| 748 | |
| 749 // Verify that kCOPT: kMIN1 forces the min CWND to 1 packet. | |
| 750 QuicTagVector options; | |
| 751 options.push_back(kMIN1); | |
| 752 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 753 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 754 sender_->OnRetransmissionTimeout(true); | |
| 755 EXPECT_EQ(1u, sender_->congestion_window()); | |
| 756 } | |
| 757 | |
| 758 TEST_F(TcpCubicSenderPacketsTest, | |
| 759 2ConnectionCongestionAvoidanceAtEndOfRecovery) { | |
| 760 sender_->SetNumEmulatedConnections(2); | |
| 761 // Ack 10 packets in 5 acks to raise the CWND to 20. | |
| 762 const int kNumberOfAcks = 5; | |
| 763 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 764 // Send our full send window. | |
| 765 SendAvailableSendWindow(); | |
| 766 AckNPackets(2); | |
| 767 } | |
| 768 SendAvailableSendWindow(); | |
| 769 QuicByteCount expected_send_window = | |
| 770 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 771 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 772 | |
| 773 LoseNPackets(1); | |
| 774 | |
| 775 // We should now have fallen out of slow start with a reduced window. | |
| 776 expected_send_window = expected_send_window * sender_->GetRenoBeta(); | |
| 777 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 778 | |
| 779 // No congestion window growth should occur in recovery phase, i.e., until the | |
| 780 // currently outstanding 20 packets are acked. | |
| 781 for (int i = 0; i < 10; ++i) { | |
| 782 // Send our full send window. | |
| 783 SendAvailableSendWindow(); | |
| 784 EXPECT_TRUE(sender_->InRecovery()); | |
| 785 AckNPackets(2); | |
| 786 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 787 } | |
| 788 EXPECT_FALSE(sender_->InRecovery()); | |
| 789 | |
| 790 // Out of recovery now. Congestion window should not grow for half an RTT. | |
| 791 size_t packets_in_send_window = expected_send_window / kDefaultTCPMSS; | |
| 792 SendAvailableSendWindow(); | |
| 793 AckNPackets(packets_in_send_window / 2 - 2); | |
| 794 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 795 | |
| 796 // Next ack should increase congestion window by 1MSS. | |
| 797 SendAvailableSendWindow(); | |
| 798 AckNPackets(2); | |
| 799 expected_send_window += kDefaultTCPMSS; | |
| 800 packets_in_send_window += 1; | |
| 801 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 802 | |
| 803 // Congestion window should remain steady again for half an RTT. | |
| 804 SendAvailableSendWindow(); | |
| 805 AckNPackets(packets_in_send_window / 2 - 1); | |
| 806 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 807 | |
| 808 // Next ack should cause congestion window to grow by 1MSS. | |
| 809 SendAvailableSendWindow(); | |
| 810 AckNPackets(2); | |
| 811 expected_send_window += kDefaultTCPMSS; | |
| 812 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 813 } | |
| 814 | |
| 815 TEST_F(TcpCubicSenderPacketsTest, | |
| 816 1ConnectionCongestionAvoidanceAtEndOfRecovery) { | |
| 817 sender_->SetNumEmulatedConnections(1); | |
| 818 // Ack 10 packets in 5 acks to raise the CWND to 20. | |
| 819 const int kNumberOfAcks = 5; | |
| 820 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 821 // Send our full send window. | |
| 822 SendAvailableSendWindow(); | |
| 823 AckNPackets(2); | |
| 824 } | |
| 825 SendAvailableSendWindow(); | |
| 826 QuicByteCount expected_send_window = | |
| 827 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 828 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 829 | |
| 830 LoseNPackets(1); | |
| 831 | |
| 832 // We should now have fallen out of slow start with a reduced window. | |
| 833 expected_send_window *= kRenoBeta; | |
| 834 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 835 | |
| 836 // No congestion window growth should occur in recovery phase, i.e., until the | |
| 837 // currently outstanding 20 packets are acked. | |
| 838 for (int i = 0; i < 10; ++i) { | |
| 839 // Send our full send window. | |
| 840 SendAvailableSendWindow(); | |
| 841 EXPECT_TRUE(sender_->InRecovery()); | |
| 842 AckNPackets(2); | |
| 843 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 844 } | |
| 845 EXPECT_FALSE(sender_->InRecovery()); | |
| 846 | |
| 847 // Out of recovery now. Congestion window should not grow during RTT. | |
| 848 for (uint64_t i = 0; i < expected_send_window / kDefaultTCPMSS - 2; i += 2) { | |
| 849 // Send our full send window. | |
| 850 SendAvailableSendWindow(); | |
| 851 AckNPackets(2); | |
| 852 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 853 } | |
| 854 | |
| 855 // Next ack should cause congestion window to grow by 1MSS. | |
| 856 SendAvailableSendWindow(); | |
| 857 AckNPackets(2); | |
| 858 expected_send_window += kDefaultTCPMSS; | |
| 859 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 860 } | |
| 861 | |
| 862 TEST_F(TcpCubicSenderPacketsTest, BandwidthResumption) { | |
| 863 // Test that when provided with CachedNetworkParameters and opted in to the | |
| 864 // bandwidth resumption experiment, that the TcpCubicSenderPackets sets | |
| 865 // initial CWND appropriately. | |
| 866 | |
| 867 // Set some common values. | |
| 868 CachedNetworkParameters cached_network_params; | |
| 869 const QuicPacketCount kNumberOfPackets = 123; | |
| 870 const int kBandwidthEstimateBytesPerSecond = | |
| 871 kNumberOfPackets * kDefaultTCPMSS; | |
| 872 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 873 kBandwidthEstimateBytesPerSecond); | |
| 874 cached_network_params.set_min_rtt_ms(1000); | |
| 875 | |
| 876 // Make sure that a bandwidth estimate results in a changed CWND. | |
| 877 cached_network_params.set_timestamp(clock_.WallNow().ToUNIXSeconds() - | |
| 878 (kNumSecondsPerHour - 1)); | |
| 879 sender_->ResumeConnectionState(cached_network_params, false); | |
| 880 EXPECT_EQ(kNumberOfPackets, sender_->congestion_window()); | |
| 881 | |
| 882 // Resumed CWND is limited to be in a sensible range. | |
| 883 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 884 (kMaxCongestionWindowPackets + 1) * kDefaultTCPMSS); | |
| 885 sender_->ResumeConnectionState(cached_network_params, false); | |
| 886 EXPECT_EQ(kMaxCongestionWindowPackets, sender_->congestion_window()); | |
| 887 | |
| 888 if (FLAGS_quic_no_lower_bw_resumption_limit) { | |
| 889 // Resume with an illegal value of 0 and verify the server uses 1 instead. | |
| 890 cached_network_params.set_bandwidth_estimate_bytes_per_second(0); | |
| 891 sender_->ResumeConnectionState(cached_network_params, false); | |
| 892 EXPECT_EQ(sender_->min_congestion_window(), sender_->congestion_window()); | |
| 893 } else { | |
| 894 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 895 (kMinCongestionWindowForBandwidthResumption - 1) * kDefaultTCPMSS); | |
| 896 sender_->ResumeConnectionState(cached_network_params, false); | |
| 897 EXPECT_EQ(kMinCongestionWindowForBandwidthResumption, | |
| 898 sender_->congestion_window()); | |
| 899 } | |
| 900 | |
| 901 // Resume to the max value. | |
| 902 cached_network_params.set_max_bandwidth_estimate_bytes_per_second( | |
| 903 kMaxCongestionWindowPackets * kDefaultTCPMSS); | |
| 904 sender_->ResumeConnectionState(cached_network_params, true); | |
| 905 EXPECT_EQ(kMaxCongestionWindowPackets * kDefaultTCPMSS, | |
| 906 sender_->GetCongestionWindow()); | |
| 907 } | |
| 908 | |
| 909 TEST_F(TcpCubicSenderPacketsTest, PaceBelowCWND) { | |
| 910 QuicConfig config; | |
| 911 | |
| 912 // Verify that kCOPT: kMIN4 forces the min CWND to 1 packet, but allows up | |
| 913 // to 4 to be sent. | |
| 914 QuicTagVector options; | |
| 915 options.push_back(kMIN4); | |
| 916 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 917 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 918 sender_->OnRetransmissionTimeout(true); | |
| 919 EXPECT_EQ(1u, sender_->congestion_window()); | |
| 920 EXPECT_TRUE( | |
| 921 sender_->TimeUntilSend(QuicTime::Zero(), kDefaultTCPMSS).IsZero()); | |
| 922 EXPECT_TRUE( | |
| 923 sender_->TimeUntilSend(QuicTime::Zero(), 2 * kDefaultTCPMSS).IsZero()); | |
| 924 EXPECT_TRUE( | |
| 925 sender_->TimeUntilSend(QuicTime::Zero(), 3 * kDefaultTCPMSS).IsZero()); | |
| 926 EXPECT_FALSE( | |
| 927 sender_->TimeUntilSend(QuicTime::Zero(), 4 * kDefaultTCPMSS).IsZero()); | |
| 928 } | |
| 929 | |
| 930 TEST_F(TcpCubicSenderPacketsTest, NoPRR) { | |
| 931 QuicTime::Delta rtt = QuicTime::Delta::FromMilliseconds(100); | |
| 932 sender_->rtt_stats_.UpdateRtt(rtt, QuicTime::Delta::Zero(), QuicTime::Zero()); | |
| 933 | |
| 934 sender_->SetNumEmulatedConnections(1); | |
| 935 // Verify that kCOPT: kNPRR allows all packets to be sent, even if only one | |
| 936 // ack has been received. | |
| 937 QuicTagVector options; | |
| 938 options.push_back(kNPRR); | |
| 939 QuicConfig config; | |
| 940 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 941 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 942 SendAvailableSendWindow(); | |
| 943 LoseNPackets(9); | |
| 944 AckNPackets(1); | |
| 945 | |
| 946 // We should now have fallen out of slow start with a reduced window. | |
| 947 EXPECT_EQ(kRenoBeta * kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 948 const QuicPacketCount window_in_packets = | |
| 949 kRenoBeta * kDefaultWindowTCP / kDefaultTCPMSS; | |
| 950 const QuicBandwidth expected_pacing_rate = | |
| 951 QuicBandwidth::FromBytesAndTimeDelta(kRenoBeta * kDefaultWindowTCP, | |
| 952 sender_->rtt_stats_.smoothed_rtt()); | |
| 953 EXPECT_EQ(expected_pacing_rate, sender_->PacingRate(0)); | |
| 954 EXPECT_EQ(window_in_packets, | |
| 955 static_cast<uint64_t>(SendAvailableSendWindow())); | |
| 956 EXPECT_EQ(expected_pacing_rate, | |
| 957 sender_->PacingRate(kRenoBeta * kDefaultWindowTCP)); | |
| 958 } | |
| 959 | |
| 960 TEST_F(TcpCubicSenderPacketsTest, PaceSlowerAboveCwnd) { | |
| 961 ValueRestore<bool> old_flag(&FLAGS_quic_rate_based_sending, true); | |
| 962 QuicTime::Delta rtt(QuicTime::Delta::FromMilliseconds(60)); | |
| 963 sender_->rtt_stats_.UpdateRtt(rtt, QuicTime::Delta::Zero(), clock_.Now()); | |
| 964 | |
| 965 QuicConfig config; | |
| 966 QuicTagVector options; | |
| 967 options.push_back(kRATE); | |
| 968 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 969 sender_->SetFromConfig(config, Perspective::IS_SERVER); | |
| 970 EXPECT_EQ(10u, sender_->congestion_window()); | |
| 971 sender_->SetNumEmulatedConnections(1); | |
| 972 // Lose a packet to exit slow start. | |
| 973 LoseNPackets(1); | |
| 974 const QuicPacketCount cwnd = 7; | |
| 975 EXPECT_EQ(cwnd * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 976 | |
| 977 EXPECT_TRUE( | |
| 978 sender_->TimeUntilSend(QuicTime::Zero(), kDefaultTCPMSS).IsZero()); | |
| 979 EXPECT_EQ( | |
| 980 sender_->PacingRate(kDefaultTCPMSS), | |
| 981 QuicBandwidth::FromBytesAndTimeDelta(7 * kDefaultTCPMSS, rtt) * 1.25); | |
| 982 for (QuicPacketCount i = cwnd + 1; i < 1.5 * cwnd; ++i) { | |
| 983 EXPECT_TRUE( | |
| 984 sender_->TimeUntilSend(QuicTime::Zero(), i * kDefaultTCPMSS).IsZero()); | |
| 985 EXPECT_EQ(sender_->PacingRate(i * kDefaultTCPMSS), | |
| 986 QuicBandwidth::FromBytesAndTimeDelta(cwnd * kDefaultTCPMSS, rtt) * | |
| 987 0.75); | |
| 988 } | |
| 989 EXPECT_FALSE( | |
| 990 sender_->TimeUntilSend(QuicTime::Zero(), 11 * kDefaultTCPMSS).IsZero()); | |
| 991 } | |
| 992 | |
| 993 TEST_F(TcpCubicSenderPacketsTest, ResetAfterConnectionMigration) { | |
| 994 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 995 EXPECT_EQ(kMaxCongestionWindowPackets, sender_->slowstart_threshold()); | |
| 996 | |
| 997 // Starts with slow start. | |
| 998 sender_->SetNumEmulatedConnections(1); | |
| 999 const int kNumberOfAcks = 10; | |
| 1000 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 1001 // Send our full send window. | |
| 1002 SendAvailableSendWindow(); | |
| 1003 AckNPackets(2); | |
| 1004 } | |
| 1005 SendAvailableSendWindow(); | |
| 1006 QuicByteCount expected_send_window = | |
| 1007 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 1008 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 1009 | |
| 1010 // Loses a packet to exit slow start. | |
| 1011 LoseNPackets(1); | |
| 1012 | |
| 1013 // We should now have fallen out of slow start with a reduced window. Slow | |
| 1014 // start threshold is also updated. | |
| 1015 expected_send_window *= kRenoBeta; | |
| 1016 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 1017 EXPECT_EQ(expected_send_window / kDefaultTCPMSS, | |
| 1018 sender_->slowstart_threshold()); | |
| 1019 | |
| 1020 // Resets cwnd and slow start threshold on connection migrations. | |
| 1021 sender_->OnConnectionMigration(); | |
| 1022 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 1023 EXPECT_EQ(kMaxCongestionWindowPackets, sender_->slowstart_threshold()); | |
| 1024 EXPECT_FALSE(sender_->hybrid_slow_start().started()); | |
| 1025 } | |
| 1026 | |
| 1027 TEST_F(TcpCubicSenderPacketsTest, DefaultMaxCwnd) { | |
| 1028 RttStats rtt_stats; | |
| 1029 QuicConnectionStats stats; | |
| 1030 std::unique_ptr<SendAlgorithmInterface> sender(SendAlgorithmInterface::Create( | |
| 1031 &clock_, &rtt_stats, kCubic, &stats, kInitialCongestionWindow)); | |
| 1032 | |
| 1033 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 1034 SendAlgorithmInterface::CongestionVector missing_packets; | |
| 1035 for (uint64_t i = 1; i < kDefaultMaxCongestionWindowPackets; ++i) { | |
| 1036 acked_packets.clear(); | |
| 1037 acked_packets.push_back(std::make_pair(i, 1350)); | |
| 1038 sender->OnCongestionEvent(true, sender->GetCongestionWindow(), | |
| 1039 acked_packets, missing_packets); | |
| 1040 } | |
| 1041 EXPECT_EQ(kDefaultMaxCongestionWindowPackets, | |
| 1042 sender->GetCongestionWindow() / kDefaultTCPMSS); | |
| 1043 } | |
| 1044 | |
| 1045 } // namespace test | |
| 1046 } // namespace net | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2193073003:
Move shared files in net/quic/ into net/quic/core/ (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master