| OLD | NEW |
|---|
| (Empty) |
| 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 <algorithm> | |
| 6 | |
| 7 #include "base/logging.h" | |
| 8 #include "base/memory/scoped_ptr.h" | |
| 9 #include "net/quic/congestion_control/rtt_stats.h" | |
| 10 #include "net/quic/congestion_control/tcp_cubic_sender.h" | |
| 11 #include "net/quic/crypto/crypto_protocol.h" | |
| 12 #include "net/quic/quic_protocol.h" | |
| 13 #include "net/quic/quic_utils.h" | |
| 14 #include "net/quic/test_tools/mock_clock.h" | |
| 15 #include "net/quic/test_tools/quic_config_peer.h" | |
| 16 #include "testing/gtest/include/gtest/gtest.h" | |
| 17 | |
| 18 using std::min; | |
| 19 | |
| 20 namespace net { | |
| 21 namespace test { | |
| 22 | |
| 23 // TODO(ianswett): A number of theses tests were written with the assumption of | |
| 24 // an initial CWND of 10. They have carefully calculated values which should be | |
| 25 // updated to be based on kInitialCongestionWindowInsecure. | |
| 26 const uint32 kInitialCongestionWindowPackets = 10; | |
| 27 const uint32 kDefaultWindowTCP = | |
| 28 kInitialCongestionWindowPackets * kDefaultTCPMSS; | |
| 29 const float kRenoBeta = 0.7f; // Reno backoff factor. | |
| 30 | |
| 31 class TcpCubicSenderPeer : public TcpCubicSender { | |
| 32 public: | |
| 33 TcpCubicSenderPeer(const QuicClock* clock, | |
| 34 bool reno, | |
| 35 QuicPacketCount max_tcp_congestion_window) | |
| 36 : TcpCubicSender( | |
| 37 clock, &rtt_stats_, reno, kInitialCongestionWindowPackets, | |
| 38 max_tcp_congestion_window, &stats_) { | |
| 39 } | |
| 40 | |
| 41 QuicPacketCount congestion_window() { | |
| 42 return congestion_window_; | |
| 43 } | |
| 44 | |
| 45 QuicPacketCount slowstart_threshold() { | |
| 46 return slowstart_threshold_; | |
| 47 } | |
| 48 | |
| 49 const HybridSlowStart& hybrid_slow_start() const { | |
| 50 return hybrid_slow_start_; | |
| 51 } | |
| 52 | |
| 53 float GetRenoBeta() const { | |
| 54 return RenoBeta(); | |
| 55 } | |
| 56 | |
| 57 RttStats rtt_stats_; | |
| 58 QuicConnectionStats stats_; | |
| 59 }; | |
| 60 | |
| 61 class TcpCubicSenderTest : public ::testing::Test { | |
| 62 protected: | |
| 63 TcpCubicSenderTest() | |
| 64 : one_ms_(QuicTime::Delta::FromMilliseconds(1)), | |
| 65 sender_(new TcpCubicSenderPeer(&clock_, true, | |
| 66 kMaxTcpCongestionWindow)), | |
| 67 sequence_number_(1), | |
| 68 acked_sequence_number_(0), | |
| 69 bytes_in_flight_(0) { | |
| 70 standard_packet_.bytes_sent = kDefaultTCPMSS; | |
| 71 } | |
| 72 | |
| 73 int SendAvailableSendWindow() { | |
| 74 // Send as long as TimeUntilSend returns Zero. | |
| 75 int packets_sent = 0; | |
| 76 bool can_send = sender_->TimeUntilSend( | |
| 77 clock_.Now(), bytes_in_flight_, HAS_RETRANSMITTABLE_DATA).IsZero(); | |
| 78 while (can_send) { | |
| 79 sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, sequence_number_++, | |
| 80 kDefaultTCPMSS, HAS_RETRANSMITTABLE_DATA); | |
| 81 ++packets_sent; | |
| 82 bytes_in_flight_ += kDefaultTCPMSS; | |
| 83 can_send = sender_->TimeUntilSend( | |
| 84 clock_.Now(), bytes_in_flight_, HAS_RETRANSMITTABLE_DATA).IsZero(); | |
| 85 } | |
| 86 return packets_sent; | |
| 87 } | |
| 88 | |
| 89 // Normal is that TCP acks every other segment. | |
| 90 void AckNPackets(int n) { | |
| 91 sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(60), | |
| 92 QuicTime::Delta::Zero(), | |
| 93 clock_.Now()); | |
| 94 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 95 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 96 for (int i = 0; i < n; ++i) { | |
| 97 ++acked_sequence_number_; | |
| 98 acked_packets.push_back( | |
| 99 std::make_pair(acked_sequence_number_, standard_packet_)); | |
| 100 } | |
| 101 sender_->OnCongestionEvent( | |
| 102 true, bytes_in_flight_, acked_packets, lost_packets); | |
| 103 bytes_in_flight_ -= n * kDefaultTCPMSS; | |
| 104 clock_.AdvanceTime(one_ms_); | |
| 105 } | |
| 106 | |
| 107 void LoseNPackets(int n) { | |
| 108 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 109 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 110 for (int i = 0; i < n; ++i) { | |
| 111 ++acked_sequence_number_; | |
| 112 lost_packets.push_back( | |
| 113 std::make_pair(acked_sequence_number_, standard_packet_)); | |
| 114 } | |
| 115 sender_->OnCongestionEvent( | |
| 116 false, bytes_in_flight_, acked_packets, lost_packets); | |
| 117 bytes_in_flight_ -= n * kDefaultTCPMSS; | |
| 118 } | |
| 119 | |
| 120 // Does not increment acked_sequence_number_. | |
| 121 void LosePacket(QuicPacketSequenceNumber sequence_number) { | |
| 122 SendAlgorithmInterface::CongestionVector acked_packets; | |
| 123 SendAlgorithmInterface::CongestionVector lost_packets; | |
| 124 lost_packets.push_back(std::make_pair(sequence_number, standard_packet_)); | |
| 125 sender_->OnCongestionEvent( | |
| 126 false, bytes_in_flight_, acked_packets, lost_packets); | |
| 127 bytes_in_flight_ -= kDefaultTCPMSS; | |
| 128 } | |
| 129 | |
| 130 const QuicTime::Delta one_ms_; | |
| 131 MockClock clock_; | |
| 132 scoped_ptr<TcpCubicSenderPeer> sender_; | |
| 133 QuicPacketSequenceNumber sequence_number_; | |
| 134 QuicPacketSequenceNumber acked_sequence_number_; | |
| 135 QuicByteCount bytes_in_flight_; | |
| 136 TransmissionInfo standard_packet_; | |
| 137 }; | |
| 138 | |
| 139 TEST_F(TcpCubicSenderTest, SimpleSender) { | |
| 140 // At startup make sure we are at the default. | |
| 141 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 142 // At startup make sure we can send. | |
| 143 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 144 0, | |
| 145 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 146 // Make sure we can send. | |
| 147 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 148 0, | |
| 149 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 150 // And that window is un-affected. | |
| 151 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 152 | |
| 153 // Fill the send window with data, then verify that we can't send. | |
| 154 SendAvailableSendWindow(); | |
| 155 EXPECT_FALSE(sender_->TimeUntilSend(clock_.Now(), | |
| 156 sender_->GetCongestionWindow(), | |
| 157 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 158 } | |
| 159 | |
| 160 TEST_F(TcpCubicSenderTest, ApplicationLimitedSlowStart) { | |
| 161 // Send exactly 10 packets and ensure the CWND ends at 14 packets. | |
| 162 const int kNumberOfAcks = 5; | |
| 163 // At startup make sure we can send. | |
| 164 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 165 0, | |
| 166 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 167 // Make sure we can send. | |
| 168 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 169 0, | |
| 170 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 171 | |
| 172 SendAvailableSendWindow(); | |
| 173 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 174 AckNPackets(2); | |
| 175 } | |
| 176 QuicByteCount bytes_to_send = sender_->GetCongestionWindow(); | |
| 177 // It's expected 2 acks will arrive when the bytes_in_flight are greater than | |
| 178 // half the CWND. | |
| 179 EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * 2, | |
| 180 bytes_to_send); | |
| 181 } | |
| 182 | |
| 183 TEST_F(TcpCubicSenderTest, ExponentialSlowStart) { | |
| 184 const int kNumberOfAcks = 20; | |
| 185 // At startup make sure we can send. | |
| 186 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 187 0, | |
| 188 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 189 EXPECT_FALSE(sender_->HasReliableBandwidthEstimate()); | |
| 190 EXPECT_EQ(QuicBandwidth::Zero(), sender_->BandwidthEstimate()); | |
| 191 // Make sure we can send. | |
| 192 EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), | |
| 193 0, | |
| 194 HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 195 | |
| 196 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 197 // Send our full send window. | |
| 198 SendAvailableSendWindow(); | |
| 199 AckNPackets(2); | |
| 200 } | |
| 201 const QuicByteCount cwnd = sender_->GetCongestionWindow(); | |
| 202 EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * kNumberOfAcks, cwnd); | |
| 203 EXPECT_FALSE(sender_->HasReliableBandwidthEstimate()); | |
| 204 EXPECT_EQ(QuicBandwidth::FromBytesAndTimeDelta( | |
| 205 cwnd, sender_->rtt_stats_.smoothed_rtt()), | |
| 206 sender_->BandwidthEstimate()); | |
| 207 } | |
| 208 | |
| 209 TEST_F(TcpCubicSenderTest, SlowStartAckTrain) { | |
| 210 sender_->SetNumEmulatedConnections(1); | |
| 211 EXPECT_EQ(kMaxTcpCongestionWindow * kDefaultTCPMSS, | |
| 212 sender_->GetSlowStartThreshold()); | |
| 213 | |
| 214 // Make sure that we fall out of slow start when we send ACK train longer | |
| 215 // than half the RTT, in this test case 30ms, which is more than 30 calls to | |
| 216 // Ack2Packets in one round. | |
| 217 // Since we start at 10 packet first round will be 5 second round 10 etc | |
| 218 // Hence we should pass 30 at 65 = 5 + 10 + 20 + 30 | |
| 219 const int kNumberOfAcks = 65; | |
| 220 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 221 // Send our full send window. | |
| 222 SendAvailableSendWindow(); | |
| 223 AckNPackets(2); | |
| 224 } | |
| 225 QuicByteCount expected_send_window = | |
| 226 kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 227 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 228 | |
| 229 // We should now have fallen out of slow start. | |
| 230 // Testing Reno phase. | |
| 231 // We should need 140(65*2+10) ACK:ed packets before increasing window by | |
| 232 // one. | |
| 233 for (int i = 0; i < 69; ++i) { | |
| 234 SendAvailableSendWindow(); | |
| 235 AckNPackets(2); | |
| 236 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 237 } | |
| 238 SendAvailableSendWindow(); | |
| 239 AckNPackets(2); | |
| 240 QuicByteCount expected_ss_tresh = expected_send_window; | |
| 241 expected_send_window += kDefaultTCPMSS; | |
| 242 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 243 EXPECT_EQ(expected_ss_tresh, sender_->GetSlowStartThreshold()); | |
| 244 EXPECT_EQ(140u, sender_->slowstart_threshold()); | |
| 245 | |
| 246 // Now RTO and ensure slow start gets reset. | |
| 247 EXPECT_TRUE(sender_->hybrid_slow_start().started()); | |
| 248 sender_->OnRetransmissionTimeout(true); | |
| 249 EXPECT_FALSE(sender_->hybrid_slow_start().started()); | |
| 250 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 251 EXPECT_EQ(expected_send_window / 2 / kDefaultTCPMSS, | |
| 252 sender_->slowstart_threshold()); | |
| 253 | |
| 254 // Now revert the RTO and ensure the CWND and slowstart threshold revert. | |
| 255 sender_->RevertRetransmissionTimeout(); | |
| 256 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 257 EXPECT_EQ(140u, sender_->slowstart_threshold()); | |
| 258 } | |
| 259 | |
| 260 TEST_F(TcpCubicSenderTest, SlowStartPacketLoss) { | |
| 261 sender_->SetNumEmulatedConnections(1); | |
| 262 const int kNumberOfAcks = 10; | |
| 263 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 264 // Send our full send window. | |
| 265 SendAvailableSendWindow(); | |
| 266 AckNPackets(2); | |
| 267 } | |
| 268 SendAvailableSendWindow(); | |
| 269 QuicByteCount expected_send_window = kDefaultWindowTCP + | |
| 270 (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 271 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 272 | |
| 273 // Lose a packet to exit slow start. | |
| 274 LoseNPackets(1); | |
| 275 size_t packets_in_recovery_window = expected_send_window / kDefaultTCPMSS; | |
| 276 | |
| 277 // We should now have fallen out of slow start with a reduced window. | |
| 278 expected_send_window *= kRenoBeta; | |
| 279 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 280 | |
| 281 // Recovery phase. We need to ack every packet in the recovery window before | |
| 282 // we exit recovery. | |
| 283 size_t number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; | |
| 284 DVLOG(1) << "number_packets: " << number_of_packets_in_window; | |
| 285 AckNPackets(packets_in_recovery_window); | |
| 286 SendAvailableSendWindow(); | |
| 287 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 288 | |
| 289 // We need to ack an entire window before we increase CWND by 1. | |
| 290 AckNPackets(number_of_packets_in_window - 2); | |
| 291 SendAvailableSendWindow(); | |
| 292 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 293 | |
| 294 // Next ack should increase cwnd by 1. | |
| 295 AckNPackets(1); | |
| 296 expected_send_window += kDefaultTCPMSS; | |
| 297 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 298 | |
| 299 // Now RTO and ensure slow start gets reset. | |
| 300 EXPECT_TRUE(sender_->hybrid_slow_start().started()); | |
| 301 sender_->OnRetransmissionTimeout(true); | |
| 302 EXPECT_FALSE(sender_->hybrid_slow_start().started()); | |
| 303 } | |
| 304 | |
| 305 TEST_F(TcpCubicSenderTest, NoPRRWhenLessThanOnePacketInFlight) { | |
| 306 SendAvailableSendWindow(); | |
| 307 LoseNPackets(kInitialCongestionWindowPackets - 1); | |
| 308 AckNPackets(1); | |
| 309 // PRR will allow 2 packets for every ack during recovery. | |
| 310 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 311 // Simulate abandoning all packets by supplying a bytes_in_flight of 0. | |
| 312 // PRR should now allow a packet to be sent, even though prr's state | |
| 313 // variables believe it has sent enough packets. | |
| 314 EXPECT_EQ(QuicTime::Delta::Zero(), | |
| 315 sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)); | |
| 316 } | |
| 317 | |
| 318 TEST_F(TcpCubicSenderTest, SlowStartPacketLossPRR) { | |
| 319 sender_->SetNumEmulatedConnections(1); | |
| 320 // Test based on the first example in RFC6937. | |
| 321 // Ack 10 packets in 5 acks to raise the CWND to 20, as in the example. | |
| 322 const int kNumberOfAcks = 5; | |
| 323 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 324 // Send our full send window. | |
| 325 SendAvailableSendWindow(); | |
| 326 AckNPackets(2); | |
| 327 } | |
| 328 SendAvailableSendWindow(); | |
| 329 QuicByteCount expected_send_window = kDefaultWindowTCP + | |
| 330 (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 331 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 332 | |
| 333 LoseNPackets(1); | |
| 334 | |
| 335 // We should now have fallen out of slow start with a reduced window. | |
| 336 size_t send_window_before_loss = expected_send_window; | |
| 337 expected_send_window *= kRenoBeta; | |
| 338 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 339 | |
| 340 // Testing TCP proportional rate reduction. | |
| 341 // We should send packets paced over the received acks for the remaining | |
| 342 // outstanding packets. The number of packets before we exit recovery is the | |
| 343 // original CWND minus the packet that has been lost and the one which | |
| 344 // triggered the loss. | |
| 345 size_t remaining_packets_in_recovery = | |
| 346 send_window_before_loss / kDefaultTCPMSS - 2; | |
| 347 | |
| 348 for (size_t i = 0; i < remaining_packets_in_recovery; ++i) { | |
| 349 AckNPackets(1); | |
| 350 SendAvailableSendWindow(); | |
| 351 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 352 } | |
| 353 | |
| 354 // We need to ack another window before we increase CWND by 1. | |
| 355 size_t number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; | |
| 356 for (size_t i = 0; i < number_of_packets_in_window; ++i) { | |
| 357 AckNPackets(1); | |
| 358 EXPECT_EQ(1, SendAvailableSendWindow()); | |
| 359 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 360 } | |
| 361 | |
| 362 AckNPackets(1); | |
| 363 expected_send_window += kDefaultTCPMSS; | |
| 364 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 365 } | |
| 366 | |
| 367 TEST_F(TcpCubicSenderTest, SlowStartBurstPacketLossPRR) { | |
| 368 sender_->SetNumEmulatedConnections(1); | |
| 369 // Test based on the second example in RFC6937, though we also implement | |
| 370 // forward acknowledgements, so the first two incoming acks will trigger | |
| 371 // PRR immediately. | |
| 372 // Ack 20 packets in 10 acks to raise the CWND to 30. | |
| 373 const int kNumberOfAcks = 10; | |
| 374 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 375 // Send our full send window. | |
| 376 SendAvailableSendWindow(); | |
| 377 AckNPackets(2); | |
| 378 } | |
| 379 SendAvailableSendWindow(); | |
| 380 QuicByteCount expected_send_window = kDefaultWindowTCP + | |
| 381 (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 382 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 383 | |
| 384 // Lose one more than the congestion window reduction, so that after loss, | |
| 385 // bytes_in_flight is lesser than the congestion window. | |
| 386 size_t send_window_after_loss = kRenoBeta * expected_send_window; | |
| 387 size_t num_packets_to_lose = | |
| 388 (expected_send_window - send_window_after_loss) / kDefaultTCPMSS + 1; | |
| 389 LoseNPackets(num_packets_to_lose); | |
| 390 // Immediately after the loss, ensure at least one packet can be sent. | |
| 391 // Losses without subsequent acks can occur with timer based loss detection. | |
| 392 EXPECT_TRUE(sender_->TimeUntilSend( | |
| 393 clock_.Now(), bytes_in_flight_, HAS_RETRANSMITTABLE_DATA).IsZero()); | |
| 394 AckNPackets(1); | |
| 395 | |
| 396 // We should now have fallen out of slow start with a reduced window. | |
| 397 expected_send_window *= kRenoBeta; | |
| 398 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 399 | |
| 400 // Only 2 packets should be allowed to be sent, per PRR-SSRB | |
| 401 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 402 | |
| 403 // Ack the next packet, which triggers another loss. | |
| 404 LoseNPackets(1); | |
| 405 AckNPackets(1); | |
| 406 | |
| 407 // Send 2 packets to simulate PRR-SSRB. | |
| 408 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 409 | |
| 410 // Ack the next packet, which triggers another loss. | |
| 411 LoseNPackets(1); | |
| 412 AckNPackets(1); | |
| 413 | |
| 414 // Send 2 packets to simulate PRR-SSRB. | |
| 415 EXPECT_EQ(2, SendAvailableSendWindow()); | |
| 416 | |
| 417 // Exit recovery and return to sending at the new rate. | |
| 418 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 419 AckNPackets(1); | |
| 420 EXPECT_EQ(1, SendAvailableSendWindow()); | |
| 421 } | |
| 422 } | |
| 423 | |
| 424 TEST_F(TcpCubicSenderTest, RTOCongestionWindowAndRevert) { | |
| 425 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 426 EXPECT_EQ(kMaxTcpCongestionWindow, sender_->slowstart_threshold()); | |
| 427 | |
| 428 // Expect the window to decrease to the minimum once the RTO fires | |
| 429 // and slow start threshold to be set to 1/2 of the CWND. | |
| 430 sender_->OnRetransmissionTimeout(true); | |
| 431 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 432 EXPECT_EQ(5u, sender_->slowstart_threshold()); | |
| 433 | |
| 434 // Now repair the RTO and ensure the slowstart threshold reverts. | |
| 435 sender_->RevertRetransmissionTimeout(); | |
| 436 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 437 EXPECT_EQ(kMaxTcpCongestionWindow, sender_->slowstart_threshold()); | |
| 438 } | |
| 439 | |
| 440 TEST_F(TcpCubicSenderTest, RTOCongestionWindowNoRetransmission) { | |
| 441 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 442 | |
| 443 // Expect the window to remain unchanged if the RTO fires but no | |
| 444 // packets are retransmitted. | |
| 445 sender_->OnRetransmissionTimeout(false); | |
| 446 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 447 } | |
| 448 | |
| 449 TEST_F(TcpCubicSenderTest, RTOTwiceOnlyHalvesSsthresh) { | |
| 450 EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); | |
| 451 | |
| 452 sender_->OnRetransmissionTimeout(true); | |
| 453 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 454 EXPECT_EQ(5u, sender_->slowstart_threshold()); | |
| 455 | |
| 456 sender_->OnRetransmissionTimeout(true); | |
| 457 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 458 EXPECT_EQ(5u, sender_->slowstart_threshold()); | |
| 459 | |
| 460 AckNPackets(2); | |
| 461 | |
| 462 EXPECT_EQ(4 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 463 EXPECT_EQ(5u, sender_->slowstart_threshold()); | |
| 464 | |
| 465 sender_->OnRetransmissionTimeout(true); | |
| 466 EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow()); | |
| 467 EXPECT_EQ(2u, sender_->slowstart_threshold()); | |
| 468 } | |
| 469 | |
| 470 TEST_F(TcpCubicSenderTest, RetransmissionDelay) { | |
| 471 const int64 kRttMs = 10; | |
| 472 const int64 kDeviationMs = 3; | |
| 473 EXPECT_EQ(QuicTime::Delta::Zero(), sender_->RetransmissionDelay()); | |
| 474 | |
| 475 sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(kRttMs), | |
| 476 QuicTime::Delta::Zero(), clock_.Now()); | |
| 477 | |
| 478 // Initial value is to set the median deviation to half of the initial | |
| 479 // rtt, the median in then multiplied by a factor of 4 and finally the | |
| 480 // smoothed rtt is added which is the initial rtt. | |
| 481 QuicTime::Delta expected_delay = | |
| 482 QuicTime::Delta::FromMilliseconds(kRttMs + kRttMs / 2 * 4); | |
| 483 EXPECT_EQ(expected_delay, sender_->RetransmissionDelay()); | |
| 484 | |
| 485 for (int i = 0; i < 100; ++i) { | |
| 486 // Run to make sure that we converge. | |
| 487 sender_->rtt_stats_.UpdateRtt( | |
| 488 QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs), | |
| 489 QuicTime::Delta::Zero(), clock_.Now()); | |
| 490 sender_->rtt_stats_.UpdateRtt( | |
| 491 QuicTime::Delta::FromMilliseconds(kRttMs - kDeviationMs), | |
| 492 QuicTime::Delta::Zero(), clock_.Now()); | |
| 493 } | |
| 494 expected_delay = QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs * 4); | |
| 495 | |
| 496 EXPECT_NEAR(kRttMs, sender_->rtt_stats_.smoothed_rtt().ToMilliseconds(), 1); | |
| 497 EXPECT_NEAR(expected_delay.ToMilliseconds(), | |
| 498 sender_->RetransmissionDelay().ToMilliseconds(), | |
| 499 1); | |
| 500 EXPECT_EQ(static_cast<int64>( | |
| 501 sender_->GetCongestionWindow() * kNumMicrosPerSecond / | |
| 502 sender_->rtt_stats_.smoothed_rtt().ToMicroseconds()), | |
| 503 sender_->BandwidthEstimate().ToBytesPerSecond()); | |
| 504 } | |
| 505 | |
| 506 TEST_F(TcpCubicSenderTest, SlowStartMaxSendWindow) { | |
| 507 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 508 const int kNumberOfAcks = 100; | |
| 509 sender_.reset( | |
| 510 new TcpCubicSenderPeer(&clock_, false, kMaxCongestionWindowTCP)); | |
| 511 | |
| 512 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 513 // Send our full send window. | |
| 514 SendAvailableSendWindow(); | |
| 515 AckNPackets(2); | |
| 516 } | |
| 517 QuicByteCount expected_send_window = | |
| 518 kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 519 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 520 } | |
| 521 | |
| 522 TEST_F(TcpCubicSenderTest, TcpRenoMaxCongestionWindow) { | |
| 523 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 524 const int kNumberOfAcks = 1000; | |
| 525 sender_.reset( | |
| 526 new TcpCubicSenderPeer(&clock_, true, kMaxCongestionWindowTCP)); | |
| 527 | |
| 528 SendAvailableSendWindow(); | |
| 529 AckNPackets(2); | |
| 530 // Make sure we fall out of slow start. | |
| 531 LoseNPackets(1); | |
| 532 | |
| 533 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 534 // Send our full send window. | |
| 535 SendAvailableSendWindow(); | |
| 536 AckNPackets(2); | |
| 537 } | |
| 538 | |
| 539 QuicByteCount expected_send_window = | |
| 540 kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 541 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 542 } | |
| 543 | |
| 544 TEST_F(TcpCubicSenderTest, TcpCubicMaxCongestionWindow) { | |
| 545 const QuicPacketCount kMaxCongestionWindowTCP = 50; | |
| 546 // Set to 10000 to compensate for small cubic alpha. | |
| 547 const int kNumberOfAcks = 10000; | |
| 548 | |
| 549 sender_.reset( | |
| 550 new TcpCubicSenderPeer(&clock_, false, kMaxCongestionWindowTCP)); | |
| 551 | |
| 552 SendAvailableSendWindow(); | |
| 553 AckNPackets(2); | |
| 554 // Make sure we fall out of slow start. | |
| 555 LoseNPackets(1); | |
| 556 | |
| 557 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 558 // Send our full send window. | |
| 559 SendAvailableSendWindow(); | |
| 560 AckNPackets(2); | |
| 561 } | |
| 562 | |
| 563 QuicByteCount expected_send_window = | |
| 564 kMaxCongestionWindowTCP * kDefaultTCPMSS; | |
| 565 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 566 } | |
| 567 | |
| 568 TEST_F(TcpCubicSenderTest, MultipleLossesInOneWindow) { | |
| 569 SendAvailableSendWindow(); | |
| 570 const QuicByteCount initial_window = sender_->GetCongestionWindow(); | |
| 571 LosePacket(acked_sequence_number_ + 1); | |
| 572 const QuicByteCount post_loss_window = sender_->GetCongestionWindow(); | |
| 573 EXPECT_GT(initial_window, post_loss_window); | |
| 574 LosePacket(acked_sequence_number_ + 3); | |
| 575 EXPECT_EQ(post_loss_window, sender_->GetCongestionWindow()); | |
| 576 LosePacket(sequence_number_ - 1); | |
| 577 EXPECT_EQ(post_loss_window, sender_->GetCongestionWindow()); | |
| 578 | |
| 579 // Lose a later packet and ensure the window decreases. | |
| 580 LosePacket(sequence_number_); | |
| 581 EXPECT_GT(post_loss_window, sender_->GetCongestionWindow()); | |
| 582 } | |
| 583 | |
| 584 TEST_F(TcpCubicSenderTest, DontTrackAckPackets) { | |
| 585 // Send a packet with no retransmittable data, and ensure it's not tracked. | |
| 586 EXPECT_FALSE(sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, | |
| 587 sequence_number_++, kDefaultTCPMSS, | |
| 588 NO_RETRANSMITTABLE_DATA)); | |
| 589 | |
| 590 // Send a data packet with retransmittable data, and ensure it is tracked. | |
| 591 EXPECT_TRUE(sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, | |
| 592 sequence_number_++, kDefaultTCPMSS, | |
| 593 HAS_RETRANSMITTABLE_DATA)); | |
| 594 } | |
| 595 | |
| 596 TEST_F(TcpCubicSenderTest, ConfigureMaxInitialWindow) { | |
| 597 QuicConfig config; | |
| 598 | |
| 599 // Verify that kCOPT: kIW10 forces the congestion window to the default of 10. | |
| 600 QuicTagVector options; | |
| 601 options.push_back(kIW10); | |
| 602 QuicConfigPeer::SetReceivedConnectionOptions(&config, options); | |
| 603 sender_->SetFromConfig(config, | |
| 604 /* is_server= */ true, | |
| 605 /* using_pacing= */ false); | |
| 606 EXPECT_EQ(10u, sender_->congestion_window()); | |
| 607 } | |
| 608 | |
| 609 TEST_F(TcpCubicSenderTest, DisableAckTrainDetectionWithPacing) { | |
| 610 EXPECT_TRUE(sender_->hybrid_slow_start().ack_train_detection()); | |
| 611 | |
| 612 QuicConfig config; | |
| 613 sender_->SetFromConfig(config, | |
| 614 /* is_server= */ true, | |
| 615 /* using_pacing= */ true); | |
| 616 EXPECT_FALSE(sender_->hybrid_slow_start().ack_train_detection()); | |
| 617 } | |
| 618 | |
| 619 TEST_F(TcpCubicSenderTest, 2ConnectionCongestionAvoidanceAtEndOfRecovery) { | |
| 620 sender_->SetNumEmulatedConnections(2); | |
| 621 // Ack 10 packets in 5 acks to raise the CWND to 20. | |
| 622 const int kNumberOfAcks = 5; | |
| 623 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 624 // Send our full send window. | |
| 625 SendAvailableSendWindow(); | |
| 626 AckNPackets(2); | |
| 627 } | |
| 628 SendAvailableSendWindow(); | |
| 629 QuicByteCount expected_send_window = kDefaultWindowTCP + | |
| 630 (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 631 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 632 | |
| 633 LoseNPackets(1); | |
| 634 | |
| 635 // We should now have fallen out of slow start with a reduced window. | |
| 636 expected_send_window = expected_send_window * sender_->GetRenoBeta(); | |
| 637 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 638 | |
| 639 // No congestion window growth should occur in recovery phase, i.e., until the | |
| 640 // currently outstanding 20 packets are acked. | |
| 641 for (int i = 0; i < 10; ++i) { | |
| 642 // Send our full send window. | |
| 643 SendAvailableSendWindow(); | |
| 644 EXPECT_TRUE(sender_->InRecovery()); | |
| 645 AckNPackets(2); | |
| 646 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 647 } | |
| 648 EXPECT_FALSE(sender_->InRecovery()); | |
| 649 | |
| 650 // Out of recovery now. Congestion window should not grow for half an RTT. | |
| 651 size_t packets_in_send_window = expected_send_window / kDefaultTCPMSS; | |
| 652 SendAvailableSendWindow(); | |
| 653 AckNPackets(packets_in_send_window / 2 - 2); | |
| 654 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 655 | |
| 656 // Next ack should increase congestion window by 1MSS. | |
| 657 SendAvailableSendWindow(); | |
| 658 AckNPackets(2); | |
| 659 expected_send_window += kDefaultTCPMSS; | |
| 660 packets_in_send_window += 1; | |
| 661 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 662 | |
| 663 // Congestion window should remain steady again for half an RTT. | |
| 664 SendAvailableSendWindow(); | |
| 665 AckNPackets(packets_in_send_window / 2 - 1); | |
| 666 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 667 | |
| 668 // Next ack should cause congestion window to grow by 1MSS. | |
| 669 SendAvailableSendWindow(); | |
| 670 AckNPackets(2); | |
| 671 expected_send_window += kDefaultTCPMSS; | |
| 672 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 673 } | |
| 674 | |
| 675 TEST_F(TcpCubicSenderTest, 1ConnectionCongestionAvoidanceAtEndOfRecovery) { | |
| 676 sender_->SetNumEmulatedConnections(1); | |
| 677 // Ack 10 packets in 5 acks to raise the CWND to 20. | |
| 678 const int kNumberOfAcks = 5; | |
| 679 for (int i = 0; i < kNumberOfAcks; ++i) { | |
| 680 // Send our full send window. | |
| 681 SendAvailableSendWindow(); | |
| 682 AckNPackets(2); | |
| 683 } | |
| 684 SendAvailableSendWindow(); | |
| 685 QuicByteCount expected_send_window = kDefaultWindowTCP + | |
| 686 (kDefaultTCPMSS * 2 * kNumberOfAcks); | |
| 687 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 688 | |
| 689 LoseNPackets(1); | |
| 690 | |
| 691 // We should now have fallen out of slow start with a reduced window. | |
| 692 expected_send_window *= kRenoBeta; | |
| 693 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 694 | |
| 695 // No congestion window growth should occur in recovery phase, i.e., until the | |
| 696 // currently outstanding 20 packets are acked. | |
| 697 for (int i = 0; i < 10; ++i) { | |
| 698 // Send our full send window. | |
| 699 SendAvailableSendWindow(); | |
| 700 EXPECT_TRUE(sender_->InRecovery()); | |
| 701 AckNPackets(2); | |
| 702 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 703 } | |
| 704 EXPECT_FALSE(sender_->InRecovery()); | |
| 705 | |
| 706 // Out of recovery now. Congestion window should not grow during RTT. | |
| 707 for (uint64 i = 0; i < expected_send_window / kDefaultTCPMSS - 2; i += 2) { | |
| 708 // Send our full send window. | |
| 709 SendAvailableSendWindow(); | |
| 710 AckNPackets(2); | |
| 711 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 712 } | |
| 713 | |
| 714 // Next ack should cause congestion window to grow by 1MSS. | |
| 715 SendAvailableSendWindow(); | |
| 716 AckNPackets(2); | |
| 717 expected_send_window += kDefaultTCPMSS; | |
| 718 EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); | |
| 719 } | |
| 720 | |
| 721 TEST_F(TcpCubicSenderTest, BandwidthResumption) { | |
| 722 // Test that when provided with CachedNetworkParameters and opted in to the | |
| 723 // bandwidth resumption experiment, that the TcpCubicSender sets initial CWND | |
| 724 // appropriately. | |
| 725 | |
| 726 // Set some common values. | |
| 727 CachedNetworkParameters cached_network_params; | |
| 728 const QuicPacketCount kNumberOfPackets = 123; | |
| 729 const int kBandwidthEstimateBytesPerSecond = | |
| 730 kNumberOfPackets * kMaxPacketSize; | |
| 731 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 732 kBandwidthEstimateBytesPerSecond); | |
| 733 cached_network_params.set_min_rtt_ms(1000); | |
| 734 | |
| 735 // Ensure that an old estimate is not used for bandwidth resumption. | |
| 736 cached_network_params.set_timestamp(clock_.WallNow().ToUNIXSeconds() - | |
| 737 (kNumSecondsPerHour + 1)); | |
| 738 EXPECT_FALSE(sender_->ResumeConnectionState(cached_network_params)); | |
| 739 EXPECT_EQ(10u, sender_->congestion_window()); | |
| 740 | |
| 741 // If the estimate is new enough, make sure it is used. | |
| 742 cached_network_params.set_timestamp(clock_.WallNow().ToUNIXSeconds() - | |
| 743 (kNumSecondsPerHour - 1)); | |
| 744 EXPECT_TRUE(sender_->ResumeConnectionState(cached_network_params)); | |
| 745 EXPECT_EQ(kNumberOfPackets, sender_->congestion_window()); | |
| 746 | |
| 747 // Resumed CWND is limited to be in a sensible range. | |
| 748 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 749 (kMaxTcpCongestionWindow + 1) * kMaxPacketSize); | |
| 750 EXPECT_TRUE(sender_->ResumeConnectionState(cached_network_params)); | |
| 751 EXPECT_EQ(kMaxTcpCongestionWindow, sender_->congestion_window()); | |
| 752 | |
| 753 cached_network_params.set_bandwidth_estimate_bytes_per_second( | |
| 754 (kMinCongestionWindowForBandwidthResumption - 1) * kMaxPacketSize); | |
| 755 EXPECT_TRUE(sender_->ResumeConnectionState(cached_network_params)); | |
| 756 EXPECT_EQ(kMinCongestionWindowForBandwidthResumption, | |
| 757 sender_->congestion_window()); | |
| 758 } | |
| 759 | |
| 760 } // namespace test | |
| 761 } // namespace net | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 992733002:
Remove //net (except for Android test stuff) and sdch (Closed)
Base URL: git@github.com:domokit/mojo.git@master