| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/logging.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "net/quic/congestion_control/tcp_cubic_sender.h" |
| #include "net/quic/congestion_control/tcp_receiver.h" |
| #include "net/quic/test_tools/mock_clock.h" |
| #include "testing/gtest/include/gtest/gtest.h" |
| |
| namespace net { |
| namespace test { |
| |
| const uint32 kDefaultWindowTCP = 10 * kDefaultTCPMSS; |
| |
| // TODO(ianswett): Remove 10000 once b/10075719 is fixed. |
| const QuicTcpCongestionWindow kDefaultMaxCongestionWindowTCP = 10000; |
| |
| class TcpCubicSenderPeer : public TcpCubicSender { |
| public: |
| TcpCubicSenderPeer(const QuicClock* clock, |
| bool reno, |
| QuicTcpCongestionWindow max_tcp_congestion_window) |
| : TcpCubicSender(clock, reno, max_tcp_congestion_window) { |
| } |
| |
| QuicTcpCongestionWindow congestion_window() { |
| return congestion_window_; |
| } |
| |
| using TcpCubicSender::AvailableSendWindow; |
| using TcpCubicSender::SendWindow; |
| using TcpCubicSender::AckAccounting; |
| }; |
| |
| class TcpCubicSenderTest : public ::testing::Test { |
| protected: |
| TcpCubicSenderTest() |
| : rtt_(QuicTime::Delta::FromMilliseconds(60)), |
| one_ms_(QuicTime::Delta::FromMilliseconds(1)), |
| sender_(new TcpCubicSenderPeer(&clock_, true, |
| kDefaultMaxCongestionWindowTCP)), |
| receiver_(new TcpReceiver()), |
| sequence_number_(1), |
| acked_sequence_number_(0) { |
| } |
| |
| void SendAvailableSendWindow() { |
| QuicByteCount bytes_to_send = sender_->AvailableSendWindow(); |
| while (bytes_to_send > 0) { |
| QuicByteCount bytes_in_packet = std::min(kDefaultTCPMSS, bytes_to_send); |
| sender_->OnPacketSent(clock_.Now(), sequence_number_++, bytes_in_packet, |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA); |
| bytes_to_send -= bytes_in_packet; |
| if (bytes_to_send > 0) { |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), NOT_RETRANSMISSION, |
| HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| } |
| } |
| } |
| // Normal is that TCP acks every other segment. |
| void AckNPackets(int n) { |
| for (int i = 0; i < n; ++i) { |
| acked_sequence_number_++; |
| sender_->OnIncomingAck(acked_sequence_number_, kDefaultTCPMSS, rtt_); |
| } |
| clock_.AdvanceTime(one_ms_); // 1 millisecond. |
| } |
| |
| const QuicTime::Delta rtt_; |
| const QuicTime::Delta one_ms_; |
| MockClock clock_; |
| SendAlgorithmInterface::SentPacketsMap not_used_; |
| scoped_ptr<TcpCubicSenderPeer> sender_; |
| scoped_ptr<TcpReceiver> receiver_; |
| QuicPacketSequenceNumber sequence_number_; |
| QuicPacketSequenceNumber acked_sequence_number_; |
| }; |
| |
| TEST_F(TcpCubicSenderTest, SimpleSender) { |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we are at the default. |
| EXPECT_EQ(kDefaultWindowTCP, sender_->AvailableSendWindow()); |
| EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // And that window is un-affected. |
| EXPECT_EQ(kDefaultWindowTCP, sender_->AvailableSendWindow()); |
| EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow()); |
| |
| // A retransmit should always return 0. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NACK_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, ExponentialSlowStart) { |
| const int kNumberOfAck = 20; |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| for (int n = 0; n < kNumberOfAck; ++n) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| QuicByteCount bytes_to_send = sender_->SendWindow(); |
| EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * kNumberOfAck, |
| bytes_to_send); |
| } |
| |
| TEST_F(TcpCubicSenderTest, SlowStartAckTrain) { |
| // Make sure that we fall out of slow start when we send ACK train longer |
| // than half the RTT, in this test case 30ms, which is more than 30 calls to |
| // Ack2Packets in one round. |
| // Since we start at 10 packet first round will be 5 second round 10 etc |
| // Hence we should pass 30 at 65 = 5 + 10 + 20 + 30 |
| const int kNumberOfAck = 65; |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| for (int n = 0; n < kNumberOfAck; ++n) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| QuicByteCount expected_send_window = |
| kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAck); |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow()); |
| // We should now have fallen out of slow start. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| expected_send_window += kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| |
| // Testing Reno phase. |
| // We should need 141(65*2+1+10) ACK:ed packets before increasing window by |
| // one. |
| for (int m = 0; m < 70; ++m) { |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| expected_send_window += kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, SlowStartPacketLoss) { |
| // Make sure that we fall out of slow start when we encounter a packet loss. |
| const int kNumberOfAck = 10; |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| for (int i = 0; i < kNumberOfAck; ++i) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| SendAvailableSendWindow(); |
| QuicByteCount expected_send_window = kDefaultWindowTCP + |
| (kDefaultTCPMSS * 2 * kNumberOfAck); |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| |
| sender_->OnIncomingLoss(clock_.Now()); |
| |
| // Make sure that we should not send right now. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), NOT_RETRANSMISSION, |
| HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsInfinite()); |
| |
| // We should now have fallen out of slow start. |
| // We expect window to be cut in half. |
| expected_send_window /= 2; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| |
| // Testing Reno phase. |
| // We need to ack half of the pending packet before we can send again. |
| int number_of_packets_in_window = expected_send_window / kDefaultTCPMSS; |
| AckNPackets(number_of_packets_in_window); |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| EXPECT_EQ(0u, sender_->AvailableSendWindow()); |
| |
| AckNPackets(1); |
| expected_send_window += kDefaultTCPMSS; |
| number_of_packets_in_window++; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| |
| // We should need number_of_packets_in_window ACK:ed packets before |
| // increasing window by one. |
| for (int k = 0; k < number_of_packets_in_window; ++k) { |
| SendAvailableSendWindow(); |
| AckNPackets(1); |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| SendAvailableSendWindow(); |
| AckNPackets(1); |
| expected_send_window += kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, RetransmissionDelay) { |
| const int64 kRttMs = 10; |
| const int64 kDeviationMs = 3; |
| EXPECT_EQ(QuicTime::Delta::Zero(), sender_->RetransmissionDelay()); |
| |
| sender_->AckAccounting(QuicTime::Delta::FromMilliseconds(kRttMs)); |
| |
| // Initial value is to set the median deviation to half of the initial |
| // rtt, the median in then multiplied by a factor of 4 and finally the |
| // smoothed rtt is added which is the initial rtt. |
| QuicTime::Delta expected_delay = |
| QuicTime::Delta::FromMilliseconds(kRttMs + kRttMs / 2 * 4); |
| EXPECT_EQ(expected_delay, sender_->RetransmissionDelay()); |
| |
| for (int i = 0; i < 100; ++i) { |
| // Run to make sure that we converge. |
| sender_->AckAccounting( |
| QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs)); |
| sender_->AckAccounting( |
| QuicTime::Delta::FromMilliseconds(kRttMs - kDeviationMs)); |
| } |
| expected_delay = QuicTime::Delta::FromMilliseconds(kRttMs + kDeviationMs * 4); |
| |
| EXPECT_NEAR(kRttMs, sender_->SmoothedRtt().ToMilliseconds(), 1); |
| EXPECT_NEAR(expected_delay.ToMilliseconds(), |
| sender_->RetransmissionDelay().ToMilliseconds(), |
| 1); |
| } |
| |
| TEST_F(TcpCubicSenderTest, SlowStartMaxSendWindow) { |
| const QuicTcpCongestionWindow kMaxCongestionWindowTCP = 50; |
| const int kNumberOfAck = 100; |
| sender_.reset( |
| new TcpCubicSenderPeer(&clock_, false, kMaxCongestionWindowTCP)); |
| |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| for (int i = 0; i < kNumberOfAck; ++i) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| QuicByteCount expected_send_window = |
| kMaxCongestionWindowTCP * kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, TcpRenoMaxCongestionWindow) { |
| const QuicTcpCongestionWindow kMaxCongestionWindowTCP = 50; |
| const int kNumberOfAck = 1000; |
| sender_.reset( |
| new TcpCubicSenderPeer(&clock_, true, kMaxCongestionWindowTCP)); |
| |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| // Make sure we fall out of slow start. |
| sender_->OnIncomingLoss(clock_.Now()); |
| |
| for (int i = 0; i < kNumberOfAck; ++i) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| |
| QuicByteCount expected_send_window = |
| kMaxCongestionWindowTCP * kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, TcpCubicMaxCongestionWindow) { |
| const QuicTcpCongestionWindow kMaxCongestionWindowTCP = 50; |
| const int kNumberOfAck = 1000; |
| sender_.reset( |
| new TcpCubicSenderPeer(&clock_, false, kMaxCongestionWindowTCP)); |
| |
| QuicCongestionFeedbackFrame feedback; |
| // At startup make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| // Get default QuicCongestionFeedbackFrame from receiver. |
| ASSERT_TRUE(receiver_->GenerateCongestionFeedback(&feedback)); |
| sender_->OnIncomingQuicCongestionFeedbackFrame(feedback, clock_.Now(), |
| not_used_); |
| // Make sure we can send. |
| EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE).IsZero()); |
| |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| // Make sure we fall out of slow start. |
| sender_->OnIncomingLoss(clock_.Now()); |
| |
| for (int i = 0; i < kNumberOfAck; ++i) { |
| // Send our full send window. |
| SendAvailableSendWindow(); |
| AckNPackets(2); |
| } |
| |
| QuicByteCount expected_send_window = |
| kMaxCongestionWindowTCP * kDefaultTCPMSS; |
| EXPECT_EQ(expected_send_window, sender_->SendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, SendWindowNotAffectedByAcks) { |
| QuicByteCount send_window = sender_->AvailableSendWindow(); |
| |
| // Send a packet with no retransmittable data, and ensure that the congestion |
| // window doesn't change. |
| QuicByteCount bytes_in_packet = std::min(kDefaultTCPMSS, send_window); |
| sender_->OnPacketSent(clock_.Now(), sequence_number_++, bytes_in_packet, |
| NOT_RETRANSMISSION, NO_RETRANSMITTABLE_DATA); |
| EXPECT_EQ(send_window, sender_->AvailableSendWindow()); |
| |
| // Send a data packet with retransmittable data, and ensure that the |
| // congestion window has shrunk. |
| sender_->OnPacketSent(clock_.Now(), sequence_number_++, bytes_in_packet, |
| NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA); |
| EXPECT_GT(send_window, sender_->AvailableSendWindow()); |
| } |
| |
| TEST_F(TcpCubicSenderTest, ConfigureMaxInitialWindow) { |
| QuicTcpCongestionWindow congestion_window = sender_->congestion_window(); |
| QuicConfig config; |
| config.set_server_initial_congestion_window(2 * congestion_window, |
| 2 * congestion_window); |
| EXPECT_EQ(2 * congestion_window, config.server_initial_congestion_window()); |
| |
| sender_->SetFromConfig(config, true); |
| EXPECT_EQ(2 * congestion_window, sender_->congestion_window()); |
| } |
| |
| } // namespace test |
| } // namespace net |