Landing Recent QUIC changes until 2016-03-15 16:26 UTC

net/quic/congestion_control/tcp_cubic_sender_bytes_test.cc

 // Copyright (c) 2015 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 "net/quic/congestion_control/tcp_cubic_sender_bytes.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 42 matching lines @@
 class TcpCubicSenderBytesTest : public ::testing::Test {
  protected:
   TcpCubicSenderBytesTest()
       : one_ms_(QuicTime::Delta::FromMilliseconds(1)),
         sender_(new TcpCubicSenderBytesPeer(&clock_, true)),
         packet_number_(1),
         acked_packet_number_(0),
         bytes_in_flight_(0) {}
 
   int SendAvailableSendWindow() {
+    return SendAvailableSendWindow(kDefaultTCPMSS);
+  }
+
+  int SendAvailableSendWindow(QuicPacketLength packet_length) {
     // Send as long as TimeUntilSend returns Zero.
     int packets_sent = 0;
-    bool can_send = sender_
-                        ->TimeUntilSend(clock_.Now(), bytes_in_flight_,
-                                        HAS_RETRANSMITTABLE_DATA)
-                        .IsZero();
+    bool can_send =
+        sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero();
     while (can_send) {
       sender_->OnPacketSent(clock_.Now(), bytes_in_flight_, packet_number_++,
                             kDefaultTCPMSS, HAS_RETRANSMITTABLE_DATA);
       ++packets_sent;
       bytes_in_flight_ += kDefaultTCPMSS;
-      can_send = sender_
-                     ->TimeUntilSend(clock_.Now(), bytes_in_flight_,
-                                     HAS_RETRANSMITTABLE_DATA)
-                     .IsZero();
+      can_send =
+          sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero();
     }
     return packets_sent;
   }
 
   // Normal is that TCP acks every other segment.
   void AckNPackets(int n) {
     sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(60),
                                   QuicTime::Delta::Zero(), clock_.Now());
     SendAlgorithmInterface::CongestionVector acked_packets;
     SendAlgorithmInterface::CongestionVector lost_packets;
     for (int i = 0; i < n; ++i) {
       ++acked_packet_number_;
       acked_packets.push_back(
           std::make_pair(acked_packet_number_, kDefaultTCPMSS));
     }
     sender_->OnCongestionEvent(true, bytes_in_flight_, acked_packets,
                                lost_packets);
     bytes_in_flight_ -= n * kDefaultTCPMSS;
     clock_.AdvanceTime(one_ms_);
   }
 
-  void LoseNPackets(int n) {
+  void LoseNPackets(int n) { LoseNPackets(n, kDefaultTCPMSS); }
+
+  void LoseNPackets(int n, QuicPacketLength packet_length) {
     SendAlgorithmInterface::CongestionVector acked_packets;
     SendAlgorithmInterface::CongestionVector lost_packets;
     for (int i = 0; i < n; ++i) {
       ++acked_packet_number_;
       lost_packets.push_back(
-          std::make_pair(acked_packet_number_, kDefaultTCPMSS));
+          std::make_pair(acked_packet_number_, packet_length));
     }
     sender_->OnCongestionEvent(false, bytes_in_flight_, acked_packets,
                                lost_packets);
-    bytes_in_flight_ -= n * kDefaultTCPMSS;
+    bytes_in_flight_ -= n * packet_length;
   }
 
   // Does not increment acked_packet_number_.
   void LosePacket(QuicPacketNumber packet_number) {
     SendAlgorithmInterface::CongestionVector acked_packets;
     SendAlgorithmInterface::CongestionVector lost_packets;
     lost_packets.push_back(std::make_pair(packet_number, kDefaultTCPMSS));
     sender_->OnCongestionEvent(false, bytes_in_flight_, acked_packets,
                                lost_packets);
     bytes_in_flight_ -= kDefaultTCPMSS;
   }
 
   const QuicTime::Delta one_ms_;
   MockClock clock_;
   scoped_ptr<TcpCubicSenderBytesPeer> sender_;
   QuicPacketNumber packet_number_;
   QuicPacketNumber acked_packet_number_;
   QuicByteCount bytes_in_flight_;
 };
 
 TEST_F(TcpCubicSenderBytesTest, SimpleSender) {
   // At startup make sure we are at the default.
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
   // At startup make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
   // Make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
   // And that window is un-affected.
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
 
   // Fill the send window with data, then verify that we can't send.
   SendAvailableSendWindow();
-  EXPECT_FALSE(sender_
-                   ->TimeUntilSend(clock_.Now(), sender_->GetCongestionWindow(),
-                                   HAS_RETRANSMITTABLE_DATA)
-                   .IsZero());
+  EXPECT_FALSE(
+      sender_->TimeUntilSend(clock_.Now(), sender_->GetCongestionWindow())
+          .IsZero());
 }
 
 TEST_F(TcpCubicSenderBytesTest, ApplicationLimitedSlowStart) {
   // Send exactly 10 packets and ensure the CWND ends at 14 packets.
   const int kNumberOfAcks = 5;
   // At startup make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
   // Make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
 
   SendAvailableSendWindow();
   for (int i = 0; i < kNumberOfAcks; ++i) {
     AckNPackets(2);
   }
   QuicByteCount bytes_to_send = sender_->GetCongestionWindow();
   // It's expected 2 acks will arrive when the bytes_in_flight are greater than
   // half the CWND.
   EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * 2, bytes_to_send);
 }
 
 TEST_F(TcpCubicSenderBytesTest, ExponentialSlowStart) {
   const int kNumberOfAcks = 20;
   // At startup make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
   EXPECT_EQ(QuicBandwidth::Zero(), sender_->BandwidthEstimate());
   // Make sure we can send.
-  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), 0).IsZero());
 
   for (int i = 0; i < kNumberOfAcks; ++i) {
     // Send our full send window.
     SendAvailableSendWindow();
     AckNPackets(2);
   }
   const QuicByteCount cwnd = sender_->GetCongestionWindow();
   EXPECT_EQ(kDefaultWindowTCP + kDefaultTCPMSS * 2 * kNumberOfAcks, cwnd);
   EXPECT_EQ(QuicBandwidth::FromBytesAndTimeDelta(
                 cwnd, sender_->rtt_stats_.smoothed_rtt()),
@@ skipping 95 matching lines @@
   AckNPackets(1);
   expected_send_window += kDefaultTCPMSS;
   EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
 
   // Now RTO and ensure slow start gets reset.
   EXPECT_TRUE(sender_->hybrid_slow_start().started());
   sender_->OnRetransmissionTimeout(true);
   EXPECT_FALSE(sender_->hybrid_slow_start().started());
 }
 
+TEST_F(TcpCubicSenderBytesTest, SlowStartHalfPacketLossWithLargeReduction) {
+  FLAGS_quic_sslr_byte_conservation = true;
+  QuicConfig config;
+  QuicTagVector options;
+  options.push_back(kSSLR);
+  QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
+  sender_->SetFromConfig(config, Perspective::IS_SERVER);
+
+  sender_->SetNumEmulatedConnections(1);
+  const int kNumberOfAcks = 10;
+  for (int i = 0; i < kNumberOfAcks; ++i) {
+    // Send our full send window in half sized packets.
+    SendAvailableSendWindow(kDefaultTCPMSS / 2);
+    AckNPackets(2);
+  }
+  SendAvailableSendWindow(kDefaultTCPMSS / 2);
+  QuicByteCount expected_send_window =
+      kDefaultWindowTCP + (kDefaultTCPMSS * 2 * kNumberOfAcks);
+  EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
+
+  // Lose a packet to exit slow start. We should now have fallen out of
+  // slow start with a window reduced by 1.
+  LoseNPackets(1);
+  expected_send_window -= kDefaultTCPMSS;
+  EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
+
+  // Lose 10 packets in recovery and verify that congestion window is reduced
+  // by 5 packets.
+  LoseNPackets(10, kDefaultTCPMSS / 2);
+  expected_send_window -= 5 * kDefaultTCPMSS;
+  EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
+}
+
 TEST_F(TcpCubicSenderBytesTest, NoPRRWhenLessThanOnePacketInFlight) {
   SendAvailableSendWindow();
   LoseNPackets(kInitialCongestionWindowPackets - 1);
   AckNPackets(1);
   // PRR will allow 2 packets for every ack during recovery.
   EXPECT_EQ(2, SendAvailableSendWindow());
   // Simulate abandoning all packets by supplying a bytes_in_flight of 0.
   // PRR should now allow a packet to be sent, even though prr's state variables
   // believe it has sent enough packets.
-  EXPECT_EQ(QuicTime::Delta::Zero(),
-            sender_->TimeUntilSend(clock_.Now(), 0, HAS_RETRANSMITTABLE_DATA));
+  EXPECT_EQ(QuicTime::Delta::Zero(), sender_->TimeUntilSend(clock_.Now(), 0));
 }
 
 TEST_F(TcpCubicSenderBytesTest, SlowStartPacketLossPRR) {
   sender_->SetNumEmulatedConnections(1);
   // Test based on the first example in RFC6937.
   // Ack 10 packets in 5 acks to raise the CWND to 20, as in the example.
   const int kNumberOfAcks = 5;
   for (int i = 0; i < kNumberOfAcks; ++i) {
     // Send our full send window.
     SendAvailableSendWindow();
@@ skipping 56 matching lines @@
   EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
 
   // Lose one more than the congestion window reduction, so that after loss,
   // bytes_in_flight is lesser than the congestion window.
   size_t send_window_after_loss = kRenoBeta * expected_send_window;
   size_t num_packets_to_lose =
       (expected_send_window - send_window_after_loss) / kDefaultTCPMSS + 1;
   LoseNPackets(num_packets_to_lose);
   // Immediately after the loss, ensure at least one packet can be sent.
   // Losses without subsequent acks can occur with timer based loss detection.
-  EXPECT_TRUE(sender_
-                  ->TimeUntilSend(clock_.Now(), bytes_in_flight_,
-                                  HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
+  EXPECT_TRUE(sender_->TimeUntilSend(clock_.Now(), bytes_in_flight_).IsZero());
   AckNPackets(1);
 
   // We should now have fallen out of slow start with a reduced window.
   expected_send_window *= kRenoBeta;
   EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
 
   // Only 2 packets should be allowed to be sent, per PRR-SSRB.
   EXPECT_EQ(2, SendAvailableSendWindow());
 
   // Ack the next packet, which triggers another loss.
@@ skipping 295 matching lines @@
   QuicConfig config;
 
   // Verify that kCOPT: kMIN4 forces the min CWND to 1 packet, but allows up
   // to 4 to be sent.
   QuicTagVector options;
   options.push_back(kMIN4);
   QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
   sender_->SetFromConfig(config, Perspective::IS_SERVER);
   sender_->OnRetransmissionTimeout(true);
   EXPECT_EQ(kDefaultTCPMSS, sender_->GetCongestionWindow());
-  EXPECT_TRUE(sender_
-                  ->TimeUntilSend(QuicTime::Zero(), kDefaultTCPMSS,
-                                  HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
-  EXPECT_TRUE(sender_
-                  ->TimeUntilSend(QuicTime::Zero(), 2 * kDefaultTCPMSS,
-                                  HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
-  EXPECT_TRUE(sender_
-                  ->TimeUntilSend(QuicTime::Zero(), 3 * kDefaultTCPMSS,
-                                  HAS_RETRANSMITTABLE_DATA)
-                  .IsZero());
-  EXPECT_FALSE(sender_
-                   ->TimeUntilSend(QuicTime::Zero(), 4 * kDefaultTCPMSS,
-                                   HAS_RETRANSMITTABLE_DATA)
-                   .IsZero());
+  EXPECT_TRUE(
+      sender_->TimeUntilSend(QuicTime::Zero(), kDefaultTCPMSS).IsZero());
+  EXPECT_TRUE(
+      sender_->TimeUntilSend(QuicTime::Zero(), 2 * kDefaultTCPMSS).IsZero());
+  EXPECT_TRUE(
+      sender_->TimeUntilSend(QuicTime::Zero(), 3 * kDefaultTCPMSS).IsZero());
+  EXPECT_FALSE(
+      sender_->TimeUntilSend(QuicTime::Zero(), 4 * kDefaultTCPMSS).IsZero());
 }
 
 TEST_F(TcpCubicSenderBytesTest, ResetAfterConnectionMigration) {
   // Starts from slow start.
   sender_->SetNumEmulatedConnections(1);
   const int kNumberOfAcks = 10;
   for (int i = 0; i < kNumberOfAcks; ++i) {
     // Send our full send window.
     SendAvailableSendWindow();
     AckNPackets(2);
@@ skipping 15 matching lines @@
   // Resets cwnd and slow start threshold on connection migrations.
   sender_->OnConnectionMigration();
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
   EXPECT_EQ(kMaxCongestionWindow * kDefaultTCPMSS,
             sender_->GetSlowStartThreshold());
   EXPECT_FALSE(sender_->hybrid_slow_start().started());
 }
 
 }  // namespace test
 }  // namespace net