net/quic/congestion_control/hybrid_slow_start_test.cc

   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 "base/logging.h"
   6 #include "base/memory/scoped_ptr.h"
   7 #include "net/quic/congestion_control/hybrid_slow_start.h"
   8 #include "net/quic/test_tools/mock_clock.h"
   9 #include "testing/gtest/include/gtest/gtest.h"
  10
  11 namespace net {
  12 namespace test {
  13
  14 class HybridSlowStartTest : public ::testing::Test {
  15  protected:
  16   HybridSlowStartTest()
  17      : one_ms_(QuicTime::Delta::FromMilliseconds(1)),
  18        rtt_(QuicTime::Delta::FromMilliseconds(60)) {
  19   }
  20   void SetUp() override { slow_start_.reset(new HybridSlowStart(&clock_)); }
  21   const QuicTime::Delta one_ms_;
  22   const QuicTime::Delta rtt_;
  23   MockClock clock_;
  24   scoped_ptr<HybridSlowStart> slow_start_;
  25 };
  26
  27 TEST_F(HybridSlowStartTest, Simple) {
  28   QuicPacketSequenceNumber sequence_number = 1;
  29   QuicPacketSequenceNumber end_sequence_number = 3;
  30   slow_start_->StartReceiveRound(end_sequence_number);
  31
  32   EXPECT_FALSE(slow_start_->IsEndOfRound(sequence_number++));
  33
  34   // Test duplicates.
  35   EXPECT_FALSE(slow_start_->IsEndOfRound(sequence_number));
  36
  37   EXPECT_FALSE(slow_start_->IsEndOfRound(sequence_number++));
  38   EXPECT_TRUE(slow_start_->IsEndOfRound(sequence_number++));
  39
  40   // Test without a new registered end_sequence_number;
  41   EXPECT_TRUE(slow_start_->IsEndOfRound(sequence_number++));
  42
  43   end_sequence_number = 20;
  44   slow_start_->StartReceiveRound(end_sequence_number);
  45   while (sequence_number < end_sequence_number) {
  46     EXPECT_FALSE(slow_start_->IsEndOfRound(sequence_number++));
  47   }
  48   EXPECT_TRUE(slow_start_->IsEndOfRound(sequence_number++));
  49 }
  50
  51 TEST_F(HybridSlowStartTest, Delay) {
  52   // We expect to detect the increase at +1/8 of the RTT; hence at a typical
  53   // RTT of 60ms the detection will happen at 67.5 ms.
  54   const int kHybridStartMinSamples = 8;  // Number of acks required to trigger.
  55
  56   QuicPacketSequenceNumber end_sequence_number = 1;
  57   slow_start_->StartReceiveRound(end_sequence_number++);
  58
  59   // Will not trigger since our lowest RTT in our burst is the same as the long
  60   // term RTT provided.
  61   for (int n = 0; n < kHybridStartMinSamples; ++n) {
  62     EXPECT_FALSE(slow_start_->ShouldExitSlowStart(
  63         rtt_.Add(QuicTime::Delta::FromMilliseconds(n)), rtt_, 100));
  64   }
  65   slow_start_->StartReceiveRound(end_sequence_number++);
  66   for (int n = 1; n < kHybridStartMinSamples; ++n) {
  67     EXPECT_FALSE(slow_start_->ShouldExitSlowStart(
  68         rtt_.Add(QuicTime::Delta::FromMilliseconds(n + 10)), rtt_, 100));
  69   }
  70   // Expect to trigger since all packets in this burst was above the long term
  71   // RTT provided.
  72   EXPECT_TRUE(slow_start_->ShouldExitSlowStart(
  73       rtt_.Add(QuicTime::Delta::FromMilliseconds(10)), rtt_, 100));
  74 }
  75
  76 }  // namespace test
  77 }  // namespace net