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