| // Copyright (c) 2016 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 "quiche/quic/core/congestion_control/windowed_filter.h" |
| |
| #include "quiche/quic/core/congestion_control/rtt_stats.h" |
| #include "quiche/quic/core/quic_bandwidth.h" |
| #include "quiche/quic/core/quic_packets.h" |
| #include "quiche/quic/platform/api/quic_logging.h" |
| #include "quiche/quic/platform/api/quic_test.h" |
| |
| namespace quic { |
| namespace test { |
| |
| class WindowedFilterTest : public QuicTest { |
| public: |
| // Set the window to 99ms, so 25ms is more than a quarter rtt. |
| WindowedFilterTest() |
| : windowed_min_rtt_(QuicTime::Delta::FromMilliseconds(99), |
| QuicTime::Delta::Zero(), QuicTime::Zero()), |
| windowed_max_bw_(QuicTime::Delta::FromMilliseconds(99), |
| QuicBandwidth::Zero(), QuicTime::Zero()) {} |
| |
| // Sets up windowed_min_rtt_ to have the following values: |
| // Best = 20ms, recorded at 25ms |
| // Second best = 40ms, recorded at 75ms |
| // Third best = 50ms, recorded at 100ms |
| void InitializeMinFilter() { |
| QuicTime now = QuicTime::Zero(); |
| QuicTime::Delta rtt_sample = QuicTime::Delta::FromMilliseconds(10); |
| for (int i = 0; i < 5; ++i) { |
| windowed_min_rtt_.Update(rtt_sample, now); |
| QUIC_VLOG(1) << "i: " << i << " sample: " << rtt_sample.ToMilliseconds() |
| << " mins: " |
| << " " << windowed_min_rtt_.GetBest().ToMilliseconds() << " " |
| << windowed_min_rtt_.GetSecondBest().ToMilliseconds() << " " |
| << windowed_min_rtt_.GetThirdBest().ToMilliseconds(); |
| now = now + QuicTime::Delta::FromMilliseconds(25); |
| rtt_sample = rtt_sample + QuicTime::Delta::FromMilliseconds(10); |
| } |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(20), |
| windowed_min_rtt_.GetBest()); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(40), |
| windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(50), |
| windowed_min_rtt_.GetThirdBest()); |
| } |
| |
| // Sets up windowed_max_bw_ to have the following values: |
| // Best = 900 bps, recorded at 25ms |
| // Second best = 700 bps, recorded at 75ms |
| // Third best = 600 bps, recorded at 100ms |
| void InitializeMaxFilter() { |
| QuicTime now = QuicTime::Zero(); |
| QuicBandwidth bw_sample = QuicBandwidth::FromBitsPerSecond(1000); |
| for (int i = 0; i < 5; ++i) { |
| windowed_max_bw_.Update(bw_sample, now); |
| QUIC_VLOG(1) << "i: " << i << " sample: " << bw_sample.ToBitsPerSecond() |
| << " maxs: " |
| << " " << windowed_max_bw_.GetBest().ToBitsPerSecond() << " " |
| << windowed_max_bw_.GetSecondBest().ToBitsPerSecond() << " " |
| << windowed_max_bw_.GetThirdBest().ToBitsPerSecond(); |
| now = now + QuicTime::Delta::FromMilliseconds(25); |
| bw_sample = bw_sample - QuicBandwidth::FromBitsPerSecond(100); |
| } |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(900), |
| windowed_max_bw_.GetBest()); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(700), |
| windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(600), |
| windowed_max_bw_.GetThirdBest()); |
| } |
| |
| protected: |
| WindowedFilter<QuicTime::Delta, MinFilter<QuicTime::Delta>, QuicTime, |
| QuicTime::Delta> |
| windowed_min_rtt_; |
| WindowedFilter<QuicBandwidth, MaxFilter<QuicBandwidth>, QuicTime, |
| QuicTime::Delta> |
| windowed_max_bw_; |
| }; |
| |
| namespace { |
| // Test helper function: updates the filter with a lot of small values in order |
| // to ensure that it is not susceptible to noise. |
| void UpdateWithIrrelevantSamples( |
| WindowedFilter<uint64_t, MaxFilter<uint64_t>, uint64_t, uint64_t>* filter, |
| uint64_t max_value, uint64_t time) { |
| for (uint64_t i = 0; i < 1000; i++) { |
| filter->Update(i % max_value, time); |
| } |
| } |
| } // namespace |
| |
| TEST_F(WindowedFilterTest, UninitializedEstimates) { |
| EXPECT_EQ(QuicTime::Delta::Zero(), windowed_min_rtt_.GetBest()); |
| EXPECT_EQ(QuicTime::Delta::Zero(), windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(QuicTime::Delta::Zero(), windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(QuicBandwidth::Zero(), windowed_max_bw_.GetBest()); |
| EXPECT_EQ(QuicBandwidth::Zero(), windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(QuicBandwidth::Zero(), windowed_max_bw_.GetThirdBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, MonotonicallyIncreasingMin) { |
| QuicTime now = QuicTime::Zero(); |
| QuicTime::Delta rtt_sample = QuicTime::Delta::FromMilliseconds(10); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(10), windowed_min_rtt_.GetBest()); |
| |
| // Gradually increase the rtt samples and ensure the windowed min rtt starts |
| // rising. |
| for (int i = 0; i < 6; ++i) { |
| now = now + QuicTime::Delta::FromMilliseconds(25); |
| rtt_sample = rtt_sample + QuicTime::Delta::FromMilliseconds(10); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| QUIC_VLOG(1) << "i: " << i << " sample: " << rtt_sample.ToMilliseconds() |
| << " mins: " |
| << " " << windowed_min_rtt_.GetBest().ToMilliseconds() << " " |
| << windowed_min_rtt_.GetSecondBest().ToMilliseconds() << " " |
| << windowed_min_rtt_.GetThirdBest().ToMilliseconds(); |
| if (i < 3) { |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(10), |
| windowed_min_rtt_.GetBest()); |
| } else if (i == 3) { |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(20), |
| windowed_min_rtt_.GetBest()); |
| } else if (i < 6) { |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(40), |
| windowed_min_rtt_.GetBest()); |
| } |
| } |
| } |
| |
| TEST_F(WindowedFilterTest, MonotonicallyDecreasingMax) { |
| QuicTime now = QuicTime::Zero(); |
| QuicBandwidth bw_sample = QuicBandwidth::FromBitsPerSecond(1000); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(1000), windowed_max_bw_.GetBest()); |
| |
| // Gradually decrease the bw samples and ensure the windowed max bw starts |
| // decreasing. |
| for (int i = 0; i < 6; ++i) { |
| now = now + QuicTime::Delta::FromMilliseconds(25); |
| bw_sample = bw_sample - QuicBandwidth::FromBitsPerSecond(100); |
| windowed_max_bw_.Update(bw_sample, now); |
| QUIC_VLOG(1) << "i: " << i << " sample: " << bw_sample.ToBitsPerSecond() |
| << " maxs: " |
| << " " << windowed_max_bw_.GetBest().ToBitsPerSecond() << " " |
| << windowed_max_bw_.GetSecondBest().ToBitsPerSecond() << " " |
| << windowed_max_bw_.GetThirdBest().ToBitsPerSecond(); |
| if (i < 3) { |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(1000), |
| windowed_max_bw_.GetBest()); |
| } else if (i == 3) { |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(900), |
| windowed_max_bw_.GetBest()); |
| } else if (i < 6) { |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(700), |
| windowed_max_bw_.GetBest()); |
| } |
| } |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesThirdBestMin) { |
| InitializeMinFilter(); |
| // RTT sample lower than the third-choice min-rtt sets that, but nothing else. |
| QuicTime::Delta rtt_sample = |
| windowed_min_rtt_.GetThirdBest() - QuicTime::Delta::FromMilliseconds(5); |
| // This assert is necessary to avoid triggering -Wstrict-overflow |
| // See crbug/616957 |
| ASSERT_GT(windowed_min_rtt_.GetThirdBest(), |
| QuicTime::Delta::FromMilliseconds(5)); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(40), |
| windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(20), windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesThirdBestMax) { |
| InitializeMaxFilter(); |
| // BW sample higher than the third-choice max sets that, but nothing else. |
| QuicBandwidth bw_sample = |
| windowed_max_bw_.GetThirdBest() + QuicBandwidth::FromBitsPerSecond(50); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(700), |
| windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(900), windowed_max_bw_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesSecondBestMin) { |
| InitializeMinFilter(); |
| // RTT sample lower than the second-choice min sets that and also |
| // the third-choice min. |
| QuicTime::Delta rtt_sample = |
| windowed_min_rtt_.GetSecondBest() - QuicTime::Delta::FromMilliseconds(5); |
| // This assert is necessary to avoid triggering -Wstrict-overflow |
| // See crbug/616957 |
| ASSERT_GT(windowed_min_rtt_.GetSecondBest(), |
| QuicTime::Delta::FromMilliseconds(5)); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(QuicTime::Delta::FromMilliseconds(20), windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesSecondBestMax) { |
| InitializeMaxFilter(); |
| // BW sample higher than the second-choice max sets that and also |
| // the third-choice max. |
| QuicBandwidth bw_sample = |
| windowed_max_bw_.GetSecondBest() + QuicBandwidth::FromBitsPerSecond(50); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(QuicBandwidth::FromBitsPerSecond(900), windowed_max_bw_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesAllMins) { |
| InitializeMinFilter(); |
| // RTT sample lower than the first-choice min-rtt sets that and also |
| // the second and third-choice mins. |
| QuicTime::Delta rtt_sample = |
| windowed_min_rtt_.GetBest() - QuicTime::Delta::FromMilliseconds(5); |
| // This assert is necessary to avoid triggering -Wstrict-overflow |
| // See crbug/616957 |
| ASSERT_GT(windowed_min_rtt_.GetBest(), QuicTime::Delta::FromMilliseconds(5)); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, SampleChangesAllMaxs) { |
| InitializeMaxFilter(); |
| // BW sample higher than the first-choice max sets that and also |
| // the second and third-choice maxs. |
| QuicBandwidth bw_sample = |
| windowed_max_bw_.GetBest() + QuicBandwidth::FromBitsPerSecond(50); |
| // Latest sample was recorded at 100ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(101); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireBestMin) { |
| InitializeMinFilter(); |
| QuicTime::Delta old_third_best = windowed_min_rtt_.GetThirdBest(); |
| QuicTime::Delta old_second_best = windowed_min_rtt_.GetSecondBest(); |
| QuicTime::Delta rtt_sample = |
| old_third_best + QuicTime::Delta::FromMilliseconds(5); |
| // Best min sample was recorded at 25ms, so expiry time is 124ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(125); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(old_third_best, windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(old_second_best, windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireBestMax) { |
| InitializeMaxFilter(); |
| QuicBandwidth old_third_best = windowed_max_bw_.GetThirdBest(); |
| QuicBandwidth old_second_best = windowed_max_bw_.GetSecondBest(); |
| QuicBandwidth bw_sample = |
| old_third_best - QuicBandwidth::FromBitsPerSecond(50); |
| // Best max sample was recorded at 25ms, so expiry time is 124ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(125); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(old_third_best, windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(old_second_best, windowed_max_bw_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireSecondBestMin) { |
| InitializeMinFilter(); |
| QuicTime::Delta old_third_best = windowed_min_rtt_.GetThirdBest(); |
| QuicTime::Delta rtt_sample = |
| old_third_best + QuicTime::Delta::FromMilliseconds(5); |
| // Second best min sample was recorded at 75ms, so expiry time is 174ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(175); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(old_third_best, windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireSecondBestMax) { |
| InitializeMaxFilter(); |
| QuicBandwidth old_third_best = windowed_max_bw_.GetThirdBest(); |
| QuicBandwidth bw_sample = |
| old_third_best - QuicBandwidth::FromBitsPerSecond(50); |
| // Second best max sample was recorded at 75ms, so expiry time is 174ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(175); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(old_third_best, windowed_max_bw_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireAllMins) { |
| InitializeMinFilter(); |
| QuicTime::Delta rtt_sample = |
| windowed_min_rtt_.GetThirdBest() + QuicTime::Delta::FromMilliseconds(5); |
| // This assert is necessary to avoid triggering -Wstrict-overflow |
| // See crbug/616957 |
| ASSERT_LT(windowed_min_rtt_.GetThirdBest(), |
| QuicTime::Delta::Infinite() - QuicTime::Delta::FromMilliseconds(5)); |
| // Third best min sample was recorded at 100ms, so expiry time is 199ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(200); |
| windowed_min_rtt_.Update(rtt_sample, now); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetThirdBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetSecondBest()); |
| EXPECT_EQ(rtt_sample, windowed_min_rtt_.GetBest()); |
| } |
| |
| TEST_F(WindowedFilterTest, ExpireAllMaxs) { |
| InitializeMaxFilter(); |
| QuicBandwidth bw_sample = |
| windowed_max_bw_.GetThirdBest() - QuicBandwidth::FromBitsPerSecond(50); |
| // Third best max sample was recorded at 100ms, so expiry time is 199ms. |
| QuicTime now = QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(200); |
| windowed_max_bw_.Update(bw_sample, now); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetThirdBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetSecondBest()); |
| EXPECT_EQ(bw_sample, windowed_max_bw_.GetBest()); |
| } |
| |
| // Test the windowed filter where the time used is an exact counter instead of a |
| // timestamp. This is useful if, for example, the time is measured in round |
| // trips. |
| TEST_F(WindowedFilterTest, ExpireCounterBasedMax) { |
| // Create a window which starts at t = 0 and expires after two cycles. |
| WindowedFilter<uint64_t, MaxFilter<uint64_t>, uint64_t, uint64_t> max_filter( |
| 2, 0, 0); |
| |
| const uint64_t kBest = 50000; |
| // Insert 50000 at t = 1. |
| max_filter.Update(50000, 1); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| UpdateWithIrrelevantSamples(&max_filter, 20, 1); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| |
| // Insert 40000 at t = 2. Nothing is expected to expire. |
| max_filter.Update(40000, 2); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| UpdateWithIrrelevantSamples(&max_filter, 20, 2); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| |
| // Insert 30000 at t = 3. Nothing is expected to expire yet. |
| max_filter.Update(30000, 3); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| UpdateWithIrrelevantSamples(&max_filter, 20, 3); |
| EXPECT_EQ(kBest, max_filter.GetBest()); |
| QUIC_VLOG(0) << max_filter.GetSecondBest(); |
| QUIC_VLOG(0) << max_filter.GetThirdBest(); |
| |
| // Insert 20000 at t = 4. 50000 at t = 1 expires, so 40000 becomes the new |
| // maximum. |
| const uint64_t kNewBest = 40000; |
| max_filter.Update(20000, 4); |
| EXPECT_EQ(kNewBest, max_filter.GetBest()); |
| UpdateWithIrrelevantSamples(&max_filter, 20, 4); |
| EXPECT_EQ(kNewBest, max_filter.GetBest()); |
| } |
| |
| } // namespace test |
| } // namespace quic |