1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
|
/*
* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "modules/congestion_controller/pcc/bitrate_controller.h"
#include <cstddef>
#include <memory>
#include <optional>
#include <utility>
#include <vector>
#include "api/transport/network_types.h"
#include "api/units/data_rate.h"
#include "api/units/data_size.h"
#include "api/units/time_delta.h"
#include "api/units/timestamp.h"
#include "modules/congestion_controller/pcc/monitor_interval.h"
#include "modules/congestion_controller/pcc/utility_function.h"
#include "test/gmock.h"
#include "test/gtest.h"
namespace webrtc {
namespace pcc {
namespace test {
namespace {
constexpr double kInitialConversionFactor = 1;
constexpr double kInitialDynamicBoundary = 0.05;
constexpr double kDynamicBoundaryIncrement = 0.1;
constexpr double kDelayGradientCoefficient = 900;
constexpr double kLossCoefficient = 11.35;
constexpr double kThroughputCoefficient = 500 * 1000;
constexpr double kThroughputPower = 0.99;
constexpr double kDelayGradientThreshold = 0.01;
constexpr double kDelayGradientNegativeBound = 10;
const DataRate kTargetSendingRate = DataRate::KilobitsPerSec(300);
const double kEpsilon = 0.05;
const Timestamp kStartTime = Timestamp::Micros(0);
const TimeDelta kPacketsDelta = TimeDelta::Millis(1);
const TimeDelta kIntervalDuration = TimeDelta::Millis(1000);
const TimeDelta kDefaultRtt = TimeDelta::Millis(1000);
const DataSize kDefaultDataSize = DataSize::Bytes(100);
std::vector<PacketResult> CreatePacketResults(
const std::vector<Timestamp>& packets_send_times,
const std::vector<Timestamp>& packets_received_times = {},
const std::vector<DataSize>& packets_sizes = {}) {
std::vector<PacketResult> packet_results;
PacketResult packet_result;
SentPacket sent_packet;
for (size_t i = 0; i < packets_send_times.size(); ++i) {
sent_packet.send_time = packets_send_times[i];
if (packets_sizes.empty()) {
sent_packet.size = kDefaultDataSize;
} else {
sent_packet.size = packets_sizes[i];
}
packet_result.sent_packet = sent_packet;
if (packets_received_times.empty()) {
packet_result.receive_time = packets_send_times[i] + kDefaultRtt;
} else {
packet_result.receive_time = packets_received_times[i];
}
packet_results.push_back(packet_result);
}
return packet_results;
}
class MockUtilityFunction : public PccUtilityFunctionInterface {
public:
MOCK_METHOD(double,
Compute,
(const PccMonitorInterval& monitor_interval),
(const, override));
};
} // namespace
TEST(PccBitrateControllerTest, IncreaseRateWhenNoChangesForTestBitrates) {
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, kDelayGradientCoefficient, kLossCoefficient,
kThroughputCoefficient, kThroughputPower, kDelayGradientThreshold,
kDelayGradientNegativeBound);
VivaceUtilityFunction utility_function(
kDelayGradientCoefficient, kLossCoefficient, kThroughputCoefficient,
kThroughputPower, kDelayGradientThreshold, kDelayGradientNegativeBound);
std::vector<PccMonitorInterval> monitor_block{
PccMonitorInterval(kTargetSendingRate * (1 + kEpsilon), kStartTime,
kIntervalDuration),
PccMonitorInterval(kTargetSendingRate * (1 - kEpsilon),
kStartTime + kIntervalDuration, kIntervalDuration)};
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + kPacketsDelta,
kStartTime + kIntervalDuration + kPacketsDelta,
kStartTime + 3 * kIntervalDuration},
{}, {}));
monitor_block[1].OnPacketsFeedback(
CreatePacketResults({kStartTime + kPacketsDelta,
kStartTime + kIntervalDuration + kPacketsDelta,
kStartTime + 3 * kIntervalDuration},
{}, {}));
// For both of the monitor intervals there were no change in rtt gradient
// and in packet loss. Since the only difference is in the sending rate,
// the higher sending rate should be chosen by congestion controller.
EXPECT_GT(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps());
}
TEST(PccBitrateControllerTest, NoChangesWhenUtilityFunctionDoesntChange) {
std::unique_ptr<MockUtilityFunction> mock_utility_function =
std::make_unique<MockUtilityFunction>();
EXPECT_CALL(*mock_utility_function, Compute(::testing::_))
.Times(2)
.WillOnce(::testing::Return(100))
.WillOnce(::testing::Return(100));
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, std::move(mock_utility_function));
std::vector<PccMonitorInterval> monitor_block{
PccMonitorInterval(kTargetSendingRate * (1 + kEpsilon), kStartTime,
kIntervalDuration),
PccMonitorInterval(kTargetSendingRate * (1 - kEpsilon),
kStartTime + kIntervalDuration, kIntervalDuration)};
// To complete collecting feedback within monitor intervals.
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
monitor_block[1].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
// Because we don't have any packets inside of monitor intervals, utility
// function should be zero for both of them and the sending rate should not
// change.
EXPECT_EQ(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps());
}
TEST(PccBitrateControllerTest, NoBoundaryWhenSmallGradient) {
std::unique_ptr<MockUtilityFunction> mock_utility_function =
std::make_unique<MockUtilityFunction>();
constexpr double kFirstMonitorIntervalUtility = 0;
const double kSecondMonitorIntervalUtility =
2 * kTargetSendingRate.bps() * kEpsilon;
EXPECT_CALL(*mock_utility_function, Compute(::testing::_))
.Times(2)
.WillOnce(::testing::Return(kFirstMonitorIntervalUtility))
.WillOnce(::testing::Return(kSecondMonitorIntervalUtility));
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, std::move(mock_utility_function));
std::vector<PccMonitorInterval> monitor_block{
PccMonitorInterval(kTargetSendingRate * (1 + kEpsilon), kStartTime,
kIntervalDuration),
PccMonitorInterval(kTargetSendingRate * (1 - kEpsilon),
kStartTime + kIntervalDuration, kIntervalDuration)};
// To complete collecting feedback within monitor intervals.
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
monitor_block[1].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
double gradient =
(kFirstMonitorIntervalUtility - kSecondMonitorIntervalUtility) /
(kTargetSendingRate.bps() * 2 * kEpsilon);
// When the gradient is small we don't hit the dynamic boundary.
EXPECT_EQ(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps() + kInitialConversionFactor * gradient);
}
TEST(PccBitrateControllerTest, FaceBoundaryWhenLargeGradient) {
std::unique_ptr<MockUtilityFunction> mock_utility_function =
std::make_unique<MockUtilityFunction>();
constexpr double kFirstMonitorIntervalUtility = 0;
const double kSecondMonitorIntervalUtility =
10 * kInitialDynamicBoundary * kTargetSendingRate.bps() * 2 *
kTargetSendingRate.bps() * kEpsilon;
EXPECT_CALL(*mock_utility_function, Compute(::testing::_))
.Times(4)
.WillOnce(::testing::Return(kFirstMonitorIntervalUtility))
.WillOnce(::testing::Return(kSecondMonitorIntervalUtility))
.WillOnce(::testing::Return(kFirstMonitorIntervalUtility))
.WillOnce(::testing::Return(kSecondMonitorIntervalUtility));
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, std::move(mock_utility_function));
std::vector<PccMonitorInterval> monitor_block{
PccMonitorInterval(kTargetSendingRate * (1 + kEpsilon), kStartTime,
kIntervalDuration),
PccMonitorInterval(kTargetSendingRate * (1 - kEpsilon),
kStartTime + kIntervalDuration, kIntervalDuration)};
// To complete collecting feedback within monitor intervals.
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
monitor_block[1].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
// The utility function gradient is too big and we hit the dynamic boundary.
EXPECT_EQ(bitrate_controller.ComputeRateUpdateForOnlineLearningMode(
monitor_block, kTargetSendingRate),
kTargetSendingRate * (1 - kInitialDynamicBoundary));
// For the second time we hit the dynamic boundary in the same direction, the
// boundary should increase.
EXPECT_EQ(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps() *
(1 - kInitialDynamicBoundary - kDynamicBoundaryIncrement));
}
TEST(PccBitrateControllerTest, SlowStartMode) {
std::unique_ptr<MockUtilityFunction> mock_utility_function =
std::make_unique<MockUtilityFunction>();
constexpr double kFirstUtilityFunction = 1000;
EXPECT_CALL(*mock_utility_function, Compute(::testing::_))
.Times(4)
// For first 3 calls we expect to stay in the SLOW_START mode and double
// the sending rate since the utility function increases its value. For
// the last call utility function decreases its value, this means that
// we should not double the sending rate and exit SLOW_START mode.
.WillOnce(::testing::Return(kFirstUtilityFunction))
.WillOnce(::testing::Return(kFirstUtilityFunction + 1))
.WillOnce(::testing::Return(kFirstUtilityFunction + 2))
.WillOnce(::testing::Return(kFirstUtilityFunction + 1));
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, std::move(mock_utility_function));
std::vector<PccMonitorInterval> monitor_block{PccMonitorInterval(
2 * kTargetSendingRate, kStartTime, kIntervalDuration)};
// To complete collecting feedback within monitor intervals.
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
EXPECT_EQ(
bitrate_controller.ComputeRateUpdateForSlowStartMode(monitor_block[0]),
kTargetSendingRate * 2);
EXPECT_EQ(
bitrate_controller.ComputeRateUpdateForSlowStartMode(monitor_block[0]),
kTargetSendingRate * 2);
EXPECT_EQ(
bitrate_controller.ComputeRateUpdateForSlowStartMode(monitor_block[0]),
kTargetSendingRate * 2);
EXPECT_EQ(
bitrate_controller.ComputeRateUpdateForSlowStartMode(monitor_block[0]),
std::nullopt);
}
TEST(PccBitrateControllerTest, StepSizeIncrease) {
std::unique_ptr<MockUtilityFunction> mock_utility_function =
std::make_unique<MockUtilityFunction>();
constexpr double kFirstMiUtilityFunction = 0;
const double kSecondMiUtilityFunction =
2 * kTargetSendingRate.bps() * kEpsilon;
EXPECT_CALL(*mock_utility_function, Compute(::testing::_))
.Times(4)
.WillOnce(::testing::Return(kFirstMiUtilityFunction))
.WillOnce(::testing::Return(kSecondMiUtilityFunction))
.WillOnce(::testing::Return(kFirstMiUtilityFunction))
.WillOnce(::testing::Return(kSecondMiUtilityFunction));
std::vector<PccMonitorInterval> monitor_block{
PccMonitorInterval(kTargetSendingRate * (1 + kEpsilon), kStartTime,
kIntervalDuration),
PccMonitorInterval(kTargetSendingRate * (1 - kEpsilon),
kStartTime + kIntervalDuration, kIntervalDuration)};
// To complete collecting feedback within monitor intervals.
monitor_block[0].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
monitor_block[1].OnPacketsFeedback(
CreatePacketResults({kStartTime + 3 * kIntervalDuration}, {}, {}));
double gradient = (kFirstMiUtilityFunction - kSecondMiUtilityFunction) /
(kTargetSendingRate.bps() * 2 * kEpsilon);
PccBitrateController bitrate_controller(
kInitialConversionFactor, kInitialDynamicBoundary,
kDynamicBoundaryIncrement, std::move(mock_utility_function));
// If we are moving in the same direction - the step size should increase.
EXPECT_EQ(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps() + kInitialConversionFactor * gradient);
EXPECT_EQ(bitrate_controller
.ComputeRateUpdateForOnlineLearningMode(monitor_block,
kTargetSendingRate)
.bps(),
kTargetSendingRate.bps() + 2 * kInitialConversionFactor * gradient);
}
} // namespace test
} // namespace pcc
} // namespace webrtc
|