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/*
* Copyright (c) 2016 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/goog_cc/probe_controller.h"
#include <memory>
#include <vector>
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "api/transport/network_types.h"
#include "api/units/data_rate.h"
#include "api/units/time_delta.h"
#include "api/units/timestamp.h"
#include "logging/rtc_event_log/mock/mock_rtc_event_log.h"
#include "system_wrappers/include/clock.h"
#include "test/explicit_key_value_config.h"
#include "test/gmock.h"
#include "test/gtest.h"
using ::testing::Gt;
using ::testing::IsEmpty;
using ::testing::NiceMock;
using ::testing::SizeIs;
namespace webrtc {
namespace test {
namespace {
constexpr DataRate kMinBitrate = DataRate::BitsPerSec(100);
constexpr DataRate kStartBitrate = DataRate::BitsPerSec(300);
constexpr DataRate kMaxBitrate = DataRate::BitsPerSec(10000);
constexpr TimeDelta kExponentialProbingTimeout = TimeDelta::Seconds(5);
constexpr TimeDelta kAlrProbeInterval = TimeDelta::Seconds(5);
constexpr TimeDelta kAlrEndedTimeout = TimeDelta::Seconds(3);
constexpr TimeDelta kBitrateDropTimeout = TimeDelta::Seconds(5);
} // namespace
class ProbeControllerFixture {
public:
explicit ProbeControllerFixture(absl::string_view field_trials = "")
: field_trial_config_(field_trials), clock_(100000000L) {}
std::unique_ptr<ProbeController> CreateController() {
return std::make_unique<ProbeController>(&field_trial_config_,
&mock_rtc_event_log);
}
Timestamp CurrentTime() { return clock_.CurrentTime(); }
void AdvanceTime(TimeDelta delta) { clock_.AdvanceTime(delta); }
ExplicitKeyValueConfig field_trial_config_;
SimulatedClock clock_;
NiceMock<MockRtcEventLog> mock_rtc_event_log;
};
TEST(ProbeControllerTest, InitiatesProbingAfterSetBitrates) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_GE(probes.size(), 2u);
}
TEST(ProbeControllerTest, InitiatesProbingWhenNetworkAvailable) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
std::vector<ProbeClusterConfig> probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
probes = probe_controller->OnNetworkAvailability({.network_available = true});
EXPECT_GE(probes.size(), 2u);
}
TEST(ProbeControllerTest, SetsDefaultTargetDurationAndTargetProbeCount) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
std::vector<ProbeClusterConfig> probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_GE(probes.size(), 2u);
EXPECT_EQ(probes[0].target_duration, TimeDelta::Millis(15));
EXPECT_EQ(probes[0].target_probe_count, 5);
}
TEST(ProbeControllerTest,
FieldTrialsOverrideDefaultTargetDurationAndTargetProbeCount) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingBehavior/"
"min_probe_packets_sent:2,min_probe_duration:123ms/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
std::vector<ProbeClusterConfig> probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_GE(probes.size(), 2u);
EXPECT_EQ(probes[0].target_duration, TimeDelta::Millis(123));
EXPECT_EQ(probes[0].target_probe_count, 2);
}
TEST(ProbeControllerTest, ProbeOnlyWhenNetworkIsUp) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
auto probes = probe_controller->OnNetworkAvailability(
{.at_time = fixture.CurrentTime(), .network_available = false});
probes = probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
kMaxBitrate, fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
probes = probe_controller->OnNetworkAvailability(
{.at_time = fixture.CurrentTime(), .network_available = true});
EXPECT_GE(probes.size(), 2u);
}
TEST(ProbeControllerTest, CanConfigureInitialProbeRateFactor) {
ProbeControllerFixture fixture("WebRTC-Bwe-ProbingConfiguration/p1:2,p2:3/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
EXPECT_EQ(probes[0].target_data_rate, kStartBitrate * 2);
EXPECT_EQ(probes[1].target_data_rate, kStartBitrate * 3);
}
TEST(ProbeControllerTest, DisableSecondInitialProbeIfRateFactorZero) {
ProbeControllerFixture fixture("WebRTC-Bwe-ProbingConfiguration/p1:2,p2:0/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, kStartBitrate * 2);
}
TEST(ProbeControllerTest, InitiatesProbingOnMaxBitrateIncrease) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
// Long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate + DataRate::BitsPerSec(100),
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), kMaxBitrate.bps() + 100);
}
TEST(ProbeControllerTest, ProbesOnMaxAllocatedBitrateIncreaseOnlyWhenInAlr) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate - DataRate::BitsPerSec(1),
BandwidthLimitedCause::kDelayBasedLimited, fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
// Probe when in alr.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probes = probe_controller->OnMaxTotalAllocatedBitrate(
kMaxBitrate + DataRate::BitsPerSec(1), fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
EXPECT_EQ(probes.at(0).target_data_rate, kMaxBitrate);
// Do not probe when not in alr.
probe_controller->SetAlrStartTimeMs(absl::nullopt);
probes = probe_controller->OnMaxTotalAllocatedBitrate(
kMaxBitrate + DataRate::BitsPerSec(2), fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, ProbesOnMaxAllocatedBitrateLimitedByCurrentBwe) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"alloc_current_bwe_limit:1.5/");
ASSERT_TRUE(kMaxBitrate > 1.5 * kStartBitrate);
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
// Probe when in alr.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probes = probe_controller->OnMaxTotalAllocatedBitrate(kMaxBitrate,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes.at(0).target_data_rate, 1.5 * kStartBitrate);
// Continue probing if probe succeeds.
probes = probe_controller->SetEstimatedBitrate(
1.5 * kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_GT(probes.at(0).target_data_rate, 1.5 * kStartBitrate);
}
TEST(ProbeControllerTest, CanDisableProbingOnMaxTotalAllocatedBitrateIncrease) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"probe_max_allocation:false/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate - DataRate::BitsPerSec(1),
BandwidthLimitedCause::kDelayBasedLimited, fixture.CurrentTime());
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
// Do no probe, since probe_max_allocation:false.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probes = probe_controller->OnMaxTotalAllocatedBitrate(
kMaxBitrate + DataRate::BitsPerSec(1), fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, InitiatesProbingOnMaxBitrateIncreaseAtMaxBitrate) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
// Long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate + DataRate::BitsPerSec(100),
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate,
kMaxBitrate + DataRate::BitsPerSec(100));
}
TEST(ProbeControllerTest, TestExponentialProbing) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
// Repeated probe should only be sent when estimated bitrate climbs above
// 0.7 * 6 * kStartBitrate = 1260.
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1000), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1800), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 2 * 1800);
}
TEST(ProbeControllerTest, ExponentialProbingStopIfMaxBitrateLow) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/abort_further:true/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_THAT(probes, SizeIs(Gt(0)));
// Repeated probe normally is sent when estimated bitrate climbs above
// 0.7 * 6 * kStartBitrate = 1260. But since max bitrate is low, expect
// exponential probing to stop.
probes = probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
/*max_bitrate=*/kStartBitrate,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1800), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
}
TEST(ProbeControllerTest, ExponentialProbingStopIfMaxAllocatedBitrateLow) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/abort_further:true/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_THAT(probes, SizeIs(Gt(0)));
// Repeated probe normally is sent when estimated bitrate climbs above
// 0.7 * 6 * kStartBitrate = 1260. But since allocated bitrate i slow, expect
// exponential probing to stop.
probes = probe_controller->OnMaxTotalAllocatedBitrate(kStartBitrate,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1800), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
}
TEST(ProbeControllerTest, InitialProbingToLowMaxAllocatedbitrate) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_THAT(probes, SizeIs(Gt(0)));
// Repeated probe is sent when estimated bitrate climbs above
// 0.7 * 6 * kStartBitrate = 1260.
probes = probe_controller->OnMaxTotalAllocatedBitrate(kStartBitrate,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
// If the inital probe result is received, a new probe is sent at 2x the
// needed max bitrate.
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1800), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 2 * kStartBitrate.bps());
}
TEST(ProbeControllerTest, InitialProbingTimeout) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_THAT(probes, SizeIs(Gt(0)));
// Advance far enough to cause a time out in waiting for probing result.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1800), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
}
TEST(ProbeControllerTest, RepeatedInitialProbingSendsNewProbeAfterTimeout) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
probe_controller->EnableRepeatedInitialProbing(true);
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_THAT(probes, SizeIs(Gt(0)));
Timestamp start_time = fixture.CurrentTime();
Timestamp last_probe_time = fixture.CurrentTime();
while (fixture.CurrentTime() < start_time + TimeDelta::Seconds(5)) {
fixture.AdvanceTime(TimeDelta::Millis(100));
probes = probe_controller->Process(fixture.CurrentTime());
if (!probes.empty()) {
// Expect a probe every second.
EXPECT_EQ(fixture.CurrentTime() - last_probe_time,
TimeDelta::Seconds(1.1));
EXPECT_EQ(probes[0].min_probe_delta, TimeDelta::Millis(20));
EXPECT_EQ(probes[0].target_duration, TimeDelta::Millis(100));
last_probe_time = fixture.CurrentTime();
} else {
EXPECT_LT(fixture.CurrentTime() - last_probe_time,
TimeDelta::Seconds(1.1));
}
}
fixture.AdvanceTime(TimeDelta::Seconds(1));
// After 5s, repeated initial probing stops.
EXPECT_THAT(probe_controller->Process(fixture.CurrentTime()), IsEmpty());
}
TEST(ProbeControllerTest, RepeatedInitialProbingStopIfMaxAllocatedBitrateSet) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
probe_controller->EnableRepeatedInitialProbing(true);
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_THAT(probes, SizeIs(Gt(0)));
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_THAT(probes, SizeIs(1));
probes = probe_controller->OnMaxTotalAllocatedBitrate(kMinBitrate,
fixture.CurrentTime());
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_THAT(probes, IsEmpty());
}
TEST(ProbeControllerTest, RequestProbeInAlr) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_GE(probes.size(), 2u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(250), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probes = probe_controller->RequestProbe(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 0.85 * 500);
}
TEST(ProbeControllerTest, RequestProbeWhenAlrEndedRecently) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(absl::nullopt);
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(250), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrEndedTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrEndedTimeout - TimeDelta::Millis(1));
probes = probe_controller->RequestProbe(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 0.85 * 500);
}
TEST(ProbeControllerTest, RequestProbeWhenAlrNotEndedRecently) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(absl::nullopt);
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(250), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrEndedTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrEndedTimeout + TimeDelta::Millis(1));
probes = probe_controller->RequestProbe(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, RequestProbeWhenBweDropNotRecent) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(250), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
fixture.AdvanceTime(kBitrateDropTimeout + TimeDelta::Millis(1));
probes = probe_controller->RequestProbe(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, PeriodicProbing) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
Timestamp start_time = fixture.CurrentTime();
// Expect the controller to send a new probe after 5s has passed.
probe_controller->SetAlrStartTimeMs(start_time.ms());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 1000);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// The following probe should be sent at 10s into ALR.
probe_controller->SetAlrStartTimeMs(start_time.ms());
fixture.AdvanceTime(TimeDelta::Seconds(4));
probes = probe_controller->Process(fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
probe_controller->SetAlrStartTimeMs(start_time.ms());
fixture.AdvanceTime(TimeDelta::Seconds(1));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, PeriodicProbingAfterReset) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
Timestamp alr_start_time = fixture.CurrentTime();
probe_controller->SetAlrStartTimeMs(alr_start_time.ms());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probe_controller->Reset(fixture.CurrentTime());
fixture.AdvanceTime(TimeDelta::Seconds(10));
probes = probe_controller->Process(fixture.CurrentTime());
// Since bitrates are not yet set, no probe is sent event though we are in ALR
// mode.
EXPECT_TRUE(probes.empty());
probes = probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
kMaxBitrate, fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
// Make sure we use `kStartBitrateBps` as the estimated bitrate
// until SetEstimatedBitrate is called with an updated estimate.
fixture.AdvanceTime(TimeDelta::Seconds(10));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, kStartBitrate * 2);
}
TEST(ProbeControllerTest, NoProbesWhenTransportIsNotWritable) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
probe_controller->EnablePeriodicAlrProbing(true);
std::vector<ProbeClusterConfig> probes =
probe_controller->OnNetworkAvailability({.network_available = false});
EXPECT_THAT(probes, IsEmpty());
EXPECT_THAT(probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
kMaxBitrate, fixture.CurrentTime()),
IsEmpty());
fixture.AdvanceTime(TimeDelta::Seconds(10));
EXPECT_THAT(probe_controller->Process(fixture.CurrentTime()), IsEmpty());
// Controller is reset after a network route change.
// But, a probe should not be sent since the transport is not writable.
// Transport is not writable until after DTLS negotiation completes.
// However, the bitrate constraints may change.
probe_controller->Reset(fixture.CurrentTime());
EXPECT_THAT(
probe_controller->SetBitrates(2 * kMinBitrate, 2 * kStartBitrate,
2 * kMaxBitrate, fixture.CurrentTime()),
IsEmpty());
fixture.AdvanceTime(TimeDelta::Seconds(10));
EXPECT_THAT(probe_controller->Process(fixture.CurrentTime()), IsEmpty());
}
TEST(ProbeControllerTest, TestExponentialProbingOverflow) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
const DataRate kMbpsMultiplier = DataRate::KilobitsPerSec(1000);
auto probes = probe_controller->SetBitrates(kMinBitrate, 10 * kMbpsMultiplier,
100 * kMbpsMultiplier,
fixture.CurrentTime());
// Verify that probe bitrate is capped at the specified max bitrate.
probes = probe_controller->SetEstimatedBitrate(
60 * kMbpsMultiplier, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, 100 * kMbpsMultiplier);
// Verify that repeated probes aren't sent.
probes = probe_controller->SetEstimatedBitrate(
100 * kMbpsMultiplier, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, TestAllocatedBitrateCap) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
const DataRate kMbpsMultiplier = DataRate::KilobitsPerSec(1000);
const DataRate kMaxBitrate = 100 * kMbpsMultiplier;
auto probes = probe_controller->SetBitrates(
kMinBitrate, 10 * kMbpsMultiplier, kMaxBitrate, fixture.CurrentTime());
// Configure ALR for periodic probing.
probe_controller->EnablePeriodicAlrProbing(true);
Timestamp alr_start_time = fixture.CurrentTime();
probe_controller->SetAlrStartTimeMs(alr_start_time.ms());
DataRate estimated_bitrate = kMaxBitrate / 10;
probes = probe_controller->SetEstimatedBitrate(
estimated_bitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Set a max allocated bitrate below the current estimate.
DataRate max_allocated = estimated_bitrate - 1 * kMbpsMultiplier;
probes = probe_controller->OnMaxTotalAllocatedBitrate(max_allocated,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty()); // No probe since lower than current max.
// Probes such as ALR capped at 2x the max allocation limit.
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, 2 * max_allocated);
// Remove allocation limit.
EXPECT_TRUE(
probe_controller
->OnMaxTotalAllocatedBitrate(DataRate::Zero(), fixture.CurrentTime())
.empty());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, estimated_bitrate * 2);
}
TEST(ProbeControllerTest, ConfigurableProbingFieldTrial) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"p1:2,p2:5,step_size:3,further_probe_threshold:0.8,"
"alloc_p1:2,alloc_p2,min_probe_packets_sent:2/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
DataRate::KilobitsPerSec(5000),
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 2u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 600);
EXPECT_EQ(probes[0].target_probe_count, 2);
EXPECT_EQ(probes[1].target_data_rate.bps(), 1500);
EXPECT_EQ(probes[1].target_probe_count, 2);
// Repeated probe should only be sent when estimated bitrate climbs above
// 0.8 * 5 * kStartBitrateBps = 1200.
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1100), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 0u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(1250), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 3 * 1250);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probes = probe_controller->OnMaxTotalAllocatedBitrate(
DataRate::KilobitsPerSec(200), fixture.CurrentTime());
EXPECT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate.bps(), 400'000);
}
TEST(ProbeControllerTest, LimitAlrProbeWhenLossBasedBweLimited) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Expect the controller to send a new probe after 5s has passed.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500),
BandwidthLimitedCause::kLossLimitedBweIncreasing, fixture.CurrentTime());
fixture.AdvanceTime(TimeDelta::Seconds(6));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, 1.5 * DataRate::BitsPerSec(500));
probes = probe_controller->SetEstimatedBitrate(
1.5 * DataRate::BitsPerSec(500),
BandwidthLimitedCause::kDelayBasedLimited, fixture.CurrentTime());
fixture.AdvanceTime(TimeDelta::Seconds(6));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_GT(probes[0].target_data_rate, 1.5 * 1.5 * DataRate::BitsPerSec(500));
}
TEST(ProbeControllerTest, PeriodicProbeAtUpperNetworkStateEstimate) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(5000), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Expect the controller to send a new probe after 5s has passed.
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = DataRate::KilobitsPerSec(6);
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, state_estimate.link_capacity_upper);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, state_estimate.link_capacity_upper);
}
TEST(ProbeControllerTest,
LimitProbeAtUpperNetworkStateEstimateIfLossBasedLimited) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Expect the controller to send a new probe after 5s has passed.
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = DataRate::BitsPerSec(700);
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
probes = probe_controller->SetEstimatedBitrate(
DataRate::BitsPerSec(500),
BandwidthLimitedCause::kLossLimitedBweIncreasing, fixture.CurrentTime());
// Expect the controller to send a new probe after 5s has passed.
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_EQ(probes[0].target_data_rate, DataRate::BitsPerSec(700));
}
TEST(ProbeControllerTest, AlrProbesLimitedByNetworkStateEstimate) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::KilobitsPerSec(6), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, kMaxBitrate);
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = DataRate::BitsPerSec(8000);
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, state_estimate.link_capacity_upper);
}
TEST(ProbeControllerTest, CanSetLongerProbeDurationAfterNetworkStateEstimate) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s,network_state_probe_duration:100ms/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
DataRate::KilobitsPerSec(5), BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_LT(probes[0].target_duration, TimeDelta::Millis(100));
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = DataRate::KilobitsPerSec(6);
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_duration, TimeDelta::Millis(100));
}
TEST(ProbeControllerTest, ProbeInAlrIfLossBasedIncreasing) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probe_controller->EnablePeriodicAlrProbing(true);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kLossLimitedBweIncreasing,
fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
// Probe when in alr.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes.at(0).target_data_rate, 1.5 * kStartBitrate);
}
TEST(ProbeControllerTest, ProbeFurtherInAlrIfLossBasedIncreasing) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probe_controller->EnablePeriodicAlrProbing(true);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kLossLimitedBweIncreasing,
fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
// Probe when in alr.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
ASSERT_EQ(probes.at(0).target_data_rate, 1.5 * kStartBitrate);
probes = probe_controller->SetEstimatedBitrate(
1.5 * kStartBitrate, BandwidthLimitedCause::kLossLimitedBweIncreasing,
fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_EQ(probes[0].target_data_rate, 1.5 * 1.5 * kStartBitrate);
}
TEST(ProbeControllerTest, NotProbeWhenInAlrIfLossBasedDecreases) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probe_controller->EnablePeriodicAlrProbing(true);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kLossLimitedBwe,
fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
// Not probe in alr when loss based estimate decreases.
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, NotProbeIfLossBasedIncreasingOutsideAlr) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probe_controller->EnablePeriodicAlrProbing(true);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kLossLimitedBweIncreasing,
fixture.CurrentTime());
// Wait long enough to time out exponential probing.
fixture.AdvanceTime(kExponentialProbingTimeout);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
probe_controller->SetAlrStartTimeMs(absl::nullopt);
fixture.AdvanceTime(kAlrProbeInterval + TimeDelta::Millis(1));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, ProbeFurtherWhenLossBasedIsSameAsDelayBasedEstimate) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 5 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
DataRate probe_target_rate = probes[0].target_data_rate;
EXPECT_LT(probe_target_rate, state_estimate.link_capacity_upper);
// Expect that more probes are sent if BWE is the same as delay based
// estimate.
probes = probe_controller->SetEstimatedBitrate(
probe_target_rate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_EQ(probes[0].target_data_rate, 2 * probe_target_rate);
}
TEST(ProbeControllerTest, ProbeIfEstimateLowerThanNetworkStateEstimate) {
// Periodic probe every 1 second if estimate is lower than 50% of the
// NetworkStateEstimate.
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/est_lower_than_network_interval:1s,"
"est_lower_than_network_ratio:0.5,limit_probe_"
"target_rate_to_loss_bwe:true/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
state_estimate.link_capacity_upper = kStartBitrate * 3;
probe_controller->SetNetworkStateEstimate(state_estimate);
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_EQ(probes.size(), 1u);
EXPECT_GT(probes[0].target_data_rate, kStartBitrate);
// If network state not increased, send another probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
// Stop probing if estimate increase. We might probe further here though.
probes = probe_controller->SetEstimatedBitrate(
2 * kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
// No more periodic probes.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, DontProbeFurtherWhenLossLimited) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 3 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
EXPECT_LT(probes[0].target_data_rate, state_estimate.link_capacity_upper);
// Expect that no more probes are sent immediately if BWE is loss limited.
probes = probe_controller->SetEstimatedBitrate(
probes[0].target_data_rate, BandwidthLimitedCause::kLossLimitedBwe,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, ProbeFurtherWhenDelayBasedLimited) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 3 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
EXPECT_LT(probes[0].target_data_rate, state_estimate.link_capacity_upper);
// Since the probe was successfull, expect to continue probing.
probes = probe_controller->SetEstimatedBitrate(
probes[0].target_data_rate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
EXPECT_EQ(probes[0].target_data_rate, state_estimate.link_capacity_upper);
}
TEST(ProbeControllerTest,
ProbeFurtherIfNetworkStateEstimateIncreaseAfterProbeSent) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 1.2 * probes[0].target_data_rate / 2;
probe_controller->SetNetworkStateEstimate(state_estimate);
// No immediate further probing since probe result is low.
probes = probe_controller->SetEstimatedBitrate(
probes[0].target_data_rate / 2, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_LE(probes[0].target_data_rate, state_estimate.link_capacity_upper);
// If the network state estimate increase above the threshold to probe
// further, and the probe suceeed, expect a new probe.
state_estimate.link_capacity_upper = 3 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
probes = probe_controller->SetEstimatedBitrate(
probes[0].target_data_rate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
// But no more probes if estimate is close to the link capacity.
probes = probe_controller->SetEstimatedBitrate(
state_estimate.link_capacity_upper * 0.9,
BandwidthLimitedCause::kDelayBasedLimited, fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, MaxAllocatedBitrateNotReset) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
probes = probe_controller->OnMaxTotalAllocatedBitrate(kStartBitrate / 4,
fixture.CurrentTime());
probe_controller->Reset(fixture.CurrentTime());
probes = probe_controller->SetBitrates(kMinBitrate, kStartBitrate,
kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_EQ(probes[0].target_data_rate, kStartBitrate / 4 * 2);
}
TEST(ProbeControllerTest, SkipAlrProbeIfEstimateLargerThanMaxProbe) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"skip_if_est_larger_than_fraction_of_max:0.9/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
fixture.AdvanceTime(TimeDelta::Seconds(10));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
// But if the max rate increase, A new probe is sent.
probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, 2 * kMaxBitrate, fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
}
TEST(ProbeControllerTest,
SkipAlrProbeIfEstimateLargerThanFractionOfMaxAllocated) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"skip_if_est_larger_than_fraction_of_max:1.0/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate / 2, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
fixture.AdvanceTime(TimeDelta::Seconds(10));
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probes = probe_controller->OnMaxTotalAllocatedBitrate(kMaxBitrate / 2,
fixture.CurrentTime());
// No probes since total allocated is not higher than the current estimate.
EXPECT_TRUE(probes.empty());
fixture.AdvanceTime(TimeDelta::Seconds(2));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
// But if the max allocated increase, A new probe is sent.
probes = probe_controller->OnMaxTotalAllocatedBitrate(
kMaxBitrate / 2 + DataRate::BitsPerSec(1), fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
}
TEST(ProbeControllerTest, SkipNetworkStateProbeIfEstimateLargerThanMaxProbe) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:2s,skip_if_est_larger_than_fraction_of_max:0.9/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
probe_controller->SetNetworkStateEstimate(
{.link_capacity_upper = 2 * kMaxBitrate});
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
fixture.AdvanceTime(TimeDelta::Seconds(10));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, SendsProbeIfNetworkStateEstimateLowerThanMaxProbe) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:2s,skip_if_est_larger_than_fraction_of_max:0.9,"
"/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
probe_controller->SetNetworkStateEstimate(
{.link_capacity_upper = 2 * kMaxBitrate});
probes = probe_controller->SetEstimatedBitrate(
kMaxBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
// Need to wait at least two seconds before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(2100));
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
probe_controller->SetNetworkStateEstimate(
{.link_capacity_upper = 2 * kStartBitrate});
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_FALSE(probes.empty());
}
TEST(ProbeControllerTest,
ProbeNotLimitedByNetworkStateEsimateIfLowerThantCurrent) {
ProbeControllerFixture fixture(
"WebRTC-Bwe-ProbingConfiguration/"
"network_state_interval:5s/");
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
probe_controller->EnablePeriodicAlrProbing(true);
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimited,
fixture.CurrentTime());
probe_controller->SetNetworkStateEstimate(
{.link_capacity_upper = kStartBitrate});
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
probe_controller->SetAlrStartTimeMs(fixture.CurrentTime().ms());
probe_controller->SetNetworkStateEstimate(
{.link_capacity_upper = kStartBitrate / 2});
fixture.AdvanceTime(TimeDelta::Seconds(6));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
EXPECT_EQ(probes[0].target_data_rate, kStartBitrate);
}
TEST(ProbeControllerTest, DontProbeIfDelayIncreased) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 3 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kDelayBasedLimitedDelayIncreased,
fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
TEST(ProbeControllerTest, DontProbeIfHighRtt) {
ProbeControllerFixture fixture;
std::unique_ptr<ProbeController> probe_controller =
fixture.CreateController();
ASSERT_THAT(
probe_controller->OnNetworkAvailability({.network_available = true}),
IsEmpty());
auto probes = probe_controller->SetBitrates(
kMinBitrate, kStartBitrate, kMaxBitrate, fixture.CurrentTime());
ASSERT_FALSE(probes.empty());
// Need to wait at least one second before process can trigger a new probe.
fixture.AdvanceTime(TimeDelta::Millis(1100));
probes = probe_controller->Process(fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
NetworkStateEstimate state_estimate;
state_estimate.link_capacity_upper = 3 * kStartBitrate;
probe_controller->SetNetworkStateEstimate(state_estimate);
probes = probe_controller->SetEstimatedBitrate(
kStartBitrate, BandwidthLimitedCause::kRttBasedBackOffHighRtt,
fixture.CurrentTime());
ASSERT_TRUE(probes.empty());
fixture.AdvanceTime(TimeDelta::Seconds(5));
probes = probe_controller->Process(fixture.CurrentTime());
EXPECT_TRUE(probes.empty());
}
} // namespace test
} // namespace webrtc