blob: acd1eead01264e92ccbc86699c9398be6db49c64 [file] [log] [blame]
/*
* 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/video_coding/nack_module2.h"
#include <algorithm>
#include <cstdint>
#include <cstring>
#include <memory>
#include "system_wrappers/include/clock.h"
#include "test/field_trial.h"
#include "test/gtest.h"
#include "test/run_loop.h"
namespace webrtc {
// TODO(bugs.webrtc.org/11594): Use the use the GlobalSimulatedTimeController
// instead of RunLoop. At the moment we mix use of the Clock and the underlying
// implementation of RunLoop, which is realtime.
class TestNackModule2 : public ::testing::TestWithParam<bool>,
public NackSender,
public KeyFrameRequestSender {
protected:
TestNackModule2()
: clock_(new SimulatedClock(0)),
field_trial_(GetParam()
? "WebRTC-ExponentialNackBackoff/enabled:true/"
: "WebRTC-ExponentialNackBackoff/enabled:false/"),
keyframes_requested_(0) {}
void SetUp() override {}
void SendNack(const std::vector<uint16_t>& sequence_numbers,
bool buffering_allowed) override {
sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(),
sequence_numbers.end());
if (waiting_for_send_nack_) {
waiting_for_send_nack_ = false;
loop_.Quit();
}
}
void RequestKeyFrame() override { ++keyframes_requested_; }
void Flush() {
// nack_module.Process();
loop_.Flush();
}
bool WaitForSendNack() {
if (timed_out_) {
RTC_NOTREACHED();
return false;
}
RTC_DCHECK(!waiting_for_send_nack_);
waiting_for_send_nack_ = true;
loop_.PostDelayedTask(
[this]() {
timed_out_ = true;
loop_.Quit();
},
1000);
loop_.Run();
if (timed_out_)
return false;
RTC_DCHECK(!waiting_for_send_nack_);
return true;
}
NackModule2& CreateNackModule(
TimeDelta interval = NackModule2::kUpdateInterval) {
RTC_DCHECK(!nack_module_.get());
nack_module_ = std::make_unique<NackModule2>(
TaskQueueBase::Current(), clock_.get(), this, this, interval);
nack_module_->UpdateRtt(kDefaultRttMs);
return *nack_module_.get();
}
static constexpr int64_t kDefaultRttMs = 20;
test::RunLoop loop_;
std::unique_ptr<SimulatedClock> clock_;
test::ScopedFieldTrials field_trial_;
std::unique_ptr<NackModule2> nack_module_;
std::vector<uint16_t> sent_nacks_;
int keyframes_requested_;
bool waiting_for_send_nack_ = false;
bool timed_out_ = false;
};
TEST_P(TestNackModule2, NackOnePacket) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(1, false, false);
nack_module.OnReceivedPacket(3, false, false);
ASSERT_EQ(1u, sent_nacks_.size());
EXPECT_EQ(2, sent_nacks_[0]);
}
TEST_P(TestNackModule2, WrappingSeqNum) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(0xfffe, false, false);
nack_module.OnReceivedPacket(1, false, false);
ASSERT_EQ(2u, sent_nacks_.size());
EXPECT_EQ(0xffff, sent_nacks_[0]);
EXPECT_EQ(0, sent_nacks_[1]);
}
TEST_P(TestNackModule2, WrappingSeqNumClearToKeyframe) {
NackModule2& nack_module = CreateNackModule(TimeDelta::Millis(10));
nack_module.OnReceivedPacket(0xfffe, false, false);
nack_module.OnReceivedPacket(1, false, false);
ASSERT_EQ(2u, sent_nacks_.size());
EXPECT_EQ(0xffff, sent_nacks_[0]);
EXPECT_EQ(0, sent_nacks_[1]);
sent_nacks_.clear();
nack_module.OnReceivedPacket(2, true, false);
ASSERT_EQ(0u, sent_nacks_.size());
nack_module.OnReceivedPacket(501, true, false);
ASSERT_EQ(498u, sent_nacks_.size());
for (int seq_num = 3; seq_num < 501; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]);
sent_nacks_.clear();
nack_module.OnReceivedPacket(1001, false, false);
EXPECT_EQ(499u, sent_nacks_.size());
for (int seq_num = 502; seq_num < 1001; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]);
sent_nacks_.clear();
clock_->AdvanceTimeMilliseconds(100);
ASSERT_TRUE(WaitForSendNack());
ASSERT_EQ(999u, sent_nacks_.size());
EXPECT_EQ(0xffff, sent_nacks_[0]);
EXPECT_EQ(0, sent_nacks_[1]);
for (int seq_num = 3; seq_num < 501; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 1]);
for (int seq_num = 502; seq_num < 1001; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 2]);
// Adding packet 1004 will cause the nack list to reach it's max limit.
// It will then clear all nacks up to the next keyframe (seq num 2),
// thus removing 0xffff and 0 from the nack list.
sent_nacks_.clear();
nack_module.OnReceivedPacket(1004, false, false);
ASSERT_EQ(2u, sent_nacks_.size());
EXPECT_EQ(1002, sent_nacks_[0]);
EXPECT_EQ(1003, sent_nacks_[1]);
sent_nacks_.clear();
clock_->AdvanceTimeMilliseconds(100);
ASSERT_TRUE(WaitForSendNack());
ASSERT_EQ(999u, sent_nacks_.size());
for (int seq_num = 3; seq_num < 501; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 3]);
for (int seq_num = 502; seq_num < 1001; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 4]);
// Adding packet 1007 will cause the nack module to overflow again, thus
// clearing everything up to 501 which is the next keyframe.
nack_module.OnReceivedPacket(1007, false, false);
sent_nacks_.clear();
clock_->AdvanceTimeMilliseconds(100);
ASSERT_TRUE(WaitForSendNack());
ASSERT_EQ(503u, sent_nacks_.size());
for (int seq_num = 502; seq_num < 1001; ++seq_num)
EXPECT_EQ(seq_num, sent_nacks_[seq_num - 502]);
EXPECT_EQ(1005, sent_nacks_[501]);
EXPECT_EQ(1006, sent_nacks_[502]);
}
TEST_P(TestNackModule2, ResendNack) {
NackModule2& nack_module = CreateNackModule(TimeDelta::Millis(1));
nack_module.OnReceivedPacket(1, false, false);
nack_module.OnReceivedPacket(3, false, false);
size_t expected_nacks_sent = 1;
ASSERT_EQ(expected_nacks_sent, sent_nacks_.size());
EXPECT_EQ(2, sent_nacks_[0]);
if (GetParam()) {
// Retry has to wait at least 5ms by default.
nack_module.UpdateRtt(1);
clock_->AdvanceTimeMilliseconds(4);
Flush(); // Too early.
EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
clock_->AdvanceTimeMilliseconds(1);
WaitForSendNack(); // Now allowed.
EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
} else {
nack_module.UpdateRtt(1);
clock_->AdvanceTimeMilliseconds(1);
WaitForSendNack(); // Fast retransmit allowed.
EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
}
// N:th try has to wait b^(N-1) * rtt by default.
const double b = GetParam() ? 1.25 : 1.0;
for (int i = 2; i < 10; ++i) {
// Change RTT, above the 40ms max for exponential backoff.
TimeDelta rtt = TimeDelta::Millis(160); // + (i * 10 - 40)
nack_module.UpdateRtt(rtt.ms());
// RTT gets capped at 160ms in backoff calculations.
TimeDelta expected_backoff_delay =
std::pow(b, i - 1) * std::min(rtt, TimeDelta::Millis(160));
// Move to one millisecond before next allowed NACK.
clock_->AdvanceTimeMilliseconds(expected_backoff_delay.ms() - 1);
Flush();
EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
// Move to one millisecond after next allowed NACK.
// After rather than on to avoid rounding errors.
clock_->AdvanceTimeMilliseconds(2);
WaitForSendNack(); // Now allowed.
EXPECT_EQ(++expected_nacks_sent, sent_nacks_.size());
}
// Giving up after 10 tries.
clock_->AdvanceTimeMilliseconds(3000);
Flush();
EXPECT_EQ(expected_nacks_sent, sent_nacks_.size());
}
TEST_P(TestNackModule2, ResendPacketMaxRetries) {
NackModule2& nack_module = CreateNackModule(TimeDelta::Millis(1));
nack_module.OnReceivedPacket(1, false, false);
nack_module.OnReceivedPacket(3, false, false);
ASSERT_EQ(1u, sent_nacks_.size());
EXPECT_EQ(2, sent_nacks_[0]);
int backoff_factor = 1;
for (size_t retries = 1; retries < 10; ++retries) {
// Exponential backoff, so that we don't reject NACK because of time.
clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs);
backoff_factor *= 2;
WaitForSendNack();
EXPECT_EQ(retries + 1, sent_nacks_.size());
}
clock_->AdvanceTimeMilliseconds(backoff_factor * kDefaultRttMs);
Flush();
EXPECT_EQ(10u, sent_nacks_.size());
}
TEST_P(TestNackModule2, TooLargeNackList) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(0, false, false);
nack_module.OnReceivedPacket(1001, false, false);
EXPECT_EQ(1000u, sent_nacks_.size());
EXPECT_EQ(0, keyframes_requested_);
nack_module.OnReceivedPacket(1003, false, false);
EXPECT_EQ(1000u, sent_nacks_.size());
EXPECT_EQ(1, keyframes_requested_);
nack_module.OnReceivedPacket(1004, false, false);
EXPECT_EQ(1000u, sent_nacks_.size());
EXPECT_EQ(1, keyframes_requested_);
}
TEST_P(TestNackModule2, TooLargeNackListWithKeyFrame) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(0, false, false);
nack_module.OnReceivedPacket(1, true, false);
nack_module.OnReceivedPacket(1001, false, false);
EXPECT_EQ(999u, sent_nacks_.size());
EXPECT_EQ(0, keyframes_requested_);
nack_module.OnReceivedPacket(1003, false, false);
EXPECT_EQ(1000u, sent_nacks_.size());
EXPECT_EQ(0, keyframes_requested_);
nack_module.OnReceivedPacket(1005, false, false);
EXPECT_EQ(1000u, sent_nacks_.size());
EXPECT_EQ(1, keyframes_requested_);
}
TEST_P(TestNackModule2, ClearUpTo) {
NackModule2& nack_module = CreateNackModule(TimeDelta::Millis(1));
nack_module.OnReceivedPacket(0, false, false);
nack_module.OnReceivedPacket(100, false, false);
EXPECT_EQ(99u, sent_nacks_.size());
sent_nacks_.clear();
clock_->AdvanceTimeMilliseconds(100);
nack_module.ClearUpTo(50);
WaitForSendNack();
ASSERT_EQ(50u, sent_nacks_.size());
EXPECT_EQ(50, sent_nacks_[0]);
}
TEST_P(TestNackModule2, ClearUpToWrap) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(0xfff0, false, false);
nack_module.OnReceivedPacket(0xf, false, false);
EXPECT_EQ(30u, sent_nacks_.size());
sent_nacks_.clear();
clock_->AdvanceTimeMilliseconds(100);
nack_module.ClearUpTo(0);
WaitForSendNack();
ASSERT_EQ(15u, sent_nacks_.size());
EXPECT_EQ(0, sent_nacks_[0]);
}
TEST_P(TestNackModule2, PacketNackCount) {
NackModule2& nack_module = CreateNackModule(TimeDelta::Millis(1));
EXPECT_EQ(0, nack_module.OnReceivedPacket(0, false, false));
EXPECT_EQ(0, nack_module.OnReceivedPacket(2, false, false));
EXPECT_EQ(1, nack_module.OnReceivedPacket(1, false, false));
sent_nacks_.clear();
nack_module.UpdateRtt(100);
EXPECT_EQ(0, nack_module.OnReceivedPacket(5, false, false));
clock_->AdvanceTimeMilliseconds(100);
WaitForSendNack();
EXPECT_EQ(4u, sent_nacks_.size());
clock_->AdvanceTimeMilliseconds(125);
WaitForSendNack();
EXPECT_EQ(6u, sent_nacks_.size());
EXPECT_EQ(3, nack_module.OnReceivedPacket(3, false, false));
EXPECT_EQ(3, nack_module.OnReceivedPacket(4, false, false));
EXPECT_EQ(0, nack_module.OnReceivedPacket(4, false, false));
}
TEST_P(TestNackModule2, NackListFullAndNoOverlapWithKeyframes) {
NackModule2& nack_module = CreateNackModule();
const int kMaxNackPackets = 1000;
const unsigned int kFirstGap = kMaxNackPackets - 20;
const unsigned int kSecondGap = 200;
uint16_t seq_num = 0;
nack_module.OnReceivedPacket(seq_num++, true, false);
seq_num += kFirstGap;
nack_module.OnReceivedPacket(seq_num++, true, false);
EXPECT_EQ(kFirstGap, sent_nacks_.size());
sent_nacks_.clear();
seq_num += kSecondGap;
nack_module.OnReceivedPacket(seq_num, true, false);
EXPECT_EQ(kSecondGap, sent_nacks_.size());
}
TEST_P(TestNackModule2, HandleFecRecoveredPacket) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(1, false, false);
nack_module.OnReceivedPacket(4, false, true);
EXPECT_EQ(0u, sent_nacks_.size());
nack_module.OnReceivedPacket(5, false, false);
EXPECT_EQ(2u, sent_nacks_.size());
}
TEST_P(TestNackModule2, SendNackWithoutDelay) {
NackModule2& nack_module = CreateNackModule();
nack_module.OnReceivedPacket(0, false, false);
nack_module.OnReceivedPacket(100, false, false);
EXPECT_EQ(99u, sent_nacks_.size());
}
INSTANTIATE_TEST_SUITE_P(WithAndWithoutBackoff,
TestNackModule2,
::testing::Values(true, false));
class TestNackModule2WithFieldTrial : public ::testing::Test,
public NackSender,
public KeyFrameRequestSender {
protected:
TestNackModule2WithFieldTrial()
: nack_delay_field_trial_("WebRTC-SendNackDelayMs/10/"),
clock_(new SimulatedClock(0)),
nack_module_(TaskQueueBase::Current(), clock_.get(), this, this),
keyframes_requested_(0) {}
void SendNack(const std::vector<uint16_t>& sequence_numbers,
bool buffering_allowed) override {
sent_nacks_.insert(sent_nacks_.end(), sequence_numbers.begin(),
sequence_numbers.end());
}
void RequestKeyFrame() override { ++keyframes_requested_; }
test::ScopedFieldTrials nack_delay_field_trial_;
std::unique_ptr<SimulatedClock> clock_;
NackModule2 nack_module_;
std::vector<uint16_t> sent_nacks_;
int keyframes_requested_;
};
TEST_F(TestNackModule2WithFieldTrial, SendNackWithDelay) {
nack_module_.OnReceivedPacket(0, false, false);
nack_module_.OnReceivedPacket(100, false, false);
EXPECT_EQ(0u, sent_nacks_.size());
clock_->AdvanceTimeMilliseconds(10);
nack_module_.OnReceivedPacket(106, false, false);
EXPECT_EQ(99u, sent_nacks_.size());
clock_->AdvanceTimeMilliseconds(10);
nack_module_.OnReceivedPacket(109, false, false);
EXPECT_EQ(104u, sent_nacks_.size());
}
} // namespace webrtc