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/*
* Copyright (c) 2020 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 "video/call_stats2.h"
#include <memory>
#include "api/task_queue/default_task_queue_factory.h"
#include "api/task_queue/task_queue_base.h"
#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
#include "rtc_base/thread.h"
#include "system_wrappers/include/metrics.h"
#include "test/gmock.h"
#include "test/gtest.h"
#include "test/run_loop.h"
using ::testing::AnyNumber;
using ::testing::InvokeWithoutArgs;
using ::testing::Return;
namespace webrtc {
namespace internal {
class MockStatsObserver : public CallStatsObserver {
public:
MockStatsObserver() {}
virtual ~MockStatsObserver() {}
MOCK_METHOD(void, OnRttUpdate, (int64_t, int64_t), (override));
};
class CallStats2Test : public ::testing::Test {
public:
CallStats2Test() { call_stats_.EnsureStarted(); }
// Queues an rtt update call on the process thread.
void AsyncSimulateRttUpdate(int64_t rtt) {
RtcpRttStats* rtcp_rtt_stats = call_stats_.AsRtcpRttStats();
task_queue_->PostTask(
[rtcp_rtt_stats, rtt] { rtcp_rtt_stats->OnRttUpdate(rtt); });
}
protected:
void FlushProcessAndWorker() {
task_queue_->PostTask([this] { loop_.PostTask([this] { loop_.Quit(); }); });
loop_.Run();
}
test::RunLoop loop_;
std::unique_ptr<TaskQueueBase, TaskQueueDeleter> task_queue_ =
CreateDefaultTaskQueueFactory()->CreateTaskQueue(
"CallStats",
TaskQueueFactory::Priority::NORMAL);
// Note: Since rtc::Thread doesn't support injecting a Clock, we're going
// to be using a mix of the fake clock (used by CallStats) as well as the
// system clock (used by rtc::Thread). This isn't ideal and will result in
// the tests taking longer to execute in some cases than they need to.
SimulatedClock fake_clock_{12345};
CallStats call_stats_{&fake_clock_, loop_.task_queue()};
};
TEST_F(CallStats2Test, AddAndTriggerCallback) {
static constexpr const int64_t kRtt = 25;
MockStatsObserver stats_observer;
EXPECT_CALL(stats_observer, OnRttUpdate(kRtt, kRtt))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] { loop_.Quit(); }));
call_stats_.RegisterStatsObserver(&stats_observer);
EXPECT_EQ(-1, call_stats_.LastProcessedRtt());
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
EXPECT_EQ(kRtt, call_stats_.LastProcessedRtt());
call_stats_.DeregisterStatsObserver(&stats_observer);
}
TEST_F(CallStats2Test, ProcessTime) {
static constexpr const int64_t kRtt = 100;
static constexpr const int64_t kRtt2 = 80;
MockStatsObserver stats_observer;
EXPECT_CALL(stats_observer, OnRttUpdate(kRtt, kRtt))
.Times(2)
.WillOnce(InvokeWithoutArgs([this] {
// Advance clock and verify we get an update.
fake_clock_.AdvanceTimeMilliseconds(CallStats::kUpdateInterval.ms());
}))
.WillRepeatedly(InvokeWithoutArgs([this] {
AsyncSimulateRttUpdate(kRtt2);
// Advance clock just too little to get an update.
fake_clock_.AdvanceTimeMilliseconds(CallStats::kUpdateInterval.ms() -
1);
}));
// In case you're reading this and wondering how this number is arrived at,
// please see comments in the ChangeRtt test that go into some detail.
static constexpr const int64_t kLastAvg = 94;
EXPECT_CALL(stats_observer, OnRttUpdate(kLastAvg, kRtt2))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] { loop_.Quit(); }));
call_stats_.RegisterStatsObserver(&stats_observer);
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
call_stats_.DeregisterStatsObserver(&stats_observer);
}
// Verify all observers get correct estimates and observers can be added and
// removed.
TEST_F(CallStats2Test, MultipleObservers) {
MockStatsObserver stats_observer_1;
call_stats_.RegisterStatsObserver(&stats_observer_1);
// Add the second observer twice, there should still be only one report to the
// observer.
MockStatsObserver stats_observer_2;
call_stats_.RegisterStatsObserver(&stats_observer_2);
call_stats_.RegisterStatsObserver(&stats_observer_2);
static constexpr const int64_t kRtt = 100;
// Verify both observers are updated.
EXPECT_CALL(stats_observer_1, OnRttUpdate(kRtt, kRtt))
.Times(AnyNumber())
.WillRepeatedly(Return());
EXPECT_CALL(stats_observer_2, OnRttUpdate(kRtt, kRtt))
.Times(AnyNumber())
.WillOnce(InvokeWithoutArgs([this] { loop_.Quit(); }))
.WillRepeatedly(Return());
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
// Deregister the second observer and verify update is only sent to the first
// observer.
call_stats_.DeregisterStatsObserver(&stats_observer_2);
EXPECT_CALL(stats_observer_1, OnRttUpdate(kRtt, kRtt))
.Times(AnyNumber())
.WillOnce(InvokeWithoutArgs([this] { loop_.Quit(); }))
.WillRepeatedly(Return());
EXPECT_CALL(stats_observer_2, OnRttUpdate(kRtt, kRtt)).Times(0);
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
// Deregister the first observer.
call_stats_.DeregisterStatsObserver(&stats_observer_1);
// Now make sure we don't get any callbacks.
EXPECT_CALL(stats_observer_1, OnRttUpdate(kRtt, kRtt)).Times(0);
EXPECT_CALL(stats_observer_2, OnRttUpdate(kRtt, kRtt)).Times(0);
AsyncSimulateRttUpdate(kRtt);
// Flush the queue on the process thread to make sure we return after
// Process() has been called.
FlushProcessAndWorker();
}
// Verify increasing and decreasing rtt triggers callbacks with correct values.
TEST_F(CallStats2Test, ChangeRtt) {
// NOTE: This test assumes things about how old reports are removed
// inside of call_stats.cc. The threshold ms value is 1500ms, but it's not
// clear here that how the clock is advanced, affects that algorithm and
// subsequently the average reported rtt.
MockStatsObserver stats_observer;
call_stats_.RegisterStatsObserver(&stats_observer);
static constexpr const int64_t kFirstRtt = 100;
static constexpr const int64_t kLowRtt = kFirstRtt - 20;
static constexpr const int64_t kHighRtt = kFirstRtt + 20;
EXPECT_CALL(stats_observer, OnRttUpdate(kFirstRtt, kFirstRtt))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] {
fake_clock_.AdvanceTimeMilliseconds(1000);
AsyncSimulateRttUpdate(kHighRtt); // Reported at T1 (1000ms).
}));
// NOTE: This relies on the internal algorithms of call_stats.cc.
// There's a weight factor there (0.3), that weighs the previous average to
// the new one by 70%, so the number 103 in this case is arrived at like so:
// (100) / 1 * 0.7 + (100+120)/2 * 0.3 = 103
static constexpr const int64_t kAvgRtt1 = 103;
EXPECT_CALL(stats_observer, OnRttUpdate(kAvgRtt1, kHighRtt))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] {
// This interacts with an internal implementation detail in call_stats
// that decays the oldest rtt value. See more below.
fake_clock_.AdvanceTimeMilliseconds(1000);
AsyncSimulateRttUpdate(kLowRtt); // Reported at T2 (2000ms).
}));
// Increase time enough for a new update, but not too much to make the
// rtt invalid. Report a lower rtt and verify the old/high value still is sent
// in the callback.
// Here, enough time must have passed in order to remove exactly the first
// report and nothing else (>1500ms has passed since the first rtt).
// So, this value is arrived by doing:
// (kAvgRtt1)/1 * 0.7 + (kHighRtt+kLowRtt)/2 * 0.3 = 102.1
static constexpr const int64_t kAvgRtt2 = 102;
EXPECT_CALL(stats_observer, OnRttUpdate(kAvgRtt2, kHighRtt))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] {
// Advance time to make the high report invalid, the lower rtt should
// now be in the callback.
fake_clock_.AdvanceTimeMilliseconds(1000);
}));
static constexpr const int64_t kAvgRtt3 = 95;
EXPECT_CALL(stats_observer, OnRttUpdate(kAvgRtt3, kLowRtt))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] { loop_.Quit(); }));
// Trigger the first rtt value and set off the chain of callbacks.
AsyncSimulateRttUpdate(kFirstRtt); // Reported at T0 (0ms).
loop_.Run();
call_stats_.DeregisterStatsObserver(&stats_observer);
}
TEST_F(CallStats2Test, LastProcessedRtt) {
MockStatsObserver stats_observer;
call_stats_.RegisterStatsObserver(&stats_observer);
static constexpr const int64_t kRttLow = 10;
static constexpr const int64_t kRttHigh = 30;
// The following two average numbers dependend on average + weight
// calculations in call_stats.cc.
static constexpr const int64_t kAvgRtt1 = 13;
static constexpr const int64_t kAvgRtt2 = 15;
EXPECT_CALL(stats_observer, OnRttUpdate(kRttLow, kRttLow))
.Times(1)
.WillOnce(InvokeWithoutArgs([this] {
EXPECT_EQ(kRttLow, call_stats_.LastProcessedRtt());
// Don't advance the clock to make sure that low and high rtt values
// are associated with the same time stamp.
AsyncSimulateRttUpdate(kRttHigh);
}));
EXPECT_CALL(stats_observer, OnRttUpdate(kAvgRtt1, kRttHigh))
.Times(AnyNumber())
.WillOnce(InvokeWithoutArgs([this] {
EXPECT_EQ(kAvgRtt1, call_stats_.LastProcessedRtt());
fake_clock_.AdvanceTimeMilliseconds(CallStats::kUpdateInterval.ms());
AsyncSimulateRttUpdate(kRttLow);
AsyncSimulateRttUpdate(kRttHigh);
}))
.WillRepeatedly(Return());
EXPECT_CALL(stats_observer, OnRttUpdate(kAvgRtt2, kRttHigh))
.Times(AnyNumber())
.WillOnce(InvokeWithoutArgs([this] {
EXPECT_EQ(kAvgRtt2, call_stats_.LastProcessedRtt());
loop_.Quit();
}))
.WillRepeatedly(Return());
// Set a first values and verify that LastProcessedRtt initially returns the
// average rtt.
fake_clock_.AdvanceTimeMilliseconds(CallStats::kUpdateInterval.ms());
AsyncSimulateRttUpdate(kRttLow);
loop_.Run();
EXPECT_EQ(kAvgRtt2, call_stats_.LastProcessedRtt());
call_stats_.DeregisterStatsObserver(&stats_observer);
}
TEST_F(CallStats2Test, ProducesHistogramMetrics) {
metrics::Reset();
static constexpr const int64_t kRtt = 123;
MockStatsObserver stats_observer;
call_stats_.RegisterStatsObserver(&stats_observer);
EXPECT_CALL(stats_observer, OnRttUpdate(kRtt, kRtt))
.Times(AnyNumber())
.WillRepeatedly(InvokeWithoutArgs([this] { loop_.Quit(); }));
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
fake_clock_.AdvanceTimeMilliseconds(metrics::kMinRunTimeInSeconds *
CallStats::kUpdateInterval.ms());
AsyncSimulateRttUpdate(kRtt);
loop_.Run();
call_stats_.DeregisterStatsObserver(&stats_observer);
call_stats_.UpdateHistogramsForTest();
EXPECT_METRIC_EQ(1, metrics::NumSamples(
"WebRTC.Video.AverageRoundTripTimeInMilliseconds"));
EXPECT_METRIC_EQ(
1, metrics::NumEvents("WebRTC.Video.AverageRoundTripTimeInMilliseconds",
kRtt));
}
} // namespace internal
} // namespace webrtc