// Copyright 2019 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/timer/lap_timer.h" #include "base/test/task_environment.h" #include "base/time/time.h" #include "build/build_config.h" #include "testing/gtest/include/gtest/gtest.h" // This file contains a minimal unit test for LapTimer, used for benchmarking. // This file is supposed to match closely with the example code, documented in // lap_timer.h. Please update that documentation if you need to change things. namespace base { namespace test { namespace { constexpr base::TimeDelta kTimeLimit = base::Milliseconds(15); constexpr base::TimeDelta kTimeAdvance = base::Milliseconds(1); constexpr int kWarmupRuns = 5; constexpr int kTimeCheckInterval = 10; } // namespace TEST(LapTimer, UsageExample) { TaskEnvironment task_environment(TaskEnvironment::TimeSource::MOCK_TIME); LapTimer timer(kWarmupRuns, kTimeLimit, kTimeCheckInterval); EXPECT_FALSE(timer.HasTimeLimitExpired()); EXPECT_FALSE(timer.IsWarmedUp()); do { task_environment.FastForwardBy(kTimeAdvance); timer.NextLap(); } while (!timer.HasTimeLimitExpired()); EXPECT_NEAR(timer.LapsPerSecond(), 1000, 0.1); EXPECT_NEAR(timer.TimePerLap().InMillisecondsF(), 1.0f, 0.1); // Output number of laps is 20, because the warm up runs are ignored and the // timer is only checked every kTimeInterval laps. EXPECT_EQ(timer.NumLaps(), 20); EXPECT_TRUE(timer.HasTimeLimitExpired()); EXPECT_TRUE(timer.IsWarmedUp()); } #if !BUILDFLAG(IS_IOS) // iOS simulator does not support using ThreadTicks. TEST(LapTimer, ThreadTicksUsageExample) { TaskEnvironment task_environment(TaskEnvironment::TimeSource::MOCK_TIME); LapTimer timer(kWarmupRuns, kTimeLimit, kTimeCheckInterval, LapTimer::TimerMethod::kUseThreadTicks); EXPECT_FALSE(timer.HasTimeLimitExpired()); EXPECT_FALSE(timer.IsWarmedUp()); do { task_environment.FastForwardBy(kTimeAdvance); timer.NextLap(); } while (!timer.HasTimeLimitExpired()); // Because advancing the TaskEnvironment time won't affect the // ThreadTicks, laps will be much faster than the regular UsageExample. EXPECT_GT(timer.LapsPerSecond(), 1000); EXPECT_LT(timer.TimePerLap().InMillisecondsF(), 1.0f); EXPECT_GT(timer.NumLaps(), 20); EXPECT_TRUE(timer.HasTimeLimitExpired()); EXPECT_TRUE(timer.IsWarmedUp()); } #endif } // namespace test } // namespace base