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// Copyright 2014 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "util/misc/clock.h"
#include <sys/types.h>
#include <algorithm>
#include "base/format_macros.h"
#include "base/logging.h"
#include "base/stl_util.h"
#include "base/strings/stringprintf.h"
#include "gtest/gtest.h"
namespace crashpad {
namespace test {
namespace {
TEST(Clock, ClockMonotonicNanoseconds) {
uint64_t start = ClockMonotonicNanoseconds();
EXPECT_GT(start, 0u);
uint64_t now = start;
for (size_t iteration = 0; iteration < 10; ++iteration) {
uint64_t last = now;
now = ClockMonotonicNanoseconds();
// Use EXPECT_GE instead of EXPECT_GT, because there are no guarantees about
// the clock’s resolution.
EXPECT_GE(now, last);
}
#if !defined(OS_WIN) // No SleepNanoseconds implemented on Windows.
// SleepNanoseconds() should sleep for at least the value of the clock’s
// resolution, so the clock’s value should definitely increase after a sleep.
// EXPECT_GT can be used instead of EXPECT_GE after the sleep.
SleepNanoseconds(1);
now = ClockMonotonicNanoseconds();
EXPECT_GT(now, start);
#endif // OS_WIN
}
#if !defined(OS_WIN) // No SleepNanoseconds implemented on Windows.
void TestSleepNanoseconds(uint64_t nanoseconds) {
uint64_t start = ClockMonotonicNanoseconds();
SleepNanoseconds(nanoseconds);
uint64_t end = ClockMonotonicNanoseconds();
uint64_t diff = end - start;
// |nanoseconds| is the lower bound for the actual amount of time spent
// sleeping.
EXPECT_GE(diff, nanoseconds);
// It’s difficult to set an upper bound for the time spent sleeping, and
// attempting to do so results in a flaky test.
}
TEST(Clock, SleepNanoseconds) {
static constexpr uint64_t kTestData[] = {
0,
1,
static_cast<uint64_t>(1E3), // 1 microsecond
static_cast<uint64_t>(1E4), // 10 microseconds
static_cast<uint64_t>(1E5), // 100 microseconds
static_cast<uint64_t>(1E6), // 1 millisecond
static_cast<uint64_t>(1E7), // 10 milliseconds
static_cast<uint64_t>(2E7), // 20 milliseconds
static_cast<uint64_t>(5E7), // 50 milliseconds
};
for (size_t index = 0; index < base::size(kTestData); ++index) {
const uint64_t nanoseconds = kTestData[index];
SCOPED_TRACE(base::StringPrintf(
"index %zu, nanoseconds %" PRIu64, index, nanoseconds));
TestSleepNanoseconds(nanoseconds);
}
}
#endif // OS_WIN
} // namespace
} // namespace test
} // namespace crashpad