118 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
// Copyright 2017 The Abseil Authors.
 | 
						|
//
 | 
						|
// 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
 | 
						|
//
 | 
						|
//      https://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 "absl/time/clock.h"
 | 
						|
 | 
						|
#include "absl/base/config.h"
 | 
						|
#if defined(ABSL_HAVE_ALARM)
 | 
						|
#include <signal.h>
 | 
						|
#include <unistd.h>
 | 
						|
#elif defined(__linux__) || defined(__APPLE__)
 | 
						|
#error all known Linux and Apple targets have alarm
 | 
						|
#endif
 | 
						|
 | 
						|
#include "gtest/gtest.h"
 | 
						|
#include "absl/time/time.h"
 | 
						|
 | 
						|
namespace {
 | 
						|
 | 
						|
TEST(Time, Now) {
 | 
						|
  const absl::Time before = absl::FromUnixNanos(absl::GetCurrentTimeNanos());
 | 
						|
  const absl::Time now = absl::Now();
 | 
						|
  const absl::Time after = absl::FromUnixNanos(absl::GetCurrentTimeNanos());
 | 
						|
  EXPECT_GE(now, before);
 | 
						|
  EXPECT_GE(after, now);
 | 
						|
}
 | 
						|
 | 
						|
enum class AlarmPolicy { kWithoutAlarm, kWithAlarm };
 | 
						|
 | 
						|
#if defined(ABSL_HAVE_ALARM)
 | 
						|
bool alarm_handler_invoked = false;
 | 
						|
 | 
						|
void AlarmHandler(int signo) {
 | 
						|
  ASSERT_EQ(signo, SIGALRM);
 | 
						|
  alarm_handler_invoked = true;
 | 
						|
}
 | 
						|
#endif
 | 
						|
 | 
						|
// Does SleepFor(d) take between lower_bound and upper_bound at least
 | 
						|
// once between now and (now + timeout)?  If requested (and supported),
 | 
						|
// add an alarm for the middle of the sleep period and expect it to fire.
 | 
						|
bool SleepForBounded(absl::Duration d, absl::Duration lower_bound,
 | 
						|
                     absl::Duration upper_bound, absl::Duration timeout,
 | 
						|
                     AlarmPolicy alarm_policy, int* attempts) {
 | 
						|
  const absl::Time deadline = absl::Now() + timeout;
 | 
						|
  while (absl::Now() < deadline) {
 | 
						|
#if defined(ABSL_HAVE_ALARM)
 | 
						|
    sig_t old_alarm = SIG_DFL;
 | 
						|
    if (alarm_policy == AlarmPolicy::kWithAlarm) {
 | 
						|
      alarm_handler_invoked = false;
 | 
						|
      old_alarm = signal(SIGALRM, AlarmHandler);
 | 
						|
      alarm(absl::ToInt64Seconds(d / 2));
 | 
						|
    }
 | 
						|
#else
 | 
						|
    EXPECT_EQ(alarm_policy, AlarmPolicy::kWithoutAlarm);
 | 
						|
#endif
 | 
						|
    ++*attempts;
 | 
						|
    absl::Time start = absl::Now();
 | 
						|
    absl::SleepFor(d);
 | 
						|
    absl::Duration actual = absl::Now() - start;
 | 
						|
#if defined(ABSL_HAVE_ALARM)
 | 
						|
    if (alarm_policy == AlarmPolicy::kWithAlarm) {
 | 
						|
      signal(SIGALRM, old_alarm);
 | 
						|
      if (!alarm_handler_invoked) continue;
 | 
						|
    }
 | 
						|
#endif
 | 
						|
    if (lower_bound <= actual && actual <= upper_bound) {
 | 
						|
      return true;  // yes, the SleepFor() was correctly bounded
 | 
						|
    }
 | 
						|
  }
 | 
						|
  return false;
 | 
						|
}
 | 
						|
 | 
						|
testing::AssertionResult AssertSleepForBounded(absl::Duration d,
 | 
						|
                                               absl::Duration early,
 | 
						|
                                               absl::Duration late,
 | 
						|
                                               absl::Duration timeout,
 | 
						|
                                               AlarmPolicy alarm_policy) {
 | 
						|
  const absl::Duration lower_bound = d - early;
 | 
						|
  const absl::Duration upper_bound = d + late;
 | 
						|
  int attempts = 0;
 | 
						|
  if (SleepForBounded(d, lower_bound, upper_bound, timeout, alarm_policy,
 | 
						|
                      &attempts)) {
 | 
						|
    return testing::AssertionSuccess();
 | 
						|
  }
 | 
						|
  return testing::AssertionFailure()
 | 
						|
         << "SleepFor(" << d << ") did not return within [" << lower_bound
 | 
						|
         << ":" << upper_bound << "] in " << attempts << " attempt"
 | 
						|
         << (attempts == 1 ? "" : "s") << " over " << timeout
 | 
						|
         << (alarm_policy == AlarmPolicy::kWithAlarm ? " with" : " without")
 | 
						|
         << " an alarm";
 | 
						|
}
 | 
						|
 | 
						|
// Tests that SleepFor() returns neither too early nor too late.
 | 
						|
TEST(SleepFor, Bounded) {
 | 
						|
  const absl::Duration d = absl::Milliseconds(2500);
 | 
						|
  const absl::Duration early = absl::Milliseconds(100);
 | 
						|
  const absl::Duration late = absl::Milliseconds(300);
 | 
						|
  const absl::Duration timeout = 48 * d;
 | 
						|
  EXPECT_TRUE(AssertSleepForBounded(d, early, late, timeout,
 | 
						|
                                    AlarmPolicy::kWithoutAlarm));
 | 
						|
#if defined(ABSL_HAVE_ALARM)
 | 
						|
  EXPECT_TRUE(AssertSleepForBounded(d, early, late, timeout,
 | 
						|
                                    AlarmPolicy::kWithAlarm));
 | 
						|
#endif
 | 
						|
}
 | 
						|
 | 
						|
}  // namespace
 |