cxx/test/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp

33 lines
1.0 KiB
C++
Raw Normal View History

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <thread>
// template <class Clock, class Duration>
// void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
#include <thread>
#include <cstdlib>
#include <cassert>
int main()
{
typedef std::chrono::system_clock Clock;
typedef Clock::time_point time_point;
typedef Clock::duration duration;
std::chrono::milliseconds ms(500);
time_point t0 = Clock::now();
std::this_thread::sleep_until(t0 + ms);
time_point t1 = Clock::now();
std::chrono::nanoseconds ns = (t1 - t0) - ms;
std::chrono::nanoseconds err = 5 * ms / 100;
// The time slept is within 5% of 500ms
assert(std::abs(ns.count()) < err.count());
}