1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// UNSUPPORTED: libcpp-has-no-threads
11
12// <thread>
13
14// template <class Clock, class Duration>
15//   void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
16
17#include <thread>
18#include <cstdlib>
19#include <cassert>
20
21int main()
22{
23    typedef std::chrono::system_clock Clock;
24    typedef Clock::time_point time_point;
25    typedef Clock::duration duration;
26    std::chrono::milliseconds ms(500);
27    time_point t0 = Clock::now();
28    std::this_thread::sleep_until(t0 + ms);
29    time_point t1 = Clock::now();
30    std::chrono::nanoseconds ns = (t1 - t0) - ms;
31    std::chrono::nanoseconds err = 5 * ms / 100;
32    // The time slept is within 5% of 500ms
33    assert(std::abs(ns.count()) < err.count());
34}
35