sleep_for.pass.cpp revision f5256e16dfc425c1d466f6308d4026d529ce9e0b 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <thread>
11
12// template <class Rep, class Period>
13//   void sleep_for(const chrono::duration<Rep, Period>& rel_time);
14
15#include <thread>
16#include <cstdlib>
17#include <cassert>
18
19int main()
20{
21    typedef std::chrono::system_clock Clock;
22    typedef Clock::time_point time_point;
23    typedef Clock::duration duration;
24    std::chrono::milliseconds ms(500);
25    time_point t0 = Clock::now();
26    std::this_thread::sleep_for(ms);
27    time_point t1 = Clock::now();
28    std::chrono::nanoseconds ns = (t1 - t0) - ms;
29    std::chrono::nanoseconds err = ms / 100;
30    // The time slept is within 1% of 500ms
31    assert(std::abs(ns.count()) < err.count());
32}
33