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//===----------------------------------------------------------------------===//
//
// 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 Rep, class Period>
// void sleep_for(const chrono::duration<Rep, Period>& rel_time);
#include <thread>
#include <cstdlib>
#include <cassert>
#include <signal.h>
#include <sys/time.h>
int main()
{
int ec;
struct sigaction action;
action.sa_handler = [](int) {};
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
ec = sigaction(SIGALRM, &action, nullptr);
assert(!ec);
struct itimerval it;
it.it_interval = { 0 };
it.it_value.tv_sec = 0;
it.it_value.tv_usec = 250000;
// This will result in a SIGALRM getting fired resulting in the nanosleep
// inside sleep_for getting EINTR.
ec = setitimer(ITIMER_REAL, &it, nullptr);
assert(!ec);
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_for(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());
}
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