//
// UNSUPPORTED: libcpp-has-no-threads
-// ALLOW_RETRIES: 2
-
// This test uses the POSIX header <sys/time.h> which Windows doesn't provide
// UNSUPPORTED: windows
int main(int, char**)
{
- int ec;
- struct sigaction action;
- action.sa_handler = &sig_action;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
+ int ec;
+ struct sigaction action;
+ action.sa_handler = &sig_action;
+ sigemptyset(&action.sa_mask);
+ action.sa_flags = 0;
- ec = sigaction(SIGALRM, &action, nullptr);
- assert(!ec);
+ ec = sigaction(SIGALRM, &action, nullptr);
+ assert(!ec);
- struct itimerval it;
- std::memset(&it, 0, sizeof(itimerval));
- 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);
+ struct itimerval it;
+ std::memset(&it, 0, sizeof(itimerval));
+ 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;
- 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());
+ typedef std::chrono::system_clock Clock;
+ typedef Clock::time_point time_point;
+ std::chrono::milliseconds ms(500);
+ time_point t0 = Clock::now();
+ std::this_thread::sleep_for(ms);
+ time_point t1 = Clock::now();
+ // NOTE: Operating systems are (by default) best effort and therefore we may
+ // have slept longer, perhaps much longer than we requested.
+ assert(t1 - t0 >= ms);
return 0;
}