/* Start the timeout after which we'll receive a SIGALRM.
Round DURATION up to the next representable value.
Treat out-of-range values as if they were maximal,
as that's more useful in practice than reporting an error.
'0' means don't timeout. */
static void
settimeout (double duration, bool warn)
{
/* timer_settime() provides potentially nanosecond resolution.
setitimer() is more portable (to Darwin for example),
but only provides microsecond resolution and thus is
a little more awkward to use with timespecs, as well as being
deprecated by POSIX. Instead we fallback to single second
resolution provided by alarm(). */
#if HAVE_TIMER_SETTIME
struct timespec ts = dtotimespec (duration);
struct itimerspec its = { {0, 0}, ts };
timer_t timerid;
if (timer_create (CLOCK_REALTIME, NULL, &timerid) == 0)
{
if (timer_settime (timerid, 0, &its, NULL) == 0)
return;
else
{
if (warn)
error (0, errno, _("warning: timer_settime"));
timer_delete (timerid);
}
}
else if (warn && errno != ENOSYS)
error (0, errno, _("warning: timer_create"));
#endif
unsigned int timeint;
if (UINT_MAX <= duration)
timeint = UINT_MAX;
else
{
unsigned int duration_floor = duration;
timeint = duration_floor + (duration_floor < duration);
}
alarm (timeint);
}
int
xnanosleep (double seconds)
{
struct timespec ts_sleep = dtotimespec (seconds);
for (;;)
{
/* Linux-2.6.8.1's nanosleep returns -1, but doesn't set errno
when resumed after being suspended. Earlier versions would
set errno to EINTR. nanosleep from linux-2.6.10, as well as
implementations by (all?) other vendors, doesn't return -1
in that case; either it continues sleeping (if time remains)
or it returns zero (if the wake-up time has passed). */
errno = 0;
if (nanosleep (&ts_sleep, NULL) == 0)
break;
if (errno != EINTR && errno != 0)
return -1;
}
return 0;
}
