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#include <sys/time.h>
#include <signal.h>
#define setvec(vec, a) \
vec.sv_handler = a; \
vec.sv_mask = vec.sv_flags = 0
static int ringring;
nap(n)
unsigned n;
{
void napx();
int omask;
struct sigvec vec, ovec;
struct itimerval itv, oitv;
register struct itimerval *itp = &itv;
if (n == 0)
return;
timerclear(&itp->it_interval);
timerclear(&itp->it_value);
if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
return;
setvec(ovec, SIG_DFL);
omask = sigblock(sigmask(SIGALRM));
itp->it_value.tv_sec = n/60;
itp->it_value.tv_usec = (n%60)*1000000/60;
if (timerisset(&oitv.it_value)) {
if (oitv.it_value.tv_sec >= itp->it_value.tv_sec) {
if (oitv.it_value.tv_sec == itp->it_value.tv_sec &&
oitv.it_value.tv_usec > itp->it_value.tv_usec)
oitv.it_value.tv_usec -= itp->it_value.tv_usec;
oitv.it_value.tv_sec -= itp->it_value.tv_sec;
}
else {
itp->it_value = oitv.it_value;
/*
* This is a hack, but we must have time to return from
* the setitimer after the alarm or else it will restart.
* And, anyway, sleep never did more than this before.
*/
oitv.it_value.tv_sec = 1;
oitv.it_value.tv_usec = 0;
}
}
setvec(vec, napx);
ringring = 0;
sigvec(SIGALRM, &vec, &ovec);
setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
while (!ringring)
sigpause(omask &~ sigmask(SIGALRM));
sigvec(SIGALRM, &ovec, (struct sigvec *)0);
setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
sigsetmask(omask);
}
static void
napx()
{
ringring = 1;
}
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