/*
* Copyright 1986 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/time.h>
#include <signal.h>
#define setvec(vec, a) \
vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
static void sleepx(void);
/*
* sleep(n)
*
* return 0 if n seconds passed
* return n - t if t seconds passed
*
* this code is gross and works just barely.
* it would be nice if someone rewrote it.
*/
unsigned
sleep(unsigned n)
{
int omask;
struct itimerval new, old, zero;
struct itimerval *newp = &new;
struct timeval left_over;
int alrm_flg;
struct sigvec vec, ovec;
if (n == 0)
return(0);
timerclear(&newp->it_interval);
timerclear(&newp->it_value);
if (setitimer(ITIMER_REAL, newp, &old) < 0)
return(n);
newp->it_value.tv_sec = n;
alrm_flg = 0;
timerclear(&left_over);
if (timerisset(&old.it_value)) {
if (timercmp(&old.it_value, &newp->it_value, >)) {
old.it_value.tv_sec -= newp->it_value.tv_sec;
++alrm_flg;
} else {
left_over.tv_sec = newp->it_value.tv_sec
- old.it_value.tv_sec;
if (old.it_value.tv_usec != 0) {
left_over.tv_sec--;
left_over.tv_usec = 1000000
- old.it_value.tv_usec;
}
newp->it_value = old.it_value;
timerclear(&old.it_value);
--alrm_flg;
}
}
if (alrm_flg >= 0) {
setvec(vec, sleepx);
(void) sigvec(SIGALRM, &vec, &ovec);
}
omask = sigblock(sigmask(SIGALRM));
(void) setitimer(ITIMER_REAL, newp, (struct itimerval *)0);
sigpause(omask &~ sigmask(SIGALRM));
timerclear(&zero.it_value);
timerclear(&zero.it_interval);
(void) setitimer(ITIMER_REAL, &zero, newp);
if (alrm_flg >= 0)
(void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
(void) sigsetmask(omask);
if (alrm_flg > 0 || (alrm_flg < 0 && timerisset(&newp->it_value))) {
struct itimerval reset;
/*
* I use reset instead of what new points to because the
* code that calculates the return value depends on the
* old value of *newp.
*/
reset = *newp;
newp = &reset;
newp->it_value.tv_usec += old.it_value.tv_usec;
newp->it_value.tv_sec += old.it_value.tv_sec;
if (newp->it_value.tv_usec >= 1000000) {
newp->it_value.tv_usec -= 1000000;
newp->it_value.tv_sec++;
}
(void) setitimer(ITIMER_REAL, newp, (struct itimerval *)0);
newp = &new;
}
left_over.tv_sec += newp->it_value.tv_sec;
left_over.tv_usec += newp->it_value.tv_usec;
if (left_over.tv_usec >= 1000000) {
left_over.tv_sec++;
left_over.tv_usec -= 1000000;
}
if (left_over.tv_usec >= 500000)
left_over.tv_sec++;
return(left_over.tv_sec);
}
static void
sleepx(void)
{
}