xref: /onnv-gate/usr/src/lib/libbc/libc/gen/sys5/sleep.c (revision 722:636b850d4ee9)
1*722Smuffin /*
2*722Smuffin  * Copyright 1986 Sun Microsystems, Inc.  All rights reserved.
3*722Smuffin  * Use is subject to license terms.
4*722Smuffin  */
50Sstevel@tonic-gate 
60Sstevel@tonic-gate /*
70Sstevel@tonic-gate  * Copyright (c) 1980 Regents of the University of California.
80Sstevel@tonic-gate  * All rights reserved.  The Berkeley software License Agreement
90Sstevel@tonic-gate  * specifies the terms and conditions for redistribution.
100Sstevel@tonic-gate  */
110Sstevel@tonic-gate 
12*722Smuffin #pragma ident	"%Z%%M%	%I%	%E% SMI"
130Sstevel@tonic-gate 
140Sstevel@tonic-gate #include <sys/time.h>
150Sstevel@tonic-gate #include <signal.h>
160Sstevel@tonic-gate 
170Sstevel@tonic-gate #define	setvec(vec, a) \
180Sstevel@tonic-gate 	vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
190Sstevel@tonic-gate 
20*722Smuffin static void	sleepx(void);
21*722Smuffin 
220Sstevel@tonic-gate /*
230Sstevel@tonic-gate  * sleep(n)
240Sstevel@tonic-gate  *
250Sstevel@tonic-gate  * return 0 if n seconds passed
260Sstevel@tonic-gate  * return n - t if t seconds passed
270Sstevel@tonic-gate  *
280Sstevel@tonic-gate  * this code is gross and works just barely.
290Sstevel@tonic-gate  * it would be nice if someone rewrote it.
300Sstevel@tonic-gate  */
310Sstevel@tonic-gate unsigned
sleep(unsigned n)32*722Smuffin sleep(unsigned n)
330Sstevel@tonic-gate {
340Sstevel@tonic-gate 	int omask;
350Sstevel@tonic-gate 	struct itimerval new, old, zero;
36*722Smuffin 	struct itimerval *newp = &new;
370Sstevel@tonic-gate 	struct timeval left_over;
380Sstevel@tonic-gate 	int alrm_flg;
390Sstevel@tonic-gate 	struct sigvec vec, ovec;
400Sstevel@tonic-gate 
410Sstevel@tonic-gate 	if (n == 0)
420Sstevel@tonic-gate 		return(0);
430Sstevel@tonic-gate 	timerclear(&newp->it_interval);
440Sstevel@tonic-gate 	timerclear(&newp->it_value);
450Sstevel@tonic-gate 	if (setitimer(ITIMER_REAL, newp, &old) < 0)
460Sstevel@tonic-gate 		return(n);
470Sstevel@tonic-gate 	newp->it_value.tv_sec = n;
480Sstevel@tonic-gate 	alrm_flg = 0;
490Sstevel@tonic-gate 	timerclear(&left_over);
500Sstevel@tonic-gate 	if (timerisset(&old.it_value)) {
510Sstevel@tonic-gate 		if (timercmp(&old.it_value, &newp->it_value, >)) {
520Sstevel@tonic-gate 			old.it_value.tv_sec -= newp->it_value.tv_sec;
530Sstevel@tonic-gate 			++alrm_flg;
540Sstevel@tonic-gate 		} else {
550Sstevel@tonic-gate 			left_over.tv_sec = newp->it_value.tv_sec
560Sstevel@tonic-gate 			    - old.it_value.tv_sec;
570Sstevel@tonic-gate 			if (old.it_value.tv_usec != 0) {
580Sstevel@tonic-gate 				left_over.tv_sec--;
590Sstevel@tonic-gate 				left_over.tv_usec = 1000000
600Sstevel@tonic-gate 				    - old.it_value.tv_usec;
610Sstevel@tonic-gate 			}
620Sstevel@tonic-gate 			newp->it_value = old.it_value;
630Sstevel@tonic-gate 			timerclear(&old.it_value);
640Sstevel@tonic-gate 			--alrm_flg;
650Sstevel@tonic-gate 		}
660Sstevel@tonic-gate 	}
670Sstevel@tonic-gate 	if (alrm_flg >= 0) {
680Sstevel@tonic-gate 		setvec(vec, sleepx);
690Sstevel@tonic-gate 		(void) sigvec(SIGALRM, &vec, &ovec);
700Sstevel@tonic-gate 	}
710Sstevel@tonic-gate 	omask = sigblock(sigmask(SIGALRM));
720Sstevel@tonic-gate 	(void) setitimer(ITIMER_REAL, newp, (struct itimerval *)0);
730Sstevel@tonic-gate 	sigpause(omask &~ sigmask(SIGALRM));
740Sstevel@tonic-gate 	timerclear(&zero.it_value);
750Sstevel@tonic-gate 	timerclear(&zero.it_interval);
760Sstevel@tonic-gate 	(void) setitimer(ITIMER_REAL, &zero, newp);
770Sstevel@tonic-gate 	if (alrm_flg >= 0)
780Sstevel@tonic-gate 		(void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
790Sstevel@tonic-gate 	(void) sigsetmask(omask);
800Sstevel@tonic-gate 	if (alrm_flg > 0 || (alrm_flg < 0 && timerisset(&newp->it_value))) {
810Sstevel@tonic-gate 		struct itimerval reset;
820Sstevel@tonic-gate 
830Sstevel@tonic-gate 		/*
840Sstevel@tonic-gate 		 * I use reset instead of what new points to because the
850Sstevel@tonic-gate 		 * code that calculates the return value depends on the
860Sstevel@tonic-gate 		 * old value of *newp.
870Sstevel@tonic-gate 		 */
880Sstevel@tonic-gate 		reset = *newp;
890Sstevel@tonic-gate 		newp = &reset;
900Sstevel@tonic-gate 		newp->it_value.tv_usec += old.it_value.tv_usec;
910Sstevel@tonic-gate 		newp->it_value.tv_sec += old.it_value.tv_sec;
920Sstevel@tonic-gate 		if (newp->it_value.tv_usec >= 1000000) {
930Sstevel@tonic-gate 			newp->it_value.tv_usec -= 1000000;
940Sstevel@tonic-gate 			newp->it_value.tv_sec++;
950Sstevel@tonic-gate 		}
960Sstevel@tonic-gate 		(void) setitimer(ITIMER_REAL, newp, (struct itimerval *)0);
970Sstevel@tonic-gate 		newp = &new;
980Sstevel@tonic-gate 	}
990Sstevel@tonic-gate 	left_over.tv_sec += newp->it_value.tv_sec;
1000Sstevel@tonic-gate 	left_over.tv_usec += newp->it_value.tv_usec;
1010Sstevel@tonic-gate 	if (left_over.tv_usec >= 1000000) {
1020Sstevel@tonic-gate 		left_over.tv_sec++;
1030Sstevel@tonic-gate 		left_over.tv_usec -= 1000000;
1040Sstevel@tonic-gate 	}
1050Sstevel@tonic-gate 	if (left_over.tv_usec >= 500000)
1060Sstevel@tonic-gate 		left_over.tv_sec++;
1070Sstevel@tonic-gate 	return(left_over.tv_sec);
1080Sstevel@tonic-gate }
1090Sstevel@tonic-gate 
1100Sstevel@tonic-gate static void
sleepx(void)111*722Smuffin sleepx(void)
1120Sstevel@tonic-gate {
1130Sstevel@tonic-gate }
114