xref: /onnv-gate/usr/src/lib/libbc/libc/gen/common/ualarm.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
2*0Sstevel@tonic-gate 	  /* from UCB 5.1 85/06/05 */
3*0Sstevel@tonic-gate 
4*0Sstevel@tonic-gate /*
5*0Sstevel@tonic-gate  * Copyright (c) 1985 Regents of the University of California.
6*0Sstevel@tonic-gate  * All rights reserved.  The Berkeley software License Agreement
7*0Sstevel@tonic-gate  * specifies the terms and conditions for redistribution.
8*0Sstevel@tonic-gate  */
9*0Sstevel@tonic-gate 
10*0Sstevel@tonic-gate #include <sys/time.h>
11*0Sstevel@tonic-gate 
12*0Sstevel@tonic-gate #define	USPS	1000000		/* # of microseconds in a second */
13*0Sstevel@tonic-gate 
14*0Sstevel@tonic-gate /*
15*0Sstevel@tonic-gate  * Generate a SIGALRM signal in ``usecs'' microseconds.
16*0Sstevel@tonic-gate  * If ``reload'' is non-zero, keep generating SIGALRM
17*0Sstevel@tonic-gate  * every ``reload'' microseconds after the first signal.
18*0Sstevel@tonic-gate  */
19*0Sstevel@tonic-gate unsigned
ualarm(usecs,reload)20*0Sstevel@tonic-gate ualarm(usecs, reload)
21*0Sstevel@tonic-gate 	register unsigned usecs;
22*0Sstevel@tonic-gate 	register unsigned reload;
23*0Sstevel@tonic-gate {
24*0Sstevel@tonic-gate 	struct itimerval new, old;
25*0Sstevel@tonic-gate 
26*0Sstevel@tonic-gate 	new.it_interval.tv_usec = reload % USPS;
27*0Sstevel@tonic-gate 	new.it_interval.tv_sec = reload / USPS;
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate 	new.it_value.tv_usec = usecs % USPS;
30*0Sstevel@tonic-gate 	new.it_value.tv_sec = usecs / USPS;
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate 	if (setitimer(ITIMER_REAL, &new, &old) == 0)
33*0Sstevel@tonic-gate 		return (old.it_value.tv_sec * USPS + old.it_value.tv_usec);
34*0Sstevel@tonic-gate 	/* else */
35*0Sstevel@tonic-gate 		return (-1);
36*0Sstevel@tonic-gate }
37