ualarm.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1985 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 "lint.h"
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#define USPS 1000000 /* # of microseconds in a second */
/*
* Generate a SIGALRM signal in ``usecs'' microseconds.
* If ``reload'' is non-zero, keep generating SIGALRM
* every ``reload'' microseconds after the first signal.
*/
useconds_t
ualarm(useconds_t usecs, useconds_t reload)
{
struct itimerval new, old;
new.it_interval.tv_usec = reload % USPS;
new.it_interval.tv_sec = reload / USPS;
new.it_value.tv_usec = usecs % USPS;
new.it_value.tv_sec = usecs / USPS;
if (setitimer(ITIMER_REAL, &new, &old) != 0)
return (0); /* no errors are defined */
return (old.it_value.tv_sec * USPS + old.it_value.tv_usec);
}