xref: /titanic_44/usr/src/lib/libc/port/gen/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);
}