libc/gen/ualarm.c

1.11       abs /*	$NetBSD: ualarm.c,v 1.11 2012/06/25 22:32:44 abs Exp $	*/
 1.4       cgd
 1.1       cgd /*
 1.4       cgd  * Copyright (c) 1985, 1993
 1.4       cgd  *	The Regents of the University of California.  All rights reserved.
 1.1       cgd  *
 1.1       cgd  * Redistribution and use in source and binary forms, with or without
 1.1       cgd  * modification, are permitted provided that the following conditions
 1.1       cgd  * are met:
 1.1       cgd  * 1. Redistributions of source code must retain the above copyright
 1.1       cgd  *    notice, this list of conditions and the following disclaimer.
 1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
 1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
 1.1       cgd  *    documentation and/or other materials provided with the distribution.
1.10       agc  * 3. Neither the name of the University nor the names of its contributors
 1.1       cgd  *    may be used to endorse or promote products derived from this software
 1.1       cgd  *    without specific prior written permission.
 1.1       cgd  *
 1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 1.1       cgd  * SUCH DAMAGE.
 1.1       cgd  */
 1.1       cgd
 1.5  christos #include <sys/cdefs.h>
 1.1       cgd #if defined(LIBC_SCCS) && !defined(lint)
 1.4       cgd #if 0
 1.4       cgd static char sccsid[] = "@(#)ualarm.c	8.1 (Berkeley) 6/4/93";
 1.4       cgd #else
1.11       abs __RCSID("$NetBSD: ualarm.c,v 1.11 2012/06/25 22:32:44 abs Exp $");
 1.4       cgd #endif
 1.1       cgd #endif /* LIBC_SCCS and not lint */
 1.1       cgd
 1.6       jtc #include "namespace.h"
 1.1       cgd #include <sys/time.h>
 1.1       cgd #include <unistd.h>
 1.6       jtc
 1.6       jtc #ifdef __weak_alias
 1.9   mycroft __weak_alias(ualarm,_ualarm)
 1.6       jtc #endif
 1.1       cgd
 1.1       cgd #define	USPS	1000000		/* # of microseconds in a second */
 1.1       cgd
 1.1       cgd /*
 1.1       cgd  * Generate a SIGALRM signal in ``usecs'' microseconds.
 1.1       cgd  * If ``reload'' is non-zero, keep generating SIGALRM
 1.1       cgd  * every ``reload'' microseconds after the first signal.
 1.1       cgd  */
 1.7    kleink useconds_t
1.11       abs ualarm(useconds_t usecs, useconds_t reload)
 1.1       cgd {
 1.1       cgd 	struct itimerval new, old;
 1.1       cgd
 1.1       cgd 	new.it_interval.tv_usec = reload % USPS;
 1.1       cgd 	new.it_interval.tv_sec = reload / USPS;
 1.1       cgd
 1.1       cgd 	new.it_value.tv_usec = usecs % USPS;
 1.1       cgd 	new.it_value.tv_sec = usecs / USPS;
 1.1       cgd
 1.1       cgd 	if (setitimer(ITIMER_REAL, &new, &old) == 0)
 1.8  christos 		return (useconds_t)(old.it_value.tv_sec * USPS +
 1.8  christos 		    old.it_value.tv_usec);
 1.8  christos
 1.8  christos 	return (useconds_t)-1;
 1.1       cgd }