lib/libc/gen/alarm.c

   1 /*      $NetBSD: alarm.c,v 1.11 2012/06/25 22:32:43 abs Exp $   */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)alarm.c     8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: alarm.c,v 1.11 2012/06/25 22:32:43 abs Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 /*
  42  * Backwards compatible alarm.
  43  */
  44 #include "namespace.h"
  45 #include <sys/time.h>
  46 #include <unistd.h>
  47
  48 #ifdef __weak_alias
  49 __weak_alias(alarm,_alarm)
  50 #endif
  51
  52 unsigned int
  53 alarm(unsigned int secs)
  54 {
  55         struct itimerval it, oitv;
  56         struct itimerval *itp = &it;
  57
  58         timerclear(&itp->it_interval);
  59         itp->it_value.tv_sec = secs;
  60         itp->it_value.tv_usec = 0;
  61         if (setitimer(ITIMER_REAL, itp, &oitv) == -1)
  62                 return (unsigned int) -1;
  63         if (oitv.it_value.tv_usec)
  64                 oitv.it_value.tv_sec++;
  65         return (unsigned int)oitv.it_value.tv_sec;
  66 }