xref: /csrg-svn/lib/libc/gen/alarm.c (revision 35304)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static char sccsid[] = "@(#)alarm.c	5.3 (Berkeley) 08/02/88";
20 #endif /* LIBC_SCCS and not lint */
21 
22 /*
23  * Backwards compatible alarm.
24  */
25 #include <sys/time.h>
26 
27 alarm(secs)
28 	int secs;
29 {
30 	struct itimerval it, oitv;
31 	register struct itimerval *itp = &it;
32 
33 	timerclear(&itp->it_interval);
34 	itp->it_value.tv_sec = secs;
35 	itp->it_value.tv_usec = 0;
36 	if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
37 		return (-1);
38 	if (oitv.it_value.tv_usec)
39 		oitv.it_value.tv_sec++;
40 	return (oitv.it_value.tv_sec);
41 }
42