xref: /netbsd/lib/libc/gen/clock.c (revision bf9ec67e)
1 /*	$NetBSD: clock.c,v 1.7 1998/03/30 14:27:17 kleink Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)clock.c	8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: clock.c,v 1.7 1998/03/30 14:27:17 kleink Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include <sys/param.h>
46 #include <sys/time.h>
47 #include <sys/resource.h>
48 
49 #include <time.h>
50 
51 /*
52  * Convert usec to clock ticks; could do (usec * CLOCKS_PER_SEC) / 1000000,
53  * but this would overflow if we switch to nanosec.
54  */
55 #define	CONVTCK(r)	(r.tv_sec * CLOCKS_PER_SEC + \
56 			 r.tv_usec / (1000000 / CLOCKS_PER_SEC))
57 
58 clock_t
59 clock()
60 {
61 	struct rusage ru;
62 
63 	if (getrusage(RUSAGE_SELF, &ru))
64 		return ((clock_t) -1);
65 	return((clock_t)((CONVTCK(ru.ru_utime) + CONVTCK(ru.ru_stime))));
66 }
67