xref: /netbsd/lib/libc/gen/nice.c (revision be58367b)
1 /*	$NetBSD: nice.c,v 1.13 2011/05/01 02:49:54 christos 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[] = "@(#)nice.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: nice.c,v 1.13 2011/05/01 02:49:54 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 #include <sys/types.h>
43 #include <sys/time.h>
44 #include <sys/resource.h>
45 #include <errno.h>
46 #include <unistd.h>
47 
48 #ifdef __weak_alias
__weak_alias(nice,_nice)49 __weak_alias(nice,_nice)
50 #endif
51 
52 /*
53  * Backwards compatible nice.
54  */
55 int
56 nice(int incr)
57 {
58 	int prio;
59 
60 	errno = 0;
61 	prio = getpriority(PRIO_PROCESS, 0);
62 	if (prio == -1 && errno)
63 		return -1;
64 	if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1) {
65 		if (errno == EACCES)
66 			errno = EPERM;
67 		return -1;
68 	}
69 	return getpriority(PRIO_PROCESS, 0);
70 }
71