1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)nice.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: src/lib/libc/gen/nice.c,v 1.4 2007/01/09 00:27:54 imp Exp $");
35
36#include <sys/types.h>
37#include <sys/time.h>
38#include <sys/resource.h>
39#include <errno.h>
40#include <unistd.h>
41#if __DARWIN_UNIX03
42#include <limits.h>
43#endif /* __DARWIN_UNIX03 */
44/*
45 * Backwards compatible nice.
46 */
47int
48nice(incr)
49	int incr;
50{
51	int prio, rv;
52
53	errno = 0;
54	prio = getpriority(PRIO_PROCESS, 0);
55	if (prio == -1 && errno)
56		return (-1);
57#if __DARWIN_UNIX03
58	if (prio + incr > NZERO-1)
59		incr = NZERO-1-prio;
60#endif /* __DARWIN_UNIX03 */
61	rv = setpriority(PRIO_PROCESS, 0, prio + incr);
62	if (rv == -1 && errno == EACCES)
63		errno = EPERM;
64	return (rv == -1) ? rv : getpriority(PRIO_PROCESS, 0);
65}
66