xref: /freebsd/lib/libc/gen/nice.c (revision fbbd9655e5107c68e4e0146ff22b73d7350475bc)
158f0484fSRodney W. Grimes /*
258f0484fSRodney W. Grimes  * Copyright (c) 1983, 1993
358f0484fSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
458f0484fSRodney W. Grimes  *
558f0484fSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
658f0484fSRodney W. Grimes  * modification, are permitted provided that the following conditions
758f0484fSRodney W. Grimes  * are met:
858f0484fSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
958f0484fSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
1058f0484fSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
1158f0484fSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
1258f0484fSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13*fbbd9655SWarner Losh  * 3. Neither the name of the University nor the names of its contributors
1458f0484fSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
1558f0484fSRodney W. Grimes  *    without specific prior written permission.
1658f0484fSRodney W. Grimes  *
1758f0484fSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
1858f0484fSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1958f0484fSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2058f0484fSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2158f0484fSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2258f0484fSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2358f0484fSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2458f0484fSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2558f0484fSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2658f0484fSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2758f0484fSRodney W. Grimes  * SUCH DAMAGE.
2858f0484fSRodney W. Grimes  */
2958f0484fSRodney W. Grimes 
3058f0484fSRodney W. Grimes #if defined(LIBC_SCCS) && !defined(lint)
3158f0484fSRodney W. Grimes static char sccsid[] = "@(#)nice.c	8.1 (Berkeley) 6/4/93";
3258f0484fSRodney W. Grimes #endif /* LIBC_SCCS and not lint */
33333fc21eSDavid E. O'Brien #include <sys/cdefs.h>
34333fc21eSDavid E. O'Brien __FBSDID("$FreeBSD$");
3558f0484fSRodney W. Grimes 
3658f0484fSRodney W. Grimes #include <sys/types.h>
3758f0484fSRodney W. Grimes #include <sys/time.h>
3858f0484fSRodney W. Grimes #include <sys/resource.h>
39e659da10SJohn Birrell #include <errno.h>
4058f0484fSRodney W. Grimes #include <unistd.h>
4158f0484fSRodney W. Grimes 
4258f0484fSRodney W. Grimes /*
4358f0484fSRodney W. Grimes  * Backwards compatible nice.
4458f0484fSRodney W. Grimes  */
4558f0484fSRodney W. Grimes int
46e220ce08SJilles Tjoelker nice(int incr)
4758f0484fSRodney W. Grimes {
48c317cb51SJilles Tjoelker 	int saverrno, prio;
4958f0484fSRodney W. Grimes 
50c317cb51SJilles Tjoelker 	saverrno = errno;
5158f0484fSRodney W. Grimes 	errno = 0;
5258f0484fSRodney W. Grimes 	prio = getpriority(PRIO_PROCESS, 0);
53c317cb51SJilles Tjoelker 	if (prio == -1 && errno != 0)
54c317cb51SJilles Tjoelker 		return (-1);
55e220ce08SJilles Tjoelker 	if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1) {
56e220ce08SJilles Tjoelker 		if (errno == EACCES)
57e220ce08SJilles Tjoelker 			errno = EPERM;
58c317cb51SJilles Tjoelker 		return (-1);
59e220ce08SJilles Tjoelker 	}
60c317cb51SJilles Tjoelker 	errno = saverrno;
61c317cb51SJilles Tjoelker 	return (0);
6258f0484fSRodney W. Grimes }
63