xref: /netbsd-src/lib/libc/gen/nice.c (revision 0a101028d4b70570bb085afb407a738437b47f33)
1*0a101028Schristos /*	$NetBSD: nice.c,v 1.13 2011/05/01 02:49:54 christos Exp $	*/
2f9f97c4fScgd 
361f28255Scgd /*
4f9f97c4fScgd  * Copyright (c) 1983, 1993
5f9f97c4fScgd  *	The Regents of the University of California.  All rights reserved.
661f28255Scgd  *
761f28255Scgd  * Redistribution and use in source and binary forms, with or without
861f28255Scgd  * modification, are permitted provided that the following conditions
961f28255Scgd  * are met:
1061f28255Scgd  * 1. Redistributions of source code must retain the above copyright
1161f28255Scgd  *    notice, this list of conditions and the following disclaimer.
1261f28255Scgd  * 2. Redistributions in binary form must reproduce the above copyright
1361f28255Scgd  *    notice, this list of conditions and the following disclaimer in the
1461f28255Scgd  *    documentation and/or other materials provided with the distribution.
15eb7c1594Sagc  * 3. Neither the name of the University nor the names of its contributors
1661f28255Scgd  *    may be used to endorse or promote products derived from this software
1761f28255Scgd  *    without specific prior written permission.
1861f28255Scgd  *
1961f28255Scgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2061f28255Scgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2161f28255Scgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2261f28255Scgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2361f28255Scgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2461f28255Scgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2561f28255Scgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2661f28255Scgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2761f28255Scgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2861f28255Scgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2961f28255Scgd  * SUCH DAMAGE.
3061f28255Scgd  */
3161f28255Scgd 
3226cc2d4fSchristos #include <sys/cdefs.h>
3361f28255Scgd #if defined(LIBC_SCCS) && !defined(lint)
34f9f97c4fScgd #if 0
35f9f97c4fScgd static char sccsid[] = "@(#)nice.c	8.1 (Berkeley) 6/4/93";
36f9f97c4fScgd #else
37*0a101028Schristos __RCSID("$NetBSD: nice.c,v 1.13 2011/05/01 02:49:54 christos Exp $");
38f9f97c4fScgd #endif
3961f28255Scgd #endif /* LIBC_SCCS and not lint */
4061f28255Scgd 
4143fa6fe3Sjtc #include "namespace.h"
42b4e10df1Smycroft #include <sys/types.h>
4361f28255Scgd #include <sys/time.h>
4461f28255Scgd #include <sys/resource.h>
45f4175535Smikel #include <errno.h>
4661f28255Scgd #include <unistd.h>
4761f28255Scgd 
4843fa6fe3Sjtc #ifdef __weak_alias
__weak_alias(nice,_nice)4960549036Smycroft __weak_alias(nice,_nice)
5043fa6fe3Sjtc #endif
5143fa6fe3Sjtc 
5261f28255Scgd /*
5361f28255Scgd  * Backwards compatible nice.
5461f28255Scgd  */
5561f28255Scgd int
56*0a101028Schristos nice(int incr)
5761f28255Scgd {
58da5a8ed7Skleink 	int prio;
5961f28255Scgd 
6061f28255Scgd 	errno = 0;
6161f28255Scgd 	prio = getpriority(PRIO_PROCESS, 0);
6261f28255Scgd 	if (prio == -1 && errno)
63*0a101028Schristos 		return -1;
64*0a101028Schristos 	if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1) {
65*0a101028Schristos 		if (errno == EACCES)
66*0a101028Schristos 			errno = EPERM;
67*0a101028Schristos 		return -1;
68*0a101028Schristos 	}
69*0a101028Schristos 	return getpriority(PRIO_PROCESS, 0);
7061f28255Scgd }
71