nice.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/* Copyright (c) 1994 Sun Microsystems, Inc. */
#pragma ident "%Z%%M% %I% %E% SMI" /* from SVr4.0 1.15 */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/cred.h>
#include <sys/proc.h>
#include <sys/debug.h>
#include <sys/class.h>
#include <sys/mutex.h>
/*
* We support the nice system call for compatibility although
* the priocntl system call supports a superset of nice's functionality.
* We support nice only for time sharing threads. It will fail
* if called by a thread from another class.
*/
int
nice(int niceness)
{
int error = 0;
int err, retval;
kthread_id_t t;
proc_t *p = curproc;
mutex_enter(&p->p_lock);
t = p->p_tlist;
do {
err = CL_DONICE(t, CRED(), niceness, &retval);
if (error == 0 && err)
error = set_errno(err);
} while ((t = t->t_forw) != p->p_tlist);
mutex_exit(&p->p_lock);
if (error)
return (error);
return (retval);
}