thr_setschedparam.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
5 * 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by Daniel Eischen.
18 * 4. Neither the name of the author nor the names of any co-contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/lib/libthr/thread/thr_setschedparam.c 330897 2018-03-14 03:19:51Z eadler $");
37
38#include "namespace.h"
39#include <sys/param.h>
40#include <errno.h>
41#include <pthread.h>
42#include "un-namespace.h"
43
44#include "thr_private.h"
45
46__weak_reference(_pthread_setschedparam, pthread_setschedparam);
47
48/*
49 * Set a thread's scheduling parameters, this should be done
50 * in kernel, doing it in userland is no-op.
51 */
52int
53_pthread_setschedparam(pthread_t pthread, int policy,
54	const struct sched_param *param)
55{
56	struct pthread	*curthread = _get_curthread();
57	int	ret;
58
59	if (pthread == curthread)
60		THR_LOCK(curthread);
61	else if ((ret = _thr_find_thread(curthread, pthread,
62		 /*include dead*/0)) != 0)
63		return (ret);
64	if (pthread->attr.sched_policy == policy &&
65	    (policy == SCHED_OTHER ||
66	     pthread->attr.prio == param->sched_priority)) {
67		pthread->attr.prio = param->sched_priority;
68		THR_THREAD_UNLOCK(curthread, pthread);
69		return (0);
70	}
71	ret = _thr_setscheduler(pthread->tid, policy, param);
72	if (ret == -1)
73		ret = errno;
74	else {
75		pthread->attr.sched_policy = policy;
76		pthread->attr.prio = param->sched_priority;
77	}
78	THR_THREAD_UNLOCK(curthread, pthread);
79	return (ret);
80}
81