thr_setschedparam.c revision 160331 
1/*
2 * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
3 * 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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by Daniel Eischen.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: head/lib/libthr/thread/thr_setschedparam.c 160331 2006-07-13 22:45:19Z davidxu $
33 */
34
35#include "namespace.h"
36#include <sys/param.h>
37#include <errno.h>
38#include <pthread.h>
39#include "un-namespace.h"
40
41#include "thr_private.h"
42
43__weak_reference(_pthread_setschedparam, pthread_setschedparam);
44
45/*
46 * Set a thread's scheduling parameters, this should be done
47 * in kernel, doing it in userland is no-op.
48 */
49int
50_pthread_setschedparam(pthread_t pthread, int policy,
51	const struct sched_param *param)
52{
53	struct pthread	*curthread = _get_curthread();
54	int	ret;
55
56	if (pthread == curthread) {
57		THR_LOCK(curthread);
58		if (curthread->attr.sched_policy == policy &&
59		    (policy == SCHED_OTHER ||
60		     curthread->attr.prio == param->sched_priority)) {
61			pthread->attr.prio = param->sched_priority;
62			THR_UNLOCK(curthread);
63			return (0);
64		}
65		ret = thr_setscheduler(curthread->tid, policy, param,
66			sizeof(param));
67		if (ret == -1)
68			ret = errno;
69		else {
70			curthread->attr.sched_policy = policy;
71			curthread->attr.prio = param->sched_priority;
72		}
73		THR_UNLOCK(curthread);
74	} else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0))
75		== 0) {
76		THR_THREAD_LOCK(curthread, pthread);
77		if (pthread->attr.sched_policy == policy &&
78		    (policy == SCHED_OTHER ||
79		     pthread->attr.prio == param->sched_priority)) {
80			pthread->attr.prio = param->sched_priority;
81			THR_THREAD_UNLOCK(curthread, pthread);
82			return (0);
83		}
84		ret = thr_setscheduler(pthread->tid, policy, param,
85			sizeof(param));
86		if (ret == -1)
87			ret = errno;
88		else {
89			pthread->attr.sched_policy = policy;
90			pthread->attr.prio = param->sched_priority;
91		}
92		THR_THREAD_UNLOCK(curthread, pthread);
93		_thr_ref_delete(curthread, pthread);
94	}
95	return (ret);
96}
97