xref: /freebsd/lib/libthr/thread/thr_getschedparam.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
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  * $FreeBSD$
33  */
34 
35 #include "namespace.h"
36 #include <sys/types.h>
37 #include <sys/rtprio.h>
38 #include <errno.h>
39 #include <pthread.h>
40 #include "un-namespace.h"
41 
42 #include "thr_private.h"
43 
44 __weak_reference(_pthread_getschedparam, pthread_getschedparam);
45 
46 int
47 _pthread_getschedparam(pthread_t pthread, int *policy,
48 	struct sched_param *param)
49 {
50 	struct pthread *curthread = _get_curthread();
51 	int ret;
52 
53 	if (policy == NULL || param == NULL)
54 		return (EINVAL);
55 
56 	if (pthread == curthread) {
57 		/*
58 		 * Avoid searching the thread list when it is the current
59 		 * thread.
60 		 */
61 		THR_LOCK(curthread);
62 		*policy = curthread->attr.sched_policy;
63 		param->sched_priority = curthread->attr.prio;
64 		THR_UNLOCK(curthread);
65 		ret = 0;
66 	}
67 	/* Find the thread in the list of active threads. */
68 	else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0))
69 	    == 0) {
70 		THR_THREAD_LOCK(curthread, pthread);
71 		*policy = pthread->attr.sched_policy;
72 		param->sched_priority = pthread->attr.prio;
73 		THR_THREAD_UNLOCK(curthread, pthread);
74 		_thr_ref_delete(curthread, pthread);
75 	}
76 	return (ret);
77 }
78