xref: /freebsd/lib/libthr/thread/thr_getschedparam.c (revision 262e143bd46171a6415a5b28af260a5efa2a3db8)
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 <errno.h>
36 #include <pthread.h>
37 
38 #include "thr_private.h"
39 
40 __weak_reference(_pthread_getschedparam, pthread_getschedparam);
41 
42 int
43 _pthread_getschedparam(pthread_t pthread, int *policy,
44 	struct sched_param *param)
45 {
46 	struct pthread *curthread = _get_curthread();
47 	int ret, tmp;
48 
49 	if ((param == NULL) || (policy == NULL))
50 		/* Return an invalid argument error: */
51 		ret = EINVAL;
52 	else if (pthread == curthread) {
53 		/*
54 		 * Avoid searching the thread list when it is the current
55 		 * thread.
56 		 */
57 		THR_THREAD_LOCK(curthread, curthread);
58 		param->sched_priority =
59 		    THR_BASE_PRIORITY(pthread->base_priority);
60 		tmp = pthread->attr.sched_policy;
61 		THR_THREAD_UNLOCK(curthread, curthread);
62 		*policy = tmp;
63 		ret = 0;
64 	}
65 	/* Find the thread in the list of active threads. */
66 	else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0))
67 	    == 0) {
68 		THR_THREAD_LOCK(curthread, pthread);
69 		param->sched_priority =
70 		    THR_BASE_PRIORITY(pthread->base_priority);
71 		tmp = pthread->attr.sched_policy;
72 		THR_THREAD_UNLOCK(curthread, pthread);
73 		_thr_ref_delete(curthread, pthread);
74 		*policy = tmp;
75 	}
76 	return (ret);
77 }
78