xref: /netbsd-src/lib/libc/sys/sched.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: sched.c,v 1.2 2008/10/31 00:29:19 rmind Exp $	*/
2 
3 /*
4  * Copyright (c) 2008, Mindaugas Rasiukevicius <rmind at NetBSD org>
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: sched.c,v 1.2 2008/10/31 00:29:19 rmind Exp $");
31 
32 #include <string.h>
33 #include <unistd.h>
34 #include <errno.h>
35 #include <sched.h>
36 #include <sys/param.h>
37 #include <sys/types.h>
38 
39 /* All LWPs in the process */
40 #define	P_ALL_LWPS		0
41 
42 /*
43  * Scheduling parameters.
44  */
45 
46 int
47 sched_setparam(pid_t pid, const struct sched_param *param)
48 {
49 	struct sched_param sp;
50 
51 	memset(&sp, 0, sizeof(struct sched_param));
52 	sp.sched_priority = param->sched_priority;
53 	return _sched_setparam(pid, P_ALL_LWPS, SCHED_NONE, &sp);
54 }
55 
56 int
57 sched_getparam(pid_t pid, struct sched_param *param)
58 {
59 
60 	return _sched_getparam(pid, P_ALL_LWPS, NULL, param);
61 }
62 
63 int
64 sched_setscheduler(pid_t pid, int policy, const struct sched_param *param)
65 {
66 	struct sched_param sp;
67 	int ret, old_policy;
68 
69 	ret = _sched_getparam(pid, P_ALL_LWPS, &old_policy, &sp);
70 	if (ret < 0)
71 		return ret;
72 
73 	memset(&sp, 0, sizeof(struct sched_param));
74 	sp.sched_priority = param->sched_priority;
75 	ret = _sched_setparam(pid, P_ALL_LWPS, policy, &sp);
76 	if (ret < 0)
77 		return ret;
78 
79 	return old_policy;
80 }
81 
82 int
83 sched_getscheduler(pid_t pid)
84 {
85 	struct sched_param sp;
86 	int ret, policy;
87 
88 	ret = _sched_getparam(pid, P_ALL_LWPS, &policy, &sp);
89 	if (ret < 0)
90 		return ret;
91 
92 	return policy;
93 }
94 
95 /*
96  * Scheduling priorities.
97  */
98 
99 int
100 sched_get_priority_max(int policy)
101 {
102 
103 	if (policy < SCHED_OTHER || policy > SCHED_RR) {
104 		errno = EINVAL;
105 		return -1;
106 	}
107 	return sysconf(_SC_SCHED_PRI_MAX);
108 }
109 
110 int
111 sched_get_priority_min(int policy)
112 {
113 
114 	if (policy < SCHED_OTHER || policy > SCHED_RR) {
115 		errno = EINVAL;
116 		return -1;
117 	}
118 	return sysconf(_SC_SCHED_PRI_MIN);
119 }
120 
121 int
122 /*ARGSUSED*/
123 sched_rr_get_interval(pid_t pid, struct timespec *interval)
124 {
125 
126 	interval->tv_sec = 0;
127 	interval->tv_nsec = sysconf(_SC_SCHED_RT_TS) * 1000;
128 	return 0;
129 }
130 
131 /*
132  * Process affinity.
133  */
134 
135 int
136 sched_getaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
137 {
138 
139 	return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
140 }
141 
142 int
143 sched_setaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
144 {
145 
146 	return _sched_setaffinity(pid, P_ALL_LWPS, size, cpuset);
147 }
148