xref: /minix3/lib/libc/sys/sched.c (revision f14fb602092e015ff630df58e17c2a9cd57d29b3)
1 /*	$NetBSD: sched.c,v 1.4 2012/03/18 02:04:39 christos 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 1.4 2012/03/18 02:04:39 christos Exp $");
31 
32 #include <string.h>
33 #include <unistd.h>
34 #include <errno.h>
35 #include <sched.h>
36 #include <signal.h>
37 #include <sys/param.h>
38 #include <sys/types.h>
39 
40 /* All LWPs in the process */
41 #define	P_ALL_LWPS		0
42 
43 /*
44  * Scheduling parameters.
45  */
46 
47 int
sched_setparam(pid_t pid,const struct sched_param * param)48 sched_setparam(pid_t pid, const struct sched_param *param)
49 {
50 	struct sched_param sp;
51 
52 	memset(&sp, 0, sizeof(struct sched_param));
53 	sp.sched_priority = param->sched_priority;
54 	return _sched_setparam(pid, P_ALL_LWPS, SCHED_NONE, &sp);
55 }
56 
57 int
sched_getparam(pid_t pid,struct sched_param * param)58 sched_getparam(pid_t pid, struct sched_param *param)
59 {
60 
61 	return _sched_getparam(pid, P_ALL_LWPS, NULL, param);
62 }
63 
64 int
sched_setscheduler(pid_t pid,int policy,const struct sched_param * param)65 sched_setscheduler(pid_t pid, int policy, const struct sched_param *param)
66 {
67 	struct sched_param sp;
68 	int ret, old_policy;
69 
70 	ret = _sched_getparam(pid, P_ALL_LWPS, &old_policy, &sp);
71 	if (ret < 0)
72 		return ret;
73 
74 	memset(&sp, 0, sizeof(struct sched_param));
75 	sp.sched_priority = param->sched_priority;
76 	ret = _sched_setparam(pid, P_ALL_LWPS, policy, &sp);
77 	if (ret < 0)
78 		return ret;
79 
80 	return old_policy;
81 }
82 
83 int
sched_getscheduler(pid_t pid)84 sched_getscheduler(pid_t pid)
85 {
86 	struct sched_param sp;
87 	int ret, policy;
88 
89 	ret = _sched_getparam(pid, P_ALL_LWPS, &policy, &sp);
90 	if (ret < 0)
91 		return ret;
92 
93 	return policy;
94 }
95 
96 /*
97  * Scheduling priorities.
98  */
99 
100 int
sched_get_priority_max(int policy)101 sched_get_priority_max(int policy)
102 {
103 
104 	if (policy < SCHED_OTHER || policy > SCHED_RR) {
105 		errno = EINVAL;
106 		return -1;
107 	}
108 	return (int)sysconf(_SC_SCHED_PRI_MAX);
109 }
110 
111 int
sched_get_priority_min(int policy)112 sched_get_priority_min(int policy)
113 {
114 
115 	if (policy < SCHED_OTHER || policy > SCHED_RR) {
116 		errno = EINVAL;
117 		return -1;
118 	}
119 	return (int)sysconf(_SC_SCHED_PRI_MIN);
120 }
121 
122 int
123 /*ARGSUSED*/
sched_rr_get_interval(pid_t pid,struct timespec * interval)124 sched_rr_get_interval(pid_t pid, struct timespec *interval)
125 {
126 
127 	if (pid && kill(pid, 0) == -1)
128 		return -1;
129 	interval->tv_sec = 0;
130 	interval->tv_nsec = sysconf(_SC_SCHED_RT_TS) * 1000;
131 	return 0;
132 }
133 
134 /*
135  * Process affinity.
136  */
137 
138 int
sched_getaffinity_np(pid_t pid,size_t size,cpuset_t * cpuset)139 sched_getaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
140 {
141 
142 	return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
143 }
144 
145 int
sched_setaffinity_np(pid_t pid,size_t size,cpuset_t * cpuset)146 sched_setaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
147 {
148 
149 	return _sched_setaffinity(pid, P_ALL_LWPS, size, cpuset);
150 }
151