lib/libc/sys/sched.c

   1 /*      $NetBSD: sched.c,v 1.1 2008/07/02 20:05:16 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 1.1 2008/07/02 20:05:16 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 }