Home | History | Annotate | Line # | Download | only in sys
sched.c revision 1.5 
      1 /*	$NetBSD: sched.c,v 1.5 2017/12/16 18:31:36 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 1.5 2017/12/16 18:31:36 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
     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
     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
     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
     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
    101 sched_get_priority_max(int policy)
    102 {
    103 
    104 	switch (policy) {
    105 	case SCHED_OTHER:
    106 		return PRI_NONE;
    107 	case SCHED_RR:
    108 	case SCHED_FIFO:
    109 		return (int)sysconf(_SC_SCHED_PRI_MAX);
    110 	default:
    111 		errno = EINVAL;
    112 		return -1;
    113 	}
    114 }
    115 
    116 int
    117 sched_get_priority_min(int policy)
    118 {
    119 
    120 	switch (policy) {
    121 	case SCHED_OTHER:
    122 		return PRI_NONE;
    123 	case SCHED_RR:
    124 	case SCHED_FIFO:
    125 		return (int)sysconf(_SC_SCHED_PRI_MIN);
    126 	default:
    127 		errno = EINVAL;
    128 		return -1;
    129 	}
    130 }
    131 
    132 int
    133 /*ARGSUSED*/
    134 sched_rr_get_interval(pid_t pid, struct timespec *interval)
    135 {
    136 
    137 	if (pid && kill(pid, 0) == -1)
    138 		return -1;
    139 	interval->tv_sec = 0;
    140 	interval->tv_nsec = sysconf(_SC_SCHED_RT_TS) * 1000;
    141 	return 0;
    142 }
    143 
    144 /*
    145  * Process affinity.
    146  */
    147 
    148 int
    149 sched_getaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
    150 {
    151 
    152 	return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
    153 }
    154 
    155 int
    156 sched_setaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
    157 {
    158 
    159 	return _sched_setaffinity(pid, P_ALL_LWPS, size, cpuset);
    160 }
    161