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      1 /*	$NetBSD: sched.c,v 1.6 2018/01/04 20:57:29 kamil 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 1.6 2018/01/04 20:57:29 kamil Exp $");
     31 
     32 #include "namespace.h"
     33 #include <string.h>
     34 #include <unistd.h>
     35 #include <errno.h>
     36 #include <sched.h>
     37 #include <signal.h>
     38 #include <sys/param.h>
     39 #include <sys/types.h>
     40 
     41 /* All LWPs in the process */
     42 #define	P_ALL_LWPS		0
     43 
     44 /*
     45  * Scheduling parameters.
     46  */
     47 
     48 int
     49 sched_setparam(pid_t pid, const struct sched_param *param)
     50 {
     51 	struct sched_param sp;
     52 
     53 	memset(&sp, 0, sizeof(struct sched_param));
     54 	sp.sched_priority = param->sched_priority;
     55 	return _sched_setparam(pid, P_ALL_LWPS, SCHED_NONE, &sp);
     56 }
     57 
     58 int
     59 sched_getparam(pid_t pid, struct sched_param *param)
     60 {
     61 
     62 	return _sched_getparam(pid, P_ALL_LWPS, NULL, param);
     63 }
     64 
     65 int
     66 sched_setscheduler(pid_t pid, int policy, const struct sched_param *param)
     67 {
     68 	struct sched_param sp;
     69 	int ret, old_policy;
     70 
     71 	ret = _sched_getparam(pid, P_ALL_LWPS, &old_policy, &sp);
     72 	if (ret < 0)
     73 		return ret;
     74 
     75 	memset(&sp, 0, sizeof(struct sched_param));
     76 	sp.sched_priority = param->sched_priority;
     77 	ret = _sched_setparam(pid, P_ALL_LWPS, policy, &sp);
     78 	if (ret < 0)
     79 		return ret;
     80 
     81 	return old_policy;
     82 }
     83 
     84 int
     85 sched_getscheduler(pid_t pid)
     86 {
     87 	struct sched_param sp;
     88 	int ret, policy;
     89 
     90 	ret = _sched_getparam(pid, P_ALL_LWPS, &policy, &sp);
     91 	if (ret < 0)
     92 		return ret;
     93 
     94 	return policy;
     95 }
     96 
     97 /*
     98  * Scheduling priorities.
     99  */
    100 
    101 int
    102 sched_get_priority_max(int policy)
    103 {
    104 
    105 	switch (policy) {
    106 	case SCHED_OTHER:
    107 		return PRI_NONE;
    108 	case SCHED_RR:
    109 	case SCHED_FIFO:
    110 		return (int)sysconf(_SC_SCHED_PRI_MAX);
    111 	default:
    112 		errno = EINVAL;
    113 		return -1;
    114 	}
    115 }
    116 
    117 int
    118 sched_get_priority_min(int policy)
    119 {
    120 
    121 	switch (policy) {
    122 	case SCHED_OTHER:
    123 		return PRI_NONE;
    124 	case SCHED_RR:
    125 	case SCHED_FIFO:
    126 		return (int)sysconf(_SC_SCHED_PRI_MIN);
    127 	default:
    128 		errno = EINVAL;
    129 		return -1;
    130 	}
    131 }
    132 
    133 int
    134 /*ARGSUSED*/
    135 sched_rr_get_interval(pid_t pid, struct timespec *interval)
    136 {
    137 
    138 	if (pid && kill(pid, 0) == -1)
    139 		return -1;
    140 	interval->tv_sec = 0;
    141 	interval->tv_nsec = sysconf(_SC_SCHED_RT_TS) * 1000;
    142 	return 0;
    143 }
    144 
    145 /*
    146  * Process affinity.
    147  */
    148 
    149 int
    150 sched_getaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
    151 {
    152 
    153 	return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
    154 }
    155 
    156 int
    157 sched_setaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
    158 {
    159 
    160 	return _sched_setaffinity(pid, P_ALL_LWPS, size, cpuset);
    161 }
    162