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sched.c revision 1.3 
      1 /*	$NetBSD: sched.c,v 1.3 2012/03/13 21:13:48 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 1.3 2012/03/13 21:13:48 christos 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 (int)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 (int)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