thr_setschedparam.c revision 157194
1/* 2 * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Daniel Eischen. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD: head/lib/libthr/thread/thr_setschedparam.c 157194 2006-03-27 23:50:21Z davidxu $ 33 */ 34 35#include <errno.h> 36#include <sys/param.h> 37#include <pthread.h> 38 39#include "thr_private.h" 40 41__weak_reference(_pthread_setschedparam, pthread_setschedparam); 42 43/* 44 * Set a thread's scheduling parameters, this should be done 45 * in kernel, doing it in userland is no-op. 46 */ 47int 48_pthread_setschedparam(pthread_t pthread, int policy, 49 const struct sched_param *param) 50{ 51 struct pthread *curthread = _get_curthread(); 52 int ret = 0; 53 54 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 55 ret = EINVAL; 56 } else if ((param->sched_priority < THR_MIN_PRIORITY) || 57 (param->sched_priority > THR_MAX_PRIORITY)) { 58 ret = ENOTSUP; 59 } else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0)) 60 == 0) { 61 /* 62 * Lock the threads scheduling queue while we change 63 * its priority: 64 */ 65 THR_THREAD_LOCK(curthread, pthread); 66 if (pthread->state == PS_DEAD) { 67 THR_THREAD_UNLOCK(curthread, pthread); 68 _thr_ref_delete(curthread, pthread); 69 return (ESRCH); 70 } 71 72 /* Set the scheduling policy: */ 73 pthread->attr.sched_policy = policy; 74 75 if (param->sched_priority == 76 THR_BASE_PRIORITY(pthread->base_priority)) 77 /* 78 * There is nothing to do; unlock the threads 79 * scheduling queue. 80 */ 81 THR_THREAD_UNLOCK(curthread, pthread); 82 else { 83 pthread->base_priority = param->sched_priority; 84 85 /* Recalculate the active priority: */ 86 pthread->active_priority = MAX(pthread->base_priority, 87 pthread->inherited_priority); 88 89 THR_THREAD_UNLOCK(curthread, pthread); 90 } 91 _thr_ref_delete(curthread, pthread); 92 } 93 return (ret); 94} 95