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: src/lib/libpthread/thread/thr_setschedparam.c,v 1.13 2003/04/21 04:02:56 deischen Exp $ 33 * $DragonFly: src/lib/libthread_xu/thread/thr_setschedparam.c,v 1.1 2005/02/01 12:38:27 davidxu Exp $ 34 */ 35 #include <errno.h> 36 #include <sys/param.h> 37 #include <pthread.h> 38 #include "thr_private.h" 39 40 __weak_reference(_pthread_setschedparam, pthread_setschedparam); 41 42 int 43 _pthread_setschedparam(pthread_t pthread, int policy, 44 const struct sched_param *param) 45 { 46 struct pthread *curthread = _get_curthread(); 47 int in_syncq; 48 int in_readyq = 0; 49 int old_prio; 50 int ret = 0; 51 52 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 53 /* Return an invalid argument error: */ 54 ret = EINVAL; 55 } else if ((param->sched_priority < THR_MIN_PRIORITY) || 56 (param->sched_priority > THR_MAX_PRIORITY)) { 57 /* Return an unsupported value error. */ 58 ret = ENOTSUP; 59 60 /* Find the thread in the list of active threads: */ 61 } else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0)) 62 == 0) { 63 /* 64 * Lock the threads scheduling queue while we change 65 * its priority: 66 */ 67 THR_THREAD_LOCK(curthread, pthread); 68 if (pthread->state == PS_DEAD) { 69 THR_THREAD_UNLOCK(curthread, pthread); 70 _thr_ref_delete(curthread, pthread); 71 return (ESRCH); 72 } 73 in_syncq = pthread->sflags & THR_FLAGS_IN_SYNCQ; 74 75 /* Set the scheduling policy: */ 76 pthread->attr.sched_policy = policy; 77 78 if (param->sched_priority == 79 THR_BASE_PRIORITY(pthread->base_priority)) 80 /* 81 * There is nothing to do; unlock the threads 82 * scheduling queue. 83 */ 84 THR_THREAD_UNLOCK(curthread, pthread); 85 else { 86 /* 87 * Remove the thread from its current priority 88 * queue before any adjustments are made to its 89 * active priority: 90 */ 91 old_prio = pthread->active_priority; 92 /* if ((pthread->flags & THR_FLAGS_IN_RUNQ) != 0) */ { 93 in_readyq = 1; 94 /* THR_RUNQ_REMOVE(pthread); */ 95 } 96 97 /* Set the thread base priority: */ 98 pthread->base_priority &= 99 (THR_SIGNAL_PRIORITY | THR_RT_PRIORITY); 100 pthread->base_priority = param->sched_priority; 101 102 /* Recalculate the active priority: */ 103 pthread->active_priority = MAX(pthread->base_priority, 104 pthread->inherited_priority); 105 106 if (in_readyq) { 107 if ((pthread->priority_mutex_count > 0) && 108 (old_prio > pthread->active_priority)) { 109 /* 110 * POSIX states that if the priority is 111 * being lowered, the thread must be 112 * inserted at the head of the queue for 113 * its priority if it owns any priority 114 * protection or inheritence mutexes. 115 */ 116 /* THR_RUNQ_INSERT_HEAD(pthread); */ 117 } 118 else 119 /* THR_RUNQ_INSERT_TAIL(pthread)*/ ; 120 } 121 122 /* Unlock the threads scheduling queue: */ 123 THR_THREAD_UNLOCK(curthread, pthread); 124 125 /* 126 * Check for any mutex priority adjustments. This 127 * includes checking for a priority mutex on which 128 * this thread is waiting. 129 */ 130 _mutex_notify_priochange(curthread, pthread, in_syncq); 131 } 132 _thr_ref_delete(curthread, pthread); 133 } 134 return (ret); 135 } 136