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 1.2 2005/03/29 19:26:20 joerg Exp $ 34 */ 35 36 #include <machine/tls.h> 37 38 #include <errno.h> 39 #include <sys/param.h> 40 #include <pthread.h> 41 #include "thr_private.h" 42 43 __weak_reference(_pthread_setschedparam, pthread_setschedparam); 44 45 int 46 _pthread_setschedparam(pthread_t pthread, int policy, 47 const struct sched_param *param) 48 { 49 struct pthread *curthread = tls_get_curthread(); 50 int in_syncq; 51 int in_readyq = 0; 52 int old_prio; 53 int ret = 0; 54 55 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 56 /* Return an invalid argument error: */ 57 ret = EINVAL; 58 } else if ((param->sched_priority < THR_MIN_PRIORITY) || 59 (param->sched_priority > THR_MAX_PRIORITY)) { 60 /* Return an unsupported value error. */ 61 ret = ENOTSUP; 62 63 /* Find the thread in the list of active threads: */ 64 } else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0)) 65 == 0) { 66 /* 67 * Lock the threads scheduling queue while we change 68 * its priority: 69 */ 70 THR_THREAD_LOCK(curthread, pthread); 71 if (pthread->state == PS_DEAD) { 72 THR_THREAD_UNLOCK(curthread, pthread); 73 _thr_ref_delete(curthread, pthread); 74 return (ESRCH); 75 } 76 in_syncq = pthread->sflags & THR_FLAGS_IN_SYNCQ; 77 78 /* Set the scheduling policy: */ 79 pthread->attr.sched_policy = policy; 80 81 if (param->sched_priority == 82 THR_BASE_PRIORITY(pthread->base_priority)) 83 /* 84 * There is nothing to do; unlock the threads 85 * scheduling queue. 86 */ 87 THR_THREAD_UNLOCK(curthread, pthread); 88 else { 89 /* 90 * Remove the thread from its current priority 91 * queue before any adjustments are made to its 92 * active priority: 93 */ 94 old_prio = pthread->active_priority; 95 /* if ((pthread->flags & THR_FLAGS_IN_RUNQ) != 0) */ { 96 in_readyq = 1; 97 /* THR_RUNQ_REMOVE(pthread); */ 98 } 99 100 /* Set the thread base priority: */ 101 pthread->base_priority &= 102 (THR_SIGNAL_PRIORITY | THR_RT_PRIORITY); 103 pthread->base_priority = param->sched_priority; 104 105 /* Recalculate the active priority: */ 106 pthread->active_priority = MAX(pthread->base_priority, 107 pthread->inherited_priority); 108 109 if (in_readyq) { 110 if ((pthread->priority_mutex_count > 0) && 111 (old_prio > pthread->active_priority)) { 112 /* 113 * POSIX states that if the priority is 114 * being lowered, the thread must be 115 * inserted at the head of the queue for 116 * its priority if it owns any priority 117 * protection or inheritence mutexes. 118 */ 119 /* THR_RUNQ_INSERT_HEAD(pthread); */ 120 } 121 else 122 /* THR_RUNQ_INSERT_TAIL(pthread)*/ ; 123 } 124 125 /* Unlock the threads scheduling queue: */ 126 THR_THREAD_UNLOCK(curthread, pthread); 127 128 /* 129 * Check for any mutex priority adjustments. This 130 * includes checking for a priority mutex on which 131 * this thread is waiting. 132 */ 133 _mutex_notify_priochange(curthread, pthread, in_syncq); 134 } 135 _thr_ref_delete(curthread, pthread); 136 } 137 return (ret); 138 } 139