thr_setschedparam.c revision 174112
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/libkse/thread/thr_setschedparam.c 174112 2007-11-30 17:20:29Z deischen $ 33 */ 34 35#include "namespace.h" 36#include <errno.h> 37#include <sys/param.h> 38#include <pthread.h> 39#include "un-namespace.h" 40#include "thr_private.h" 41 42LT10_COMPAT_PRIVATE(_pthread_setschedparam); 43LT10_COMPAT_DEFAULT(pthread_setschedparam); 44 45__weak_reference(_pthread_setschedparam, pthread_setschedparam); 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 in_syncq; 53 int in_readyq = 0; 54 int old_prio; 55 int ret = 0; 56 57 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 58 /* Return an invalid argument error: */ 59 ret = EINVAL; 60 } else if ((param->sched_priority < THR_MIN_PRIORITY) || 61 (param->sched_priority > THR_MAX_PRIORITY)) { 62 /* Return an unsupported value error. */ 63 ret = ENOTSUP; 64 65 /* Find the thread in the list of active threads: */ 66 } else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0)) 67 == 0) { 68 /* 69 * Lock the threads scheduling queue while we change 70 * its priority: 71 */ 72 THR_SCHED_LOCK(curthread, pthread); 73 if ((pthread->state == PS_DEAD) || 74 (pthread->state == PS_DEADLOCK) || 75 ((pthread->flags & THR_FLAGS_EXITING) != 0)) { 76 THR_SCHED_UNLOCK(curthread, pthread); 77 _thr_ref_delete(curthread, pthread); 78 return (ESRCH); 79 } 80 in_syncq = pthread->sflags & THR_FLAGS_IN_SYNCQ; 81 82 /* Set the scheduling policy: */ 83 pthread->attr.sched_policy = policy; 84 85 if (param->sched_priority == 86 THR_BASE_PRIORITY(pthread->base_priority)) 87 /* 88 * There is nothing to do; unlock the threads 89 * scheduling queue. 90 */ 91 THR_SCHED_UNLOCK(curthread, pthread); 92 else { 93 /* 94 * Remove the thread from its current priority 95 * queue before any adjustments are made to its 96 * active priority: 97 */ 98 old_prio = pthread->active_priority; 99 if ((pthread->flags & THR_FLAGS_IN_RUNQ) != 0) { 100 in_readyq = 1; 101 THR_RUNQ_REMOVE(pthread); 102 } 103 104 /* Set the thread base priority: */ 105 pthread->base_priority &= 106 (THR_SIGNAL_PRIORITY | THR_RT_PRIORITY); 107 pthread->base_priority = param->sched_priority; 108 109 /* Recalculate the active priority: */ 110 pthread->active_priority = MAX(pthread->base_priority, 111 pthread->inherited_priority); 112 113 if (in_readyq) { 114 if ((pthread->priority_mutex_count > 0) && 115 (old_prio > pthread->active_priority)) { 116 /* 117 * POSIX states that if the priority is 118 * being lowered, the thread must be 119 * inserted at the head of the queue for 120 * its priority if it owns any priority 121 * protection or inheritence mutexes. 122 */ 123 THR_RUNQ_INSERT_HEAD(pthread); 124 } 125 else 126 THR_RUNQ_INSERT_TAIL(pthread); 127 } 128 129 /* Unlock the threads scheduling queue: */ 130 THR_SCHED_UNLOCK(curthread, pthread); 131 132 /* 133 * Check for any mutex priority adjustments. This 134 * includes checking for a priority mutex on which 135 * this thread is waiting. 136 */ 137 _mutex_notify_priochange(curthread, pthread, in_syncq); 138 } 139 _thr_ref_delete(curthread, pthread); 140 } 141 return (ret); 142} 143