thr_setschedparam.c revision 67097
1254721Semaste/* 2254721Semaste * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>. 3254721Semaste * All rights reserved. 4254721Semaste * 5254721Semaste * Redistribution and use in source and binary forms, with or without 6254721Semaste * modification, are permitted provided that the following conditions 7254721Semaste * are met: 8254721Semaste * 1. Redistributions of source code must retain the above copyright 9254721Semaste * notice, this list of conditions and the following disclaimer. 10254721Semaste * 2. Redistributions in binary form must reproduce the above copyright 11254721Semaste * notice, this list of conditions and the following disclaimer in the 12254721Semaste * documentation and/or other materials provided with the distribution. 13254721Semaste * 3. All advertising materials mentioning features or use of this software 14254721Semaste * must display the following acknowledgement: 15254721Semaste * This product includes software developed by Daniel Eischen. 16254721Semaste * 4. Neither the name of the author nor the names of any co-contributors 17254721Semaste * may be used to endorse or promote products derived from this software 18254721Semaste * without specific prior written permission. 19254721Semaste * 20254721Semaste * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND 21254721Semaste * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22254721Semaste * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23254721Semaste * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24254721Semaste * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25254721Semaste * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26254721Semaste * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27254721Semaste * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28254721Semaste * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29254721Semaste * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30254721Semaste * SUCH DAMAGE. 31254721Semaste * 32254721Semaste * $FreeBSD: head/lib/libkse/thread/thr_setschedparam.c 67097 2000-10-13 22:12:32Z deischen $ 33254721Semaste */ 34254721Semaste#include <errno.h> 35254721Semaste#include <sys/param.h> 36254721Semaste#ifdef _THREAD_SAFE 37254721Semaste#include <pthread.h> 38254721Semaste#include "pthread_private.h" 39254721Semaste 40254721Semasteint 41254721Semastepthread_setschedparam(pthread_t pthread, int policy, 42254721Semaste const struct sched_param *param) 43254721Semaste{ 44254721Semaste int old_prio, in_readyq = 0, ret = 0; 45254721Semaste 46254721Semaste if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 47254721Semaste /* Return an invalid argument error: */ 48254721Semaste ret = EINVAL; 49254721Semaste } else if ((param->sched_priority < PTHREAD_MIN_PRIORITY) || 50254721Semaste (param->sched_priority > PTHREAD_MAX_PRIORITY)) { 51254721Semaste /* Return an unsupported value error. */ 52254721Semaste ret = ENOTSUP; 53254721Semaste 54254721Semaste /* Find the thread in the list of active threads: */ 55254721Semaste } else if ((ret = _find_thread(pthread)) == 0) { 56254721Semaste /* 57254721Semaste * Defer signals to protect the scheduling queues from 58254721Semaste * access by the signal handler: 59254721Semaste */ 60254721Semaste _thread_kern_sig_defer(); 61254721Semaste 62254721Semaste if (param->sched_priority != 63254721Semaste PTHREAD_BASE_PRIORITY(pthread->base_priority)) { 64254721Semaste /* 65254721Semaste * Remove the thread from its current priority 66254721Semaste * queue before any adjustments are made to its 67254721Semaste * active priority: 68254721Semaste */ 69254721Semaste old_prio = pthread->active_priority; 70254721Semaste if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) { 71254721Semaste in_readyq = 1; 72254721Semaste PTHREAD_PRIOQ_REMOVE(pthread); 73254721Semaste } 74254721Semaste 75254721Semaste /* Set the thread base priority: */ 76254721Semaste pthread->base_priority &= 77254721Semaste (PTHREAD_SIGNAL_PRIORITY | PTHREAD_RT_PRIORITY); 78254721Semaste pthread->base_priority = param->sched_priority; 79254721Semaste 80254721Semaste /* Recalculate the active priority: */ 81254721Semaste pthread->active_priority = MAX(pthread->base_priority, 82254721Semaste pthread->inherited_priority); 83254721Semaste 84254721Semaste if (in_readyq) { 85254721Semaste if ((pthread->priority_mutex_count > 0) && 86254721Semaste (old_prio > pthread->active_priority)) { 87254721Semaste /* 88254721Semaste * POSIX states that if the priority is 89254721Semaste * being lowered, the thread must be 90254721Semaste * inserted at the head of the queue for 91254721Semaste * its priority if it owns any priority 92254721Semaste * protection or inheritence mutexes. 93254721Semaste */ 94254721Semaste PTHREAD_PRIOQ_INSERT_HEAD(pthread); 95254721Semaste } 96254721Semaste else 97254721Semaste PTHREAD_PRIOQ_INSERT_TAIL(pthread); 98254721Semaste } 99254721Semaste 100254721Semaste /* 101263363Semaste * Check for any mutex priority adjustments. This 102254721Semaste * includes checking for a priority mutex on which 103254721Semaste * this thread is waiting. 104254721Semaste */ 105254721Semaste _mutex_notify_priochange(pthread); 106254721Semaste } 107254721Semaste 108254721Semaste /* Set the scheduling policy: */ 109254721Semaste pthread->attr.sched_policy = policy; 110254721Semaste 111254721Semaste /* 112254721Semaste * Undefer and handle pending signals, yielding if 113254721Semaste * necessary: 114254721Semaste */ 115254721Semaste _thread_kern_sig_undefer(); 116254721Semaste } 117254721Semaste return(ret); 118254721Semaste} 119254721Semaste#endif 120254721Semaste