thr_setschedparam.c revision 67097
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 67097 2000-10-13 22:12:32Z deischen $ 33 */ 34#include <errno.h> 35#include <sys/param.h> 36#ifdef _THREAD_SAFE 37#include <pthread.h> 38#include "pthread_private.h" 39 40int 41pthread_setschedparam(pthread_t pthread, int policy, 42 const struct sched_param *param) 43{ 44 int old_prio, in_readyq = 0, ret = 0; 45 46 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) { 47 /* Return an invalid argument error: */ 48 ret = EINVAL; 49 } else if ((param->sched_priority < PTHREAD_MIN_PRIORITY) || 50 (param->sched_priority > PTHREAD_MAX_PRIORITY)) { 51 /* Return an unsupported value error. */ 52 ret = ENOTSUP; 53 54 /* Find the thread in the list of active threads: */ 55 } else if ((ret = _find_thread(pthread)) == 0) { 56 /* 57 * Defer signals to protect the scheduling queues from 58 * access by the signal handler: 59 */ 60 _thread_kern_sig_defer(); 61 62 if (param->sched_priority != 63 PTHREAD_BASE_PRIORITY(pthread->base_priority)) { 64 /* 65 * Remove the thread from its current priority 66 * queue before any adjustments are made to its 67 * active priority: 68 */ 69 old_prio = pthread->active_priority; 70 if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) { 71 in_readyq = 1; 72 PTHREAD_PRIOQ_REMOVE(pthread); 73 } 74 75 /* Set the thread base priority: */ 76 pthread->base_priority &= 77 (PTHREAD_SIGNAL_PRIORITY | PTHREAD_RT_PRIORITY); 78 pthread->base_priority = param->sched_priority; 79 80 /* Recalculate the active priority: */ 81 pthread->active_priority = MAX(pthread->base_priority, 82 pthread->inherited_priority); 83 84 if (in_readyq) { 85 if ((pthread->priority_mutex_count > 0) && 86 (old_prio > pthread->active_priority)) { 87 /* 88 * POSIX states that if the priority is 89 * being lowered, the thread must be 90 * inserted at the head of the queue for 91 * its priority if it owns any priority 92 * protection or inheritence mutexes. 93 */ 94 PTHREAD_PRIOQ_INSERT_HEAD(pthread); 95 } 96 else 97 PTHREAD_PRIOQ_INSERT_TAIL(pthread); 98 } 99 100 /* 101 * Check for any mutex priority adjustments. This 102 * includes checking for a priority mutex on which 103 * this thread is waiting. 104 */ 105 _mutex_notify_priochange(pthread); 106 } 107 108 /* Set the scheduling policy: */ 109 pthread->attr.sched_policy = policy; 110 111 /* 112 * Undefer and handle pending signals, yielding if 113 * necessary: 114 */ 115 _thread_kern_sig_undefer(); 116 } 117 return(ret); 118} 119#endif 120