2 * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
35 #include <sys/param.h>
38 #include "pthread_private.h"
41 pthread_setschedparam(pthread_t pthread, int policy,
42 const struct sched_param *param)
44 int old_prio, in_readyq = 0, ret = 0;
46 if ((param == NULL) || (param->sched_priority < PTHREAD_MIN_PRIORITY) ||
47 (param->sched_priority > PTHREAD_MAX_PRIORITY) ||
48 (policy < SCHED_FIFO) || (policy > SCHED_RR))
49 /* Return an invalid argument error: */
52 /* Find the thread in the list of active threads: */
53 else if ((ret = _find_thread(pthread)) == 0) {
55 * Defer signals to protect the scheduling queues from
56 * access by the signal handler:
58 _thread_kern_sig_defer();
60 if (param->sched_priority != pthread->base_priority) {
62 * Remove the thread from its current priority
63 * queue before any adjustments are made to its
66 if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) {
68 old_prio = pthread->active_priority;
69 PTHREAD_PRIOQ_REMOVE(pthread);
72 /* Set the thread base priority: */
73 pthread->base_priority = param->sched_priority;
75 /* Recalculate the active priority: */
76 pthread->active_priority = MAX(pthread->base_priority,
77 pthread->inherited_priority);
80 if ((pthread->priority_mutex_count > 0) &&
81 (old_prio > pthread->active_priority)) {
83 * POSIX states that if the priority is
84 * being lowered, the thread must be
85 * inserted at the head of the queue for
86 * its priority if it owns any priority
87 * protection or inheritence mutexes.
89 PTHREAD_PRIOQ_INSERT_HEAD(pthread);
92 PTHREAD_PRIOQ_INSERT_TAIL(pthread);
96 * Check for any mutex priority adjustments. This
97 * includes checking for a priority mutex on which
98 * this thread is waiting.
100 _mutex_notify_priochange(pthread);
103 /* Set the scheduling policy: */
104 pthread->attr.sched_policy = policy;
107 * Undefer and handle pending signals, yielding if
110 _thread_kern_sig_undefer();