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>
37 #include "pthread_private.h"
39 __weak_reference(_pthread_setschedparam, pthread_setschedparam);
42 _pthread_setschedparam(pthread_t pthread, int policy,
43 const struct sched_param *param)
45 int old_prio, in_readyq = 0, ret = 0;
47 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) {
48 /* Return an invalid argument error: */
50 } else if ((param->sched_priority < PTHREAD_MIN_PRIORITY) ||
51 (param->sched_priority > PTHREAD_MAX_PRIORITY)) {
52 /* Return an unsupported value error. */
55 /* Find the thread in the list of active threads: */
56 } else if ((ret = _find_thread(pthread)) == 0) {
58 * Defer signals to protect the scheduling queues from
59 * access by the signal handler:
61 _thread_kern_sig_defer();
63 if (param->sched_priority !=
64 PTHREAD_BASE_PRIORITY(pthread->base_priority)) {
66 * Remove the thread from its current priority
67 * queue before any adjustments are made to its
70 old_prio = pthread->active_priority;
71 if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) {
73 PTHREAD_PRIOQ_REMOVE(pthread);
76 /* Set the thread base priority: */
77 pthread->base_priority &=
78 (PTHREAD_SIGNAL_PRIORITY | PTHREAD_RT_PRIORITY);
79 pthread->base_priority = param->sched_priority;
81 /* Recalculate the active priority: */
82 pthread->active_priority = MAX(pthread->base_priority,
83 pthread->inherited_priority);
86 if ((pthread->priority_mutex_count > 0) &&
87 (old_prio > pthread->active_priority)) {
89 * POSIX states that if the priority is
90 * being lowered, the thread must be
91 * inserted at the head of the queue for
92 * its priority if it owns any priority
93 * protection or inheritence mutexes.
95 PTHREAD_PRIOQ_INSERT_HEAD(pthread);
98 PTHREAD_PRIOQ_INSERT_TAIL(pthread);
102 * Check for any mutex priority adjustments. This
103 * includes checking for a priority mutex on which
104 * this thread is waiting.
106 _mutex_notify_priochange(pthread);
109 /* Set the scheduling policy: */
110 pthread->attr.sched_policy = policy;
113 * Undefer and handle pending signals, yielding if
116 _thread_kern_sig_undefer();