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
32 * $FreeBSD: src/lib/libc_r/uthread/uthread_setschedparam.c,v 1.5.2.3 2002/10/22 14:44:03 fjoe Exp $
33 * $DragonFly: src/lib/libc_r/uthread/uthread_setschedparam.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
36 #include <sys/param.h>
38 #include "pthread_private.h"
40 __weak_reference(_pthread_setschedparam, pthread_setschedparam);
43 _pthread_setschedparam(pthread_t pthread, int policy,
44 const struct sched_param *param)
46 int old_prio, in_readyq = 0, ret = 0;
48 if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) {
49 /* Return an invalid argument error: */
51 } else if ((param->sched_priority < PTHREAD_MIN_PRIORITY) ||
52 (param->sched_priority > PTHREAD_MAX_PRIORITY)) {
53 /* Return an unsupported value error. */
56 /* Find the thread in the list of active threads: */
57 } else if ((ret = _find_thread(pthread)) == 0) {
59 * Defer signals to protect the scheduling queues from
60 * access by the signal handler:
62 _thread_kern_sig_defer();
64 if (param->sched_priority !=
65 PTHREAD_BASE_PRIORITY(pthread->base_priority)) {
67 * Remove the thread from its current priority
68 * queue before any adjustments are made to its
71 old_prio = pthread->active_priority;
72 if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) {
74 PTHREAD_PRIOQ_REMOVE(pthread);
77 /* Set the thread base priority: */
78 pthread->base_priority &=
79 (PTHREAD_SIGNAL_PRIORITY | PTHREAD_RT_PRIORITY);
80 pthread->base_priority = param->sched_priority;
82 /* Recalculate the active priority: */
83 pthread->active_priority = MAX(pthread->base_priority,
84 pthread->inherited_priority);
87 if ((pthread->priority_mutex_count > 0) &&
88 (old_prio > pthread->active_priority)) {
90 * POSIX states that if the priority is
91 * being lowered, the thread must be
92 * inserted at the head of the queue for
93 * its priority if it owns any priority
94 * protection or inheritence mutexes.
96 PTHREAD_PRIOQ_INSERT_HEAD(pthread);
99 PTHREAD_PRIOQ_INSERT_TAIL(pthread);
103 * Check for any mutex priority adjustments. This
104 * includes checking for a priority mutex on which
105 * this thread is waiting.
107 _mutex_notify_priochange(pthread);
110 /* Set the scheduling policy: */
111 pthread->attr.sched_policy = policy;
114 * Undefer and handle pending signals, yielding if
117 _thread_kern_sig_undefer();