diff options
Diffstat (limited to 'lib/libkse/thread/thr_setschedparam.c')
| -rw-r--r-- | lib/libkse/thread/thr_setschedparam.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/lib/libkse/thread/thr_setschedparam.c b/lib/libkse/thread/thr_setschedparam.c new file mode 100644 index 0000000..93635da --- /dev/null +++ b/lib/libkse/thread/thr_setschedparam.c @@ -0,0 +1,113 @@ +/* + * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Daniel Eischen. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ +#include <errno.h> +#include <sys/param.h> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + +int +pthread_setschedparam(pthread_t pthread, int policy, struct sched_param *param) +{ + int old_prio, in_readyq = 0, ret = 0; + + if ((param == NULL) || (param->sched_priority < PTHREAD_MIN_PRIORITY) || + (param->sched_priority > PTHREAD_MAX_PRIORITY) || + (policy < SCHED_FIFO) || (policy > SCHED_RR)) + /* Return an invalid argument error: */ + ret = EINVAL; + + /* Find the thread in the list of active threads: */ + else if ((ret = _find_thread(pthread)) == 0) { + /* + * Guard against being preempted by a scheduling + * signal: + */ + _thread_kern_sched_defer(); + + if (param->sched_priority != pthread->base_priority) { + /* + * Remove the thread from its current priority + * queue before any adjustments are made to its + * active priority: + */ + if ((pthread != _thread_run) && + (pthread->state == PS_RUNNING)) { + in_readyq = 1; + old_prio = pthread->active_priority; + PTHREAD_PRIOQ_REMOVE(pthread); + } + + /* Set the thread base priority: */ + pthread->base_priority = param->sched_priority; + + /* Recalculate the active priority: */ + pthread->active_priority = MAX(pthread->base_priority, + pthread->inherited_priority); + + if (in_readyq) { + if ((pthread->priority_mutex_count > 0) && + (old_prio > pthread->active_priority)) { + /* + * POSIX states that if the priority is + * being lowered, the thread must be + * inserted at the head of the queue for + * its priority if it owns any priority + * protection or inheritence mutexes. + */ + PTHREAD_PRIOQ_INSERT_HEAD(pthread); + } + else + PTHREAD_PRIOQ_INSERT_TAIL(pthread); + } + + /* + * Check for any mutex priority adjustments. This + * includes checking for a priority mutex on which + * this thread is waiting. + */ + _mutex_notify_priochange(pthread); + } + + /* Set the scheduling policy: */ + pthread->attr.sched_policy = policy; + + /* + * Renable preemption and yield if a scheduling signal + * arrived while in the critical region: + */ + _thread_kern_sched_undefer(); + } + return(ret); +} +#endif |
