diff options
Diffstat (limited to 'lib/libthr/thread/thr_setschedparam.c')
-rw-r--r-- | lib/libthr/thread/thr_setschedparam.c | 127 |
1 files changed, 65 insertions, 62 deletions
diff --git a/lib/libthr/thread/thr_setschedparam.c b/lib/libthr/thread/thr_setschedparam.c index 3e69641..e90def4 100644 --- a/lib/libthr/thread/thr_setschedparam.c +++ b/lib/libthr/thread/thr_setschedparam.c @@ -34,86 +34,89 @@ #include <errno.h> #include <sys/param.h> #include <pthread.h> +#include <stdlib.h> #include "thr_private.h" +__weak_reference(_pthread_getschedparam, pthread_getschedparam); __weak_reference(_pthread_setschedparam, pthread_setschedparam); int +_pthread_getschedparam(pthread_t pthread, int *policy, + struct sched_param *param) +{ + if (param == NULL || policy == NULL) + return (EINVAL); + if (_find_thread(pthread) == ESRCH) + return (ESRCH); + param->sched_priority = pthread->base_priority; + *policy = pthread->attr.sched_policy; + return(0); +} + +int _pthread_setschedparam(pthread_t pthread, int policy, const struct sched_param *param) { -#if 0 - int old_prio = 0; - int in_readyq = 0; -#endif - int ret = 0; + struct pthread_mutex *mtx; + int old_prio; + mtx = NULL; + old_prio = 0; if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) return (EINVAL); - if ((param->sched_priority < PTHREAD_MIN_PRIORITY) || (param->sched_priority > PTHREAD_MAX_PRIORITY)) return (ENOTSUP); + if (_find_thread(pthread) != 0) + return (ESRCH); -#if 0 /* XXX pthread priorities don't work anyways */ - /* Find the thread in the list of active threads: */ - if ((ret = _find_thread(pthread)) == 0) { - GIANT_LOCK(curthread); - - if (param->sched_priority != - PTHREAD_BASE_PRIORITY(pthread->base_priority)) { - /* - * Remove the thread from its current priority - * queue before any adjustments are made to its - * active priority: - */ - old_prio = pthread->active_priority; -#if 0 /* XXXTHR */ - if ((pthread->flags & PTHREAD_FLAGS_IN_PRIOQ) != 0) { - in_readyq = 1; - PTHREAD_PRIOQ_REMOVE(pthread); - } -#endif - - /* Set the thread base priority: */ - pthread->base_priority &= - (PTHREAD_SIGNAL_PRIORITY | PTHREAD_RT_PRIORITY); - pthread->base_priority = param->sched_priority; - - /* Recalculate the active priority: */ - pthread->active_priority = MAX(pthread->base_priority, - pthread->inherited_priority); -#if 0 - 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); - } -#endif + /* + * If the pthread is waiting on a mutex grab it now. Doing it now + * even though we do not need it immediately greatly simplifies the + * LOR avoidance code. + */ + do { + _thread_critical_enter(pthread); + if (pthread->state == PS_MUTEX_WAIT) { + mtx = pthread->data.mutex; + if (_spintrylock(&mtx->lock) == EBUSY) + _thread_critical_exit(pthread); + else + break; + } else { + break; + } + } while (1); - /* - * Check for any mutex priority adjustments. This - * includes checking for a priority mutex on which - * this thread is waiting. - */ - _mutex_notify_priochange(pthread); + PTHREAD_ASSERT(pthread->active_priority >= pthread->inherited_priority, + "active priority cannot be less than inherited priority"); + old_prio = pthread->base_priority; + pthread->base_priority = param->sched_priority; + if (param->sched_priority <= pthread->active_priority) { + /* + * Active priority is affected only if it was the + * base priority and the new base priority is lower. + */ + if (pthread->active_priority == old_prio && + pthread->active_priority != pthread->inherited_priority) { + pthread->active_priority = param->sched_priority; + readjust_priorities(pthread, mtx); } - /* Set the scheduling policy: */ - pthread->attr.sched_policy = policy; + } else { + /* + * New base priority is greater than active priority. This + * only affects threads that are holding priority inheritance + * mutexes this thread is waiting on and its position in the + * queue. + */ + pthread->active_priority = param->sched_priority; + readjust_priorities(pthread, mtx); - GIANT_UNLOCK(curthread); } -#endif /* XXX pthread priorities don't work anyways */ - return(ret); + pthread->attr.sched_policy = policy; + _thread_critical_exit(pthread); + if (mtx != NULL) + _SPINUNLOCK(&mtx->lock); + return(0); } |