Function rt_mutex_setprioceiling

src/ipc.c:1152–1184

* @brief set the prioceiling attribute of the mutex. * * @param mutex is a pointer to a mutex object. * @param priority is the priority should be set to mutex. * * @return return the old priority ceiling */

 * @return return the old priority ceiling
 */
rt_uint8_t rt_mutex_setprioceiling(rt_mutex_t mutex, rt_uint8_t priority)
{
    rt_uint8_t ret_priority = 0xFF;
    rt_uint8_t highest_prio;
    rt_sched_lock_level_t slvl;

    RT_DEBUG_IN_THREAD_CONTEXT;

    if ((mutex) && (priority < RT_THREAD_PRIORITY_MAX))
    {
        /* critical section here if multiple updates to one mutex happen */
        rt_spin_lock(&(mutex->spinlock));
        ret_priority = mutex->ceiling_priority;
        mutex->ceiling_priority = priority;
        if (mutex->owner)
        {
            rt_sched_lock(&slvl);
            highest_prio = _thread_get_mutex_priority(mutex->owner);
            if (highest_prio != rt_sched_thread_get_curr_prio(mutex->owner))
            {
                _thread_update_priority(mutex->owner, highest_prio, RT_UNINTERRUPTIBLE);
            }
            rt_sched_unlock(slvl);
        }
        rt_spin_unlock(&(mutex->spinlock));
    }
    else
    {
        rt_set_errno(-RT_EINVAL);
    }

    return ret_priority;
}
RTM_EXPORT(rt_mutex_setprioceiling);