Function rt_mb_urgent

src/ipc.c:2772–2820

* @brief This function will send an urgent mail to the mailbox object. * * @note This function is almost the same as the rt_mb_send() function. The only difference is that * when sending an urgent mail, the mail will be placed at the head of the mail queue so that * the recipient can receive the urgent mail first. * * @see rt_mb_send() * * @param mb is a

 *           If the return value is any other values, it means that the mailbox detach failed.
 */
rt_err_t rt_mb_urgent(rt_mailbox_t mb, rt_ubase_t value)
{
    rt_base_t level;

    /* parameter check */
    RT_ASSERT(mb != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);

    RT_OBJECT_HOOK_CALL(rt_object_put_hook, (&(mb->parent.parent)));

    level = rt_spin_lock_irqsave(&(mb->spinlock));

    if (mb->entry == mb->size)
    {
        rt_spin_unlock_irqrestore(&(mb->spinlock), level);
        return -RT_EFULL;
    }

    /* rewind to the previous position */
    if (mb->out_offset > 0)
    {
        mb->out_offset --;
    }
    else
    {
        mb->out_offset = mb->size - 1;
    }

    /* set ptr */
    mb->msg_pool[mb->out_offset] = value;

    /* increase message entry */
    mb->entry ++;

    /* resume suspended thread */
    if (!rt_list_isempty(&mb->parent.suspend_thread))
    {
        rt_susp_list_dequeue(&(mb->parent.suspend_thread), RT_EOK);

        rt_spin_unlock_irqrestore(&(mb->spinlock), level);

        rt_schedule();

        return RT_EOK;
    }
    rt_spin_unlock_irqrestore(&(mb->spinlock), level);

    return RT_EOK;
}
RTM_EXPORT(rt_mb_urgent);