sys_mbox_free

/**
 * Destroys a mailbox.
 *
 * @param mbox is the mailbox to be destroyed.
 */
void
sys_mbox_free(sys_mbox_t *mbox)
{
    u32_t i;
  /* There should not be any messages waiting (if there are it is a bug).  If
     any are waiting, increment the mailbox error count. */
#if RTOS_FREERTOS
  if(uxQueueMessagesWaiting(mbox->queue) != 0) {
#endif /* RTOS_FREERTOS */

#if SYS_STATS
    STATS_INC(sys.mbox.err);
#endif /* SYS_STATS */
  }

    /* Find a mailbox that is in use. */
    for(i = 0; i < SYS_MBOX_MAX; i++) {
      if(mboxes[i].queue == mbox->queue) {
        break;
      }
    }

  /* Delete Sem , By Jin */
    vQueueDelete(mbox->queue);
  /* Clear the queue handle. */
  mbox->queue = 0;
  /* Clear the queue handle in global array. */
  mboxes[i].queue = 0;

  /* Update the mailbox statistics. */
#if SYS_STATS
   STATS_DEC(sys.mbox.used);
#endif /* SYS_STATS */
}