Function rt_wm_que_dec

components/vbus/watermark_queue.h:102–129

Decrease the water level. * * It should be called by the consumer that drain the water out. If the water * level reached low mark, all the thread suspended in this queue will be waken * up. It's safe to call this function in interrupt context. */

 * up. It's safe to call this function in interrupt context.
 */
rt_inline void rt_wm_que_dec(struct rt_watermark_queue *wg)
{
    int need_sched = 0;
    rt_base_t level;

    if (wg->level == 0)
        return;

    level = rt_hw_interrupt_disable();
    wg->level--;
    if (wg->level == wg->low_mark)
    {
        /* There should be spaces between the low mark and high mark, so it's
         * safe to resume all the threads. */
        while (!rt_list_isempty(&wg->suspended_threads))
        {
            rt_thread_t thread;

            thread = RT_THREAD_LIST_NODE_ENTRY(wg->suspended_threads.next);
            rt_thread_resume(thread);
            need_sched = 1;
        }
    }
    rt_hw_interrupt_enable(level);

    if (need_sched)
        rt_schedule();
}