Function alarm_update

components/drivers/rtc/dev_alarm.c:233–322

}

static void alarm_update(rt_uint32_t event)
{
    struct rt_alarm *alm_prev = RT_NULL, *alm_next = RT_NULL;
    struct rt_alarm *alarm;
    rt_int32_t sec_now, sec_alarm, sec_tmp;
    rt_int32_t sec_next = 24 * 3600, sec_prev = 0;
    time_t timestamp = (time_t)0;
    struct tm now;
    rt_list_t *next;

    rt_mutex_take(&_container.mutex, RT_WAITING_FOREVER);
    if (!rt_list_isempty(&_container.head))
    {
        /* get time of now */
        get_timestamp(&timestamp);
#ifdef RT_ALARM_USING_LOCAL_TIME
        localtime_r(&timestamp, &now);
#else
        gmtime_r(&timestamp, &now);
#endif

        for (next = _container.head.next; next != &_container.head; next = next->next)
        {
            alarm = rt_list_entry(next, struct rt_alarm, list);
            /* check the overtime alarm */
            alarm_wakeup(alarm, &now);
        }

        /* get time of now */
        get_timestamp(&timestamp);
#ifdef RT_ALARM_USING_LOCAL_TIME
        localtime_r(&timestamp, &now);
#else
        gmtime_r(&timestamp, &now);
#endif
        sec_now = alarm_mkdaysec(&now);

        for (next = _container.head.next; next != &_container.head; next = next->next)
        {
            alarm = rt_list_entry(next, struct rt_alarm, list);
            /* calculate seconds from 00:00:00 */
            sec_alarm = alarm_mkdaysec(&alarm->wktime);
            if (alarm->flag & RT_ALARM_STATE_START)
            {
                sec_tmp = sec_alarm - sec_now;
                if (sec_tmp > 0)
                {
                    /* find alarm after now(now to 23:59:59) and the most recent */
                    if (sec_tmp < sec_next)
                    {
                        sec_next = sec_tmp;
                        alm_next = alarm;
                    }
                }
                else
                {
                    /* find alarm before now(00:00:00 to now) and furthest from now */
                    if (sec_tmp < sec_prev)