Function check_and_split_time_list

modules/tm/timer.c:841–894

detach items passed by the time from timer list */

/* detach items passed by the time from timer list */
static struct timer_link  *check_and_split_time_list( struct timer *timer_list,
		utime_t time )
{
	struct timer_link *tl , *end, *ret;


	/* quick check whether it is worth entering the lock */
	if (timer_list->first_tl.next_tl==&timer_list->last_tl
			|| ( /* timer_list->first_tl.next_tl
				&& */ timer_list->first_tl.next_tl->time_out > time) )
		return NULL;

	/* the entire timer list is locked now -- no one else can manipulate it */
	lock(timer_list->mutex);

#ifdef TM_TIMER_DEBUG
	check_timer_list( timer_list, "before split" );
#endif
	end = &timer_list->last_tl;
	tl = timer_list->first_tl.next_tl;
	while( tl!=end && tl->time_out <= time)
		tl=tl->ld_tl->next_tl;

	/* nothing to delete found */
	if (tl->prev_tl==&(timer_list->first_tl)) {
		ret = NULL;
	} else { /* we did find timers to be fired! */
		/* the detached list begins with current beginning */
		ret = timer_list->first_tl.next_tl;
		/* and we mark the end of the split list */
		tl->prev_tl->next_tl = NULL;
		/* the shortened list starts from where we suspended */
		timer_list->first_tl.next_tl = tl;
		tl->prev_tl = & timer_list->first_tl;

		for( tl=ret ; tl ; tl=tl->next_tl )
			tl->timer_list = DETACHED_LIST;
	}
#ifdef TM_TIMER_DEBUG
	check_timer_list( timer_list, "after split" );
#endif

#ifdef EXTRA_DEBUG
	if (timer_list->last_tl.prev_tl==0) {
		LM_CRIT("Oh no, zero link in trailing timer element\n");
		abort();
	};
#endif

	/* give the list lock away */
	unlock(timer_list->mutex);

	return ret;
}