用 EBtree 索引任务期限，并延后不必要的重排

400	 * has been disabled, it's useless to leave the queue as well. We'll401	 * rely on wake_expired_tasks() to catch the node and move it to the402	 * proper place should it ever happen. Finally we only add the task403	 * to the queue if it was not there or if it was further than what404	 * we want.405	 */406	if (!tick_isset(task->expire))407		return;408409	BUG_ON(task->tid >= 0 && task->tid != tid);410411	if (!task_in_wq(task) || tick_is_lt(task->expire, task->wq.key)) {412		if (likely(caller)) {413			caller = HA_ATOMIC_XCHG(&task->caller, caller);414			BUG_ON((ulong)caller & 1);415#ifdef DEBUG_TASK416			HA_ATOMIC_STORE(&task->debug.prev_caller, caller);417#endif418		}419		__task_queue(task);420	}

327	if (likely(task_in_wq(task)))328		__task_unlink_wq(task);329330	/* the task is not in the queue now */331	task->wq.key = task->expire;332#ifdef DEBUG_CHECK_INVALID_EXPIRATION_DATES333	if (tick_is_lt(task->wq.key, now_ms))334		/* we're queuing too far away or in the past (most likely) */335		return;336#endif337338	eb32_insert(&th_ctx->timers, &task->wq);339}

277		old_node_bit = old->node.bit;278279		/* Stop going down when we don't have common bits anymore. We280		 * also stop in front of a duplicates tree because it means we281		 * have to insert above.282		 */283284		if ((old_node_bit < 0) || /* we're above a duplicate tree, stop here */285		    (((new->key ^ old->key) >> old_node_bit) >= EB_NODE_BRANCHES)) {286			/* The tree did not contain the key, so we insert <new> before the node287			 * <old>, and set ->bit to designate the lowest bit position in <new>288			 * which applies to ->branches.b[].289			 */290			new->node.node_p = old->node.node_p;291			up_ptr = &old->node.node_p;292			break;293		}294295		/* walk down */296		side = (newkey >> old_node_bit) & EB_NODE_BRANCH_MASK;297		troot = side ? old->node.branches.b[1] : old->node.branches.b[0];298		root = &old->node.branches;

345void wake_expired_tasks()346{347	struct thread_ctx * const tt = th_ctx; // thread's tasks348	int max_processed = global.tune.runqueue_depth;349	struct task *task;350	struct eb32_node *eb;351352	while (1) {353		if (max_processed-- <= 0)354			goto leave;355356		eb = eb32_lookup_ge(&tt->timers, now_ms - TIMER_LOOK_BACK);357		if (!eb) {358			/* we might have reached the end of the tree, typically because359			* <now_ms> is in the first half and we're first scanning the last360			* half. Let's loop back to the beginning of the tree now.361			*/362			eb = eb32_first(&tt->timers);363			if (likely(!eb))364				break;365		}

385		task = eb32_entry(eb, struct task, wq);386		if (tick_is_expired(task->expire, now_ms)) {387			int set_running = 0;388389			/* expired task, wake it up */390			__task_unlink_wq(task);391			/*392			 * If it's a shared task, see whether we should hand it393			 * to a less loaded thread.394			 */

432			if (set_running)433				task_drop_running(task, TASK_WOKEN_TIMER);434			else435				_task_wakeup(task, TASK_WOKEN_TIMER, 0);436		}437		else if (task->expire != eb->key) {438			/* task is not expired but its key doesn't match so let's439			 * update it and skip to next apparently expired task.440			 */441			__task_unlink_wq(task);442			if (tick_isset(task->expire))443				__task_queue(task);444		}445		else {446			/* task not expired and correctly placed. It may not be eternal. */447			BUG_ON(task->expire == TICK_ETERNITY);448			break;449		}