Function ngthread

freebsd/netgraph/ng_base.c:3398–3445

* Worklist routines **********************************************************************/ * Pick a node off the list of nodes with work, * try get an item to process off it. Remove the node from the list. */

 * try get an item to process off it. Remove the node from the list.
 */
static void
ngthread(void *arg)
{
	for (;;) {
		struct epoch_tracker et;
		node_p  node;

		/* Get node from the worklist. */
		NG_WORKLIST_LOCK();
		while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
			NG_WORKLIST_SLEEP();
		STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
		NG_WORKLIST_UNLOCK();
		CURVNET_SET(node->nd_vnet);
		CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
		    __func__, node->nd_ID, node);
		/*
		 * We have the node. We also take over the reference
		 * that the list had on it.
		 * Now process as much as you can, until it won't
		 * let you have another item off the queue.
		 * All this time, keep the reference
		 * that lets us be sure that the node still exists.
		 * Let the reference go at the last minute.
		 */
		NET_EPOCH_ENTER(et);
		for (;;) {
			item_p item;
			int rw;

			NG_QUEUE_LOCK(&node->nd_input_queue);
			item = ng_dequeue(node, &rw);
			if (item == NULL) {
				node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
				NG_QUEUE_UNLOCK(&node->nd_input_queue);
				break; /* go look for another node */
			} else {
				NG_QUEUE_UNLOCK(&node->nd_input_queue);
				NGI_GET_NODE(item, node); /* zaps stored node */
				ng_apply_item(node, item, rw);
				NG_NODE_UNREF(node);
			}
		}
		NET_EPOCH_EXIT(et);
		NG_NODE_UNREF(node);
		CURVNET_RESTORE();
	}
}

/*
 * XXX