Function tcp_log_expire

freebsd/netinet/tcp_log_buf.c:1196–1288

Remove entries */

/* Remove entries */
static void
tcp_log_expire(void *unused __unused)
{
	struct tcp_log_id_bucket *tlb;
	struct tcp_log_id_node *tln;
	sbintime_t expiry_limit;
	int tree_locked;

	TCPLOG_EXPIREQ_LOCK();
	if (callout_pending(&tcp_log_expireq_callout)) {
		/* Callout was reset. */
		TCPLOG_EXPIREQ_UNLOCK();
		return;
	}

	/*
	 * Process entries until we reach one that expires too far in the
	 * future. Look one second in the future.
	 */
	expiry_limit = getsbinuptime() + SBT_1S;
	tree_locked = TREE_UNLOCKED;

	while ((tln = STAILQ_FIRST(&tcp_log_expireq_head)) != NULL &&
	    tln->tln_expiretime <= expiry_limit) {
		if (!callout_active(&tcp_log_expireq_callout)) {
			/*
			 * Callout was stopped. I guess we should
			 * just quit at this point.
			 */
			TCPLOG_EXPIREQ_UNLOCK();
			return;
		}

		/*
		 * Remove the node from the head of the list and unlock
		 * the list. Change the expiry time to SBT_MAX as a signal
		 * to other threads that we now own this.
		 */
		STAILQ_REMOVE_HEAD(&tcp_log_expireq_head, tln_expireq);
		tln->tln_expiretime = SBT_MAX;
		TCPLOG_EXPIREQ_UNLOCK();

		/*
		 * Remove the node from the bucket.
		 */
		tlb = tln->tln_bucket;
		TCPID_BUCKET_LOCK(tlb);
		if (tcp_log_remove_id_node(NULL, NULL, tlb, tln, &tree_locked)) {
			tcp_log_id_validate_tree_lock(tree_locked);
			if (tree_locked == TREE_WLOCKED)
				TCPID_TREE_WUNLOCK();
			else
				TCPID_TREE_RUNLOCK();
			tree_locked = TREE_UNLOCKED;
		}

		/* Drop the INP reference. */
		INP_WLOCK(tln->tln_inp);