Make client reference counts work the same way as all

other reference counts: replace ns_client_wait() and
ns_client_unwait() by ns_client_attach() and ns_client_detach(),
respectively

bin/named/client.c

@@ -273,8 +273,8 @@ exit_check(ns_client_t *client) {
 	 *
 	 *  - The resolver will not shut down until the view refcount is zero
 	 *  - The view refcount does not go to zero until all clients detach
-	 *  - The client does not detach from the view until nwaiting is zero
-	 *  - nwaiting does not go to zero until the resolver has shut down
+	 *  - The client does not detach from the view until references is zero
+	 *  - references does not go to zero until the resolver has shut down
 	 *
 	 */
 	if (client->newstate == NS_CLIENTSTATE_FREED && client->view != NULL)
@@ -295,7 +295,7 @@ exit_check(ns_client_t *client) {
 			isc_socket_cancel(socket, client->task,
 					  ISC_SOCKCANCEL_SEND);
 		}
-		if (! (client->nsends == 0 && client->nwaiting == 0)) {
+		if (! (client->nsends == 0 && client->references == 0)) {
 			/*
 			 * Still waiting for I/O cancel completion.
 			 * or lingering references.
@@ -1045,7 +1045,7 @@ client_create(ns_clientmgr_t *manager, ns_client_t **clientp)
 	client->naccepts = 0;
 	client->nreads = 0;
 	client->nsends = 0;
-	client->nwaiting = 0;
+	client->references = 0;
 	client->attributes = 0;
 	client->view = NULL;
 	client->lockview = NULL;
@@ -1236,8 +1236,20 @@ client_accept(ns_client_t *client) {
 }
 
 void
-ns_client_wait(ns_client_t *client) {
-	client->nwaiting++;
+ns_client_attach(ns_client_t *source, ns_client_t **targetp) {
+	REQUIRE(NS_CLIENT_VALID(source));
+	REQUIRE(targetp != NULL && *targetp == NULL);
+	source->references++;
+	*targetp = source;
+}
+
+void
+ns_client_detach(ns_client_t **clientp) {
+	ns_client_t *client = *clientp;
+	client->references--;
+	INSIST(client->references >= 0);
+	*clientp = NULL;
+	(void) exit_check(client);
 }
 
 isc_boolean_t
@@ -1245,13 +1257,6 @@ ns_client_shuttingdown(ns_client_t *client) {
 	return (client->newstate == NS_CLIENTSTATE_FREED);
 }
 
-void
-ns_client_unwait(ns_client_t *client) {
-	client->nwaiting--;
-	INSIST(client->nwaiting >= 0);
-	(void) exit_check(client);
-}
-
 isc_result_t
 ns_client_replace(ns_client_t *client) {
 	isc_result_t result;

bin/named/include/named/client.h

@@ -88,7 +88,7 @@ struct ns_client {
 	int				naccepts;
 	int				nreads;
 	int				nsends;
-	int				nwaiting;
+	int				references;
 	unsigned int			attributes;
 	isc_task_t *			task;
 	dns_view_t *			view;
@@ -167,16 +167,15 @@ ns_client_shuttingdown(ns_client_t *client);
  */
 
 void
-ns_client_wait(ns_client_t *client);
+ns_client_attach(ns_client_t *source, ns_client_t **target);
 /*
- * Increment reference count.  The client object will
- * not be destroyed while the reference count is nonzero.
+ * Attach '*targetp' to 'source'.
  */
 
 void
-ns_client_unwait(ns_client_t *client);
+ns_client_detach(ns_client_t **clientp);
 /*
- * Decrement reference count.
+ * Detach '*clientp' from its client.
  */
 
 isc_result_t

bin/named/query.c

@@ -1679,7 +1679,7 @@ query_resume(isc_task_t *task, isc_event_t *event) {
 		isc_event_free(&event);
 		ns_client_next(client, ISC_R_CANCELED);
 		/* This may destroy the client. */
-		ns_client_unwait(client);
+		ns_client_detach(&client);
 	} else {
 		RWLOCK(&ns_g_server->conflock, isc_rwlocktype_read);
 		dns_zonemgr_lockconf(ns_g_server->zonemgr, isc_rwlocktype_read);
@@ -2597,7 +2597,7 @@ query_find(ns_client_t *client, dns_fetchevent_t *event) {
 
 	if (eresult != ISC_R_SUCCESS && !PARTIALANSWER(client)) {
 		ns_client_error(client, eresult);
-		ns_client_unwait(client);
+		ns_client_detach(&client);
 	} else if (!RECURSING(client)) {
 		/*
 		 * We are done.  Make a final tweak to the AA bit if the
@@ -2609,7 +2609,7 @@ query_find(ns_client_t *client, dns_fetchevent_t *event) {
 			client->message->flags |= DNS_MESSAGEFLAG_AA;
 		
 		ns_client_send(client);
-		ns_client_unwait(client);		
+		ns_client_detach(&client);		
 	}
 	CTRACE("query_find: done");
 }
@@ -2672,7 +2672,8 @@ ns_query_start(ns_client_t *client) {
 	dns_message_t *message = client->message;
 	dns_rdataset_t *rdataset;
 	isc_boolean_t set_ra = ISC_TRUE;
-
+	ns_client_t *qclient;
+	
 	CTRACE("ns_query_start");
 
 	/*
@@ -2802,6 +2803,7 @@ ns_query_start(ns_client_t *client) {
 	 */
 	message->flags |= DNS_MESSAGEFLAG_AD;
 
-	ns_client_wait(client);
-	query_find(client, NULL);
+	qclient = NULL;
+	ns_client_attach(client, &qclient);
+	query_find(qclient, NULL);
 }

bin/named/xfrout.c

@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
- /* $Id: xfrout.c,v 1.42 2000/02/09 22:58:45 gson Exp $ */
+ /* $Id: xfrout.c,v 1.43 2000/02/11 20:56:18 gson Exp $ */
 
 #include <config.h>
 
@@ -1052,8 +1052,8 @@ xfrout_ctx_create(isc_mem_t *mctx, ns_client_t *client, unsigned int id,
 	if (xfr == NULL)
 		return (DNS_R_NOMEMORY);
 	xfr->mctx = mctx;
-	xfr->client = client;
-	ns_client_wait(client);
+	xfr->client = NULL;
+	ns_client_attach(client, &xfr->client);
 	xfr->id = id;
 	xfr->qname = qname;
 	xfr->qtype = qtype;
@@ -1397,7 +1397,7 @@ xfrout_ctx_destroy(xfrout_ctx_t **xfrp) {
 	if (xfr->db != NULL)
 		dns_db_detach(&xfr->db);
 
-	ns_client_unwait(xfr->client);
+	ns_client_detach(&xfr->client);
 
 	isc_mem_put(xfr->mctx, xfr, sizeof(*xfr));