From 21eaa048582b19d3fe7a2c9f9b3455256dbae77b Mon Sep 17 00:00:00 2001
From: Andreas Gustafsson <source@isc.org>
Date: Thu, 15 Jun 2000 16:11:50 +0000
Subject: [PATCH] added dns_zonemgr_attach(); also changed comments for other
 attach() functions to consistently say that the new reference attaches to the
 object, not vice versa

---
 lib/dns/include/dns/zone.h | 21 ++++++++++++++++-----
 lib/dns/zone.c             | 17 +++++++++++++++--
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/lib/dns/include/dns/zone.h b/lib/dns/include/dns/zone.h
index 5abbc1ad7d..0f6c2b5a49 100644
--- a/lib/dns/include/dns/zone.h
+++ b/lib/dns/include/dns/zone.h
@@ -51,7 +51,7 @@ ISC_LANG_BEGINDECLS
 isc_result_t
 dns_zone_create(dns_zone_t **zonep, isc_mem_t *mctx);
 /*
- *	Creates a new empty zone and attach to it.
+ *	Creates a new empty zone and attach '*zonep' to it.
  *
  * Requires:
  *	'zonep' to point to a NULL pointer.
@@ -178,7 +178,7 @@ dns_zone_load(dns_zone_t *zone);
 void
 dns_zone_attach(dns_zone_t *source, dns_zone_t **target);
 /*
- *	Attach 'zone' to 'target' incrementing its external
+ *	Attach '*target' to 'source' incrementing its external
  * 	reference count.
  *
  * Require:
@@ -200,7 +200,7 @@ dns_zone_detach(dns_zone_t **zonep);
 void
 dns_zone_iattach(dns_zone_t *source, dns_zone_t **target);
 /*
- *	Attach 'zone' to 'target' incrementing its internal 
+ *	Attach '*target' to 'source' incrementing its internal 
  * 	reference count.  This is intended for use by operations
  * 	such as zone transfers that need to prevent the zone
  * 	object from being freed but not from shutting down.
@@ -260,7 +260,7 @@ dns_zone_cleardbargs(dns_zone_t *zone);
 isc_result_t
 dns_zone_getdb(dns_zone_t *zone, dns_db_t **dbp);
 /*
- * 	Attach the database to '*dbp' if it exists otherwise
+ * 	Attach '*dbp' to the database to if it exists otherwise
  *	return DNS_R_NOTLOADED.
  *
  * Require:
@@ -715,7 +715,7 @@ dns_zone_settask(dns_zone_t *zone, isc_task_t *task);
 void
 dns_zone_gettask(dns_zone_t *zone, isc_task_t **target);
 /*
- * Attach the zone's task to '*target'.
+ * Attach '*target' to the zone's task.
  *
  * Requires:
  *	'zone' to be valid initialised zone.
@@ -918,6 +918,17 @@ dns_zonemgr_shutdown(dns_zonemgr_t *zmgr);
  *	'zmgr' to be a valid zone manager.
  */
 
+void
+dns_zonemgr_attach(dns_zonemgr_t *source, dns_zonemgr_t **target);
+/*
+ *	Attach '*target' to 'source' incrementing its external
+ * 	reference count.
+ *
+ * Require:
+ *	'zone' to be a valid zone.
+ *	'target' to be non NULL and '*target' to be NULL.
+ */
+	
 void
 dns_zonemgr_detach(dns_zonemgr_t **zmgrp);
 /*
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 04628764f7..d0ac141277 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
-/* $Id: zone.c,v 1.146 2000/06/15 02:45:47 marka Exp $ */
+/* $Id: zone.c,v 1.147 2000/06/15 16:11:49 gson Exp $ */
 
 #include <config.h>
 
@@ -184,7 +184,7 @@ struct dns_zone {
 struct dns_zonemgr {
 	unsigned int		magic;
 	isc_mem_t *		mctx;
-	int			refs;
+	int			refs; 		/* Locked by rwlock */
 	isc_taskmgr_t *		taskmgr;
 	isc_timermgr_t *	timermgr;
 	isc_socketmgr_t *	socketmgr;
@@ -4097,6 +4097,19 @@ dns_zonemgr_releasezone(dns_zonemgr_t *zmgr, dns_zone_t *zone) {
 	ENSURE(zone->zmgr == NULL);
 }
 
+void
+dns_zonemgr_attach(dns_zonemgr_t *source, dns_zonemgr_t **target) {
+	REQUIRE(DNS_ZONEMGR_VALID(source));
+	REQUIRE(target != NULL && *target == NULL);
+
+	RWLOCK(&source->rwlock, isc_rwlocktype_write);
+	REQUIRE(source->refs > 0);
+	source->refs++;
+	INSIST(source->refs > 0);
+	RWUNLOCK(&source->rwlock, isc_rwlocktype_write);
+	*target = source;
+}
+
 void
 dns_zonemgr_detach(dns_zonemgr_t **zmgrp) {
 	dns_zonemgr_t *zmgr;