From e2fd12f3a020ca8c5de168a44fb72e339cdaa3e9 Mon Sep 17 00:00:00 2001
From: Brian Wellington <source@isc.org>
Date: Tue, 29 May 2001 18:34:24 +0000
Subject: [PATCH]  841.   [bug]		When sdb modules were not declared
 threadsafe, their 			create and destroy functions were not
 serialized.

---
 CHANGES       |  3 +++
 lib/dns/sdb.c | 50 ++++++++++++++++++++++++++++----------------------
 2 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/CHANGES b/CHANGES
index 8a5348e254..f2133be92f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+ 841.	[bug]		When sdb modules were not declared threadsafe, their
+ 			create and destroy functions were not serialized.
+
  840.	[bug]		The config file parser could print the wrong file
 			name if an error was detected after an included file
 			was parsed. [RT #1353]
diff --git a/lib/dns/sdb.c b/lib/dns/sdb.c
index 8cecfc33e9..fac888afc0 100644
--- a/lib/dns/sdb.c
+++ b/lib/dns/sdb.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: sdb.c,v 1.31 2001/05/02 19:25:19 bwelling Exp $ */
+/* $Id: sdb.c,v 1.32 2001/05/29 18:34:24 bwelling Exp $ */
 
 #include <config.h>
 
@@ -52,6 +52,7 @@ struct dns_sdbimplementation {
 	void				*driverdata;
 	unsigned int			flags;
 	isc_mem_t			*mctx;
+	isc_mutex_t			driverlock;
 	dns_dbimplementation_t		*dbimp;
 };
 
@@ -62,7 +63,6 @@ struct dns_sdb {
 	dns_sdbimplementation_t		*implementation;
 	void				*dbdata;
 	isc_mutex_t			lock;
-	isc_mutex_t			driverlock;
 	/* Locked */
 	unsigned int			references;
 
@@ -119,14 +119,14 @@ typedef struct sdb_rdatasetiter {
 	do {								\
 		unsigned int flags = sdb->implementation->flags;	\
 		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)		\
-			LOCK(&sdb->driverlock);				\
+			LOCK(&sdb->implementation->driverlock);		\
 	} while (0)
 
 #define MAYBE_UNLOCK(sdb)						\
 	do {								\
 		unsigned int flags = sdb->implementation->flags;	\
 		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)		\
-			UNLOCK(&sdb->driverlock);			\
+			UNLOCK(&sdb->implementation->driverlock);	\
 	} while (0)
 
 static int dummy;
@@ -220,16 +220,28 @@ dns_sdb_register(const char *drivername, const dns_sdbmethods_t *methods,
 	imp->flags = flags;
 	imp->mctx = NULL;
 	isc_mem_attach(mctx, &imp->mctx);
+	result = isc_mutex_init(&imp->driverlock);
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_mutex_init() failed: %s",
+				 isc_result_totext(result));
+		goto cleanup_mctx;
+	}
+
 	imp->dbimp = NULL;
 	result = dns_db_register(drivername, dns_sdb_create, imp, mctx,
 				 &imp->dbimp);
-	if (result != ISC_R_SUCCESS) {
-		dns_sdb_unregister(&imp);
-		return (result);
-	}
+	if (result != ISC_R_SUCCESS)
+		goto cleanup_mutex;
 	*sdbimp = imp;
 
 	return (ISC_R_SUCCESS);
+
+ cleanup_mutex:
+	DESTROYLOCK(&imp->driverlock);
+ cleanup_mctx:
+	isc_mem_put(mctx, imp, sizeof(dns_sdbimplementation_t));
+	return (result);
 }
 
 void
@@ -241,6 +253,7 @@ dns_sdb_unregister(dns_sdbimplementation_t **sdbimp) {
 
 	imp = *sdbimp;
 	dns_db_unregister(&imp->dbimp);
+	DESTROYLOCK(&imp->driverlock);
 
 	mctx = imp->mctx;
 	isc_mem_put(mctx, imp, sizeof(dns_sdbimplementation_t));
@@ -476,13 +489,15 @@ destroy(dns_sdb_t *sdb) {
 
 	mctx = sdb->common.mctx;
 
-	if (imp->methods->destroy != NULL)
+	if (imp->methods->destroy != NULL) {
+		MAYBE_LOCK(sdb);
 		imp->methods->destroy(sdb->zone, imp->driverdata,
 				      &sdb->dbdata);
+		MAYBE_UNLOCK(sdb);
+	}
 
 	isc_mem_free(mctx, sdb->zone);
 	DESTROYLOCK(&sdb->lock);
-	DESTROYLOCK(&sdb->driverlock);
 
 	sdb->common.magic = 0;
 	sdb->common.impmagic = 0;
@@ -1195,18 +1210,9 @@ dns_sdb_create(isc_mem_t *mctx, dns_name_t *origin, dns_dbtype_t type,
 		goto cleanup_mctx;
 	}
 
-	result = isc_mutex_init(&sdb->driverlock);
-	if (result != ISC_R_SUCCESS) {
-		UNEXPECTED_ERROR(__FILE__, __LINE__,
-				 "isc_mutex_init() failed: %s",
-				 isc_result_totext(result));
-		result = ISC_R_UNEXPECTED;
-		goto cleanup_lock;
-	}
-
 	result = dns_name_dupwithoffsets(origin, mctx, &sdb->common.origin);
 	if (result != ISC_R_SUCCESS)
-		goto cleanup_driverlock;
+		goto cleanup_lock;
 
 	isc_buffer_init(&b, zonestr, sizeof(zonestr));
 	result = dns_name_totext(origin, ISC_TRUE, &b);
@@ -1222,8 +1228,10 @@ dns_sdb_create(isc_mem_t *mctx, dns_name_t *origin, dns_dbtype_t type,
 
 	sdb->dbdata = NULL;
 	if (imp->methods->create != NULL) {
+		MAYBE_LOCK(sdb);
 		result = imp->methods->create(sdb->zone, argc, argv,
 					      imp->driverdata, &sdb->dbdata);
+		MAYBE_UNLOCK(sdb);
 		if (result != ISC_R_SUCCESS)
 			goto cleanup_zonestr;
 	}
@@ -1241,8 +1249,6 @@ dns_sdb_create(isc_mem_t *mctx, dns_name_t *origin, dns_dbtype_t type,
 	isc_mem_free(mctx, sdb->zone);
  cleanup_origin:
 	dns_name_free(&sdb->common.origin, mctx);
- cleanup_driverlock:
-	isc_mutex_destroy(&sdb->driverlock);
  cleanup_lock:
 	isc_mutex_destroy(&sdb->lock);
  cleanup_mctx: