Pulling rt15970 into 9.4 pre-release.

diff --git a/lib/dns/acache.c b/lib/dns/acache.c
index 13a0c89664cae392edc743e0e3240a2ab6d96ec4..4e319f5e6e795b5ad28a62e6d06283ac85670af4 100644 (file)
--- a/lib/dns/acache.c
+++ b/lib/dns/acache.c
@@ -14,7 +14,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: acache.c,v 1.3.2.10 2006/04/26 11:31:51 shane Exp $ */
+/* $Id: acache.c,v 1.3.2.11 2006/04/26 12:12:07 shane Exp $ */
 
 #include <config.h>
 
@@ -1247,6 +1247,21 @@ dns_acache_createentry(dns_acache_t *acache, dns_db_t *origdb,
        REQUIRE(entryp != NULL && *entryp == NULL);
        REQUIRE(origdb != NULL);
 
+       /* 
+        * Should we exceed our memory limit for some reason (for 
+        * example, if the cleaner does not run aggressively enough), 
+        * then we will not create additional entries.
+        *
+        * XXX: It might be better to lock the acache->cleaner->lock,
+        * but locking may be an expensive bottleneck. If we misread 
+        * the value, we will occasionally refuse to create a few 
+        * cache entries, or create a few that we should not. I do not
+        * expect this to happen often, and it will not have very bad
+        * effects when it does. So no lock for now.
+        */
+       if (acache->cleaner.overmem)
+               return (ISC_R_NORESOURCES);
+
        newentry = isc_mem_get(acache->mctx, sizeof(*newentry));
        if (newentry == NULL)
                return (ISC_R_NOMEMORY);