Re #1974: Remove DNS cache entry from resolver's hash table when app callback has a reference.

Thanks to Richard Mudgett for the patch.



git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@5475 74dad513-b988-da41-8d7b-12977e46ad98

1 files changed, 15 insertions, 14 deletions

diff --git a/pjlib-util/src/pjlib-util/resolver.c b/pjlib-util/src/pjlib-util/resolver.c
index 6dba6e25..cfca16ad 100644
--- a/pjlib-util/src/pjlib-util/resolver.c
+++ b/pjlib-util/src/pjlib-util/resolver.c
@@ -1471,10 +1471,12 @@ static void update_res_cache(pj_dns_resolver *resolver,
     if (ttl > resolver->settings.cache_max_ttl)
 	ttl = resolver->settings.cache_max_ttl;
 
+    /* Get a cache response entry */
+    cache = (struct cached_res *) pj_hash_get(resolver->hrescache, key,
+    					      sizeof(*key), &hval);
+
     /* If TTL is zero, clear the same entry in the hash table */
     if (ttl == 0) {
-	cache = (struct cached_res *) pj_hash_get(resolver->hrescache, key, 
-						  sizeof(*key), &hval);
 	/* Remove the entry before releasing its pool (see ticket #1710) */
 	pj_hash_set(NULL, resolver->hrescache, key, sizeof(*key), hval, NULL);
 
@@ -1484,24 +1486,23 @@ static void update_res_cache(pj_dns_resolver *resolver,
 	return;
     }
 
-    /* Get a cache response entry */
-    cache = (struct cached_res *) pj_hash_get(resolver->hrescache, key, 
-    					      sizeof(*key), &hval);
     if (cache == NULL) {
 	cache = alloc_entry(resolver);
-    } else if (cache->ref_cnt > 1) {
-	/* When cache entry is being used by callback (to app), just decrement
-	 * ref_cnt so it will be freed after the callback returns and allocate
-	 * new entry.
-	 */
-	cache->ref_cnt--;
-	cache = alloc_entry(resolver);
     } else {
 	/* Remove the entry before resetting its pool (see ticket #1710) */
 	pj_hash_set(NULL, resolver->hrescache, key, sizeof(*key), hval, NULL);
 
-	/* Reset cache to avoid bloated cache pool */
-	reset_entry(&cache);
+	if (cache->ref_cnt > 1) {
+	    /* When cache entry is being used by callback (to app),
+	     * just decrement ref_cnt so it will be freed after
+	     * the callback returns and allocate new entry.
+	     */
+	    cache->ref_cnt--;
+	    cache = alloc_entry(resolver);
+	} else {
+	    /* Reset cache to avoid bloated cache pool */
+	    reset_entry(&cache);
+	}
     }
 
     /* Duplicate the packet.