Changeset 2124

Timestamp:

Jul 12, 2008 9:50:48 AM (16 years ago)

Author:

bennylp

Message:

Ticket #560: Optimize the memory usage of DNS resolver

Location:

pjproject/trunk/pjlib-util

Files:

• include/pjlib-util/config.h (modified) (1 diff)
• src/pjlib-util/resolver.c (modified) (17 diffs)

pjproject/trunk/pjlib-util/include/pjlib-util/config.h

@@ -179 +179 @@
  * (#pj_dns_packet_dup()) is also capable of performing name compressions.
  *
- * Default: 1000 (as a broad guidance, 400 is good for 4 SRV entries).
+ * Default: 512
  */
 #ifndef PJ_DNS_RESOLVER_RES_BUF_SIZE
-#   define PJ_DNS_RESOLVER_RES_BUF_SIZE             1000
+#   define PJ_DNS_RESOLVER_RES_BUF_SIZE             512
 #endif
 

pjproject/trunk/pjlib-util/src/pjlib-util/resolver.c

@@ -151 +151 @@
     PJ_DECL_LIST_MEMBER(struct cached_res);
 
+    pj_pool_t               *pool;          /**< Cache's pool.              */
     struct res_key           key;           /**< Resource key.              */
-    char                     buf[RES_BUF_SZ];/**< Resource buffer.          */
     pj_hash_entry_buf        hbuf;          /**< Hash buffer                */
     pj_time_val              expiry_time;   /**< Expiration time.           */
@@ -195 +195 @@
     /* Hash table for cached response */
     pj_hash_table_t     *hrescache;     /**< Cached response in hash table  */
-
-    /* Cached response free list */
-    struct cached_res    res_free_nodes;
 
     /* Pending asynchronous query, hashed by transaction ID. */
@@ -296 +293 @@
     }
 
-    /* Response cache hash table and item list */
+    /* Response cache hash table */
     resv->hrescache = pj_hash_create(pool, RES_HASH_TABLE_SIZE);
-    pj_list_init(&resv->res_free_nodes);
 
     /* Query hash table and free list. */
@@ -352 +348 @@
                                              pj_bool_t notify)
 {
+    pj_hash_iterator_t it_buf, *it;
     PJ_ASSERT_RETURN(resolver, PJ_EINVAL);
 
@@ -358 +355 @@
          * Notify pending queries if requested.
          */
-        pj_hash_iterator_t it_buf, *it;
-
         it = pj_hash_first(resolver->hquerybyid, &it_buf);
         while (it) {
@@ -378 +373 @@
     }
 
+    /* Destroy cached entries */
+    it = pj_hash_first(resolver->hrescache, &it_buf);
+    while (it) {
+        struct cached_res *cache;
+
+        cache = (struct cached_res*) pj_hash_this(resolver->hrescache, it);
+        pj_hash_set(NULL, resolver->hrescache, &cache->key, 
+                    sizeof(cache->key), 0, NULL);
+        pj_pool_release(cache->pool);
+
+        it = pj_hash_first(resolver->hrescache, &it_buf);
+    }
+
     if (resolver->own_timer && resolver->timer) {
         pj_timer_heap_destroy(resolver->timer);
@@ -640 +648 @@
 
 
+/* Allocate new cache entry */
+static struct cached_res *alloc_entry(pj_dns_resolver *resolver)
+{
+    pj_pool_t *pool;
+    struct cached_res *cache;
+
+    pool = pj_pool_create(resolver->pool->factory, "dnscache",
+                          RES_BUF_SZ, 256, NULL);
+    cache = PJ_POOL_ZALLOC_T(pool, struct cached_res);
+    cache->pool = pool;
+
+    return cache;
+}
+
+/* Put unused/expired cached entry to the free list */
+static void free_entry(pj_dns_resolver *resolver, struct cached_res *cache)
+{
+    PJ_UNUSED_ARG(resolver);
+    pj_pool_release(cache->pool);
+}
+
+
 /*
  * Create and start asynchronous DNS query for a single resource.
@@ -724 +754 @@
 
         /* Store the entry into free nodes */
-        pj_list_push_back(&resolver->res_free_nodes, cache);
+        free_entry(resolver, cache);
 
         /* Must continue with creating a query now */
@@ -1066 +1096 @@
 {
     struct cached_res *cache;
-    pj_pool_t *res_pool;
     pj_uint32_t hval=0, ttl;
-    PJ_USE_EXCEPTION;
 
     /* If status is unsuccessful, clear the same entry from the cache */
@@ -1075 +1103 @@
                                                   sizeof(*key), &hval);
         if (cache)
-            pj_list_push_back(&resolver->res_free_nodes, cache);
+            free_entry(resolver, cache);
         pj_hash_set(NULL, resolver->hrescache, key, sizeof(*key), hval, NULL);
     }
@@ -1111 +1139 @@
                                                   sizeof(*key), &hval);
         if (cache)
-            pj_list_push_back(&resolver->res_free_nodes, cache);
+            free_entry(resolver, cache);
         pj_hash_set(NULL, resolver->hrescache, key, sizeof(*key), hval, NULL);
         return;
@@ -1120 +1148 @@
                                               sizeof(*key), &hval);
     if (cache == NULL) {
-        if (!pj_list_empty(&resolver->res_free_nodes)) {
-            cache = resolver->res_free_nodes.next;
-            pj_list_erase(cache);
-        } else {
-            cache = PJ_POOL_ZALLOC_T(resolver->pool, struct cached_res);
-        }
+        cache = alloc_entry(resolver);
     }
 
@@ -1134 +1157 @@
      * the name being requested.
      */
-    res_pool = pj_pool_create_on_buf("respool", cache->buf, sizeof(cache->buf));
-    PJ_TRY {
-        cache->pkt = NULL;
-        pj_dns_packet_dup(res_pool, pkt, 
-                          PJ_DNS_NO_NS | PJ_DNS_NO_AR,
-                          &cache->pkt);
-    }
-    PJ_CATCH_ANY {
-        PJ_LOG(1,(THIS_FILE, 
-                  "Not enough memory to duplicate DNS response. Response was "
-                  "truncated."));
-    }
-    PJ_END;
+    cache->pkt = NULL;
+    pj_dns_packet_dup(cache->pool, pkt, 
+                      PJ_DNS_NO_NS | PJ_DNS_NO_AR,
+                      &cache->pkt);
 
     /* Calculate expiration time */
@@ -1163 +1177 @@
     pj_hash_set_np(resolver->hrescache, &cache->key, sizeof(*key), hval,
                    cache->hbuf, cache);
+
 }
 
@@ -1253 +1268 @@
 {
     pj_dns_resolver *resolver;
-    pj_pool_t *pool;
+    pj_pool_t *pool = NULL;
     pj_dns_parsed_packet *dns_pkt;
     pj_dns_async_query *q;
@@ -1383 +1398 @@
 
 read_next_packet:
+    if (pool) {
+        /* needed just in case PJ_HAS_POOL_ALT_API is set */
+        pj_pool_release(pool);
+    }
     bytes_read = sizeof(resolver->udp_rx_pkt);
     resolver->udp_addr_len = sizeof(resolver->udp_src_addr);
@@ -1516 +1535 @@
         }
     }
-    PJ_LOG(3,(resolver->name.ptr, "  Nb. of cached response free nodes: %u",
-              pj_list_size(&resolver->res_free_nodes)));
     PJ_LOG(3,(resolver->name.ptr, "  Nb. of pending queries: %u (%u)",
               pj_hash_count(resolver->hquerybyid),