rbtree: don't use temporary context to destroy rbtree
authorRusty Russell <rusty@rustcorp.com.au>
Mon, 10 Jan 2011 05:17:24 +0000 (15:47 +1030)
committerRusty Russell <rusty@rustcorp.com.au>
Mon, 10 Jan 2011 05:17:24 +0000 (15:47 +1030)
It leads to a memory leak if the allocation fails (as we reparent onto NULL).
Also, the extra allocation in the failure path increases test time for
failtest (under valgrind) by a factor of 2.

ccan/rbtree/rbtree.c

index 753935b3dcc73647b065df9a28cd1716416505d6..e3b4a9518fe0b64537c5933c30ab8578b10c46c8 100644 (file)
 #include <ccan/rbtree/rbtree.h>
 
 static void
-tree_destructor_traverse_node(TALLOC_CTX *mem_ctx, trbt_node_t *node)
+tree_destructor_traverse_node(trbt_node_t *node)
 {
        talloc_set_destructor(node, NULL);
        if (node->left) {
-               tree_destructor_traverse_node(mem_ctx, node->left);
+               tree_destructor_traverse_node(node->left);
        }
        if (node->right) {
-               tree_destructor_traverse_node(mem_ctx, node->right);
+               tree_destructor_traverse_node(node->right);
        }
-       talloc_steal(mem_ctx, node);
+       talloc_free(node);
 }
 
 /*
@@ -36,7 +36,6 @@ tree_destructor_traverse_node(TALLOC_CTX *mem_ctx, trbt_node_t *node)
  */
 static int tree_destructor(trbt_tree_t *tree)
 {
-       TALLOC_CTX *tmp_ctx;
        trbt_node_t *node;
 
        if (tree == NULL) {
@@ -48,17 +47,14 @@ static int tree_destructor(trbt_tree_t *tree)
                return 0;
        }
 
-       /* traverse the tree and remove the node destructor and steal
-          the node to the temporary context.
+       /* traverse the tree and remove the node destructor then delete it.
           we dont want to use the existing destructor for the node
           since that will remove the nodes one by one from the tree.
           since the entire tree will be completely destroyed we dont care
           if it is inconsistent or unbalanced while freeing the
           individual nodes
        */
-       tmp_ctx = talloc_new(NULL);
-       tree_destructor_traverse_node(tmp_ctx, node);
-       talloc_free(tmp_ctx);
+       tree_destructor_traverse_node(node);
 
        return 0;
 }