1 files changed, 24 insertions, 10 deletions

diff --git a/src/avl.c b/src/avl.c
index 324afeeb..1ec1b8ad 100644
--- a/src/avl.c
+++ b/src/avl.c
@@ -283,18 +283,30 @@ avl *avl_remove(avl_tree *tree, avl *item) {
 // ---------------------------
 // traversing
 
-void avl_walker(avl *node, void (*callback)(void *)) {
-    if(node->avl_link[0])
-        avl_walker(node->avl_link[0], callback);
+int avl_walker(avl *node, int (*callback)(void *entry, void *data), void *data) {
+    int total = 0, ret = 0;
 
-    callback(node);
+    if(node->avl_link[0]) {
+        ret = avl_walker(node->avl_link[0], callback, data);
+        if(ret < 0) return ret;
+        total += ret;
+    }
+
+    ret = callback(node, data);
+    if(ret < 0) return ret;
+    total += ret;
 
-    if(node->avl_link[1])
-        avl_walker(node->avl_link[1], callback);
+    if(node->avl_link[1]) {
+        ret = avl_walker(node->avl_link[1], callback, data);
+        if (ret < 0) return ret;
+        total += ret;
+    }
+
+    return total;
 }
 
-void avl_traverse(avl_tree *t, void (*callback)(void *)) {
-    avl_walker(t->root, callback);
+int avl_traverse(avl_tree *t, int (*callback)(void *entry, void *data), void *data) {
+    return avl_walker(t->root, callback, data);
 }
 
 // ---------------------------
@@ -372,10 +384,12 @@ avl *avl_insert_lock(avl_tree_lock *t, avl *a) {
     return ret;
 }
 
-void avl_traverse_lock(avl_tree_lock *t, void (*callback)(void *)) {
+int avl_traverse_lock(avl_tree_lock *t, int (*callback)(void *entry, void *data), void *data) {
+    int ret;
     avl_read_lock(t);
-    avl_traverse(&t->avl_tree, callback);
+    ret = avl_traverse(&t->avl_tree, callback, data);
     avl_unlock(t);
+    return ret;
 }
 
 void avl_init(avl_tree *t, int (*compar)(void *a, void *b)) {