--- a/src/parallel_execution/rb_tree.c	Thu Sep 29 19:02:49 2016 +0900
+++ b/src/parallel_execution/rb_tree.c	Thu Sep 29 22:22:36 2016 +0900
@@ -110,31 +110,32 @@
                      context->data[Traverse]->traverse.result);
 }
 
-__code insertNode(struct Context* context, struct Traverse* traverse, struct Tree* tree, struct Node* node, struct Node* newNode) {
+__code insertNode(struct Context* context, struct Traverse* traverse, struct Node* node, struct Node* newNode) {
     *newNode = *node;
     newNode->color = Red;
     traverse->current = newNode;
-    tree->root->color = Black;
     goto meta(context, InsertCase1);
 }
 
 __code insertNode_stub(struct Context* context) {
     goto insertNode(context,
                     &context->data[Traverse]->traverse,
-                    &context->data[Tree]->tree,
                     &context->data[Node]->node,
                     context->data[Traverse]->traverse.newNode);
 }
 
-__code insertCase1(struct Context* context, struct Element* nodeStack) {
+__code insertCase1(struct Context* context, struct Tree* tree,struct Element* nodeStack) {
     if (nodeStack!=NULL) {
         goto meta(context, InsertCase2);
     }
+    tree->root->color = Black;
     goto meta(context, StackClear);
 }
 
 __code insert1_stub(struct Context* context) {
-    goto insertCase1(context, context->data[Traverse]->traverse.nodeStack);
+    goto insertCase1(context, 
+        &context->data[Tree]->tree,
+        context->data[Traverse]->traverse.nodeStack);
 }
 
 __code insertCase2(struct Context* context, struct Node* parent) {
@@ -331,6 +332,7 @@
 
 __code stackClear(struct Context* context, stack_ptr node_stack, struct Traverse* traverse) {
     traverse->current = 0;
+    traverse->nodeStack = NULL;
 
     goto meta(context, context->next);
 }