Add Progress::ActiveScope to define the scope in which a progress node is active.

Progress/ProgressNode.hh

@@ -56,6 +56,22 @@ private:
 
 extern thread_local Node* actv_node; // active node
 
+struct ActiveScope
+{
+  Node* prnt_node;
+
+  ActiveScope(Node* _node)
+    : prnt_node(actv_node)
+  {
+    actv_node = _node;
+  }
+
+  ~ActiveScope()
+  {
+    actv_node = prnt_node;
+  }
+};
+
 typedef Node* (*MakeNodeFunction)(Node* _next);
 
 inline Node* make_children_list() { return nullptr; }
@@ -101,10 +117,14 @@ inline Node* make_children_list(MakeNodeFunction _make_node_fnct,
   (NODE)->tick(__FILE__, __PROGRESS_FUNCTION__); } 
 #define PROGRESS_ACTIVE_TICK PROGRESS_TICK(Progress::actv_node)
 
+#define PROGRESS_ACTIVE_SCOPE(NAME, NODE) Progress::ActiveScope NAME = \
+  Progress::ActiveScope(Progress::PROGRESS_NODE_NAME(NODE))
+
 #else
 
 #define PROGRESS_DECLARE_NODE(OPRT) 
 #define PROGRESS_DEFINE_NODE(OPRT, ...) 
+#define PROGRESS_ACTIVE_SCOPE(NAME, NODE) 
 
 #endif// PROGRESS_ON