Update Future.h

Fixed a race condition caused by the double checked locking pattern by using an std::atomic that ensures correct and deterministic create and assignment logic.

ACE/ace/Future.h

@@ -197,7 +197,7 @@ class ACE_Future_Rep
   int ready () const;
 
   /// Pointer to the result.
-  T *value_;
+  std::atomic<T*> value_;
 
   /// Reference count.
   int ref_count_;