--- a/src/hotspot/share/gc/shared/gcId.hpp	Wed Feb 21 07:46:40 2018 +0100
+++ b/src/hotspot/share/gc/shared/gcId.hpp	Wed Feb 21 07:50:33 2018 +0100
@@ -28,38 +28,32 @@
 #include "memory/allocation.hpp"
 
 class GCId : public AllStatic {
+private:
   friend class GCIdMark;
-  friend class GCIdMarkAndRestore;
+
   static uint _next_id;
   static const uint UNDEFINED = (uint)-1;
-  static const uint create();
+  static uint create();
 
- public:
+public:
   // Returns the currently active GC id. Asserts that there is an active GC id.
-  static const uint current();
+  static uint current();
   // Same as current() but can return undefined() if no GC id is currently active
-  static const uint current_or_undefined();
+  static uint current_or_undefined();
   // Returns the next expected GCId.
-  static const uint peek();
-  static const uint undefined() { return UNDEFINED; }
+  static uint peek();
+  static uint undefined() { return UNDEFINED; }
   static size_t print_prefix(char* buf, size_t len);
 };
 
 class GCIdMark : public StackObj {
-  uint _gc_id;
- public:
+private:
+  const uint _previous_gc_id;
+
+public:
   GCIdMark();
   GCIdMark(uint gc_id);
   ~GCIdMark();
 };
 
-class GCIdMarkAndRestore : public StackObj {
-  uint _gc_id;
-  uint _previous_gc_id;
- public:
-  GCIdMarkAndRestore();
-  GCIdMarkAndRestore(uint gc_id);
-  ~GCIdMarkAndRestore();
-};
-
 #endif // SHARE_VM_GC_SHARED_GCID_HPP