--- old/src/hotspot/share/gc/shared/taskqueue.hpp	2018-11-26 21:29:48.045240918 +0100
+++ new/src/hotspot/share/gc/shared/taskqueue.hpp	2018-11-26 21:29:47.892242267 +0100
@@ -448,7 +448,7 @@
 #undef TRACESPINNING
 
 class ParallelTaskTerminator: public StackObj {
-private:
+protected:
   uint _n_threads;
   TaskQueueSetSuper* _queue_set;
   volatile uint _offered_termination;
@@ -481,7 +481,7 @@
   // As above, but it also terminates if the should_exit_termination()
   // method of the terminator parameter returns true. If terminator is
   // NULL, then it is ignored.
-  bool offer_termination(TerminatorTerminator* terminator);
+  virtual bool offer_termination(TerminatorTerminator* terminator);
 
   // Reset the terminator, so that it may be reused again.
   // The caller is responsible for ensuring that this is done