--- old/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp	2020-04-25 20:53:34.603330956 +0800
+++ new/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp	2020-04-25 20:53:34.423331507 +0800
@@ -616,6 +616,10 @@
   void ensure_parsability(bool retire_tlabs);
   void make_parsable(bool retire_tlabs);
 
+  // Runs the given AbstractGangTask with the current active workers, returning the
+  // total time taken.
+  virtual Tickspan run_task(AbstractGangTask* task);
+
 // ---------- Marking support
 //
 private: