--- old/src/hotspot/share/gc/serial/serialHeap.hpp	2020-08-11 22:49:21.319960237 +0800
+++ new/src/hotspot/share/gc/serial/serialHeap.hpp	2020-08-11 22:49:21.139960814 +0800
@@ -75,6 +75,10 @@
   template <typename OopClosureType1, typename OopClosureType2>
   void oop_since_save_marks_iterate(OopClosureType1* cur,
                                     OopClosureType2* older);
+
+  // Runs the given AbstractGangTask with the current active workers.
+  // No workGang for SerialHeap, work serially with thread 0.
+  virtual void run_task(AbstractGangTask* task);
 };
 
 #endif // SHARE_GC_SERIAL_SERIALHEAP_HPP