--- old/src/hotspot/share/gc/z/zHeap.cpp	2020-04-25 22:41:18.593497934 +0800
+++ new/src/hotspot/share/gc/z/zHeap.cpp	2020-04-25 22:41:18.421498701 +0800
@@ -35,6 +35,7 @@
 #include "gc/z/zResurrection.hpp"
 #include "gc/z/zStat.hpp"
 #include "gc/z/zThread.inline.hpp"
+#include "gc/z/zTask.hpp"
 #include "gc/z/zVerify.hpp"
 #include "gc/z/zWorkers.inline.hpp"
 #include "logging/log.hpp"
@@ -45,6 +46,7 @@
 #include "runtime/thread.hpp"
 #include "utilities/debug.hpp"
 
+class ZTask;
 static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes);
 static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes);
 static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes);
@@ -206,6 +208,28 @@
   _workers.print_threads_on(st);
 }
 
+// A delegate class for AbstractGangTask to Ztask.
+class DelegatedZAbstractGangTask : public ZTask {
+ private:
+  AbstractGangTask* _task;
+
+ public:
+  DelegatedZAbstractGangTask(AbstractGangTask* task) :
+      ZTask(task->name()),
+      _task(task) { }
+
+  virtual void work() {
+    _task->work(ZThread::worker_id());
+  }
+};
+
+Tickspan ZHeap::run_task(AbstractGangTask* task) {
+  Ticks start = Ticks::now();
+  DelegatedZAbstractGangTask dtask(task);
+  _workers.run_parallel(&dtask);
+  return Ticks::now() - start;
+}
+
 void ZHeap::out_of_memory() {
   ResourceMark rm;