--- old/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	2020-08-05 21:29:25.825604296 +0800
+++ new/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	2020-08-05 21:29:25.521604285 +0800
@@ -2300,6 +2300,30 @@
   heap_region_iterate(&blk);
 }
 
+class G1ParallelObjectIterator : public ParallelObjectIterator {
+private:
+  G1CollectedHeap*  _heap;
+  HeapRegionClaimer _claimer;
+
+public:
+  G1ParallelObjectIterator(uint thread_num) :
+      _heap(G1CollectedHeap::heap()),
+      _claimer(thread_num == 0 ? G1CollectedHeap::heap()->workers()->active_workers() : thread_num) {}
+
+  virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
+    _heap->object_iterate_parallel(cl, worker_id, &_claimer);
+  }
+};
+
+ParallelObjectIterator* G1CollectedHeap::parallel_object_iterator(uint thread_num) {
+  return new G1ParallelObjectIterator(thread_num);
+}
+
+void G1CollectedHeap::object_iterate_parallel(ObjectClosure* cl, uint worker_id, HeapRegionClaimer* claimer) {
+  IterateObjectClosureRegionClosure blk(cl);
+  heap_region_par_iterate_from_worker_offset(&blk, claimer, worker_id);
+}
+
 void G1CollectedHeap::keep_alive(oop obj) {
   G1BarrierSet::enqueue(obj);
 }
@@ -4919,27 +4943,3 @@
 GrowableArray<MemoryPool*> G1CollectedHeap::memory_pools() {
   return _g1mm->memory_pools();
 }
-
-class G1ParallelObjectIterator : public ParallelObjectIterator {
-private:
-  G1CollectedHeap*  _heap;
-  HeapRegionClaimer _claimer;
-
-public:
-  G1ParallelObjectIterator(uint thread_num) :
-      _heap(G1CollectedHeap::heap()),
-      _claimer(thread_num == 0 ? G1CollectedHeap::heap()->workers()->active_workers() : thread_num) {}
-
-  virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
-    _heap->object_iterate_parallel(cl, worker_id, &_claimer);
-  }
-};
-
-ParallelObjectIterator* G1CollectedHeap::parallel_object_iterator(uint thread_num) {
-  return new G1ParallelObjectIterator(thread_num);
-}
-
-void G1CollectedHeap::object_iterate_parallel(ObjectClosure* cl, uint worker_id, HeapRegionClaimer* claimer) {
-  IterateObjectClosureRegionClosure blk(cl);
-  heap_region_par_iterate_from_worker_offset(&blk, claimer, worker_id);
-}