--- /dev/null	2019-01-28 17:45:50.000000000 +0800
+++ new/src/share/vm/jfr/leakprofiler/chains/dfsClosure.hpp	2019-01-28 17:45:50.000000000 +0800
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_LEAKPROFILER_CHAINS_DFSCLOSURE_HPP
+#define SHARE_VM_JFR_LEAKPROFILER_CHAINS_DFSCLOSURE_HPP
+
+#include "memory/iterator.hpp"
+#include "oops/oop.hpp"
+
+class BitSet;
+class Edge;
+class EdgeStore;
+class EdgeQueue;
+
+// Class responsible for iterating the heap depth-first
+class DFSClosure: public ExtendedOopClosure {
+ private:
+  static EdgeStore* _edge_store;
+  static BitSet*    _mark_bits;
+  static const Edge*_start_edge;
+  static size_t _max_depth;
+  static bool _ignore_root_set;
+  DFSClosure* _parent;
+  const oop* _reference;
+  size_t _depth;
+
+  void add_chain();
+  void closure_impl(const oop* reference, const oop pointee);
+
+  DFSClosure* parent() const { return _parent; }
+  const oop* reference() const { return _reference; }
+
+  DFSClosure(DFSClosure* parent, size_t depth);
+  DFSClosure();
+
+ public:
+  static void find_leaks_from_edge(EdgeStore* edge_store, BitSet* mark_bits, const Edge* start_edge);
+  static void find_leaks_from_root_set(EdgeStore* edge_store, BitSet* mark_bits);
+
+  virtual void do_oop(oop* ref);
+  virtual void do_oop(narrowOop* ref);
+};
+
+#endif // SHARE_VM_JFR_LEAKPROFILER_CHAINS_DFSCLOSURE_HPP