--- /dev/null	2019-01-28 17:45:51.000000000 +0800
+++ new/src/share/vm/jfr/leakprofiler/chains/edge.cpp	2019-01-28 17:45:51.000000000 +0800
@@ -0,0 +1,64 @@
+/*
+ * 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.
+ *
+ */
+#include "precompiled.hpp"
+#include "jfr/leakprofiler/chains/edge.hpp"
+#include "jfr/leakprofiler/utilities/unifiedOop.hpp"
+
+Edge::Edge() : _parent(NULL), _reference(NULL) {}
+
+Edge::Edge(const Edge* parent, const oop* reference) : _parent(parent),
+                                                       _reference(reference) {}
+
+const oop Edge::pointee() const {
+  return UnifiedOop::dereference(_reference);
+}
+
+const oop Edge::reference_owner() const {
+  return is_root() ? (oop)NULL : UnifiedOop::dereference(_parent->reference());
+}
+
+static const Klass* resolve_klass(const oop obj) {
+  assert(obj != NULL, "invariant");
+  return java_lang_Class::is_instance(obj) ?
+    java_lang_Class::as_Klass(obj) : obj->klass();
+}
+
+const Klass* Edge::pointee_klass() const {
+  return resolve_klass(pointee());
+}
+
+const Klass* Edge::reference_owner_klass() const {
+  const oop ref_owner = reference_owner();
+  return ref_owner != NULL ? resolve_klass(ref_owner) : NULL;
+}
+
+size_t Edge::distance_to_root() const {
+  size_t depth = 0;
+  const Edge* current = _parent;
+  while (current != NULL) {
+    depth++;
+    current = current->parent();
+  }
+  return depth;
+}