--- /dev/null	2019-01-28 17:45:54.000000000 +0800
+++ new/src/share/vm/jfr/leakprofiler/chains/edgeQueue.hpp	2019-01-28 17:45:54.000000000 +0800
@@ -0,0 +1,60 @@
+/*
+ * 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_EDGEQUEUE_HPP
+#define SHARE_VM_JFR_LEAKPROFILER_CHAINS_EDGEQUEUE_HPP
+
+#include "memory/allocation.hpp"
+#include "jfr/leakprofiler/chains/edge.hpp"
+
+class JfrVirtualMemory;
+
+class EdgeQueue : public CHeapObj<mtTracing> {
+ private:
+  JfrVirtualMemory* _vmm;
+  const size_t _reservation_size_bytes;
+  const size_t _commit_block_size_bytes;
+  mutable size_t _top_index;
+  mutable size_t _bottom_index;
+ public:
+  EdgeQueue(size_t reservation_size_bytes, size_t commit_block_size_bytes);
+  ~EdgeQueue();
+
+  bool initialize();
+
+  void add(const Edge* parent, const oop* ref);
+  const Edge* remove() const;
+  const Edge* element_at(size_t index) const;
+
+  size_t top() const;
+  size_t bottom() const;
+  bool is_empty() const;
+  bool is_full() const;
+
+  size_t reserved_size() const;
+  size_t live_set() const;
+  size_t sizeof_edge() const; // with alignments
+};
+
+#endif // SHARE_VM_JFR_LEAKPROFILER_CHAINS_EDGEQUEUE_HPP