--- /dev/null	2019-02-14 11:31:37.500399000 +0100
+++ new/src/hotspot/share/gc/z/zNMethodData.hpp	2019-02-21 09:29:27.971032105 +0100
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2017, 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 "gc/z/zLock.hpp"
+#include "oops/oopsHierarchy.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class nmethod;
+template <typename T> class GrowableArray;
+
+class ZNMethodDataOops {
+private:
+  const size_t _nimmediates;
+  bool         _has_non_immediates;
+
+  static size_t header_size();
+
+  ZNMethodDataOops(const GrowableArray<oop*>& immediates, bool has_non_immediates);
+
+public:
+  static ZNMethodDataOops* create(const GrowableArray<oop*>& immediates, bool has_non_immediates);
+  static void destroy(ZNMethodDataOops* oops);
+
+  size_t immediates_count() const;
+  oop**  immediates_begin() const;
+  oop**  immediates_end()   const;
+
+  bool   has_non_immediates() const;
+};
+
+class ZNMethodData {
+private:
+  ZReentrantLock             _lock;
+  ZNMethodDataOops* volatile _oops;
+
+  ZNMethodData(nmethod* nm);
+
+public:
+  static ZNMethodData* create(nmethod* nm);
+  static void destroy(ZNMethodData* data);
+
+  ZReentrantLock* lock();
+
+  ZNMethodDataOops* oops() const;
+  ZNMethodDataOops* swap_oops(ZNMethodDataOops* oops);
+};