diff --git a/src/hotspot/share/gc/z/zNMethodBarrier.hpp b/src/hotspot/share/gc/z/zNMethodBarrier.hpp
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+++ b/src/hotspot/share/gc/z/zNMethodBarrier.hpp
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+/*
+ * Copyright (c) 2018, 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_GC_Z_ZNMETHODBARRIER_HPP
+#define SHARE_GC_Z_ZNMETHODBARRIER_HPP
+
+#include "code/nmethodBarrier.hpp"
+#include "memory/allocation.hpp"
+
+class nmethod;
+
+class ZNMethodBarrier: AllStatic {
+
+  static void load_barrier(nmethod* nm);
+
+  static bool nmethod_barrier(nmethod* nm, nmethodBarrier* nmbarrier);
+  static bool osr_nmethod_barrier(nmethod* nm);
+
+  static bool enter(nmethod* nm, nmethodBarrier* barrier);
+  static void leave(nmethod* nm, nmethodBarrier* barrier);
+
+public:
+  static void cleanup_nmethod(nmethod* nm, bool unloading_occrred);
+  static void cleanup_nmethod_caches(nmethod* nm, bool unloading_occurred) {
+    if (enter(nm, NULL)) {
+      cleanup_nmethod(nm, unloading_occurred);
+      leave(nm, NULL);
+    }
+  }
+  static bool phantom_load(nmethod* nm, nmethodBarrier* barrier);
+  static bool on_nmethod_entry_barrier(nmethod* nm, nmethodBarrier* nmbarrier);
+};
+
+#endif // SHARE_Z_ZNMETHODBARRIER_HPP