--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zMarkTerminate.hpp	2018-06-08 19:46:19.477689479 +0200
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017, 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_ZMARKTERMINATE_HPP
+#define SHARE_GC_Z_ZMARKTERMINATE_HPP
+
+#include "gc/z/zGlobals.hpp"
+#include "memory/allocation.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class ZMarkTerminate {
+private:
+  uint          _nworkers;
+  volatile uint _nworking_stage0 ATTRIBUTE_ALIGNED(ZCacheLineSize);
+  volatile uint _nworking_stage1;
+
+  bool enter_stage(volatile uint* nworking_stage);
+  void exit_stage(volatile uint* nworking_stage);
+  bool try_exit_stage(volatile uint* nworking_stage);
+
+public:
+  ZMarkTerminate();
+
+  void reset(uint nworkers);
+
+  bool enter_stage0();
+  void exit_stage0();
+  bool try_exit_stage0();
+
+  bool enter_stage1();
+  bool try_exit_stage1();
+};
+
+#endif // SHARE_GC_Z_ZMARKTERMINATE_HPP