--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zDriver.hpp	2018-06-01 22:30:29.801414351 +0200
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2015, 2017, 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_ZDRIVER_HPP
+#define SHARE_GC_Z_ZDRIVER_HPP
+
+#include "gc/shared/concurrentGCThread.hpp"
+#include "gc/shared/gcCause.hpp"
+#include "gc/z/zMessagePort.hpp"
+
+class ZOperationClosure;
+
+class ZDriver : public ConcurrentGCThread {
+private:
+  ZMessagePort<GCCause::Cause> _gc_cycle_port;
+  ZRendezvousPort              _gc_locker_port;
+
+  bool vm_operation(ZOperationClosure* cl);
+
+  GCCause::Cause start_gc_cycle();
+  void run_gc_cycle(GCCause::Cause cause);
+  void end_gc_cycle();
+
+protected:
+  virtual void run_service();
+  virtual void stop_service();
+
+public:
+  ZDriver();
+
+  void collect(GCCause::Cause cause);
+};
+
+#endif // SHARE_GC_Z_ZDRIVER_HPP