--- /dev/null	2017-11-09 09:38:01.297999907 +0100
+++ new/src/hotspot/share/jfr/writers/jfrStorageHost.hpp	2018-04-09 15:30:23.724725590 +0200
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2016, 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_VM_JFR_WRITERS_JFRSTORAGEHOST_HPP
+#define SHARE_VM_JFR_WRITERS_JFRSTORAGEHOST_HPP
+
+#include "jfr/writers/jfrPosition.inline.hpp"
+
+template <typename Adapter, typename AP> // Adapter and AllocationPolicy
+class StorageHost : public Position<AP> {
+ public:
+  typedef typename Adapter::StorageType StorageType;
+ private:
+  Adapter _adapter;
+
+ protected:
+  void bind();
+  void soft_reset();
+  void hard_reset();
+  void cancel();
+  bool is_backed();
+  bool accommodate(size_t used, size_t requested);
+  void commit();
+  void release();
+  StorageHost(StorageType* storage, Thread* thread);
+  StorageHost(StorageType* storage, size_t size);
+  StorageHost(Thread* thread);
+
+ public:
+  StorageType* storage();
+  bool is_valid() const;
+  void set_storage(StorageType* storage);
+  void flush();
+  void seek(intptr_t offset);
+};
+
+#endif // SHARE_VM_JFR_WRITERS_JFRSTORAGEHOST_HPP
+