--- /dev/null	2019-10-01 11:37:31.106015611 +0200
+++ new/src/hotspot/os/windows/gc/z/zBackingFile_windows.hpp	2019-10-31 09:39:42.133000256 +0100
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 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.
+ */
+
+#ifndef OS_WINDOWS_GC_Z_ZBACKINGFILE_WINDOWS_HPP
+#define OS_WINDOWS_GC_Z_ZBACKINGFILE_WINDOWS_HPP
+
+#include "gc/z/zGranuleMap.hpp"
+#include "memory/allocation.hpp"
+
+#include <Windows.h>
+
+class ZBackingFile {
+private:
+  ZGranuleMap<HANDLE> _handles;
+  size_t              _size;
+
+  HANDLE get_handle(uintptr_t offset) const;
+  void put_handle(uintptr_t offset, HANDLE handle);
+  void clear_handle(uintptr_t offset);
+
+  size_t commit_from_paging_file(size_t offset, size_t size);
+  size_t uncommit_from_paging_file(size_t offset, size_t size);
+
+public:
+  ZBackingFile();
+
+  size_t size() const;
+
+  size_t commit(size_t offset, size_t length);
+  size_t uncommit(size_t offset, size_t length);
+
+  void map(uintptr_t addr, size_t size, size_t offset) const;
+  void unmap(uintptr_t addr, size_t size) const;
+};
+
+#endif // OS_WINDOWS_GC_Z_ZBACKINGFILE_WINDOWS_HPP