/*

 * Copyright (c) 2015, 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 SHARE_GC_Z_ZFORWARDING_HPP

#define SHARE_GC_Z_ZFORWARDING_HPP

#include "gc/z/zForwardingEntry.hpp"

#include "gc/z/zVirtualMemory.hpp"

class ZPage;

typedef uint32_t ZForwardingCursor;

class ZForwarding {

  friend class VMStructs;

  friend class ZForwardingTest;

private:

  const ZVirtualMemory _virtual;

  const size_t         _object_alignment_shift;

  const uint32_t       _nentries;

  ZPage*               _page;

  volatile uint32_t    _refcount;

  volatile bool        _pinned;

  bool inc_refcount();

  bool dec_refcount();

  ZForwardingEntry* entries() const;

  ZForwardingEntry at(ZForwardingCursor* cursor) const;

  ZForwardingEntry first(uintptr_t from_index, ZForwardingCursor* cursor) const;

  ZForwardingEntry next(ZForwardingCursor* cursor) const;

  ZForwarding(ZPage* page, uint32_t nentries);

public:

  static ZForwarding* create(ZPage* page);

  static void destroy(ZForwarding* forwarding);

  uintptr_t start() const;

  size_t size() const;

  size_t object_alignment_shift() const;

  ZPage* page() const;

  bool is_pinned() const;

  void set_pinned();

  bool retain_page();

  void release_page();

  ZForwardingEntry find(uintptr_t from_index) const;

  ZForwardingEntry find(uintptr_t from_index, ZForwardingCursor* cursor) const;

  uintptr_t insert(uintptr_t from_index, uintptr_t to_offset, ZForwardingCursor* cursor);

  void verify() const;

};

#endif // SHARE_GC_Z_ZFORWARDING_HPP