/*

 * Copyright (c) 2012, 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_MEMORY_METASPACE_METABASE_HPP

#define SHARE_MEMORY_METASPACE_METABASE_HPP

#include "utilities/globalDefinitions.hpp"

namespace metaspace {

// Super class of Metablock and Metachunk to allow them to

// be put on the FreeList and in the BinaryTreeDictionary.

template <class T>

class Metabase {

  size_t _word_size;

  T*     _next;

  T*     _prev;

 protected:

  Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {}

 public:

  T* next() const         { return _next; }

  T* prev() const         { return _prev; }

  void set_next(T* v)     { _next = v; assert(v != this, "Boom");}

  void set_prev(T* v)     { _prev = v; assert(v != this, "Boom");}

  void clear_next()       { set_next(NULL); }

  void clear_prev()       { set_prev(NULL); }

  size_t size() const volatile { return _word_size; }

  void set_size(size_t v) { _word_size = v; }

  void link_next(T* ptr)  { set_next(ptr); }

  void link_prev(T* ptr)  { set_prev(ptr); }

  void link_after(T* ptr) {

    link_next(ptr);

    if (ptr != NULL) ptr->link_prev((T*)this);

  }

  uintptr_t* end() const        { return ((uintptr_t*) this) + size(); }

  bool cantCoalesce() const     { return false; }

  // Debug support

#ifdef ASSERT

  void* prev_addr() const { return (void*)&_prev; }

  void* next_addr() const { return (void*)&_next; }

  void* size_addr() const { return (void*)&_word_size; }

#endif

  bool verify_chunk_in_free_list(T* tc) const { return true; }

  bool verify_par_locked() { return true; }

  void assert_is_mangled() const {/* Don't check "\*/}

  bool is_free()                 { return true; }

};

} // namespace metaspace

#endif // SHARE_MEMORY_METASPACE_METABASE_HPP