/*

 * Copyright (c) 1997, 2012, 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.

 *

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 */

#ifndef SHARE_VM_OOPS_INSTANCEOOP_HPP

#define SHARE_VM_OOPS_INSTANCEOOP_HPP

#include "oops/oop.hpp"

// An instanceOop is an instance of a Java Class

// Evaluating "new HashTable()" will create an instanceOop.

class instanceOopDesc : public oopDesc {

 public:

  // aligned header size.

  static int header_size() { return sizeof(instanceOopDesc)/HeapWordSize; }

  // If compressed, the offset of the fields of the instance may not be aligned.

  static int base_offset_in_bytes() {

    // offset computation code breaks if UseCompressedKlassPointers

    // only is true

    return (UseCompressedOops && UseCompressedKlassPointers) ?

             klass_gap_offset_in_bytes() :

             sizeof(instanceOopDesc);

  }

  static bool contains_field_offset(int offset, int nonstatic_field_size) {

    int base_in_bytes = base_offset_in_bytes();

    return (offset >= base_in_bytes &&

            (offset-base_in_bytes) < nonstatic_field_size * heapOopSize);

  }

};

#endif // SHARE_VM_OOPS_INSTANCEOOP_HPP