/*

 * Copyright (c) 2011, 2013, 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_INSTANCEMIRRORKLASS_HPP

#define SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP

#include "classfile/systemDictionary.hpp"

#include "memory/specialized_oop_closures.hpp"

#include "oops/instanceKlass.hpp"

#include "runtime/handles.hpp"

#include "utilities/macros.hpp"

// An InstanceMirrorKlass is a specialized InstanceKlass for

// java.lang.Class instances.  These instances are special because

// they contain the static fields of the class in addition to the

// normal fields of Class.  This means they are variable sized

// instances and need special logic for computing their size and for

// iteration of their oops.

class InstanceMirrorKlass: public InstanceKlass {

  friend class VMStructs;

  friend class InstanceKlass;

 private:

  static int _offset_of_static_fields;

  // Constructor

  InstanceMirrorKlass(int vtable_len, int itable_len, int static_field_size, int nonstatic_oop_map_size, ReferenceType rt, AccessFlags access_flags,  bool is_anonymous)

    : InstanceKlass(vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt, access_flags, is_anonymous) {}

 public:

  InstanceMirrorKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }

  // Type testing

  bool oop_is_instanceMirror() const             { return true; }

  // Casting from Klass*

  static InstanceMirrorKlass* cast(Klass* k) {

    assert(k->oop_is_instanceMirror(), "cast to InstanceMirrorKlass");

    return (InstanceMirrorKlass*) k;

  }

  // Returns the size of the instance including the extra static fields.

  virtual int oop_size(oop obj) const;

  // Static field offset is an offset into the Heap, should be converted by

  // based on UseCompressedOop for traversal

  static HeapWord* start_of_static_fields(oop obj) {

    return (HeapWord*)(cast_from_oop<intptr_t>(obj) + offset_of_static_fields());

  }

  static void init_offset_of_static_fields() {

    // Cache the offset of the static fields in the Class instance

    assert(_offset_of_static_fields == 0, "once");

    _offset_of_static_fields = InstanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize;

  }

  static int offset_of_static_fields() {

    return _offset_of_static_fields;

  }

  int compute_static_oop_field_count(oop obj);

  // Given a Klass return the size of the instance

  int instance_size(KlassHandle k);

  // allocation

  instanceOop allocate_instance(KlassHandle k, TRAPS);

#define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)           \

  int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);                       \

  int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);

  ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL)

#if INCLUDE_ALL_GCS

#define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \

  int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);

  ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)

#endif // INCLUDE_ALL_GCS

};

#endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP