/*

 * Copyright (c) 2011, 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

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 */

#ifndef SHARE_OOPS_INSTANCEMIRRORKLASS_HPP

#define SHARE_OOPS_INSTANCEMIRRORKLASS_HPP

#include "classfile/systemDictionary.hpp"

#include "oops/instanceKlass.hpp"

#include "runtime/handles.hpp"

#include "utilities/macros.hpp"

class ClassFileParser;

// 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;

 public:

  static const KlassID ID = InstanceMirrorKlassID;

 private:

  static int _offset_of_static_fields;

  InstanceMirrorKlass(const ClassFileParser& parser) : InstanceKlass(parser, InstanceKlass::_misc_kind_mirror, ID) {}

 public:

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

  // Casting from Klass*

  static InstanceMirrorKlass* cast(Klass* k) {

    assert(InstanceKlass::cast(k)->is_mirror_instance_klass(),

           "cast to InstanceMirrorKlass");

    return static_cast<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(Klass* k);

  // allocation

  instanceOop allocate_instance(Klass* k, TRAPS);

  static void serialize_offsets(class SerializeClosure* f) NOT_CDS_RETURN;

  // Oop fields (and metadata) iterators

  //

  // The InstanceMirrorKlass iterators also visit the hidden Klass pointer.

  // Iterate over the static fields.

  template <typename T, class OopClosureType>

  inline void oop_oop_iterate_statics(oop obj, OopClosureType* closure);

  // Forward iteration

  // Iterate over the oop fields and metadata.

  template <typename T, class OopClosureType>

  inline void oop_oop_iterate(oop obj, OopClosureType* closure);

  // Reverse iteration

  // Iterate over the oop fields and metadata.

  template <typename T, class OopClosureType>

  inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);

  // Bounded range iteration

  // Iterate over the oop fields and metadata.

  template <typename T, class OopClosureType>

  inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);

 private:

  // Iterate over the static fields.

  template <typename T, class OopClosureType>

  inline void oop_oop_iterate_statics_bounded(oop obj, OopClosureType* closure, MemRegion mr);

};

#endif // SHARE_OOPS_INSTANCEMIRRORKLASS_HPP