/*

 * Copyright (c) 1997, 2010, 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_VM_OOPS_INSTANCEREFKLASS_HPP

#define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP

#include "oops/instanceKlass.hpp"

// An instanceRefKlass is a specialized instanceKlass for Java

// classes that are subclasses of java/lang/ref/Reference.

//

// These classes are used to implement soft/weak/final/phantom

// references and finalization, and need special treatment by the

// garbage collector.

//

// During GC discovered reference objects are added (chained) to one

// of the four lists below, depending on the type of reference.

// The linked occurs through the next field in class java/lang/ref/Reference.

//

// Afterwards, the discovered references are processed in decreasing

// order of reachability. Reference objects eligible for notification

// are linked to the static pending_list in class java/lang/ref/Reference,

// and the pending list lock object in the same class is notified.

class instanceRefKlass: public instanceKlass {

 public:

  // Type testing

  bool oop_is_instanceRef() const             { return true; }

  // Casting from klassOop

  static instanceRefKlass* cast(klassOop k) {

    assert(k->klass_part()->oop_is_instanceRef(), "cast to instanceRefKlass");

    return (instanceRefKlass*) k->klass_part();

  }

  // allocation

  DEFINE_ALLOCATE_PERMANENT(instanceRefKlass);

  // Garbage collection

  int  oop_adjust_pointers(oop obj);

  void oop_follow_contents(oop obj);

  // Parallel Scavenge and Parallel Old

  PARALLEL_GC_DECLS

  int oop_oop_iterate(oop obj, OopClosure* blk) {

    return oop_oop_iterate_v(obj, blk);

  }

  int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {

    return oop_oop_iterate_v_m(obj, blk, mr);

  }

#define InstanceRefKlass_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(InstanceRefKlass_OOP_OOP_ITERATE_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL)

#ifndef SERIALGC

#define InstanceRefKlass_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(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)

#endif // !SERIALGC

  static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);

  static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);

  static bool owns_pending_list_lock(JavaThread* thread);

  // Update non-static oop maps so 'referent', 'nextPending' and

  // 'discovered' will look like non-oops

  static void update_nonstatic_oop_maps(klassOop k);

 public:

  // Verification

  void oop_verify_on(oop obj, outputStream* st);

};

#endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP