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 * 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_INSTANCEREFKLASS_HPP

#define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP

#include "gc/shared/specialized_oop_closures.hpp"

#include "oops/instanceKlass.hpp"

#include "utilities/macros.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 {

  friend class InstanceKlass;

  // Constructor

  InstanceRefKlass(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:

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

  // Type testing

  bool oop_is_instanceRef() const             { return true; }

  // Casting from Klass*

  static InstanceRefKlass* cast(Klass* k) {

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

    return (InstanceRefKlass*) k;

  }

  // GC specific object visitors

  //

  // Mark Sweep

  void oop_ms_follow_contents(oop obj);

  int  oop_ms_adjust_pointers(oop obj);

#if INCLUDE_ALL_GCS

  // Parallel Scavenge

  void oop_ps_push_contents(  oop obj, PSPromotionManager* pm);

  // Parallel Compact

  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);

  void oop_pc_update_pointers(oop obj);

#endif

  // Oop fields (and metadata) iterators

  //  [nv = true]  Use non-virtual calls to do_oop_nv.

  //  [nv = false] Use virtual calls to do_oop.

  //

  // The InstanceRefKlass iterators also support reference processing.

  // Forward iteration

private:

  // Iterate over all oop fields and metadata.

  template <bool nv, class OopClosureType>

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

  // Reverse iteration

#if INCLUDE_ALL_GCS

  // Iterate over all oop fields and metadata.

  template <bool nv, class OopClosureType>

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

#endif // INCLUDE_ALL_GCS

  // Bounded range iteration

  // Iterate over all oop fields and metadata.

  template <bool nv, class OopClosureType>

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

  // Reference processing part of the iterators.

  // Specialized for [T = oop] or [T = narrowOop].

  template <bool nv, typename T, class OopClosureType, class Contains>

  inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains);

  // Only perform reference processing if the referent object is within mr.

  template <bool nv, class OopClosureType>

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

  // Reference processing

  template <bool nv, class OopClosureType>

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

 public:

#if INCLUDE_ALL_GCS

#endif // INCLUDE_ALL_GCS

  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(Klass* k);

 public:

  // Verification

  void oop_verify_on(oop obj, outputStream* st);

};

#endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP