/*

 * Copyright (c) 2015, 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_GC_Z_ZREFERENCEPROCESSOR_HPP

#define SHARE_GC_Z_ZREFERENCEPROCESSOR_HPP

#include "gc/shared/referenceDiscoverer.hpp"

#include "gc/z/zValue.hpp"

class ReferencePolicy;

class ZWorkers;

class ZReferenceProcessor : public ReferenceDiscoverer {

  friend class ZReferenceProcessorTask;

private:

  static const size_t reference_type_count = REF_PHANTOM + 1;

  typedef size_t Counters[reference_type_count];

  ZWorkers* const      _workers;

  ReferencePolicy*     _soft_reference_policy;

  ZPerWorker<Counters> _encountered_count;

  ZPerWorker<Counters> _discovered_count;

  ZPerWorker<Counters> _enqueued_count;

  ZPerWorker<oop>      _discovered_list;

  ZContended<oop>      _pending_list;

  oop*                 _pending_list_tail;

  bool is_inactive(oop reference, oop referent, ReferenceType type) const;

  bool is_strongly_live(oop referent) const;

  bool is_softly_live(oop reference, ReferenceType type) const;

  bool should_discover(oop reference, ReferenceType type) const;

  bool should_drop(oop reference, ReferenceType type) const;

  void keep_alive(oop reference, ReferenceType type) const;

  void make_inactive(oop reference, ReferenceType type) const;

  void discover(oop reference, ReferenceType type);

  oop drop(oop reference, ReferenceType type);

  oop* keep(oop reference, ReferenceType type);

  bool is_empty() const;

  void work();

  void collect_statistics();

public:

  ZReferenceProcessor(ZWorkers* workers);

  void set_soft_reference_policy(bool clear);

  void reset_statistics();

  virtual bool discover_reference(oop reference, ReferenceType type);

  void process_references();

  void enqueue_references();

};

#endif // SHARE_GC_Z_ZREFERENCEPROCESSOR_HPP