/*

 * Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP

#define SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP

#include "memory/allocation.hpp"

#include "gc/shenandoah/shenandoahHeap.hpp"

#include "gc/shenandoah/shenandoahHeapRegion.hpp"

class ShenandoahCollectionSet : public CHeapObj<mtGC> {

  friend class ShenandoahHeap;

private:

  size_t const          _map_size;

  size_t const          _region_size_bytes_shift;

  jbyte* const          _cset_map;

  // Bias cset map's base address for fast test if an oop is in cset

  jbyte* const          _biased_cset_map;

  ShenandoahHeap* const _heap;

  size_t                _garbage;

  size_t                _live_data;

  size_t                _used;

  size_t                _region_count;

  DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));

  volatile jint         _current_index;

  DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);

public:

  ShenandoahCollectionSet(ShenandoahHeap* heap, HeapWord* heap_base);

  // Add region to collection set

  void add_region(ShenandoahHeapRegion* r);

  bool add_region_check_for_duplicates(ShenandoahHeapRegion* r);

  // Bring per-region statuses to consistency with this collection.

  // TODO: This is a transitional interface that bridges the gap between

  // region statuses and this collection. Should go away after we merge them.

  void update_region_status();

  // Remove region from collection set

  void remove_region(ShenandoahHeapRegion* r);

  // MT version

  ShenandoahHeapRegion* claim_next();

  // Single-thread version

  ShenandoahHeapRegion* next();

  size_t count()  const { return _region_count; }

  bool is_empty() const { return _region_count == 0; }

  void clear_current_index() {

    _current_index = 0;

  }

  inline bool is_in(ShenandoahHeapRegion* r) const;

  inline bool is_in(size_t region_number)    const;

  inline bool is_in(HeapWord* p)             const;

  void print_on(outputStream* out) const;

  size_t used()      const { return _used; }

  size_t live_data() const { return _live_data; }

  size_t garbage()   const { return _garbage;   }

  void clear();

private:

  jbyte* biased_map_address() const {

    return _biased_cset_map;

  }

};

#endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP