/*

 * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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_GC_G1_G1COLLECTIONSETCHOOSER_HPP

#define SHARE_GC_G1_G1COLLECTIONSETCHOOSER_HPP

#include "gc/g1/heapRegion.hpp"

#include "memory/allocation.hpp"

#include "runtime/globals.hpp"

class G1CollectionSetCandidates;

class WorkGang;

// Helper class to calculate collection set candidates, and containing some related

// methods.

class G1CollectionSetChooser : public AllStatic {

  static uint calculate_work_chunk_size(uint num_workers, uint num_regions);

public:

  static size_t mixed_gc_live_threshold_bytes() {

    return HeapRegion::GrainBytes * (size_t) G1MixedGCLiveThresholdPercent / 100;

  }

  static bool region_occupancy_low_enough_for_evac(size_t live_bytes) {

    return live_bytes < mixed_gc_live_threshold_bytes();

  }

  // Determine whether to add the given region to the collection set candidates or

  // not. Currently, we skip pinned regions and regions whose live

  // bytes are over the threshold. Humongous regions may be reclaimed during cleanup.

  // Regions also need a complete remembered set to be a candidate.

  static bool should_add(HeapRegion* hr);

  // Build and return set of collection set candidates sorted by decreasing gc

  // efficiency.

  static G1CollectionSetCandidates* build(WorkGang* workers, uint max_num_regions);

};

#endif // SHARE_GC_G1_G1COLLECTIONSETCHOOSER_HPP