/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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_GC_G1_G1HEAPSIZINGPOLICY_HPP
#define SHARE_VM_GC_G1_G1HEAPSIZINGPOLICY_HPP

#include "memory/allocation.hpp"

class G1Analytics;
class G1CollectedHeap;

class G1HeapSizingPolicy: public CHeapObj<mtGC> {
  // MinOverThresholdForGrowth must be less than the number of recorded
  // pause times in G1Analytics, representing the minimum number of pause
  // time ratios that exceed GCTimeRatio before a heap expansion will be triggered.
  const static uint MinOverThresholdForGrowth = 4;

  const G1CollectedHeap* _g1;
  const G1Analytics* _analytics;

  const uint _num_prev_pauses_for_heuristics;
  // Ratio check data for determining if heap growth is necessary.
  uint _ratio_over_threshold_count;
  double _ratio_over_threshold_sum;
  uint _pauses_since_start;


protected:
  G1HeapSizingPolicy(const G1CollectedHeap* g1, const G1Analytics* analytics) :
      _g1(g1),
      _analytics(analytics),
      _num_prev_pauses_for_heuristics(analytics->number_of_recorded_pause_times()) {
    clear_ratio_check_data();
  }
public:

  // If an expansion would be appropriate, because recent GC overhead had
  // exceeded the desired limit, return an amount to expand by.
  virtual size_t expansion_amount();

  // Clear ratio tracking data used by expansion_amount().
  void clear_ratio_check_data();

  static G1HeapSizingPolicy* create(const G1CollectedHeap* g1, const G1Analytics* analytics);
};

#endif // SRC_SHARE_VM_GC_G1_G1HEAPSIZINGPOLICY_HPP