/*

 * Copyright (c) 2001, 2012, 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

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

 * questions.

 *

 */

#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP

#define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP

#include "gc_implementation/g1/collectionSetChooser.hpp"

#include "gc_implementation/g1/g1MMUTracker.hpp"

#include "memory/collectorPolicy.hpp"

// A G1CollectorPolicy makes policy decisions that determine the

// characteristics of the collector.  Examples include:

//   * choice of collection set.

//   * when to collect.

class HeapRegion;

class CollectionSetChooser;

public:

};

};

// There are three command line options related to the young gen size:

// NewSize, MaxNewSize and NewRatio (There is also -Xmn, but that is

// just a short form for NewSize==MaxNewSize). G1 will use its internal

// heuristics to calculate the actual young gen size, so these options

// basically only limit the range within which G1 can pick a young gen

// size. Also, these are general options taking byte sizes. G1 will

// internally work with a number of regions instead. So, some rounding

// will occur.

//

// If nothing related to the the young gen size is set on the command

// line we should allow the young gen to be between

// G1DefaultMinNewGenPercent and G1DefaultMaxNewGenPercent of the

// heap size. This means that every time the heap size changes the

// limits for the young gen size will be updated.

//

// If only -XX:NewSize is set we should use the specified value as the

// minimum size for young gen. Still using G1DefaultMaxNewGenPercent

// of the heap as maximum.

//

// If only -XX:MaxNewSize is set we should use the specified value as the

// maximum size for young gen. Still using G1DefaultMinNewGenPercent

// of the heap as minimum.

//

// If -XX:NewSize and -XX:MaxNewSize are both specified we use these values.

// No updates when the heap size changes. There is a special case when

// NewSize==MaxNewSize. This is interpreted as "fixed" and will use a

// different heuristic for calculating the collection set when we do mixed

// collection.

//

// If only -XX:NewRatio is set we should use the specified ratio of the heap

// as both min and max. This will be interpreted as "fixed" just like the

// NewSize==MaxNewSize case above. But we will update the min and max

// everytime the heap size changes.

//

// NewSize and MaxNewSize override NewRatio. So, NewRatio is ignored if it is

// combined with either NewSize or MaxNewSize. (A warning message is printed.)

class G1YoungGenSizer : public CHeapObj {

private:

  enum SizerKind {

    SizerDefaults,

    SizerNewSizeOnly,

    SizerMaxNewSizeOnly,

    SizerMaxAndNewSize,

    SizerNewRatio

  };

  SizerKind _sizer_kind;

  uint _min_desired_young_length;

  uint _max_desired_young_length;

  bool _adaptive_size;

  uint calculate_default_min_length(uint new_number_of_heap_regions);

  uint calculate_default_max_length(uint new_number_of_heap_regions);

public:

  G1YoungGenSizer();

  void heap_size_changed(uint new_number_of_heap_regions);

  uint min_desired_young_length() {

    return _min_desired_young_length;

  }

  uint max_desired_young_length() {

    return _max_desired_young_length;

  }

  bool adaptive_young_list_length() {

    return _adaptive_size;

  }

};

class G1CollectorPolicy: public CollectorPolicy {

private:

  // either equal to the number of parallel threads, if ParallelGCThreads

  // has been set, or 1 otherwise

  int _parallel_gc_threads;

  // The number of GC threads currently active.

  uintx _no_of_gc_threads;

  enum SomePrivateConstants {

    NumPrevPausesForHeuristics = 10

  };

  G1MMUTracker* _mmu_tracker;

  void initialize_flags();

  void initialize_all() {

    initialize_flags();

    initialize_size_info();

    initialize_perm_generation(PermGen::MarkSweepCompact);

  }

  CollectionSetChooser* _collectionSetChooser;

  double _cur_collection_start_sec;

  size_t _cur_collection_pause_used_at_start_bytes;

  uint   _cur_collection_pause_used_regions_at_start;

  double _cur_collection_par_time_ms;

  double _cur_collection_code_root_fixup_time_ms;

  double _cur_clear_ct_time_ms;

  double _cur_ref_proc_time_ms;

  double _cur_ref_enq_time_ms;

#ifndef PRODUCT

  // Card Table Count Cache stats

  double _min_clear_cc_time_ms;         // min

  double _max_clear_cc_time_ms;         // max

  double _cur_clear_cc_time_ms;         // clearing time during current pause

  double _cum_clear_cc_time_ms;         // cummulative clearing time

  jlong  _num_cc_clears;                // number of times the card count cache has been cleared

#endif

  // These exclude marking times.

  TruncatedSeq* _recent_gc_times_ms;

  TruncatedSeq* _concurrent_mark_remark_times_ms;

  TruncatedSeq* _concurrent_mark_cleanup_times_ms;

  double _stop_world_start;

  double* _par_last_gc_worker_start_times_ms;

  double* _par_last_ext_root_scan_times_ms;

  double* _par_last_satb_filtering_times_ms;

  double* _par_last_update_rs_times_ms;

  double* _par_last_update_rs_processed_buffers;

  double* _par_last_scan_rs_times_ms;

  double* _par_last_obj_copy_times_ms;

  double* _par_last_termination_times_ms;

  double* _par_last_termination_attempts;

  double* _par_last_gc_worker_end_times_ms;

  double* _par_last_gc_worker_times_ms;

  // Each workers 'other' time i.e. the elapsed time of the parallel

  // code executed by a worker minus the sum of the individual sub-phase

  // times for that worker thread.

  double* _par_last_gc_worker_other_times_ms;

  // indicates whether we are in young or mixed GC mode

  bool _gcs_are_young;

  uint _young_list_target_length;

  uint _young_list_fixed_length;

  size_t _prev_eden_capacity; // used for logging

  // The max number of regions we can extend the eden by while the GC

  // locker is active. This should be >= _young_list_target_length;

  uint _young_list_max_length;

  bool                  _last_gc_was_young;

  bool                  _during_marking;

  bool                  _in_marking_window;

  bool                  _in_marking_window_im;

  SurvRateGroup*        _short_lived_surv_rate_group;

  SurvRateGroup*        _survivor_surv_rate_group;

  // add here any more surv rate groups

  double                _gc_overhead_perc;

  double _reserve_factor;

  uint _reserve_regions;

  bool during_marking() {

    return _during_marking;

  }

private:

  enum PredictionConstants {

    TruncatedSeqLength = 10

  };

  TruncatedSeq* _alloc_rate_ms_seq;

  double        _prev_collection_pause_end_ms;

  TruncatedSeq* _pending_card_diff_seq;

  TruncatedSeq* _rs_length_diff_seq;

  TruncatedSeq* _cost_per_card_ms_seq;

  TruncatedSeq* _young_cards_per_entry_ratio_seq;

  TruncatedSeq* _mixed_cards_per_entry_ratio_seq;

  TruncatedSeq* _cost_per_entry_ms_seq;

  TruncatedSeq* _mixed_cost_per_entry_ms_seq;

  TruncatedSeq* _cost_per_byte_ms_seq;

  TruncatedSeq* _constant_other_time_ms_seq;

  TruncatedSeq* _young_other_cost_per_region_ms_seq;

  TruncatedSeq* _non_young_other_cost_per_region_ms_seq;

  TruncatedSeq* _pending_cards_seq;

  TruncatedSeq* _rs_lengths_seq;

  TruncatedSeq* _cost_per_byte_ms_during_cm_seq;

  G1YoungGenSizer* _young_gen_sizer;

  uint _eden_cset_region_length;

  uint _survivor_cset_region_length;

  uint _old_cset_region_length;

  void init_cset_region_lengths(uint eden_cset_region_length,

                                uint survivor_cset_region_length);

  uint eden_cset_region_length()     { return _eden_cset_region_length;     }

  uint survivor_cset_region_length() { return _survivor_cset_region_length; }

  uint old_cset_region_length()      { return _old_cset_region_length;      }

  uint _free_regions_at_end_of_collection;

  size_t _recorded_rs_lengths;

  size_t _max_rs_lengths;

  double _recorded_young_free_cset_time_ms;

  double _recorded_non_young_free_cset_time_ms;

  double _sigma;

  size_t _rs_lengths_prediction;

  double sigma() { return _sigma; }

  // A function that prevents us putting too much stock in small sample

  // sets.  Returns a number between 2.0 and 1.0, depending on the number

  // of samples.  5 or more samples yields one; fewer scales linearly from

  // 2.0 at 1 sample to 1.0 at 5.

  double confidence_factor(int samples) {

    if (samples > 4) return 1.0;

    else return  1.0 + sigma() * ((double)(5 - samples))/2.0;

  }

  double get_new_neg_prediction(TruncatedSeq* seq) {

    return seq->davg() - sigma() * seq->dsd();

  }

#ifndef PRODUCT

  bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group);

#endif // PRODUCT

  void adjust_concurrent_refinement(double update_rs_time,

                                    double update_rs_processed_buffers,

                                    double goal_ms);

  uintx no_of_gc_threads() { return _no_of_gc_threads; }

  void set_no_of_gc_threads(uintx v) { _no_of_gc_threads = v; }

  double _pause_time_target_ms;

  double _recorded_young_cset_choice_time_ms;

  double _recorded_non_young_cset_choice_time_ms;

  size_t _pending_cards;

  size_t _max_pending_cards;

public:

  // Accessors

  void set_region_eden(HeapRegion* hr, int young_index_in_cset) {

    hr->set_young();

    hr->install_surv_rate_group(_short_lived_surv_rate_group);

    hr->set_young_index_in_cset(young_index_in_cset);

  }

  void set_region_survivor(HeapRegion* hr, int young_index_in_cset) {

    assert(hr->is_young() && hr->is_survivor(), "pre-condition");

    hr->install_surv_rate_group(_survivor_surv_rate_group);

    hr->set_young_index_in_cset(young_index_in_cset);

  }

#ifndef PRODUCT

  bool verify_young_ages();

#endif // PRODUCT

  double get_new_prediction(TruncatedSeq* seq) {

    return MAX2(seq->davg() + sigma() * seq->dsd(),

                seq->davg() * confidence_factor(seq->num()));

  }

  void record_max_rs_lengths(size_t rs_lengths) {

    _max_rs_lengths = rs_lengths;

  }

  size_t predict_pending_card_diff() {

    double prediction = get_new_neg_prediction(_pending_card_diff_seq);

    if (prediction < 0.00001) {

      return 0;

    } else {

      return (size_t) prediction;

    }

  }

  size_t predict_pending_cards() {

    size_t max_pending_card_num = _g1->max_pending_card_num();

    size_t diff = predict_pending_card_diff();

    size_t prediction;

    if (diff > max_pending_card_num) {

      prediction = max_pending_card_num;

    } else {

      prediction = max_pending_card_num - diff;

    }

    return prediction;

  }

  size_t predict_rs_length_diff() {

    return (size_t) get_new_prediction(_rs_length_diff_seq);

  }

  double predict_alloc_rate_ms() {

    return get_new_prediction(_alloc_rate_ms_seq);

  }

  double predict_cost_per_card_ms() {

    return get_new_prediction(_cost_per_card_ms_seq);

  }

  double predict_rs_update_time_ms(size_t pending_cards) {

    return (double) pending_cards * predict_cost_per_card_ms();

  }

  double predict_young_cards_per_entry_ratio() {

    return get_new_prediction(_young_cards_per_entry_ratio_seq);

  }

  double predict_mixed_cards_per_entry_ratio() {

    if (_mixed_cards_per_entry_ratio_seq->num() < 2) {

      return predict_young_cards_per_entry_ratio();

    } else {

      return get_new_prediction(_mixed_cards_per_entry_ratio_seq);

    }

  }

  size_t predict_young_card_num(size_t rs_length) {

    return (size_t) ((double) rs_length *

                     predict_young_cards_per_entry_ratio());

  }

  size_t predict_non_young_card_num(size_t rs_length) {

    return (size_t) ((double) rs_length *

                     predict_mixed_cards_per_entry_ratio());

  }

  double predict_rs_scan_time_ms(size_t card_num) {

    if (gcs_are_young()) {

      return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);

    } else {

      return predict_mixed_rs_scan_time_ms(card_num);

    }

  }

  double predict_mixed_rs_scan_time_ms(size_t card_num) {

    if (_mixed_cost_per_entry_ms_seq->num() < 3) {

      return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);

    } else {

      return (double) (card_num *

                       get_new_prediction(_mixed_cost_per_entry_ms_seq));

    }

  }

  double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {

    if (_cost_per_byte_ms_during_cm_seq->num() < 3) {

      return (1.1 * (double) bytes_to_copy) *

              get_new_prediction(_cost_per_byte_ms_seq);

    } else {

      return (double) bytes_to_copy *

             get_new_prediction(_cost_per_byte_ms_during_cm_seq);

    }

  }

  double predict_object_copy_time_ms(size_t bytes_to_copy) {

    if (_in_marking_window && !_in_marking_window_im) {

      return predict_object_copy_time_ms_during_cm(bytes_to_copy);

    } else {

      return (double) bytes_to_copy *

              get_new_prediction(_cost_per_byte_ms_seq);

    }

  }

  double predict_constant_other_time_ms() {

    return get_new_prediction(_constant_other_time_ms_seq);

  }

  double predict_young_other_time_ms(size_t young_num) {

    return (double) young_num *

           get_new_prediction(_young_other_cost_per_region_ms_seq);

  }

  double predict_non_young_other_time_ms(size_t non_young_num) {

    return (double) non_young_num *

           get_new_prediction(_non_young_other_cost_per_region_ms_seq);

  }

  double predict_base_elapsed_time_ms(size_t pending_cards);

  double predict_base_elapsed_time_ms(size_t pending_cards,

                                      size_t scanned_cards);

  size_t predict_bytes_to_copy(HeapRegion* hr);

  double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);

  void set_recorded_rs_lengths(size_t rs_lengths);

  uint cset_region_length()       { return young_cset_region_length() +

                                           old_cset_region_length(); }

  uint young_cset_region_length() { return eden_cset_region_length() +

                                           survivor_cset_region_length(); }

  void record_young_free_cset_time_ms(double time_ms) {

    _recorded_young_free_cset_time_ms = time_ms;

  }