class HeapRegion;

class CollectionSetChooser;

#define define_num_seq(name) \

private: \

NumberSeq _all_##name##_times_ms; \

public: \

void record_##name##_time_ms(double ms) { \

_all_##name##_times_ms.add(ms); \

} \

NumberSeq* get_##name##_seq() { \

return &_all_##name##_times_ms; \

}

class MainBodySummary;

class PauseSummary: public CHeapObj {

define_num_seq(total)

define_num_seq(other)

public:

virtual MainBodySummary* main_body_summary() { return NULL; }

};

class MainBodySummary: public CHeapObj {

define_num_seq(satb_drain) // optional

define_num_seq(parallel) // parallel only

define_num_seq(ext_root_scan)

define_num_seq(mark_stack_scan)

define_num_seq(scan_only)

define_num_seq(update_rs)

define_num_seq(scan_rs)

define_num_seq(scan_new_refs) // Only for temp use; added to

// in parallel case.

define_num_seq(obj_copy)

define_num_seq(termination) // parallel only

define_num_seq(parallel_other) // parallel only

define_num_seq(mark_closure)

define_num_seq(clear_ct) // parallel only

};

class Summary: public PauseSummary,

public MainBodySummary {

public:

virtual MainBodySummary* main_body_summary() { return this; }

};

class AbandonedSummary: public PauseSummary {

};

class G1CollectorPolicy: public CollectorPolicy {

protected:

// The number of pauses during the execution.

long _n_pauses;

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

// has been set, or 1 otherwise

int _parallel_gc_threads;

enum SomePrivateConstants {

NumPrevPausesForHeuristics = 10,

NumPrevGCsForHeuristics = 10,

NumAPIs = HeapRegion::MaxAge

};

G1MMUTracker* _mmu_tracker;

void initialize_flags();

void initialize_all() {

initialize_flags();

initialize_size_info();

initialize_perm_generation(PermGen::MarkSweepCompact);

}

virtual size_t default_init_heap_size() {

// Pick some reasonable default.

return 8*M;

}

double _cur_collection_start_sec;

size_t _cur_collection_pause_used_at_start_bytes;

size_t _cur_collection_pause_used_regions_at_start;

size_t _prev_collection_pause_used_at_end_bytes;

double _cur_collection_par_time_ms;

double _cur_satb_drain_time_ms;

double _cur_clear_ct_time_ms;

bool _satb_drain_time_set;

double _cur_CH_strong_roots_end_sec;

double _cur_CH_strong_roots_dur_ms;

double _cur_G1_strong_roots_end_sec;

double _cur_G1_strong_roots_dur_ms;

// Statistics for recent GC pauses. See below for how indexed.

TruncatedSeq* _recent_CH_strong_roots_times_ms;

TruncatedSeq* _recent_G1_strong_roots_times_ms;

TruncatedSeq* _recent_evac_times_ms;

// These exclude marking times.

TruncatedSeq* _recent_pause_times_ms;

TruncatedSeq* _recent_gc_times_ms;

TruncatedSeq* _recent_CS_bytes_used_before;

TruncatedSeq* _recent_CS_bytes_surviving;

TruncatedSeq* _recent_rs_sizes;

TruncatedSeq* _concurrent_mark_init_times_ms;

TruncatedSeq* _concurrent_mark_remark_times_ms;

TruncatedSeq* _concurrent_mark_cleanup_times_ms;

Summary* _summary;

AbandonedSummary* _abandoned_summary;

NumberSeq* _all_pause_times_ms;

NumberSeq* _all_full_gc_times_ms;

double _stop_world_start;

NumberSeq* _all_stop_world_times_ms;

NumberSeq* _all_yield_times_ms;

size_t _region_num_young;

size_t _region_num_tenured;

size_t _prev_region_num_young;

size_t _prev_region_num_tenured;

NumberSeq* _all_mod_union_times_ms;

int _aux_num;

NumberSeq* _all_aux_times_ms;

double* _cur_aux_start_times_ms;

double* _cur_aux_times_ms;

bool* _cur_aux_times_set;

double* _par_last_ext_root_scan_times_ms;

double* _par_last_mark_stack_scan_times_ms;

double* _par_last_scan_only_times_ms;

double* _par_last_scan_only_regions_scanned;

double* _par_last_update_rs_start_times_ms;

double* _par_last_update_rs_times_ms;

double* _par_last_update_rs_processed_buffers;

double* _par_last_scan_rs_start_times_ms;

double* _par_last_scan_rs_times_ms;

double* _par_last_scan_new_refs_times_ms;

double* _par_last_obj_copy_times_ms;

double* _par_last_termination_times_ms;

// indicates that we are in young GC mode

bool _in_young_gc_mode;

// indicates whether we are in full young or partially young GC mode

bool _full_young_gcs;

// if true, then it tries to dynamically adjust the length of the

// young list

bool _adaptive_young_list_length;

size_t _young_list_min_length;

size_t _young_list_target_length;

size_t _young_list_so_prefix_length;

size_t _young_list_fixed_length;

size_t _young_cset_length;

bool _last_young_gc_full;

double _target_pause_time_ms;

unsigned _full_young_pause_num;

unsigned _partial_young_pause_num;

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

bool during_marking() {

return _during_marking;

}

// <NEW PREDICTION>

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* _cost_per_scan_only_region_ms_seq;

TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;

TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;

TruncatedSeq* _cost_per_entry_ms_seq;

TruncatedSeq* _partially_young_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* _scanned_cards_seq;

TruncatedSeq* _rs_lengths_seq;

TruncatedSeq* _cost_per_byte_ms_during_cm_seq;

TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq;

TruncatedSeq* _young_gc_eff_seq;

TruncatedSeq* _max_conc_overhead_seq;

size_t _recorded_young_regions;

size_t _recorded_scan_only_regions;

size_t _recorded_non_young_regions;

size_t _recorded_region_num;

size_t _free_regions_at_end_of_collection;

size_t _scan_only_regions_at_end_of_collection;

size_t _recorded_rs_lengths;

size_t _max_rs_lengths;

size_t _recorded_marked_bytes;

size_t _recorded_young_bytes;

size_t _predicted_pending_cards;

size_t _predicted_cards_scanned;

size_t _predicted_rs_lengths;

size_t _predicted_bytes_to_copy;

double _predicted_survival_ratio;

double _predicted_rs_update_time_ms;

double _predicted_rs_scan_time_ms;

double _predicted_scan_only_scan_time_ms;

double _predicted_object_copy_time_ms;

double _predicted_constant_other_time_ms;

double _predicted_young_other_time_ms;

double _predicted_non_young_other_time_ms;

double _predicted_pause_time_ms;

double _vtime_diff_ms;

double _recorded_young_free_cset_time_ms;

double _recorded_non_young_free_cset_time_ms;

double _sigma;

double _expensive_region_limit_ms;

size_t _rs_lengths_prediction;

size_t _known_garbage_bytes;

double _known_garbage_ratio;

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

protected:

double _pause_time_target_ms;

double _recorded_young_cset_choice_time_ms;

double _recorded_non_young_cset_choice_time_ms;

bool _within_target;

size_t _pending_cards;

size_t _max_pending_cards;

public:

void set_region_short_lived(HeapRegion* hr) {

hr->install_surv_rate_group(_short_lived_surv_rate_group);

}

void set_region_survivors(HeapRegion* hr) {

hr->install_surv_rate_group(_survivor_surv_rate_group);

}

#ifndef PRODUCT

bool verify_young_ages();

#endif // PRODUCT

void tag_scan_only(size_t short_lived_scan_only_length);

double get_new_prediction(TruncatedSeq* seq) {

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

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

}

size_t young_cset_length() {

return _young_cset_length;

}

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_fully_young_cards_per_entry_ratio() {

return get_new_prediction(_fully_young_cards_per_entry_ratio_seq);

}

double predict_partially_young_cards_per_entry_ratio() {

if (_partially_young_cards_per_entry_ratio_seq->num() < 2)

return predict_fully_young_cards_per_entry_ratio();

else

return get_new_prediction(_partially_young_cards_per_entry_ratio_seq);

}

size_t predict_young_card_num(size_t rs_length) {

return (size_t) ((double) rs_length *

predict_fully_young_cards_per_entry_ratio());

}

size_t predict_non_young_card_num(size_t rs_length) {

return (size_t) ((double) rs_length *

predict_partially_young_cards_per_entry_ratio());

}

double predict_rs_scan_time_ms(size_t card_num) {

if (full_young_gcs())

return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);

else

return predict_partially_young_rs_scan_time_ms(card_num);

}

double predict_partially_young_rs_scan_time_ms(size_t card_num) {

if (_partially_young_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(_partially_young_cost_per_entry_ms_seq);

}

double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) {

if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3)

return 1.5 * (double) scan_only_region_num *

get_new_prediction(_cost_per_scan_only_region_ms_seq);

else

return (double) scan_only_region_num *

get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq);

}

double predict_scan_only_time_ms(size_t scan_only_region_num) {

if (_in_marking_window_im)

return predict_scan_only_time_ms_during_cm(scan_only_region_num);

else

return (double) scan_only_region_num *

get_new_prediction(_cost_per_scan_only_region_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);

}

void check_if_region_is_too_expensive(double predicted_time_ms);

double predict_young_collection_elapsed_time_ms(size_t adjustment);

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);

// for use by: calculate_optimal_so_length(length)

void predict_gc_eff(size_t young_region_num,

size_t so_length,

double base_time_ms,

double *gc_eff,

double *pause_time_ms);

// for use by: calculate_young_list_target_config(rs_length)

bool predict_gc_eff(size_t young_region_num,

size_t so_length,

double base_time_with_so_ms,

size_t init_free_regions,

double target_pause_time_ms,

double* gc_eff);

void start_recording_regions();

void record_cset_region(HeapRegion* hr, bool young);

void record_scan_only_regions(size_t scan_only_length);

void end_recording_regions();

void record_vtime_diff_ms(double vtime_diff_ms) {

_vtime_diff_ms = vtime_diff_ms;

}

void record_young_free_cset_time_ms(double time_ms) {

_recorded_young_free_cset_time_ms = time_ms;

}

void record_non_young_free_cset_time_ms(double time_ms) {

_recorded_non_young_free_cset_time_ms = time_ms;

}

double predict_young_gc_eff() {

return get_new_neg_prediction(_young_gc_eff_seq);

}

double predict_survivor_regions_evac_time();

// </NEW PREDICTION>

public:

void cset_regions_freed() {

bool propagate = _last_young_gc_full && !_in_marking_window;

_short_lived_surv_rate_group->all_surviving_words_recorded(propagate);

_survivor_surv_rate_group->all_surviving_words_recorded(propagate);

// also call it on any more surv rate groups

}

void set_known_garbage_bytes(size_t known_garbage_bytes) {

_known_garbage_bytes = known_garbage_bytes;

size_t heap_bytes = _g1->capacity();

_known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;

}

void decrease_known_garbage_bytes(size_t known_garbage_bytes) {

guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" );

_known_garbage_bytes -= known_garbage_bytes;

size_t heap_bytes = _g1->capacity();

_known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;

}

G1MMUTracker* mmu_tracker() {

return _mmu_tracker;

}

double predict_init_time_ms() {

return get_new_prediction(_concurrent_mark_init_times_ms);

}

double predict_remark_time_ms() {

return get_new_prediction(_concurrent_mark_remark_times_ms);

}

double predict_cleanup_time_ms() {

return get_new_prediction(_concurrent_mark_cleanup_times_ms);

}

// Returns an estimate of the survival rate of the region at yg-age

// "yg_age".

double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) {

TruncatedSeq* seq = surv_rate_group->get_seq(age);

if (seq->num() == 0)

gclog_or_tty->print("BARF! age is %d", age);

guarantee( seq->num() > 0, "invariant" );

double pred = get_new_prediction(seq);

if (pred > 1.0)

pred = 1.0;

return pred;

}

double predict_yg_surv_rate(int age) {

return predict_yg_surv_rate(age, _short_lived_surv_rate_group);

}

double accum_yg_surv_rate_pred(int age) {

return _short_lived_surv_rate_group->accum_surv_rate_pred(age);

}

protected:

void print_stats (int level, const char* str, double value);

void print_stats (int level, const char* str, int value);

void print_par_stats (int level, const char* str, double* data) {

print_par_stats(level, str, data, true);

}

void print_par_stats (int level, const char* str, double* data, bool summary);

void print_par_buffers (int level, const char* str, double* data, bool summary);

void check_other_times(int level,

NumberSeq* other_times_ms,

NumberSeq* calc_other_times_ms) const;

void print_summary (PauseSummary* stats) const;

void print_abandoned_summary(PauseSummary* summary) const;

void print_summary (int level, const char* str, NumberSeq* seq) const;

void print_summary_sd (int level, const char* str, NumberSeq* seq) const;

double avg_value (double* data);

double max_value (double* data);

double sum_of_values (double* data);

double max_sum (double* data1, double* data2);

int _last_satb_drain_processed_buffers;

int _last_update_rs_processed_buffers;

double _last_pause_time_ms;

size_t _bytes_in_to_space_before_gc;

size_t _bytes_in_to_space_after_gc;

size_t bytes_in_to_space_during_gc() {

return

_bytes_in_to_space_after_gc - _bytes_in_to_space_before_gc;

}

size_t _bytes_in_collection_set_before_gc;

// Used to count used bytes in CS.

friend class CountCSClosure;

// Statistics kept per GC stoppage, pause or full.

TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;

// We track markings.

int _num_markings;

double _mark_thread_startup_sec; // Time at startup of marking thread

// Add a new GC of the given duration and end time to the record.

void update_recent_gc_times(double end_time_sec, double elapsed_ms);

// The head of the list (via "next_in_collection_set()") representing the

// current collection set.

HeapRegion* _collection_set;

size_t _collection_set_size;

size_t _collection_set_bytes_used_before;

// Info about marking.

int _n_marks; // Sticky at 2, so we know when we've done at least 2.

// The number of collection pauses at the end of the last mark.

size_t _n_pauses_at_mark_end;

// Stash a pointer to the g1 heap.

G1CollectedHeap* _g1;

// The average time in ms per collection pause, averaged over recent pauses.

double recent_avg_time_for_pauses_ms();

// The average time in ms for processing CollectedHeap strong roots, per

// collection pause, averaged over recent pauses.

double recent_avg_time_for_CH_strong_ms();

// The average time in ms for processing the G1 remembered set, per

// pause, averaged over recent pauses.

double recent_avg_time_for_G1_strong_ms();

// The average time in ms for "evacuating followers", per pause, averaged

// over recent pauses.

double recent_avg_time_for_evac_ms();

// The number of "recent" GCs recorded in the number sequences

int number_of_recent_gcs();

// The average survival ratio, computed by the total number of bytes

// suriviving / total number of bytes before collection over the last

// several recent pauses.

double recent_avg_survival_fraction();

// The survival fraction of the most recent pause; if there have been no

// pauses, returns 1.0.

double last_survival_fraction();

// Returns a "conservative" estimate of the recent survival rate, i.e.,

// one that may be higher than "recent_avg_survival_fraction".

// This is conservative in several ways:

// If there have been few pauses, it will assume a potential high

// variance, and err on the side of caution.

// It puts a lower bound (currently 0.1) on the value it will return.

// To try to detect phase changes, if the most recent pause ("latest") has a

// higher-than average ("avg") survival rate, it returns that rate.

// "work" version is a utility function; young is restricted to young regions.

double conservative_avg_survival_fraction_work(double avg,

double latest);

// The arguments are the two sequences that keep track of the number of bytes

// surviving and the total number of bytes before collection, resp.,

// over the last evereal recent pauses

// Returns the survival rate for the category in the most recent pause.

// If there have been no pauses, returns 1.0.

double last_survival_fraction_work(TruncatedSeq* surviving,

TruncatedSeq* before);

// The arguments are the two sequences that keep track of the number of bytes

// surviving and the total number of bytes before collection, resp.,

// over the last several recent pauses

// Returns the average survival ration over the last several recent pauses

// If there have been no pauses, return 1.0

double recent_avg_survival_fraction_work(TruncatedSeq* surviving,

TruncatedSeq* before);

double conservative_avg_survival_fraction() {

double avg = recent_avg_survival_fraction();

double latest = last_survival_fraction();

return conservative_avg_survival_fraction_work(avg, latest);

}

// The ratio of gc time to elapsed time, computed over recent pauses.

double _recent_avg_pause_time_ratio;

double recent_avg_pause_time_ratio() {

return _recent_avg_pause_time_ratio;

}

// Number of pauses between concurrent marking.

size_t _pauses_btwn_concurrent_mark;

size_t _n_marks_since_last_pause;

// True iff CM has been initiated.

bool _conc_mark_initiated;

// True iff CM should be initiated

bool _should_initiate_conc_mark;

bool _should_revert_to_full_young_gcs;

bool _last_full_young_gc;

// This set of variables tracks the collector efficiency, in order to

// determine whether we should initiate a new marking.

double _cur_mark_stop_world_time_ms;

double _mark_init_start_sec;

double _mark_remark_start_sec;

double _mark_cleanup_start_sec;

double _mark_closure_time_ms;

void calculate_young_list_min_length();

void calculate_young_list_target_config();

void calculate_young_list_target_config(size_t rs_lengths);

size_t calculate_optimal_so_length(size_t young_list_length);

public:

G1CollectorPolicy();

virtual G1CollectorPolicy* as_g1_policy() { return this; }

virtual CollectorPolicy::Name kind() {

return CollectorPolicy::G1CollectorPolicyKind;

}

void check_prediction_validity();

size_t bytes_in_collection_set() {

return _bytes_in_collection_set_before_gc;

}

size_t bytes_in_to_space() {

return bytes_in_to_space_during_gc();

}

unsigned calc_gc_alloc_time_stamp() {

return _all_pause_times_ms->num() + 1;

}

protected:

// Count the number of bytes used in the CS.

void count_CS_bytes_used();

// Together these do the base cleanup-recording work. Subclasses might

// want to put something between them.

void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,

size_t max_live_bytes);

void record_concurrent_mark_cleanup_end_work2();

public:

virtual void init();

// Create jstat counters for the policy.

virtual void initialize_gc_policy_counters();

virtual HeapWord* mem_allocate_work(size_t size,

bool is_tlab,

bool* gc_overhead_limit_was_exceeded);

// This method controls how a collector handles one or more

// of its generations being fully allocated.

virtual HeapWord* satisfy_failed_allocation(size_t size,

bool is_tlab);

BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; }

GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }

// The number of collection pauses so far.

long n_pauses() const { return _n_pauses; }

// Update the heuristic info to record a collection pause of the given

// start time, where the given number of bytes were used at the start.

// This may involve changing the desired size of a collection set.

virtual void record_stop_world_start();

virtual void record_collection_pause_start(double start_time_sec,

size_t start_used);

// Must currently be called while the world is stopped.

virtual void record_concurrent_mark_init_start();

virtual void record_concurrent_mark_init_end();

void record_concurrent_mark_init_end_pre(double

mark_init_elapsed_time_ms);

void record_mark_closure_time(double mark_closure_time_ms);

virtual void record_concurrent_mark_remark_start();

virtual void record_concurrent_mark_remark_end();

virtual void record_concurrent_mark_cleanup_start();

virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,

size_t max_live_bytes);

virtual void record_concurrent_mark_cleanup_completed();

virtual void record_concurrent_pause();

virtual void record_concurrent_pause_end();

virtual void record_collection_pause_end_CH_strong_roots();

virtual void record_collection_pause_end_G1_strong_roots();

virtual void record_collection_pause_end(bool abandoned);

// Record the fact that a full collection occurred.

virtual void record_full_collection_start();

virtual void record_full_collection_end();

void record_ext_root_scan_time(int worker_i, double ms) {

_par_last_ext_root_scan_times_ms[worker_i] = ms;

}

void record_mark_stack_scan_time(int worker_i, double ms) {

_par_last_mark_stack_scan_times_ms[worker_i] = ms;

}

void record_scan_only_time(int worker_i, double ms, int n) {

_par_last_scan_only_times_ms[worker_i] = ms;

_par_last_scan_only_regions_scanned[worker_i] = (double) n;

}

void record_satb_drain_time(double ms) {

_cur_satb_drain_time_ms = ms;

_satb_drain_time_set = true;

}

void record_satb_drain_processed_buffers (int processed_buffers) {

_last_satb_drain_processed_buffers = processed_buffers;

}

void record_mod_union_time(double ms) {

_all_mod_union_times_ms->add(ms);

}

void record_update_rs_start_time(int thread, double ms) {

_par_last_update_rs_start_times_ms[thread] = ms;

}

void record_update_rs_time(int thread, double ms) {

_par_last_update_rs_times_ms[thread] = ms;

}

void record_update_rs_processed_buffers (int thread,

double processed_buffers) {

_par_last_update_rs_processed_buffers[thread] = processed_buffers;

}

void record_scan_rs_start_time(int thread, double ms) {

_par_last_scan_rs_start_times_ms[thread] = ms;

}

void record_scan_rs_time(int thread, double ms) {

_par_last_scan_rs_times_ms[thread] = ms;

}

void record_scan_new_refs_time(int thread, double ms) {

_par_last_scan_new_refs_times_ms[thread] = ms;

}

double get_scan_new_refs_time(int thread) {

return _par_last_scan_new_refs_times_ms[thread];

}

void reset_obj_copy_time(int thread) {

_par_last_obj_copy_times_ms[thread] = 0.0;

}

void reset_obj_copy_time() {

reset_obj_copy_time(0);

}

void record_obj_copy_time(int thread, double ms) {

_par_last_obj_copy_times_ms[thread] += ms;

}

void record_obj_copy_time(double ms) {

record_obj_copy_time(0, ms);

}

void record_termination_time(int thread, double ms) {

_par_last_termination_times_ms[thread] = ms;

}

void record_termination_time(double ms) {

record_termination_time(0, ms);

}

void record_pause_time_ms(double ms) {

_last_pause_time_ms = ms;

}

void record_clear_ct_time(double ms) {

_cur_clear_ct_time_ms = ms;

}

void record_par_time(double ms) {

_cur_collection_par_time_ms = ms;

}

void record_aux_start_time(int i) {

guarantee(i < _aux_num, "should be within range");

_cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0;

}

void record_aux_end_time(int i) {

guarantee(i < _aux_num, "should be within range");

double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i];

_cur_aux_times_set[i] = true;

_cur_aux_times_ms[i] += ms;

}

// Record the fact that "bytes" bytes allocated in a region.

void record_before_bytes(size_t bytes);

void record_after_bytes(size_t bytes);

// Returns "true" if this is a good time to do a collection pause.

// The "word_size" argument, if non-zero, indicates the size of an

// allocation request that is prompting this query.

virtual bool should_do_collection_pause(size_t word_size) = 0;

// Choose a new collection set. Marks the chosen regions as being

// "in_collection_set", and links them together. The head and number of

// the collection set are available via access methods.

virtual void choose_collection_set() = 0;

void clear_collection_set() { _collection_set = NULL; }

// The head of the list (via "next_in_collection_set()") representing the

// current collection set.

HeapRegion* collection_set() { return _collection_set; }

// The number of elements in the current collection set.

size_t collection_set_size() { return _collection_set_size; }

// Add "hr" to the CS.

void add_to_collection_set(HeapRegion* hr);

bool should_initiate_conc_mark() { return _should_initiate_conc_mark; }

void set_should_initiate_conc_mark() { _should_initiate_conc_mark = true; }

void unset_should_initiate_conc_mark(){ _should_initiate_conc_mark = false; }

void checkpoint_conc_overhead();

// 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();

// note start of mark thread

void note_start_of_mark_thread();

// The marked bytes of the "r" has changed; reclassify it's desirability

// for marking. Also asserts that "r" is eligible for a CS.

virtual void note_change_in_marked_bytes(HeapRegion* r) = 0;

#ifndef PRODUCT

// Check any appropriate marked bytes info, asserting false if

// something's wrong, else returning "true".

virtual bool assertMarkedBytesDataOK() = 0;

#endif

// Print tracing information.

void print_tracing_info() const;

// Print stats on young survival ratio

void print_yg_surv_rate_info() const;

void finished_recalculating_age_indexes(bool is_survivors) {

if (is_survivors) {

_survivor_surv_rate_group->finished_recalculating_age_indexes();

} else {

_short_lived_surv_rate_group->finished_recalculating_age_indexes();

}

// do that for any other surv rate groups

}

bool should_add_next_region_to_young_list();

bool in_young_gc_mode() {

return _in_young_gc_mode;

}

void set_in_young_gc_mode(bool in_young_gc_mode) {

_in_young_gc_mode = in_young_gc_mode;

}

bool full_young_gcs() {

return _full_young_gcs;

}

void set_full_young_gcs(bool full_young_gcs) {

_full_young_gcs = full_young_gcs;

}

bool adaptive_young_list_length() {

return _adaptive_young_list_length;

}

void set_adaptive_young_list_length(bool adaptive_young_list_length) {

_adaptive_young_list_length = adaptive_young_list_length;

}

inline double get_gc_eff_factor() {

double ratio = _known_garbage_ratio;

double square = ratio * ratio;

// square = square * square;

double ret = square * 9.0 + 1.0;

#if 0

gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret);

#endif // 0

guarantee(0.0 <= ret && ret < 10.0, "invariant!");

return ret;

}

//

// Survivor regions policy.

//

protected:

// Current tenuring threshold, set to 0 if the collector reaches the

// maximum amount of suvivors regions.

int _tenuring_threshold;

// The limit on the number of regions allocated for survivors.

size_t _max_survivor_regions;

// The amount of survor regions after a collection.

size_t _recorded_survivor_regions;

// List of survivor regions.

HeapRegion* _recorded_survivor_head;

HeapRegion* _recorded_survivor_tail;

ageTable _survivors_age_table;

public:

inline GCAllocPurpose

evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) {

if (age < _tenuring_threshold && src_region->is_young()) {

return GCAllocForSurvived;

} else {

return GCAllocForTenured;

}

}

inline bool track_object_age(GCAllocPurpose purpose) {

return purpose == GCAllocForSurvived;

}

inline GCAllocPurpose alternative_purpose(int purpose) {

return GCAllocForTenured;

}

static const size_t REGIONS_UNLIMITED = ~(size_t)0;

size_t max_regions(int purpose);

// The limit on regions for a particular purpose is reached.

void note_alloc_region_limit_reached(int purpose) {

if (purpose == GCAllocForSurvived) {

_tenuring_threshold = 0;

}

}

void note_start_adding_survivor_regions() {

_survivor_surv_rate_group->start_adding_regions();

}

void note_stop_adding_survivor_regions() {

_survivor_surv_rate_group->stop_adding_regions();

}

void record_survivor_regions(size_t regions,

HeapRegion* head,

HeapRegion* tail) {

_recorded_survivor_regions = regions;

_recorded_survivor_head = head;

_recorded_survivor_tail = tail;

}

size_t recorded_survivor_regions() {

return _recorded_survivor_regions;

}

void record_thread_age_table(ageTable* age_table)

{

_survivors_age_table.merge_par(age_table);

}

// Calculates survivor space parameters.

void calculate_survivors_policy();

};

class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy {

CollectionSetChooser* _collectionSetChooser;

// If the estimated is less then desirable, resize if possible.

void expand_if_possible(size_t numRegions);

virtual void choose_collection_set();

virtual void record_collection_pause_start(double start_time_sec,

size_t start_used);

virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,

size_t max_live_bytes);

virtual void record_full_collection_end();

public:

G1CollectorPolicy_BestRegionsFirst() {

_collectionSetChooser = new CollectionSetChooser();

}

void record_collection_pause_end(bool abandoned);

bool should_do_collection_pause(size_t word_size);

// This is not needed any more, after the CSet choosing code was

// changed to use the pause prediction work. But let's leave the

// hook in just in case.

void note_change_in_marked_bytes(HeapRegion* r) { }

#ifndef PRODUCT

bool assertMarkedBytesDataOK();

#endif

};

inline double variance(int n, double sum_of_squares, double sum) {

double n_d = (double)n;

double avg = sum/n_d;

return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d;

}