/* * Copyright (c) 2001, 2015, 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_G1_G1COLLECTORPOLICY_HPP #define SHARE_VM_GC_G1_G1COLLECTORPOLICY_HPP #include "gc/g1/collectionSetChooser.hpp" #include "gc/g1/g1CollectorState.hpp" #include "gc/g1/g1GCPhaseTimes.hpp" #include "gc/g1/g1InCSetState.hpp" #include "gc/g1/g1InitialMarkToMixedTimeTracker.hpp" #include "gc/g1/g1MMUTracker.hpp" #include "gc/g1/g1Predictions.hpp" #include "gc/shared/collectorPolicy.hpp" #include "utilities/pair.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; class G1IHOPControl; // TraceYoungGenTime collects data on _both_ young and mixed evacuation pauses // (the latter may contain non-young regions - i.e. regions that are // technically in old) while TraceOldGenTime collects data about full GCs. class TraceYoungGenTimeData : public CHeapObj { private: unsigned _young_pause_num; unsigned _mixed_pause_num; NumberSeq _all_stop_world_times_ms; NumberSeq _all_yield_times_ms; NumberSeq _total; NumberSeq _other; NumberSeq _root_region_scan_wait; NumberSeq _parallel; NumberSeq _ext_root_scan; NumberSeq _satb_filtering; NumberSeq _update_rs; NumberSeq _scan_rs; NumberSeq _obj_copy; NumberSeq _termination; NumberSeq _parallel_other; NumberSeq _clear_ct; void print_summary(const char* str, const NumberSeq* seq) const; void print_summary_sd(const char* str, const NumberSeq* seq) const; public: TraceYoungGenTimeData() : _young_pause_num(0), _mixed_pause_num(0) {}; void record_start_collection(double time_to_stop_the_world_ms); void record_yield_time(double yield_time_ms); void record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times); void increment_young_collection_count(); void increment_mixed_collection_count(); void print() const; }; class TraceOldGenTimeData : public CHeapObj { private: NumberSeq _all_full_gc_times; public: void record_full_collection(double full_gc_time_ms); void print() const; }; // 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 G1NewSizePercent // and G1MaxNewSizePercent of the heap size. This means that every time // the heap size changes, the limits for the young gen size will be // recalculated. // // If only -XX:NewSize is set we should use the specified value as the // minimum size for young gen. Still using G1MaxNewSizePercent 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 G1NewSizePercent 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 // every time 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); // Update the given values for minimum and maximum young gen length in regions // given the number of heap regions depending on the kind of sizing algorithm. void recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length); public: G1YoungGenSizer(); // Calculate the maximum length of the young gen given the number of regions // depending on the sizing algorithm. uint max_young_length(uint number_of_heap_regions); 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() const { return _adaptive_size; } }; class G1CollectorPolicy: public CollectorPolicy { private: G1IHOPControl* _ihop_control; G1IHOPControl* create_ihop_control() const; // Update the IHOP control with necessary statistics. void update_ihop_prediction(double mutator_time_s, size_t mutator_alloc_bytes, size_t young_gen_size); void report_ihop_statistics(); G1Predictions _predictor; double get_new_prediction(TruncatedSeq const* seq) const; // 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; G1MMUTracker* _mmu_tracker; void initialize_alignments(); void initialize_flags(); CollectionSetChooser* _collectionSetChooser; double _full_collection_start_sec; uint _cur_collection_pause_used_regions_at_start; // These exclude marking times. TruncatedSeq* _recent_gc_times_ms; TruncatedSeq* _concurrent_mark_remark_times_ms; TruncatedSeq* _concurrent_mark_cleanup_times_ms; TraceYoungGenTimeData _trace_young_gen_time_data; TraceOldGenTimeData _trace_old_gen_time_data; double _stop_world_start; uint _young_list_target_length; uint _young_list_fixed_length; // 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; 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; enum PredictionConstants { TruncatedSeqLength = 10, NumPrevPausesForHeuristics = 10 }; TruncatedSeq* _alloc_rate_ms_seq; double _prev_collection_pause_end_ms; TruncatedSeq* _rs_length_diff_seq; TruncatedSeq* _cost_per_card_ms_seq; TruncatedSeq* _cost_scan_hcc_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() const { return _eden_cset_region_length; } uint survivor_cset_region_length() const { return _survivor_cset_region_length; } uint old_cset_region_length() const { return _old_cset_region_length; } uint _free_regions_at_end_of_collection; size_t _recorded_rs_lengths; size_t _max_rs_lengths; size_t _rs_lengths_prediction; #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; size_t _pending_cards; // The amount of allocated bytes in old gen during the last mutator and the following // young GC phase. size_t _last_old_allocated_bytes; G1InitialMarkToMixedTimeTracker _initial_mark_to_mixed; public: const G1Predictions& predictor() const { return _predictor; } // Add the given number of bytes to the total number of allocated bytes in the old gen. void add_last_old_allocated_bytes(size_t bytes) { _last_old_allocated_bytes += bytes; } // Accessors void set_region_eden(HeapRegion* hr, int young_index_in_cset) { hr->set_eden(); 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_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 void record_max_rs_lengths(size_t rs_lengths) { _max_rs_lengths = rs_lengths; } size_t predict_rs_length_diff() const; double predict_alloc_rate_ms() const; double predict_cost_per_card_ms() const; double predict_scan_hcc_ms() const; double predict_rs_update_time_ms(size_t pending_cards) const; double predict_young_cards_per_entry_ratio() const; double predict_mixed_cards_per_entry_ratio() const; size_t predict_young_card_num(size_t rs_length) const; size_t predict_non_young_card_num(size_t rs_length) const; double predict_rs_scan_time_ms(size_t card_num) const; double predict_mixed_rs_scan_time_ms(size_t card_num) const; double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const; double predict_object_copy_time_ms(size_t bytes_to_copy) const; double predict_constant_other_time_ms() const; double predict_young_other_time_ms(size_t young_num) const; double predict_non_young_other_time_ms(size_t non_young_num) const; double predict_base_elapsed_time_ms(size_t pending_cards) const; double predict_base_elapsed_time_ms(size_t pending_cards, size_t scanned_cards) const; size_t predict_bytes_to_copy(HeapRegion* hr) const; double predict_region_elapsed_time_ms(HeapRegion* hr, bool for_young_gc) const; void set_recorded_rs_lengths(size_t rs_lengths); uint cset_region_length() const { return young_cset_region_length() + old_cset_region_length(); } uint young_cset_region_length() const { return eden_cset_region_length() + survivor_cset_region_length(); } double predict_survivor_regions_evac_time() const; bool should_update_surv_rate_group_predictors() { return collector_state()->last_gc_was_young() && !collector_state()->in_marking_window(); } void cset_regions_freed() { bool update = should_update_surv_rate_group_predictors(); _short_lived_surv_rate_group->all_surviving_words_recorded(update); _survivor_surv_rate_group->all_surviving_words_recorded(update); } G1MMUTracker* mmu_tracker() { return _mmu_tracker; } const G1MMUTracker* mmu_tracker() const { return _mmu_tracker; } double max_pause_time_ms() const { return _mmu_tracker->max_gc_time() * 1000.0; } double predict_remark_time_ms() const; double predict_cleanup_time_ms() const; // 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) const; double predict_yg_surv_rate(int age) const; double accum_yg_surv_rate_pred(int age) const; protected: virtual double average_time_ms(G1GCPhaseTimes::GCParPhases phase) const; virtual double other_time_ms(double pause_time_ms) const; double young_other_time_ms() const; double non_young_other_time_ms() const; double constant_other_time_ms(double pause_time_ms) const; private: // Statistics kept per GC stoppage, pause or full. TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec; // 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. Set from the incrementally built collection // set at the start of the pause. HeapRegion* _collection_set; // The number of bytes in the collection set before the pause. Set from // the incrementally built collection set at the start of an evacuation // pause, and incremented in finalize_old_cset_part() when adding old regions // (if any) to the collection set. size_t _collection_set_bytes_used_before; // The number of bytes copied during the GC. size_t _bytes_copied_during_gc; // The associated information that is maintained while the incremental // collection set is being built with young regions. Used to populate // the recorded info for the evacuation pause. enum CSetBuildType { Active, // We are actively building the collection set Inactive // We are not actively building the collection set }; CSetBuildType _inc_cset_build_state; // The head of the incrementally built collection set. HeapRegion* _inc_cset_head; // The tail of the incrementally built collection set. HeapRegion* _inc_cset_tail; // The number of bytes in the incrementally built collection set. // Used to set _collection_set_bytes_used_before at the start of // an evacuation pause. size_t _inc_cset_bytes_used_before; // Used to record the highest end of heap region in collection set HeapWord* _inc_cset_max_finger; // The RSet lengths recorded for regions in the CSet. It is updated // by the thread that adds a new region to the CSet. We assume that // only one thread can be allocating a new CSet region (currently, // it does so after taking the Heap_lock) hence no need to // synchronize updates to this field. size_t _inc_cset_recorded_rs_lengths; // A concurrent refinement thread periodically samples the young // region RSets and needs to update _inc_cset_recorded_rs_lengths as // the RSets grow. Instead of having to synchronize updates to that // field we accumulate them in this field and add it to // _inc_cset_recorded_rs_lengths_diffs at the start of a GC. ssize_t _inc_cset_recorded_rs_lengths_diffs; // The predicted elapsed time it will take to collect the regions in // the CSet. This is updated by the thread that adds a new region to // the CSet. See the comment for _inc_cset_recorded_rs_lengths about // MT-safety assumptions. double _inc_cset_predicted_elapsed_time_ms; // See the comment for _inc_cset_recorded_rs_lengths_diffs. double _inc_cset_predicted_elapsed_time_ms_diffs; // Stash a pointer to the g1 heap. G1CollectedHeap* _g1; G1GCPhaseTimes* _phase_times; // The ratio of gc time to elapsed time, computed over recent pauses. double _recent_avg_pause_time_ratio; double recent_avg_pause_time_ratio() const { return _recent_avg_pause_time_ratio; } // 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_remark_start_sec; double _mark_cleanup_start_sec; // Updates the internal young list maximum and target lengths. Returns the // unbounded young list target length. uint update_young_list_max_and_target_length(); uint update_young_list_max_and_target_length(size_t rs_lengths); // Update the young list target length either by setting it to the // desired fixed value or by calculating it using G1's pause // prediction model. If no rs_lengths parameter is passed, predict // the RS lengths using the prediction model, otherwise use the // given rs_lengths as the prediction. // Returns the unbounded young list target length. uint update_young_list_target_length(size_t rs_lengths); // Calculate and return the minimum desired young list target // length. This is the minimum desired young list length according // to the user's inputs. uint calculate_young_list_desired_min_length(uint base_min_length) const; // Calculate and return the maximum desired young list target // length. This is the maximum desired young list length according // to the user's inputs. uint calculate_young_list_desired_max_length() const; // Calculate and return the maximum young list target length that // can fit into the pause time goal. The parameters are: rs_lengths // represent the prediction of how large the young RSet lengths will // be, base_min_length is the already existing number of regions in // the young list, min_length and max_length are the desired min and // max young list length according to the user's inputs. uint calculate_young_list_target_length(size_t rs_lengths, uint base_min_length, uint desired_min_length, uint desired_max_length) const; // Result of the bounded_young_list_target_length() method, containing both the // bounded as well as the unbounded young list target lengths in this order. typedef Pair YoungTargetLengths; YoungTargetLengths young_list_target_lengths(size_t rs_lengths) const; void update_rs_lengths_prediction(); void update_rs_lengths_prediction(size_t prediction); // Calculate and return chunk size (in number of regions) for parallel // concurrent mark cleanup. uint calculate_parallel_work_chunk_size(uint n_workers, uint n_regions) const; // Check whether a given young length (young_length) fits into the // given target pause time and whether the prediction for the amount // of objects to be copied for the given length will fit into the // given free space (expressed by base_free_regions). It is used by // calculate_young_list_target_length(). bool predict_will_fit(uint young_length, double base_time_ms, uint base_free_regions, double target_pause_time_ms) const; // Calculate the minimum number of old regions we'll add to the CSet // during a mixed GC. uint calc_min_old_cset_length() const; // Calculate the maximum number of old regions we'll add to the CSet // during a mixed GC. uint calc_max_old_cset_length() const; // Returns the given amount of uncollected reclaimable space // as a percentage of the current heap capacity. double reclaimable_bytes_perc(size_t reclaimable_bytes) const; // Sets up marking if proper conditions are met. void maybe_start_marking(); // The kind of STW pause. enum PauseKind { FullGC, YoungOnlyGC, MixedGC, LastYoungGC, InitialMarkGC, Cleanup, Remark }; // Calculate PauseKind from internal state. PauseKind young_gc_pause_kind() const; // Record the given STW pause with the given start and end times (in s). void record_pause(PauseKind kind, double start, double end); // Indicate that we aborted marking before doing any mixed GCs. void abort_time_to_mixed_tracking(); public: G1CollectorPolicy(); virtual ~G1CollectorPolicy(); virtual G1CollectorPolicy* as_g1_policy() { return this; } G1CollectorState* collector_state() const; G1GCPhaseTimes* phase_times() const { return _phase_times; } // Check the current value of the young list RSet lengths and // compare it against the last prediction. If the current value is // higher, recalculate the young list target length prediction. void revise_young_list_target_length_if_necessary(); // This should be called after the heap is resized. void record_new_heap_size(uint new_number_of_regions); void init(); virtual void note_gc_start(uint num_active_workers); // 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); bool need_to_start_conc_mark(const char* source, size_t alloc_word_size = 0); bool about_to_start_mixed_phase() const; // Record the start and end of an evacuation pause. void record_collection_pause_start(double start_time_sec); void record_collection_pause_end(double pause_time_ms, size_t cards_scanned); // Record the start and end of a full collection. void record_full_collection_start(); void record_full_collection_end(); // Must currently be called while the world is stopped. void record_concurrent_mark_init_end(double mark_init_elapsed_time_ms); // Record start and end of remark. void record_concurrent_mark_remark_start(); void record_concurrent_mark_remark_end(); // Record start, end, and completion of cleanup. void record_concurrent_mark_cleanup_start(); void record_concurrent_mark_cleanup_end(); void record_concurrent_mark_cleanup_completed(); // Records the information about the heap size for reporting in // print_detailed_heap_transition void record_heap_size_info_at_start(bool full); // Print heap sizing transition (with less and more detail). void print_heap_transition(size_t bytes_before) const; void print_heap_transition() const; void print_detailed_heap_transition(bool full = false) const; virtual void print_phases(double pause_time_sec); void record_stop_world_start(); void record_concurrent_pause(); // Record how much space we copied during a GC. This is typically // called when a GC alloc region is being retired. void record_bytes_copied_during_gc(size_t bytes) { _bytes_copied_during_gc += bytes; } // The amount of space we copied during a GC. size_t bytes_copied_during_gc() const { return _bytes_copied_during_gc; } size_t collection_set_bytes_used_before() const { return _collection_set_bytes_used_before; } // Determine whether there are candidate regions so that the // next GC should be mixed. The two action strings are used // in the ergo output when the method returns true or false. bool next_gc_should_be_mixed(const char* true_action_str, const char* false_action_str) const; // 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. double finalize_young_cset_part(double target_pause_time_ms); virtual void finalize_old_cset_part(double time_remaining_ms); // The head of the list (via "next_in_collection_set()") representing the // current collection set. HeapRegion* collection_set() { return _collection_set; } void clear_collection_set() { _collection_set = NULL; } // Add old region "hr" to the CSet. void add_old_region_to_cset(HeapRegion* hr); // Incremental CSet Support // The head of the incrementally built collection set. HeapRegion* inc_cset_head() { return _inc_cset_head; } // The tail of the incrementally built collection set. HeapRegion* inc_set_tail() { return _inc_cset_tail; } // Initialize incremental collection set info. void start_incremental_cset_building(); // Perform any final calculations on the incremental CSet fields // before we can use them. void finalize_incremental_cset_building(); void clear_incremental_cset() { _inc_cset_head = NULL; _inc_cset_tail = NULL; } // Stop adding regions to the incremental collection set void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; } // Add information about hr to the aggregated information for the // incrementally built collection set. void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length); // Update information about hr in the aggregated information for // the incrementally built collection set. void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length); private: // Update the incremental cset information when adding a region // (should not be called directly). void add_region_to_incremental_cset_common(HeapRegion* hr); public: // Add hr to the LHS of the incremental collection set. void add_region_to_incremental_cset_lhs(HeapRegion* hr); // Add hr to the RHS of the incremental collection set. void add_region_to_incremental_cset_rhs(HeapRegion* hr); #ifndef PRODUCT void print_collection_set(HeapRegion* list_head, outputStream* st); #endif // !PRODUCT // This sets the initiate_conc_mark_if_possible() flag to start a // new cycle, as long as we are not already in one. It's best if it // is called during a safepoint when the test whether a cycle is in // progress or not is stable. bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause); // This is called at the very beginning of an evacuation pause (it // has to be the first thing that the pause does). If // initiate_conc_mark_if_possible() is true, and the concurrent // marking thread has completed its work during the previous cycle, // it will set during_initial_mark_pause() to so that the pause does // the initial-mark work and start a marking cycle. void decide_on_conc_mark_initiation(); // 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() const; // 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 } size_t young_list_target_length() const { return _young_list_target_length; } bool is_young_list_full() const; bool can_expand_young_list() const; uint young_list_max_length() const { return _young_list_max_length; } bool adaptive_young_list_length() const { return _young_gen_sizer->adaptive_young_list_length(); } private: // // Survivor regions policy. // // Current tenuring threshold, set to 0 if the collector reaches the // maximum amount of survivors regions. uint _tenuring_threshold; // The limit on the number of regions allocated for survivors. uint _max_survivor_regions; // For reporting purposes. // The value of _heap_bytes_before_gc is also used to calculate // the cost of copying. size_t _eden_used_bytes_before_gc; // Eden occupancy before GC size_t _survivor_used_bytes_before_gc; // Survivor occupancy before GC size_t _heap_used_bytes_before_gc; // Heap occupancy before GC size_t _metaspace_used_bytes_before_gc; // Metaspace occupancy before GC size_t _eden_capacity_bytes_before_gc; // Eden capacity before GC size_t _heap_capacity_bytes_before_gc; // Heap capacity before GC // The amount of survivor regions after a collection. uint _recorded_survivor_regions; // List of survivor regions. HeapRegion* _recorded_survivor_head; HeapRegion* _recorded_survivor_tail; ageTable _survivors_age_table; public: uint tenuring_threshold() const { return _tenuring_threshold; } static const uint REGIONS_UNLIMITED = (uint) -1; uint max_regions(InCSetState dest) const { switch (dest.value()) { case InCSetState::Young: return _max_survivor_regions; case InCSetState::Old: return REGIONS_UNLIMITED; default: assert(false, "Unknown dest state: " CSETSTATE_FORMAT, dest.value()); break; } // keep some compilers happy return 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(uint regions, HeapRegion* head, HeapRegion* tail) { _recorded_survivor_regions = regions; _recorded_survivor_head = head; _recorded_survivor_tail = tail; } uint recorded_survivor_regions() const { return _recorded_survivor_regions; } void record_age_table(ageTable* age_table) { _survivors_age_table.merge(age_table); } void update_max_gc_locker_expansion(); // Calculates survivor space parameters. void update_survivors_policy(); virtual void post_heap_initialize(); }; #endif // SHARE_VM_GC_G1_G1COLLECTORPOLICY_HPP