Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp @ 11813:9af8b109ec0f
Truffle: force slow path on StringBuilder methods.
author | Andreas Woess <andreas.woess@jku.at> |
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date | Thu, 26 Sep 2013 16:44:54 +0200 |
parents | f2110083203d |
children | 4288e54fd145 |
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/* * Copyright (c) 2001, 2013, 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; class G1GCPhaseTimes; // TraceGen0Time collects data on _both_ young and mixed evacuation pauses // (the latter may contain non-young regions - i.e. regions that are // technically in Gen1) while TraceGen1Time collects data about full GCs. class TraceGen0TimeData : public CHeapObj<mtGC> { 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: TraceGen0TimeData() : _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 TraceGen1TimeData : public CHeapObj<mtGC> { 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 // 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<mtGC> { 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(); } 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; TraceGen0TimeData _trace_gen0_time_data; TraceGen1TimeData _trace_gen1_time_data; double _stop_world_start; // indicates whether we are in young or mixed GC mode bool _gcs_are_young; 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; 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* _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 _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; size_t _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_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 for_young_gc); 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(); } double predict_survivor_regions_evac_time(); void cset_regions_freed() { bool propagate = _last_gc_was_young && !_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 } G1MMUTracker* mmu_tracker() { return _mmu_tracker; } double max_pause_time_ms() { return _mmu_tracker->max_gc_time() * 1000.0; } 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); } 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_cset() 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 periodcially samples the young // region RSets and needs to update _inc_cset_recorded_rs_lengths as // the RSets grow. Instead of having to syncronize 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() { return _recent_avg_pause_time_ratio; } // At the end of a pause we check the heap occupancy and we decide // whether we will start a marking cycle during the next pause. If // we decide that we want to do that, we will set this parameter to // true. So, this parameter will stay true between the end of a // pause and the beginning of a subsequent pause (not necessarily // the next one, see the comments on the next field) when we decide // that we will indeed start a marking cycle and do the initial-mark // work. volatile bool _initiate_conc_mark_if_possible; // If initiate_conc_mark_if_possible() is set at the beginning of a // pause, it is a suggestion that the pause should start a marking // cycle by doing the initial-mark work. However, it is possible // that the concurrent marking thread is still finishing up the // previous marking cycle (e.g., clearing the next marking // bitmap). If that is the case we cannot start a new cycle and // we'll have to wait for the concurrent marking thread to finish // what it is doing. In this case we will postpone the marking cycle // initiation decision for the next pause. When we eventually decide // to start a cycle, we will set _during_initial_mark_pause which // will stay true until the end of the initial-mark pause and it's // the condition that indicates that a pause is doing the // initial-mark work. volatile bool _during_initial_mark_pause; bool _last_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_remark_start_sec; double _mark_cleanup_start_sec; // 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. void update_young_list_target_length(size_t rs_lengths = (size_t) -1); // 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); // 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(); // 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 alreay 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); // 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); // Calculate the minimum number of old regions we'll add to the CSet // during a mixed GC. uint calc_min_old_cset_length(); // Calculate the maximum number of old regions we'll add to the CSet // during a mixed GC. uint calc_max_old_cset_length(); // Returns the given amount of uncollected reclaimable space // as a percentage of the current heap capacity. double reclaimable_bytes_perc(size_t reclaimable_bytes); public: G1CollectorPolicy(); virtual G1CollectorPolicy* as_g1_policy() { return this; } virtual CollectorPolicy::Name kind() { return CollectorPolicy::G1CollectorPolicyKind; } 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(); // 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; } bool need_to_start_conc_mark(const char* source, size_t alloc_word_size = 0); // 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, EvacuationInfo& evacuation_info); // 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(int no_of_gc_threads); 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(); void print_detailed_heap_transition(bool full = false); 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() { return _bytes_copied_during_gc; } // 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); // 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. void finalize_cset(double target_pause_time_ms, EvacuationInfo& evacuation_info); // 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 bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; } void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; } void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; } bool during_initial_mark_pause() { return _during_initial_mark_pause; } void set_during_initial_mark_pause() { _during_initial_mark_pause = true; } void clear_during_initial_mark_pause(){ _during_initial_mark_pause = false; } // 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. size_t expansion_amount(); // 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 is_young_list_full() { uint young_list_length = _g1->young_list()->length(); uint young_list_target_length = _young_list_target_length; return young_list_length >= young_list_target_length; } bool can_expand_young_list() { uint young_list_length = _g1->young_list()->length(); uint young_list_max_length = _young_list_max_length; return young_list_length < young_list_max_length; } uint young_list_max_length() { return _young_list_max_length; } bool gcs_are_young() { return _gcs_are_young; } void set_gcs_are_young(bool gcs_are_young) { _gcs_are_young = gcs_are_young; } bool adaptive_young_list_length() { 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; } inline GCAllocPurpose evacuation_destination(HeapRegion* src_region, uint 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; } static const uint REGIONS_UNLIMITED = (uint) -1; uint 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(uint regions, HeapRegion* head, HeapRegion* tail) { _recorded_survivor_regions = regions; _recorded_survivor_head = head; _recorded_survivor_tail = tail; } uint recorded_survivor_regions() { return _recorded_survivor_regions; } void record_thread_age_table(ageTable* age_table) { _survivors_age_table.merge_par(age_table); } void update_max_gc_locker_expansion(); // Calculates survivor space parameters. void update_survivors_policy(); }; // This should move to some place more general... // If we have "n" measurements, and we've kept track of their "sum" and the // "sum_of_squares" of the measurements, this returns the variance of the // sequence. 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; } #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP