1 /*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_GC_G1_G1COLLECTORPOLICY_HPP
26 #define SHARE_VM_GC_G1_G1COLLECTORPOLICY_HPP
27
28 #include "gc/g1/collectionSetChooser.hpp"
29 #include "gc/g1/g1CollectorState.hpp"
30 #include "gc/g1/g1GCPhaseTimes.hpp"
31 #include "gc/g1/g1InCSetState.hpp"
32 #include "gc/g1/g1InitialMarkToMixedTimeTracker.hpp"
33 #include "gc/g1/g1MMUTracker.hpp"
34 #include "gc/g1/g1Predictions.hpp"
35 #include "gc/shared/collectorPolicy.hpp"
36 #include "utilities/pair.hpp"
37
38 // A G1CollectorPolicy makes policy decisions that determine the
39 // characteristics of the collector. Examples include:
40 // * choice of collection set.
41 // * when to collect.
42
43 class HeapRegion;
44 class CollectionSetChooser;
45 class G1IHOPControl;
46 class G1YoungGenSizer;
47
48 class G1CollectorPolicy: public CollectorPolicy {
49 private:
50 G1IHOPControl* _ihop_control;
51
52 G1IHOPControl* create_ihop_control() const;
53 // Update the IHOP control with necessary statistics.
54 void update_ihop_prediction(double mutator_time_s,
55 size_t mutator_alloc_bytes,
56 size_t young_gen_size);
57 void report_ihop_statistics();
58
59 G1Predictions _predictor;
60
61 double get_new_prediction(TruncatedSeq const* seq) const;
62 size_t get_new_size_prediction(TruncatedSeq const* seq) const;
63
64 G1MMUTracker* _mmu_tracker;
65
66 void initialize_alignments();
67 void initialize_flags();
68
69 CollectionSetChooser* _cset_chooser;
70
71 double _full_collection_start_sec;
72
73 // These exclude marking times.
74 TruncatedSeq* _recent_gc_times_ms;
75
76 TruncatedSeq* _concurrent_mark_remark_times_ms;
77 TruncatedSeq* _concurrent_mark_cleanup_times_ms;
78
79 // Ratio check data for determining if heap growth is necessary.
80 uint _ratio_over_threshold_count;
81 double _ratio_over_threshold_sum;
82 uint _pauses_since_start;
83
84 uint _young_list_target_length;
85 uint _young_list_fixed_length;
86
87 // The max number of regions we can extend the eden by while the GC
88 // locker is active. This should be >= _young_list_target_length;
89 uint _young_list_max_length;
90
91 SurvRateGroup* _short_lived_surv_rate_group;
92 SurvRateGroup* _survivor_surv_rate_group;
93 // add here any more surv rate groups
94
95 double _gc_overhead_perc;
96
97 double _reserve_factor;
98 uint _reserve_regions;
99
100 enum PredictionConstants {
101 TruncatedSeqLength = 10,
102 NumPrevPausesForHeuristics = 10,
103 // MinOverThresholdForGrowth must be less than NumPrevPausesForHeuristics,
104 // representing the minimum number of pause time ratios that exceed
105 // GCTimeRatio before a heap expansion will be triggered.
106 MinOverThresholdForGrowth = 4
107 };
108
109 TruncatedSeq* _alloc_rate_ms_seq;
110 double _prev_collection_pause_end_ms;
111
112 TruncatedSeq* _rs_length_diff_seq;
113 TruncatedSeq* _cost_per_card_ms_seq;
114 TruncatedSeq* _cost_scan_hcc_seq;
115 TruncatedSeq* _young_cards_per_entry_ratio_seq;
116 TruncatedSeq* _mixed_cards_per_entry_ratio_seq;
117 TruncatedSeq* _cost_per_entry_ms_seq;
118 TruncatedSeq* _mixed_cost_per_entry_ms_seq;
119 TruncatedSeq* _cost_per_byte_ms_seq;
120 TruncatedSeq* _constant_other_time_ms_seq;
121 TruncatedSeq* _young_other_cost_per_region_ms_seq;
122 TruncatedSeq* _non_young_other_cost_per_region_ms_seq;
123
124 TruncatedSeq* _pending_cards_seq;
125 TruncatedSeq* _rs_lengths_seq;
126
127 TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
128
129 G1YoungGenSizer* _young_gen_sizer;
130
131 uint _eden_cset_region_length;
132 uint _survivor_cset_region_length;
133 uint _old_cset_region_length;
134
135 void init_cset_region_lengths(uint eden_cset_region_length,
136 uint survivor_cset_region_length);
137
138 uint eden_cset_region_length() const { return _eden_cset_region_length; }
139 uint survivor_cset_region_length() const { return _survivor_cset_region_length; }
140 uint old_cset_region_length() const { return _old_cset_region_length; }
141
142 uint _free_regions_at_end_of_collection;
143
144 size_t _recorded_rs_lengths;
145 size_t _max_rs_lengths;
146
147 size_t _rs_lengths_prediction;
148
149 #ifndef PRODUCT
150 bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group);
151 #endif // PRODUCT
152
153 void adjust_concurrent_refinement(double update_rs_time,
154 double update_rs_processed_buffers,
155 double goal_ms);
156
157 double _pause_time_target_ms;
158
159 size_t _pending_cards;
160
161 // The amount of allocated bytes in old gen during the last mutator and the following
162 // young GC phase.
163 size_t _bytes_allocated_in_old_since_last_gc;
164
165 G1InitialMarkToMixedTimeTracker _initial_mark_to_mixed;
166 public:
167 const G1Predictions& predictor() const { return _predictor; }
168
169 // Add the given number of bytes to the total number of allocated bytes in the old gen.
170 void add_bytes_allocated_in_old_since_last_gc(size_t bytes) { _bytes_allocated_in_old_since_last_gc += bytes; }
171
172 // Accessors
173
174 void set_region_eden(HeapRegion* hr, int young_index_in_cset) {
175 hr->set_eden();
176 hr->install_surv_rate_group(_short_lived_surv_rate_group);
177 hr->set_young_index_in_cset(young_index_in_cset);
178 }
179
180 void set_region_survivor(HeapRegion* hr, int young_index_in_cset) {
181 assert(hr->is_survivor(), "pre-condition");
182 hr->install_surv_rate_group(_survivor_surv_rate_group);
183 hr->set_young_index_in_cset(young_index_in_cset);
184 }
185
186 #ifndef PRODUCT
187 bool verify_young_ages();
188 #endif // PRODUCT
189
190 void record_max_rs_lengths(size_t rs_lengths) {
191 _max_rs_lengths = rs_lengths;
192 }
193
194 size_t predict_rs_length_diff() const;
195
196 double predict_alloc_rate_ms() const;
197
198 double predict_cost_per_card_ms() const;
199
200 double predict_scan_hcc_ms() const;
201
202 double predict_rs_update_time_ms(size_t pending_cards) const;
203
204 double predict_young_cards_per_entry_ratio() const;
205
206 double predict_mixed_cards_per_entry_ratio() const;
207
208 size_t predict_young_card_num(size_t rs_length) const;
209
210 size_t predict_non_young_card_num(size_t rs_length) const;
211
212 double predict_rs_scan_time_ms(size_t card_num) const;
213
214 double predict_mixed_rs_scan_time_ms(size_t card_num) const;
215
216 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const;
217
218 double predict_object_copy_time_ms(size_t bytes_to_copy) const;
219
220 double predict_constant_other_time_ms() const;
221
222 double predict_young_other_time_ms(size_t young_num) const;
223
224 double predict_non_young_other_time_ms(size_t non_young_num) const;
225
226 double predict_base_elapsed_time_ms(size_t pending_cards) const;
227 double predict_base_elapsed_time_ms(size_t pending_cards,
228 size_t scanned_cards) const;
229 size_t predict_bytes_to_copy(HeapRegion* hr) const;
230 double predict_region_elapsed_time_ms(HeapRegion* hr, bool for_young_gc) const;
231
232 void set_recorded_rs_lengths(size_t rs_lengths);
233
234 uint cset_region_length() const { return young_cset_region_length() +
235 old_cset_region_length(); }
236 uint young_cset_region_length() const { return eden_cset_region_length() +
237 survivor_cset_region_length(); }
238
239 double predict_survivor_regions_evac_time() const;
240
241 bool should_update_surv_rate_group_predictors() {
242 return collector_state()->last_gc_was_young() && !collector_state()->in_marking_window();
243 }
244
245 void cset_regions_freed() {
246 bool update = should_update_surv_rate_group_predictors();
247
248 _short_lived_surv_rate_group->all_surviving_words_recorded(update);
249 _survivor_surv_rate_group->all_surviving_words_recorded(update);
250 }
251
252 G1MMUTracker* mmu_tracker() {
253 return _mmu_tracker;
254 }
255
256 const G1MMUTracker* mmu_tracker() const {
257 return _mmu_tracker;
258 }
259
260 double max_pause_time_ms() const {
261 return _mmu_tracker->max_gc_time() * 1000.0;
262 }
263
264 double predict_remark_time_ms() const;
265
266 double predict_cleanup_time_ms() const;
267
268 // Returns an estimate of the survival rate of the region at yg-age
269 // "yg_age".
270 double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) const;
271
272 double predict_yg_surv_rate(int age) const;
273
274 double accum_yg_surv_rate_pred(int age) const;
275
276 protected:
277 virtual double average_time_ms(G1GCPhaseTimes::GCParPhases phase) const;
278 virtual double other_time_ms(double pause_time_ms) const;
279
280 double young_other_time_ms() const;
281 double non_young_other_time_ms() const;
282 double constant_other_time_ms(double pause_time_ms) const;
283
284 CollectionSetChooser* cset_chooser() const {
285 return _cset_chooser;
286 }
287
288 private:
289 // Statistics kept per GC stoppage, pause or full.
290 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;
291
292 // Add a new GC of the given duration and end time to the record.
293 void update_recent_gc_times(double end_time_sec, double elapsed_ms);
294
295 // The head of the list (via "next_in_collection_set()") representing the
296 // current collection set. Set from the incrementally built collection
297 // set at the start of the pause.
298 HeapRegion* _collection_set;
299
300 // The number of bytes in the collection set before the pause. Set from
301 // the incrementally built collection set at the start of an evacuation
302 // pause, and incremented in finalize_old_cset_part() when adding old regions
303 // (if any) to the collection set.
304 size_t _collection_set_bytes_used_before;
305
306 // The number of bytes copied during the GC.
307 size_t _bytes_copied_during_gc;
308
309 // The associated information that is maintained while the incremental
310 // collection set is being built with young regions. Used to populate
311 // the recorded info for the evacuation pause.
312
313 enum CSetBuildType {
314 Active, // We are actively building the collection set
315 Inactive // We are not actively building the collection set
316 };
317
318 CSetBuildType _inc_cset_build_state;
319
320 // The head of the incrementally built collection set.
321 HeapRegion* _inc_cset_head;
322
323 // The tail of the incrementally built collection set.
324 HeapRegion* _inc_cset_tail;
325
326 // The number of bytes in the incrementally built collection set.
327 // Used to set _collection_set_bytes_used_before at the start of
328 // an evacuation pause.
329 size_t _inc_cset_bytes_used_before;
330
331 // The RSet lengths recorded for regions in the CSet. It is updated
332 // by the thread that adds a new region to the CSet. We assume that
333 // only one thread can be allocating a new CSet region (currently,
334 // it does so after taking the Heap_lock) hence no need to
335 // synchronize updates to this field.
336 size_t _inc_cset_recorded_rs_lengths;
337
338 // A concurrent refinement thread periodically samples the young
339 // region RSets and needs to update _inc_cset_recorded_rs_lengths as
340 // the RSets grow. Instead of having to synchronize updates to that
341 // field we accumulate them in this field and add it to
342 // _inc_cset_recorded_rs_lengths_diffs at the start of a GC.
343 ssize_t _inc_cset_recorded_rs_lengths_diffs;
344
345 // The predicted elapsed time it will take to collect the regions in
346 // the CSet. This is updated by the thread that adds a new region to
347 // the CSet. See the comment for _inc_cset_recorded_rs_lengths about
348 // MT-safety assumptions.
349 double _inc_cset_predicted_elapsed_time_ms;
350
351 // See the comment for _inc_cset_recorded_rs_lengths_diffs.
352 double _inc_cset_predicted_elapsed_time_ms_diffs;
353
354 // Stash a pointer to the g1 heap.
355 G1CollectedHeap* _g1;
356
357 G1GCPhaseTimes* _phase_times;
358
359 // The ratio of gc time to elapsed time, computed over recent pauses,
360 // and the ratio for just the last pause.
361 double _recent_avg_pause_time_ratio;
362 double _last_pause_time_ratio;
363
364 double recent_avg_pause_time_ratio() const {
365 return _recent_avg_pause_time_ratio;
366 }
367
368 // This set of variables tracks the collector efficiency, in order to
369 // determine whether we should initiate a new marking.
370 double _mark_remark_start_sec;
371 double _mark_cleanup_start_sec;
372
373 // Updates the internal young list maximum and target lengths. Returns the
374 // unbounded young list target length.
375 uint update_young_list_max_and_target_length();
376 uint update_young_list_max_and_target_length(size_t rs_lengths);
377
378 // Update the young list target length either by setting it to the
379 // desired fixed value or by calculating it using G1's pause
380 // prediction model. If no rs_lengths parameter is passed, predict
381 // the RS lengths using the prediction model, otherwise use the
382 // given rs_lengths as the prediction.
383 // Returns the unbounded young list target length.
384 uint update_young_list_target_length(size_t rs_lengths);
385
386 // Calculate and return the minimum desired young list target
387 // length. This is the minimum desired young list length according
388 // to the user's inputs.
389 uint calculate_young_list_desired_min_length(uint base_min_length) const;
390
391 // Calculate and return the maximum desired young list target
392 // length. This is the maximum desired young list length according
393 // to the user's inputs.
394 uint calculate_young_list_desired_max_length() const;
395
396 // Calculate and return the maximum young list target length that
397 // can fit into the pause time goal. The parameters are: rs_lengths
398 // represent the prediction of how large the young RSet lengths will
399 // be, base_min_length is the already existing number of regions in
400 // the young list, min_length and max_length are the desired min and
401 // max young list length according to the user's inputs.
402 uint calculate_young_list_target_length(size_t rs_lengths,
403 uint base_min_length,
404 uint desired_min_length,
405 uint desired_max_length) const;
406
407 // Result of the bounded_young_list_target_length() method, containing both the
408 // bounded as well as the unbounded young list target lengths in this order.
409 typedef Pair<uint, uint, StackObj> YoungTargetLengths;
410 YoungTargetLengths young_list_target_lengths(size_t rs_lengths) const;
411
412 void update_rs_lengths_prediction();
413 void update_rs_lengths_prediction(size_t prediction);
414
415 // Calculate and return chunk size (in number of regions) for parallel
416 // concurrent mark cleanup.
417 uint calculate_parallel_work_chunk_size(uint n_workers, uint n_regions) const;
418
419 // Check whether a given young length (young_length) fits into the
420 // given target pause time and whether the prediction for the amount
421 // of objects to be copied for the given length will fit into the
422 // given free space (expressed by base_free_regions). It is used by
423 // calculate_young_list_target_length().
424 bool predict_will_fit(uint young_length, double base_time_ms,
425 uint base_free_regions, double target_pause_time_ms) const;
426
427 // Calculate the minimum number of old regions we'll add to the CSet
428 // during a mixed GC.
429 uint calc_min_old_cset_length() const;
430
431 // Calculate the maximum number of old regions we'll add to the CSet
432 // during a mixed GC.
433 uint calc_max_old_cset_length() const;
434
435 // Returns the given amount of uncollected reclaimable space
436 // as a percentage of the current heap capacity.
437 double reclaimable_bytes_perc(size_t reclaimable_bytes) const;
438
439 // Sets up marking if proper conditions are met.
440 void maybe_start_marking();
441
442 // The kind of STW pause.
443 enum PauseKind {
444 FullGC,
445 YoungOnlyGC,
446 MixedGC,
447 LastYoungGC,
448 InitialMarkGC,
449 Cleanup,
450 Remark
451 };
452
453 // Calculate PauseKind from internal state.
454 PauseKind young_gc_pause_kind() const;
455 // Record the given STW pause with the given start and end times (in s).
456 void record_pause(PauseKind kind, double start, double end);
457 // Indicate that we aborted marking before doing any mixed GCs.
458 void abort_time_to_mixed_tracking();
459 public:
460
461 G1CollectorPolicy();
462
463 virtual ~G1CollectorPolicy();
464
465 virtual G1CollectorPolicy* as_g1_policy() { return this; }
466
467 G1CollectorState* collector_state() const;
468
469 G1GCPhaseTimes* phase_times() const { return _phase_times; }
470
471 // Check the current value of the young list RSet lengths and
472 // compare it against the last prediction. If the current value is
473 // higher, recalculate the young list target length prediction.
474 void revise_young_list_target_length_if_necessary(size_t rs_lengths);
475
476 // This should be called after the heap is resized.
477 void record_new_heap_size(uint new_number_of_regions);
478
479 void init();
480
481 virtual void note_gc_start(uint num_active_workers);
482
483 // Create jstat counters for the policy.
484 virtual void initialize_gc_policy_counters();
485
486 bool need_to_start_conc_mark(const char* source, size_t alloc_word_size = 0);
487
488 bool about_to_start_mixed_phase() const;
489
490 // Record the start and end of an evacuation pause.
491 void record_collection_pause_start(double start_time_sec);
492 void record_collection_pause_end(double pause_time_ms, size_t cards_scanned, size_t heap_used_bytes_before_gc);
493
494 // Record the start and end of a full collection.
495 void record_full_collection_start();
496 void record_full_collection_end();
497
498 // Must currently be called while the world is stopped.
499 void record_concurrent_mark_init_end(double mark_init_elapsed_time_ms);
500
501 // Record start and end of remark.
502 void record_concurrent_mark_remark_start();
503 void record_concurrent_mark_remark_end();
504
505 // Record start, end, and completion of cleanup.
506 void record_concurrent_mark_cleanup_start();
507 void record_concurrent_mark_cleanup_end();
508 void record_concurrent_mark_cleanup_completed();
509
510 virtual void print_phases();
511
512 // Record how much space we copied during a GC. This is typically
513 // called when a GC alloc region is being retired.
514 void record_bytes_copied_during_gc(size_t bytes) {
515 _bytes_copied_during_gc += bytes;
516 }
517
518 // The amount of space we copied during a GC.
519 size_t bytes_copied_during_gc() const {
520 return _bytes_copied_during_gc;
521 }
522
523 size_t collection_set_bytes_used_before() const {
524 return _collection_set_bytes_used_before;
525 }
526
527 // Determine whether there are candidate regions so that the
528 // next GC should be mixed. The two action strings are used
529 // in the ergo output when the method returns true or false.
530 bool next_gc_should_be_mixed(const char* true_action_str,
531 const char* false_action_str) const;
532
533 // Choose a new collection set. Marks the chosen regions as being
534 // "in_collection_set", and links them together. The head and number of
535 // the collection set are available via access methods.
536 double finalize_young_cset_part(double target_pause_time_ms);
537 virtual void finalize_old_cset_part(double time_remaining_ms);
538
539 // The head of the list (via "next_in_collection_set()") representing the
540 // current collection set.
541 HeapRegion* collection_set() { return _collection_set; }
542
543 void clear_collection_set() { _collection_set = NULL; }
544
545 // Add old region "hr" to the CSet.
546 void add_old_region_to_cset(HeapRegion* hr);
547
548 // Incremental CSet Support
549
550 // The head of the incrementally built collection set.
551 HeapRegion* inc_cset_head() { return _inc_cset_head; }
552
553 // The tail of the incrementally built collection set.
554 HeapRegion* inc_set_tail() { return _inc_cset_tail; }
555
556 // Initialize incremental collection set info.
557 void start_incremental_cset_building();
558
559 // Perform any final calculations on the incremental CSet fields
560 // before we can use them.
561 void finalize_incremental_cset_building();
562
563 void clear_incremental_cset() {
564 _inc_cset_head = NULL;
565 _inc_cset_tail = NULL;
566 }
567
568 // Stop adding regions to the incremental collection set
569 void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
570
571 // Add information about hr to the aggregated information for the
572 // incrementally built collection set.
573 void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
574
575 // Update information about hr in the aggregated information for
576 // the incrementally built collection set.
577 void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
578
579 private:
580 // Update the incremental cset information when adding a region
581 // (should not be called directly).
582 void add_region_to_incremental_cset_common(HeapRegion* hr);
583
584 // Set the state to start a concurrent marking cycle and clear
585 // _initiate_conc_mark_if_possible because it has now been
586 // acted on.
587 void initiate_conc_mark();
588
589 public:
590 // Add hr to the LHS of the incremental collection set.
591 void add_region_to_incremental_cset_lhs(HeapRegion* hr);
592
593 // Add hr to the RHS of the incremental collection set.
594 void add_region_to_incremental_cset_rhs(HeapRegion* hr);
595
596 #ifndef PRODUCT
597 void print_collection_set(HeapRegion* list_head, outputStream* st);
598 #endif // !PRODUCT
599
600 // This sets the initiate_conc_mark_if_possible() flag to start a
601 // new cycle, as long as we are not already in one. It's best if it
602 // is called during a safepoint when the test whether a cycle is in
603 // progress or not is stable.
604 bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause);
605
606 // This is called at the very beginning of an evacuation pause (it
607 // has to be the first thing that the pause does). If
608 // initiate_conc_mark_if_possible() is true, and the concurrent
609 // marking thread has completed its work during the previous cycle,
610 // it will set during_initial_mark_pause() to so that the pause does
611 // the initial-mark work and start a marking cycle.
612 void decide_on_conc_mark_initiation();
613
614 // If an expansion would be appropriate, because recent GC overhead had
615 // exceeded the desired limit, return an amount to expand by.
616 virtual size_t expansion_amount();
617
618 // Clear ratio tracking data used by expansion_amount().
619 void clear_ratio_check_data();
620
621 // Print stats on young survival ratio
622 void print_yg_surv_rate_info() const;
623
624 void finished_recalculating_age_indexes(bool is_survivors) {
625 if (is_survivors) {
626 _survivor_surv_rate_group->finished_recalculating_age_indexes();
627 } else {
628 _short_lived_surv_rate_group->finished_recalculating_age_indexes();
629 }
630 // do that for any other surv rate groups
631 }
632
633 size_t young_list_target_length() const { return _young_list_target_length; }
634
635 bool is_young_list_full() const;
636
637 bool can_expand_young_list() const;
638
639 uint young_list_max_length() const {
640 return _young_list_max_length;
641 }
642
643 bool adaptive_young_list_length() const;
644
645 virtual bool should_process_references() const {
646 return true;
647 }
648
649 private:
650 //
651 // Survivor regions policy.
652 //
653
654 // Current tenuring threshold, set to 0 if the collector reaches the
655 // maximum amount of survivors regions.
656 uint _tenuring_threshold;
657
658 // The limit on the number of regions allocated for survivors.
659 uint _max_survivor_regions;
660
661 // For reporting purposes.
662 // The value of _heap_bytes_before_gc is also used to calculate
663 // the cost of copying.
664
665 // The amount of survivor regions after a collection.
666 uint _recorded_survivor_regions;
667 // List of survivor regions.
668 HeapRegion* _recorded_survivor_head;
669 HeapRegion* _recorded_survivor_tail;
670
671 AgeTable _survivors_age_table;
672
673 public:
674 uint tenuring_threshold() const { return _tenuring_threshold; }
675
676 uint max_survivor_regions() {
677 return _max_survivor_regions;
678 }
679
680 static const uint REGIONS_UNLIMITED = (uint) -1;
681
682 uint max_regions(InCSetState dest) const {
683 switch (dest.value()) {
684 case InCSetState::Young:
685 return _max_survivor_regions;
686 case InCSetState::Old:
687 return REGIONS_UNLIMITED;
688 default:
689 assert(false, "Unknown dest state: " CSETSTATE_FORMAT, dest.value());
690 break;
691 }
692 // keep some compilers happy
693 return 0;
694 }
695
696 void note_start_adding_survivor_regions() {
697 _survivor_surv_rate_group->start_adding_regions();
698 }
699
700 void note_stop_adding_survivor_regions() {
701 _survivor_surv_rate_group->stop_adding_regions();
702 }
703
704 void record_survivor_regions(uint regions,
705 HeapRegion* head,
706 HeapRegion* tail) {
707 _recorded_survivor_regions = regions;
708 _recorded_survivor_head = head;
709 _recorded_survivor_tail = tail;
710 }
711
712 uint recorded_survivor_regions() const {
713 return _recorded_survivor_regions;
714 }
715
716 void record_age_table(AgeTable* age_table) {
717 _survivors_age_table.merge(age_table);
718 }
719
720 void update_max_gc_locker_expansion();
721
722 // Calculates survivor space parameters.
723 void update_survivors_policy();
724
725 virtual void post_heap_initialize();
726 };
727
728 #endif // SHARE_VM_GC_G1_G1COLLECTORPOLICY_HPP