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rev 2591 : [mq]: g1-reference-processing
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--- old/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
+++ new/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
1 1 /*
2 2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 20 * or visit www.oracle.com if you need additional information or have any
21 21 * questions.
22 22 *
23 23 */
24 24
25 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
26 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
27 27
28 28 #include "gc_implementation/g1/collectionSetChooser.hpp"
29 29 #include "gc_implementation/g1/g1MMUTracker.hpp"
30 30 #include "memory/collectorPolicy.hpp"
31 31
32 32 // A G1CollectorPolicy makes policy decisions that determine the
33 33 // characteristics of the collector. Examples include:
34 34 // * choice of collection set.
35 35 // * when to collect.
36 36
37 37 class HeapRegion;
38 38 class CollectionSetChooser;
39 39
40 40 // Yes, this is a bit unpleasant... but it saves replicating the same thing
41 41 // over and over again and introducing subtle problems through small typos and
42 42 // cutting and pasting mistakes. The macros below introduces a number
43 43 // sequnce into the following two classes and the methods that access it.
44 44
45 45 #define define_num_seq(name) \
46 46 private: \
47 47 NumberSeq _all_##name##_times_ms; \
48 48 public: \
49 49 void record_##name##_time_ms(double ms) { \
50 50 _all_##name##_times_ms.add(ms); \
51 51 } \
52 52 NumberSeq* get_##name##_seq() { \
53 53 return &_all_##name##_times_ms; \
54 54 }
55 55
56 56 class MainBodySummary;
57 57
58 58 class PauseSummary: public CHeapObj {
59 59 define_num_seq(total)
60 60 define_num_seq(other)
61 61
62 62 public:
63 63 virtual MainBodySummary* main_body_summary() { return NULL; }
64 64 };
65 65
66 66 class MainBodySummary: public CHeapObj {
67 67 define_num_seq(satb_drain) // optional
68 68 define_num_seq(parallel) // parallel only
69 69 define_num_seq(ext_root_scan)
70 70 define_num_seq(mark_stack_scan)
71 71 define_num_seq(update_rs)
72 72 define_num_seq(scan_rs)
73 73 define_num_seq(obj_copy)
74 74 define_num_seq(termination) // parallel only
75 75 define_num_seq(parallel_other) // parallel only
76 76 define_num_seq(mark_closure)
77 77 define_num_seq(clear_ct) // parallel only
78 78 };
79 79
80 80 class Summary: public PauseSummary,
81 81 public MainBodySummary {
82 82 public:
83 83 virtual MainBodySummary* main_body_summary() { return this; }
84 84 };
85 85
86 86 class G1CollectorPolicy: public CollectorPolicy {
87 87 protected:
88 88 // The number of pauses during the execution.
89 89 long _n_pauses;
90 90
91 91 // either equal to the number of parallel threads, if ParallelGCThreads
92 92 // has been set, or 1 otherwise
93 93 int _parallel_gc_threads;
94 94
95 95 enum SomePrivateConstants {
96 96 NumPrevPausesForHeuristics = 10
97 97 };
98 98
99 99 G1MMUTracker* _mmu_tracker;
100 100
101 101 void initialize_flags();
102 102
103 103 void initialize_all() {
104 104 initialize_flags();
105 105 initialize_size_info();
106 106 initialize_perm_generation(PermGen::MarkSweepCompact);
107 107 }
108 108
109 109 virtual size_t default_init_heap_size() {
110 110 // Pick some reasonable default.
111 111 return 8*M;
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112 112 }
113 113
114 114 double _cur_collection_start_sec;
115 115 size_t _cur_collection_pause_used_at_start_bytes;
116 116 size_t _cur_collection_pause_used_regions_at_start;
117 117 size_t _prev_collection_pause_used_at_end_bytes;
118 118 double _cur_collection_par_time_ms;
119 119 double _cur_satb_drain_time_ms;
120 120 double _cur_clear_ct_time_ms;
121 121 bool _satb_drain_time_set;
122 + double _cur_ref_proc_time_ms;
123 + double _cur_ref_enq_time_ms;
122 124
123 125 #ifndef PRODUCT
124 126 // Card Table Count Cache stats
125 127 double _min_clear_cc_time_ms; // min
126 128 double _max_clear_cc_time_ms; // max
127 129 double _cur_clear_cc_time_ms; // clearing time during current pause
128 130 double _cum_clear_cc_time_ms; // cummulative clearing time
129 131 jlong _num_cc_clears; // number of times the card count cache has been cleared
130 132 #endif
131 133
132 134 // Statistics for recent GC pauses. See below for how indexed.
133 135 TruncatedSeq* _recent_rs_scan_times_ms;
134 136
135 137 // These exclude marking times.
136 138 TruncatedSeq* _recent_pause_times_ms;
137 139 TruncatedSeq* _recent_gc_times_ms;
138 140
139 141 TruncatedSeq* _recent_CS_bytes_used_before;
140 142 TruncatedSeq* _recent_CS_bytes_surviving;
141 143
142 144 TruncatedSeq* _recent_rs_sizes;
143 145
144 146 TruncatedSeq* _concurrent_mark_init_times_ms;
145 147 TruncatedSeq* _concurrent_mark_remark_times_ms;
146 148 TruncatedSeq* _concurrent_mark_cleanup_times_ms;
147 149
148 150 Summary* _summary;
149 151
150 152 NumberSeq* _all_pause_times_ms;
151 153 NumberSeq* _all_full_gc_times_ms;
152 154 double _stop_world_start;
153 155 NumberSeq* _all_stop_world_times_ms;
154 156 NumberSeq* _all_yield_times_ms;
155 157
156 158 size_t _region_num_young;
157 159 size_t _region_num_tenured;
158 160 size_t _prev_region_num_young;
159 161 size_t _prev_region_num_tenured;
160 162
161 163 NumberSeq* _all_mod_union_times_ms;
162 164
163 165 int _aux_num;
164 166 NumberSeq* _all_aux_times_ms;
165 167 double* _cur_aux_start_times_ms;
166 168 double* _cur_aux_times_ms;
167 169 bool* _cur_aux_times_set;
168 170
169 171 double* _par_last_gc_worker_start_times_ms;
170 172 double* _par_last_ext_root_scan_times_ms;
171 173 double* _par_last_mark_stack_scan_times_ms;
172 174 double* _par_last_update_rs_times_ms;
173 175 double* _par_last_update_rs_processed_buffers;
174 176 double* _par_last_scan_rs_times_ms;
175 177 double* _par_last_obj_copy_times_ms;
176 178 double* _par_last_termination_times_ms;
177 179 double* _par_last_termination_attempts;
178 180 double* _par_last_gc_worker_end_times_ms;
179 181 double* _par_last_gc_worker_times_ms;
180 182
181 183 // indicates that we are in young GC mode
182 184 bool _in_young_gc_mode;
183 185
184 186 // indicates whether we are in full young or partially young GC mode
185 187 bool _full_young_gcs;
186 188
187 189 // if true, then it tries to dynamically adjust the length of the
188 190 // young list
189 191 bool _adaptive_young_list_length;
190 192 size_t _young_list_min_length;
191 193 size_t _young_list_target_length;
192 194 size_t _young_list_fixed_length;
193 195
194 196 // The max number of regions we can extend the eden by while the GC
195 197 // locker is active. This should be >= _young_list_target_length;
196 198 size_t _young_list_max_length;
197 199
198 200 size_t _young_cset_length;
199 201 bool _last_young_gc_full;
200 202
201 203 unsigned _full_young_pause_num;
202 204 unsigned _partial_young_pause_num;
203 205
204 206 bool _during_marking;
205 207 bool _in_marking_window;
206 208 bool _in_marking_window_im;
207 209
208 210 SurvRateGroup* _short_lived_surv_rate_group;
209 211 SurvRateGroup* _survivor_surv_rate_group;
210 212 // add here any more surv rate groups
211 213
212 214 double _gc_overhead_perc;
213 215
214 216 bool during_marking() {
215 217 return _during_marking;
216 218 }
217 219
218 220 // <NEW PREDICTION>
219 221
220 222 private:
221 223 enum PredictionConstants {
222 224 TruncatedSeqLength = 10
223 225 };
224 226
225 227 TruncatedSeq* _alloc_rate_ms_seq;
226 228 double _prev_collection_pause_end_ms;
227 229
228 230 TruncatedSeq* _pending_card_diff_seq;
229 231 TruncatedSeq* _rs_length_diff_seq;
230 232 TruncatedSeq* _cost_per_card_ms_seq;
231 233 TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
232 234 TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
233 235 TruncatedSeq* _cost_per_entry_ms_seq;
234 236 TruncatedSeq* _partially_young_cost_per_entry_ms_seq;
235 237 TruncatedSeq* _cost_per_byte_ms_seq;
236 238 TruncatedSeq* _constant_other_time_ms_seq;
237 239 TruncatedSeq* _young_other_cost_per_region_ms_seq;
238 240 TruncatedSeq* _non_young_other_cost_per_region_ms_seq;
239 241
240 242 TruncatedSeq* _pending_cards_seq;
241 243 TruncatedSeq* _scanned_cards_seq;
242 244 TruncatedSeq* _rs_lengths_seq;
243 245
244 246 TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
245 247
246 248 TruncatedSeq* _young_gc_eff_seq;
247 249
248 250 TruncatedSeq* _max_conc_overhead_seq;
249 251
250 252 size_t _recorded_young_regions;
251 253 size_t _recorded_non_young_regions;
252 254 size_t _recorded_region_num;
253 255
254 256 size_t _free_regions_at_end_of_collection;
255 257
256 258 size_t _recorded_rs_lengths;
257 259 size_t _max_rs_lengths;
258 260
259 261 size_t _recorded_marked_bytes;
260 262 size_t _recorded_young_bytes;
261 263
262 264 size_t _predicted_pending_cards;
263 265 size_t _predicted_cards_scanned;
264 266 size_t _predicted_rs_lengths;
265 267 size_t _predicted_bytes_to_copy;
266 268
267 269 double _predicted_survival_ratio;
268 270 double _predicted_rs_update_time_ms;
269 271 double _predicted_rs_scan_time_ms;
270 272 double _predicted_object_copy_time_ms;
271 273 double _predicted_constant_other_time_ms;
272 274 double _predicted_young_other_time_ms;
273 275 double _predicted_non_young_other_time_ms;
274 276 double _predicted_pause_time_ms;
275 277
276 278 double _vtime_diff_ms;
277 279
278 280 double _recorded_young_free_cset_time_ms;
279 281 double _recorded_non_young_free_cset_time_ms;
280 282
281 283 double _sigma;
282 284 double _expensive_region_limit_ms;
283 285
284 286 size_t _rs_lengths_prediction;
285 287
286 288 size_t _known_garbage_bytes;
287 289 double _known_garbage_ratio;
288 290
289 291 double sigma() {
290 292 return _sigma;
291 293 }
292 294
293 295 // A function that prevents us putting too much stock in small sample
294 296 // sets. Returns a number between 2.0 and 1.0, depending on the number
295 297 // of samples. 5 or more samples yields one; fewer scales linearly from
296 298 // 2.0 at 1 sample to 1.0 at 5.
297 299 double confidence_factor(int samples) {
298 300 if (samples > 4) return 1.0;
299 301 else return 1.0 + sigma() * ((double)(5 - samples))/2.0;
300 302 }
301 303
302 304 double get_new_neg_prediction(TruncatedSeq* seq) {
303 305 return seq->davg() - sigma() * seq->dsd();
304 306 }
305 307
306 308 #ifndef PRODUCT
307 309 bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group);
308 310 #endif // PRODUCT
309 311
310 312 void adjust_concurrent_refinement(double update_rs_time,
311 313 double update_rs_processed_buffers,
312 314 double goal_ms);
313 315
314 316 protected:
315 317 double _pause_time_target_ms;
316 318 double _recorded_young_cset_choice_time_ms;
317 319 double _recorded_non_young_cset_choice_time_ms;
318 320 bool _within_target;
319 321 size_t _pending_cards;
320 322 size_t _max_pending_cards;
321 323
322 324 public:
323 325
324 326 void set_region_short_lived(HeapRegion* hr) {
325 327 hr->install_surv_rate_group(_short_lived_surv_rate_group);
326 328 }
327 329
328 330 void set_region_survivors(HeapRegion* hr) {
329 331 hr->install_surv_rate_group(_survivor_surv_rate_group);
330 332 }
331 333
332 334 #ifndef PRODUCT
333 335 bool verify_young_ages();
334 336 #endif // PRODUCT
335 337
336 338 double get_new_prediction(TruncatedSeq* seq) {
337 339 return MAX2(seq->davg() + sigma() * seq->dsd(),
338 340 seq->davg() * confidence_factor(seq->num()));
339 341 }
340 342
341 343 size_t young_cset_length() {
342 344 return _young_cset_length;
343 345 }
344 346
345 347 void record_max_rs_lengths(size_t rs_lengths) {
346 348 _max_rs_lengths = rs_lengths;
347 349 }
348 350
349 351 size_t predict_pending_card_diff() {
350 352 double prediction = get_new_neg_prediction(_pending_card_diff_seq);
351 353 if (prediction < 0.00001)
352 354 return 0;
353 355 else
354 356 return (size_t) prediction;
355 357 }
356 358
357 359 size_t predict_pending_cards() {
358 360 size_t max_pending_card_num = _g1->max_pending_card_num();
359 361 size_t diff = predict_pending_card_diff();
360 362 size_t prediction;
361 363 if (diff > max_pending_card_num)
362 364 prediction = max_pending_card_num;
363 365 else
364 366 prediction = max_pending_card_num - diff;
365 367
366 368 return prediction;
367 369 }
368 370
369 371 size_t predict_rs_length_diff() {
370 372 return (size_t) get_new_prediction(_rs_length_diff_seq);
371 373 }
372 374
373 375 double predict_alloc_rate_ms() {
374 376 return get_new_prediction(_alloc_rate_ms_seq);
375 377 }
376 378
377 379 double predict_cost_per_card_ms() {
378 380 return get_new_prediction(_cost_per_card_ms_seq);
379 381 }
380 382
381 383 double predict_rs_update_time_ms(size_t pending_cards) {
382 384 return (double) pending_cards * predict_cost_per_card_ms();
383 385 }
384 386
385 387 double predict_fully_young_cards_per_entry_ratio() {
386 388 return get_new_prediction(_fully_young_cards_per_entry_ratio_seq);
387 389 }
388 390
389 391 double predict_partially_young_cards_per_entry_ratio() {
390 392 if (_partially_young_cards_per_entry_ratio_seq->num() < 2)
391 393 return predict_fully_young_cards_per_entry_ratio();
392 394 else
393 395 return get_new_prediction(_partially_young_cards_per_entry_ratio_seq);
394 396 }
395 397
396 398 size_t predict_young_card_num(size_t rs_length) {
397 399 return (size_t) ((double) rs_length *
398 400 predict_fully_young_cards_per_entry_ratio());
399 401 }
400 402
401 403 size_t predict_non_young_card_num(size_t rs_length) {
402 404 return (size_t) ((double) rs_length *
403 405 predict_partially_young_cards_per_entry_ratio());
404 406 }
405 407
406 408 double predict_rs_scan_time_ms(size_t card_num) {
407 409 if (full_young_gcs())
408 410 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
409 411 else
410 412 return predict_partially_young_rs_scan_time_ms(card_num);
411 413 }
412 414
413 415 double predict_partially_young_rs_scan_time_ms(size_t card_num) {
414 416 if (_partially_young_cost_per_entry_ms_seq->num() < 3)
415 417 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
416 418 else
417 419 return (double) card_num *
418 420 get_new_prediction(_partially_young_cost_per_entry_ms_seq);
419 421 }
420 422
421 423 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
422 424 if (_cost_per_byte_ms_during_cm_seq->num() < 3)
423 425 return 1.1 * (double) bytes_to_copy *
424 426 get_new_prediction(_cost_per_byte_ms_seq);
425 427 else
426 428 return (double) bytes_to_copy *
427 429 get_new_prediction(_cost_per_byte_ms_during_cm_seq);
428 430 }
429 431
430 432 double predict_object_copy_time_ms(size_t bytes_to_copy) {
431 433 if (_in_marking_window && !_in_marking_window_im)
432 434 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
433 435 else
434 436 return (double) bytes_to_copy *
435 437 get_new_prediction(_cost_per_byte_ms_seq);
436 438 }
437 439
438 440 double predict_constant_other_time_ms() {
439 441 return get_new_prediction(_constant_other_time_ms_seq);
440 442 }
441 443
442 444 double predict_young_other_time_ms(size_t young_num) {
443 445 return
444 446 (double) young_num *
445 447 get_new_prediction(_young_other_cost_per_region_ms_seq);
446 448 }
447 449
448 450 double predict_non_young_other_time_ms(size_t non_young_num) {
449 451 return
450 452 (double) non_young_num *
451 453 get_new_prediction(_non_young_other_cost_per_region_ms_seq);
452 454 }
453 455
454 456 void check_if_region_is_too_expensive(double predicted_time_ms);
455 457
456 458 double predict_young_collection_elapsed_time_ms(size_t adjustment);
457 459 double predict_base_elapsed_time_ms(size_t pending_cards);
458 460 double predict_base_elapsed_time_ms(size_t pending_cards,
459 461 size_t scanned_cards);
460 462 size_t predict_bytes_to_copy(HeapRegion* hr);
461 463 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
462 464
463 465 // for use by: calculate_young_list_target_length(rs_length)
464 466 bool predict_will_fit(size_t young_region_num,
465 467 double base_time_ms,
466 468 size_t init_free_regions,
467 469 double target_pause_time_ms);
468 470
469 471 void start_recording_regions();
470 472 void record_cset_region_info(HeapRegion* hr, bool young);
471 473 void record_non_young_cset_region(HeapRegion* hr);
472 474
473 475 void set_recorded_young_regions(size_t n_regions);
474 476 void set_recorded_young_bytes(size_t bytes);
475 477 void set_recorded_rs_lengths(size_t rs_lengths);
476 478 void set_predicted_bytes_to_copy(size_t bytes);
477 479
478 480 void end_recording_regions();
479 481
480 482 void record_vtime_diff_ms(double vtime_diff_ms) {
481 483 _vtime_diff_ms = vtime_diff_ms;
482 484 }
483 485
484 486 void record_young_free_cset_time_ms(double time_ms) {
485 487 _recorded_young_free_cset_time_ms = time_ms;
486 488 }
487 489
488 490 void record_non_young_free_cset_time_ms(double time_ms) {
489 491 _recorded_non_young_free_cset_time_ms = time_ms;
490 492 }
491 493
492 494 double predict_young_gc_eff() {
493 495 return get_new_neg_prediction(_young_gc_eff_seq);
494 496 }
495 497
496 498 double predict_survivor_regions_evac_time();
497 499
498 500 // </NEW PREDICTION>
499 501
500 502 public:
501 503 void cset_regions_freed() {
502 504 bool propagate = _last_young_gc_full && !_in_marking_window;
503 505 _short_lived_surv_rate_group->all_surviving_words_recorded(propagate);
504 506 _survivor_surv_rate_group->all_surviving_words_recorded(propagate);
505 507 // also call it on any more surv rate groups
506 508 }
507 509
508 510 void set_known_garbage_bytes(size_t known_garbage_bytes) {
509 511 _known_garbage_bytes = known_garbage_bytes;
510 512 size_t heap_bytes = _g1->capacity();
511 513 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
512 514 }
513 515
514 516 void decrease_known_garbage_bytes(size_t known_garbage_bytes) {
515 517 guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" );
516 518
517 519 _known_garbage_bytes -= known_garbage_bytes;
518 520 size_t heap_bytes = _g1->capacity();
519 521 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
520 522 }
521 523
522 524 G1MMUTracker* mmu_tracker() {
523 525 return _mmu_tracker;
524 526 }
525 527
526 528 double max_pause_time_ms() {
527 529 return _mmu_tracker->max_gc_time() * 1000.0;
528 530 }
529 531
530 532 double predict_init_time_ms() {
531 533 return get_new_prediction(_concurrent_mark_init_times_ms);
532 534 }
533 535
534 536 double predict_remark_time_ms() {
535 537 return get_new_prediction(_concurrent_mark_remark_times_ms);
536 538 }
537 539
538 540 double predict_cleanup_time_ms() {
539 541 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
540 542 }
541 543
542 544 // Returns an estimate of the survival rate of the region at yg-age
543 545 // "yg_age".
544 546 double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) {
545 547 TruncatedSeq* seq = surv_rate_group->get_seq(age);
546 548 if (seq->num() == 0)
547 549 gclog_or_tty->print("BARF! age is %d", age);
548 550 guarantee( seq->num() > 0, "invariant" );
549 551 double pred = get_new_prediction(seq);
550 552 if (pred > 1.0)
551 553 pred = 1.0;
552 554 return pred;
553 555 }
554 556
555 557 double predict_yg_surv_rate(int age) {
556 558 return predict_yg_surv_rate(age, _short_lived_surv_rate_group);
557 559 }
558 560
559 561 double accum_yg_surv_rate_pred(int age) {
560 562 return _short_lived_surv_rate_group->accum_surv_rate_pred(age);
561 563 }
562 564
563 565 protected:
564 566 void print_stats(int level, const char* str, double value);
565 567 void print_stats(int level, const char* str, int value);
566 568
567 569 void print_par_stats(int level, const char* str, double* data);
568 570 void print_par_sizes(int level, const char* str, double* data);
569 571
570 572 void check_other_times(int level,
571 573 NumberSeq* other_times_ms,
572 574 NumberSeq* calc_other_times_ms) const;
573 575
574 576 void print_summary (PauseSummary* stats) const;
575 577
576 578 void print_summary (int level, const char* str, NumberSeq* seq) const;
577 579 void print_summary_sd (int level, const char* str, NumberSeq* seq) const;
578 580
579 581 double avg_value (double* data);
580 582 double max_value (double* data);
581 583 double sum_of_values (double* data);
582 584 double max_sum (double* data1, double* data2);
583 585
584 586 int _last_satb_drain_processed_buffers;
585 587 int _last_update_rs_processed_buffers;
586 588 double _last_pause_time_ms;
587 589
588 590 size_t _bytes_in_collection_set_before_gc;
589 591 size_t _bytes_copied_during_gc;
590 592
591 593 // Used to count used bytes in CS.
592 594 friend class CountCSClosure;
593 595
594 596 // Statistics kept per GC stoppage, pause or full.
595 597 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;
596 598
597 599 // We track markings.
598 600 int _num_markings;
599 601 double _mark_thread_startup_sec; // Time at startup of marking thread
600 602
601 603 // Add a new GC of the given duration and end time to the record.
602 604 void update_recent_gc_times(double end_time_sec, double elapsed_ms);
603 605
604 606 // The head of the list (via "next_in_collection_set()") representing the
605 607 // current collection set. Set from the incrementally built collection
606 608 // set at the start of the pause.
607 609 HeapRegion* _collection_set;
608 610
609 611 // The number of regions in the collection set. Set from the incrementally
610 612 // built collection set at the start of an evacuation pause.
611 613 size_t _collection_set_size;
612 614
613 615 // The number of bytes in the collection set before the pause. Set from
614 616 // the incrementally built collection set at the start of an evacuation
615 617 // pause.
616 618 size_t _collection_set_bytes_used_before;
617 619
618 620 // The associated information that is maintained while the incremental
619 621 // collection set is being built with young regions. Used to populate
620 622 // the recorded info for the evacuation pause.
621 623
622 624 enum CSetBuildType {
623 625 Active, // We are actively building the collection set
624 626 Inactive // We are not actively building the collection set
625 627 };
626 628
627 629 CSetBuildType _inc_cset_build_state;
628 630
629 631 // The head of the incrementally built collection set.
630 632 HeapRegion* _inc_cset_head;
631 633
632 634 // The tail of the incrementally built collection set.
633 635 HeapRegion* _inc_cset_tail;
634 636
635 637 // The number of regions in the incrementally built collection set.
636 638 // Used to set _collection_set_size at the start of an evacuation
637 639 // pause.
638 640 size_t _inc_cset_size;
639 641
640 642 // Used as the index in the surving young words structure
641 643 // which tracks the amount of space, for each young region,
642 644 // that survives the pause.
643 645 size_t _inc_cset_young_index;
644 646
645 647 // The number of bytes in the incrementally built collection set.
646 648 // Used to set _collection_set_bytes_used_before at the start of
647 649 // an evacuation pause.
648 650 size_t _inc_cset_bytes_used_before;
649 651
650 652 // Used to record the highest end of heap region in collection set
651 653 HeapWord* _inc_cset_max_finger;
652 654
653 655 // The number of recorded used bytes in the young regions
654 656 // of the collection set. This is the sum of the used() bytes
655 657 // of retired young regions in the collection set.
656 658 size_t _inc_cset_recorded_young_bytes;
657 659
658 660 // The RSet lengths recorded for regions in the collection set
659 661 // (updated by the periodic sampling of the regions in the
660 662 // young list/collection set).
661 663 size_t _inc_cset_recorded_rs_lengths;
662 664
663 665 // The predicted elapsed time it will take to collect the regions
664 666 // in the collection set (updated by the periodic sampling of the
665 667 // regions in the young list/collection set).
666 668 double _inc_cset_predicted_elapsed_time_ms;
667 669
668 670 // The predicted bytes to copy for the regions in the collection
669 671 // set (updated by the periodic sampling of the regions in the
670 672 // young list/collection set).
671 673 size_t _inc_cset_predicted_bytes_to_copy;
672 674
673 675 // Info about marking.
674 676 int _n_marks; // Sticky at 2, so we know when we've done at least 2.
675 677
676 678 // The number of collection pauses at the end of the last mark.
677 679 size_t _n_pauses_at_mark_end;
678 680
679 681 // Stash a pointer to the g1 heap.
680 682 G1CollectedHeap* _g1;
681 683
682 684 // The average time in ms per collection pause, averaged over recent pauses.
683 685 double recent_avg_time_for_pauses_ms();
684 686
685 687 // The average time in ms for RS scanning, per pause, averaged
686 688 // over recent pauses. (Note the RS scanning time for a pause
687 689 // is itself an average of the RS scanning time for each worker
688 690 // thread.)
689 691 double recent_avg_time_for_rs_scan_ms();
690 692
691 693 // The number of "recent" GCs recorded in the number sequences
692 694 int number_of_recent_gcs();
693 695
694 696 // The average survival ratio, computed by the total number of bytes
695 697 // suriviving / total number of bytes before collection over the last
696 698 // several recent pauses.
697 699 double recent_avg_survival_fraction();
698 700 // The survival fraction of the most recent pause; if there have been no
699 701 // pauses, returns 1.0.
700 702 double last_survival_fraction();
701 703
702 704 // Returns a "conservative" estimate of the recent survival rate, i.e.,
703 705 // one that may be higher than "recent_avg_survival_fraction".
704 706 // This is conservative in several ways:
705 707 // If there have been few pauses, it will assume a potential high
706 708 // variance, and err on the side of caution.
707 709 // It puts a lower bound (currently 0.1) on the value it will return.
708 710 // To try to detect phase changes, if the most recent pause ("latest") has a
709 711 // higher-than average ("avg") survival rate, it returns that rate.
710 712 // "work" version is a utility function; young is restricted to young regions.
711 713 double conservative_avg_survival_fraction_work(double avg,
712 714 double latest);
713 715
714 716 // The arguments are the two sequences that keep track of the number of bytes
715 717 // surviving and the total number of bytes before collection, resp.,
716 718 // over the last evereal recent pauses
717 719 // Returns the survival rate for the category in the most recent pause.
718 720 // If there have been no pauses, returns 1.0.
719 721 double last_survival_fraction_work(TruncatedSeq* surviving,
720 722 TruncatedSeq* before);
721 723
722 724 // The arguments are the two sequences that keep track of the number of bytes
723 725 // surviving and the total number of bytes before collection, resp.,
724 726 // over the last several recent pauses
725 727 // Returns the average survival ration over the last several recent pauses
726 728 // If there have been no pauses, return 1.0
727 729 double recent_avg_survival_fraction_work(TruncatedSeq* surviving,
728 730 TruncatedSeq* before);
729 731
730 732 double conservative_avg_survival_fraction() {
731 733 double avg = recent_avg_survival_fraction();
732 734 double latest = last_survival_fraction();
733 735 return conservative_avg_survival_fraction_work(avg, latest);
734 736 }
735 737
736 738 // The ratio of gc time to elapsed time, computed over recent pauses.
737 739 double _recent_avg_pause_time_ratio;
738 740
739 741 double recent_avg_pause_time_ratio() {
740 742 return _recent_avg_pause_time_ratio;
741 743 }
742 744
743 745 // Number of pauses between concurrent marking.
744 746 size_t _pauses_btwn_concurrent_mark;
745 747
746 748 size_t _n_marks_since_last_pause;
747 749
748 750 // At the end of a pause we check the heap occupancy and we decide
749 751 // whether we will start a marking cycle during the next pause. If
750 752 // we decide that we want to do that, we will set this parameter to
751 753 // true. So, this parameter will stay true between the end of a
752 754 // pause and the beginning of a subsequent pause (not necessarily
753 755 // the next one, see the comments on the next field) when we decide
754 756 // that we will indeed start a marking cycle and do the initial-mark
755 757 // work.
756 758 volatile bool _initiate_conc_mark_if_possible;
757 759
758 760 // If initiate_conc_mark_if_possible() is set at the beginning of a
759 761 // pause, it is a suggestion that the pause should start a marking
760 762 // cycle by doing the initial-mark work. However, it is possible
761 763 // that the concurrent marking thread is still finishing up the
762 764 // previous marking cycle (e.g., clearing the next marking
763 765 // bitmap). If that is the case we cannot start a new cycle and
764 766 // we'll have to wait for the concurrent marking thread to finish
765 767 // what it is doing. In this case we will postpone the marking cycle
766 768 // initiation decision for the next pause. When we eventually decide
767 769 // to start a cycle, we will set _during_initial_mark_pause which
768 770 // will stay true until the end of the initial-mark pause and it's
769 771 // the condition that indicates that a pause is doing the
770 772 // initial-mark work.
771 773 volatile bool _during_initial_mark_pause;
772 774
773 775 bool _should_revert_to_full_young_gcs;
774 776 bool _last_full_young_gc;
775 777
776 778 // This set of variables tracks the collector efficiency, in order to
777 779 // determine whether we should initiate a new marking.
778 780 double _cur_mark_stop_world_time_ms;
779 781 double _mark_init_start_sec;
780 782 double _mark_remark_start_sec;
781 783 double _mark_cleanup_start_sec;
782 784 double _mark_closure_time_ms;
783 785
784 786 void calculate_young_list_min_length();
785 787 void calculate_young_list_target_length();
786 788 void calculate_young_list_target_length(size_t rs_lengths);
787 789
788 790 public:
789 791
790 792 G1CollectorPolicy();
791 793
792 794 virtual G1CollectorPolicy* as_g1_policy() { return this; }
793 795
794 796 virtual CollectorPolicy::Name kind() {
795 797 return CollectorPolicy::G1CollectorPolicyKind;
796 798 }
797 799
798 800 void check_prediction_validity();
799 801
800 802 size_t bytes_in_collection_set() {
801 803 return _bytes_in_collection_set_before_gc;
802 804 }
803 805
804 806 unsigned calc_gc_alloc_time_stamp() {
805 807 return _all_pause_times_ms->num() + 1;
806 808 }
807 809
808 810 protected:
809 811
810 812 // Count the number of bytes used in the CS.
811 813 void count_CS_bytes_used();
812 814
813 815 // Together these do the base cleanup-recording work. Subclasses might
814 816 // want to put something between them.
815 817 void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
816 818 size_t max_live_bytes);
817 819 void record_concurrent_mark_cleanup_end_work2();
818 820
819 821 public:
820 822
821 823 virtual void init();
822 824
823 825 // Create jstat counters for the policy.
824 826 virtual void initialize_gc_policy_counters();
825 827
826 828 virtual HeapWord* mem_allocate_work(size_t size,
827 829 bool is_tlab,
828 830 bool* gc_overhead_limit_was_exceeded);
829 831
830 832 // This method controls how a collector handles one or more
831 833 // of its generations being fully allocated.
832 834 virtual HeapWord* satisfy_failed_allocation(size_t size,
833 835 bool is_tlab);
834 836
835 837 BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; }
836 838
837 839 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
838 840
839 841 // The number of collection pauses so far.
840 842 long n_pauses() const { return _n_pauses; }
841 843
842 844 // Update the heuristic info to record a collection pause of the given
843 845 // start time, where the given number of bytes were used at the start.
844 846 // This may involve changing the desired size of a collection set.
845 847
846 848 virtual void record_stop_world_start();
847 849
848 850 virtual void record_collection_pause_start(double start_time_sec,
849 851 size_t start_used);
850 852
851 853 // Must currently be called while the world is stopped.
852 854 virtual void record_concurrent_mark_init_start();
853 855 virtual void record_concurrent_mark_init_end();
854 856 void record_concurrent_mark_init_end_pre(double
855 857 mark_init_elapsed_time_ms);
856 858
857 859 void record_mark_closure_time(double mark_closure_time_ms);
858 860
859 861 virtual void record_concurrent_mark_remark_start();
860 862 virtual void record_concurrent_mark_remark_end();
861 863
862 864 virtual void record_concurrent_mark_cleanup_start();
863 865 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
864 866 size_t max_live_bytes);
865 867 virtual void record_concurrent_mark_cleanup_completed();
866 868
867 869 virtual void record_concurrent_pause();
868 870 virtual void record_concurrent_pause_end();
869 871
870 872 virtual void record_collection_pause_end();
871 873 void print_heap_transition();
872 874
873 875 // Record the fact that a full collection occurred.
874 876 virtual void record_full_collection_start();
875 877 virtual void record_full_collection_end();
876 878
877 879 void record_gc_worker_start_time(int worker_i, double ms) {
878 880 _par_last_gc_worker_start_times_ms[worker_i] = ms;
879 881 }
880 882
881 883 void record_ext_root_scan_time(int worker_i, double ms) {
882 884 _par_last_ext_root_scan_times_ms[worker_i] = ms;
883 885 }
884 886
885 887 void record_mark_stack_scan_time(int worker_i, double ms) {
886 888 _par_last_mark_stack_scan_times_ms[worker_i] = ms;
887 889 }
888 890
889 891 void record_satb_drain_time(double ms) {
890 892 _cur_satb_drain_time_ms = ms;
891 893 _satb_drain_time_set = true;
892 894 }
893 895
894 896 void record_satb_drain_processed_buffers (int processed_buffers) {
895 897 _last_satb_drain_processed_buffers = processed_buffers;
896 898 }
897 899
898 900 void record_mod_union_time(double ms) {
899 901 _all_mod_union_times_ms->add(ms);
900 902 }
901 903
902 904 void record_update_rs_time(int thread, double ms) {
903 905 _par_last_update_rs_times_ms[thread] = ms;
904 906 }
905 907
906 908 void record_update_rs_processed_buffers (int thread,
907 909 double processed_buffers) {
908 910 _par_last_update_rs_processed_buffers[thread] = processed_buffers;
909 911 }
910 912
911 913 void record_scan_rs_time(int thread, double ms) {
912 914 _par_last_scan_rs_times_ms[thread] = ms;
913 915 }
914 916
915 917 void reset_obj_copy_time(int thread) {
916 918 _par_last_obj_copy_times_ms[thread] = 0.0;
917 919 }
918 920
919 921 void reset_obj_copy_time() {
920 922 reset_obj_copy_time(0);
921 923 }
922 924
923 925 void record_obj_copy_time(int thread, double ms) {
924 926 _par_last_obj_copy_times_ms[thread] += ms;
925 927 }
926 928
927 929 void record_termination(int thread, double ms, size_t attempts) {
928 930 _par_last_termination_times_ms[thread] = ms;
929 931 _par_last_termination_attempts[thread] = (double) attempts;
930 932 }
931 933
932 934 void record_gc_worker_end_time(int worker_i, double ms) {
933 935 _par_last_gc_worker_end_times_ms[worker_i] = ms;
934 936 }
935 937
936 938 void record_pause_time_ms(double ms) {
937 939 _last_pause_time_ms = ms;
938 940 }
939 941
940 942 void record_clear_ct_time(double ms) {
941 943 _cur_clear_ct_time_ms = ms;
942 944 }
943 945
944 946 void record_par_time(double ms) {
945 947 _cur_collection_par_time_ms = ms;
946 948 }
947 949
948 950 void record_aux_start_time(int i) {
949 951 guarantee(i < _aux_num, "should be within range");
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950 952 _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0;
951 953 }
952 954
953 955 void record_aux_end_time(int i) {
954 956 guarantee(i < _aux_num, "should be within range");
955 957 double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i];
956 958 _cur_aux_times_set[i] = true;
957 959 _cur_aux_times_ms[i] += ms;
958 960 }
959 961
962 + void record_ref_proc_time(double ms) {
963 + _cur_ref_proc_time_ms = ms;
964 + }
965 +
966 + void record_ref_enq_time(double ms) {
967 + _cur_ref_enq_time_ms = ms;
968 + }
969 +
960 970 #ifndef PRODUCT
961 971 void record_cc_clear_time(double ms) {
962 972 if (_min_clear_cc_time_ms < 0.0 || ms <= _min_clear_cc_time_ms)
963 973 _min_clear_cc_time_ms = ms;
964 974 if (_max_clear_cc_time_ms < 0.0 || ms >= _max_clear_cc_time_ms)
965 975 _max_clear_cc_time_ms = ms;
966 976 _cur_clear_cc_time_ms = ms;
967 977 _cum_clear_cc_time_ms += ms;
968 978 _num_cc_clears++;
969 979 }
970 980 #endif
971 981
972 982 // Record how much space we copied during a GC. This is typically
973 983 // called when a GC alloc region is being retired.
974 984 void record_bytes_copied_during_gc(size_t bytes) {
975 985 _bytes_copied_during_gc += bytes;
976 986 }
977 987
978 988 // The amount of space we copied during a GC.
979 989 size_t bytes_copied_during_gc() {
980 990 return _bytes_copied_during_gc;
981 991 }
982 992
983 993 // Choose a new collection set. Marks the chosen regions as being
984 994 // "in_collection_set", and links them together. The head and number of
985 995 // the collection set are available via access methods.
986 996 virtual void choose_collection_set(double target_pause_time_ms) = 0;
987 997
988 998 // The head of the list (via "next_in_collection_set()") representing the
989 999 // current collection set.
990 1000 HeapRegion* collection_set() { return _collection_set; }
991 1001
992 1002 void clear_collection_set() { _collection_set = NULL; }
993 1003
994 1004 // The number of elements in the current collection set.
995 1005 size_t collection_set_size() { return _collection_set_size; }
996 1006
997 1007 // Add "hr" to the CS.
998 1008 void add_to_collection_set(HeapRegion* hr);
999 1009
1000 1010 // Incremental CSet Support
1001 1011
1002 1012 // The head of the incrementally built collection set.
1003 1013 HeapRegion* inc_cset_head() { return _inc_cset_head; }
1004 1014
1005 1015 // The tail of the incrementally built collection set.
1006 1016 HeapRegion* inc_set_tail() { return _inc_cset_tail; }
1007 1017
1008 1018 // The number of elements in the incrementally built collection set.
1009 1019 size_t inc_cset_size() { return _inc_cset_size; }
1010 1020
1011 1021 // Initialize incremental collection set info.
1012 1022 void start_incremental_cset_building();
1013 1023
1014 1024 void clear_incremental_cset() {
1015 1025 _inc_cset_head = NULL;
1016 1026 _inc_cset_tail = NULL;
1017 1027 }
1018 1028
1019 1029 // Stop adding regions to the incremental collection set
1020 1030 void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
1021 1031
1022 1032 // Add/remove information about hr to the aggregated information
1023 1033 // for the incrementally built collection set.
1024 1034 void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
1025 1035 void remove_from_incremental_cset_info(HeapRegion* hr);
1026 1036
1027 1037 // Update information about hr in the aggregated information for
1028 1038 // the incrementally built collection set.
1029 1039 void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
1030 1040
1031 1041 private:
1032 1042 // Update the incremental cset information when adding a region
1033 1043 // (should not be called directly).
1034 1044 void add_region_to_incremental_cset_common(HeapRegion* hr);
1035 1045
1036 1046 public:
1037 1047 // Add hr to the LHS of the incremental collection set.
1038 1048 void add_region_to_incremental_cset_lhs(HeapRegion* hr);
1039 1049
1040 1050 // Add hr to the RHS of the incremental collection set.
1041 1051 void add_region_to_incremental_cset_rhs(HeapRegion* hr);
1042 1052
1043 1053 #ifndef PRODUCT
1044 1054 void print_collection_set(HeapRegion* list_head, outputStream* st);
1045 1055 #endif // !PRODUCT
1046 1056
1047 1057 bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; }
1048 1058 void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; }
1049 1059 void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; }
1050 1060
1051 1061 bool during_initial_mark_pause() { return _during_initial_mark_pause; }
1052 1062 void set_during_initial_mark_pause() { _during_initial_mark_pause = true; }
1053 1063 void clear_during_initial_mark_pause(){ _during_initial_mark_pause = false; }
1054 1064
1055 1065 // This sets the initiate_conc_mark_if_possible() flag to start a
1056 1066 // new cycle, as long as we are not already in one. It's best if it
1057 1067 // is called during a safepoint when the test whether a cycle is in
1058 1068 // progress or not is stable.
1059 1069 bool force_initial_mark_if_outside_cycle();
1060 1070
1061 1071 // This is called at the very beginning of an evacuation pause (it
1062 1072 // has to be the first thing that the pause does). If
1063 1073 // initiate_conc_mark_if_possible() is true, and the concurrent
1064 1074 // marking thread has completed its work during the previous cycle,
1065 1075 // it will set during_initial_mark_pause() to so that the pause does
1066 1076 // the initial-mark work and start a marking cycle.
1067 1077 void decide_on_conc_mark_initiation();
1068 1078
1069 1079 // If an expansion would be appropriate, because recent GC overhead had
1070 1080 // exceeded the desired limit, return an amount to expand by.
1071 1081 virtual size_t expansion_amount();
1072 1082
1073 1083 // note start of mark thread
1074 1084 void note_start_of_mark_thread();
1075 1085
1076 1086 // The marked bytes of the "r" has changed; reclassify it's desirability
1077 1087 // for marking. Also asserts that "r" is eligible for a CS.
1078 1088 virtual void note_change_in_marked_bytes(HeapRegion* r) = 0;
1079 1089
1080 1090 #ifndef PRODUCT
1081 1091 // Check any appropriate marked bytes info, asserting false if
1082 1092 // something's wrong, else returning "true".
1083 1093 virtual bool assertMarkedBytesDataOK() = 0;
1084 1094 #endif
1085 1095
1086 1096 // Print tracing information.
1087 1097 void print_tracing_info() const;
1088 1098
1089 1099 // Print stats on young survival ratio
1090 1100 void print_yg_surv_rate_info() const;
1091 1101
1092 1102 void finished_recalculating_age_indexes(bool is_survivors) {
1093 1103 if (is_survivors) {
1094 1104 _survivor_surv_rate_group->finished_recalculating_age_indexes();
1095 1105 } else {
1096 1106 _short_lived_surv_rate_group->finished_recalculating_age_indexes();
1097 1107 }
1098 1108 // do that for any other surv rate groups
1099 1109 }
1100 1110
1101 1111 bool is_young_list_full() {
1102 1112 size_t young_list_length = _g1->young_list()->length();
1103 1113 size_t young_list_target_length = _young_list_target_length;
1104 1114 if (G1FixedEdenSize) {
1105 1115 young_list_target_length -= _max_survivor_regions;
1106 1116 }
1107 1117 return young_list_length >= young_list_target_length;
1108 1118 }
1109 1119
1110 1120 bool can_expand_young_list() {
1111 1121 size_t young_list_length = _g1->young_list()->length();
1112 1122 size_t young_list_max_length = _young_list_max_length;
1113 1123 if (G1FixedEdenSize) {
1114 1124 young_list_max_length -= _max_survivor_regions;
1115 1125 }
1116 1126 return young_list_length < young_list_max_length;
1117 1127 }
1118 1128
1119 1129 void update_region_num(bool young);
1120 1130
1121 1131 bool in_young_gc_mode() {
1122 1132 return _in_young_gc_mode;
1123 1133 }
1124 1134 void set_in_young_gc_mode(bool in_young_gc_mode) {
1125 1135 _in_young_gc_mode = in_young_gc_mode;
1126 1136 }
1127 1137
1128 1138 bool full_young_gcs() {
1129 1139 return _full_young_gcs;
1130 1140 }
1131 1141 void set_full_young_gcs(bool full_young_gcs) {
1132 1142 _full_young_gcs = full_young_gcs;
1133 1143 }
1134 1144
1135 1145 bool adaptive_young_list_length() {
1136 1146 return _adaptive_young_list_length;
1137 1147 }
1138 1148 void set_adaptive_young_list_length(bool adaptive_young_list_length) {
1139 1149 _adaptive_young_list_length = adaptive_young_list_length;
1140 1150 }
1141 1151
1142 1152 inline double get_gc_eff_factor() {
1143 1153 double ratio = _known_garbage_ratio;
1144 1154
1145 1155 double square = ratio * ratio;
1146 1156 // square = square * square;
1147 1157 double ret = square * 9.0 + 1.0;
1148 1158 #if 0
1149 1159 gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret);
1150 1160 #endif // 0
1151 1161 guarantee(0.0 <= ret && ret < 10.0, "invariant!");
1152 1162 return ret;
1153 1163 }
1154 1164
1155 1165 //
1156 1166 // Survivor regions policy.
1157 1167 //
1158 1168 protected:
1159 1169
1160 1170 // Current tenuring threshold, set to 0 if the collector reaches the
1161 1171 // maximum amount of suvivors regions.
1162 1172 int _tenuring_threshold;
1163 1173
1164 1174 // The limit on the number of regions allocated for survivors.
1165 1175 size_t _max_survivor_regions;
1166 1176
1167 1177 // For reporting purposes.
1168 1178 size_t _eden_bytes_before_gc;
1169 1179 size_t _survivor_bytes_before_gc;
1170 1180 size_t _capacity_before_gc;
1171 1181
1172 1182 // The amount of survor regions after a collection.
1173 1183 size_t _recorded_survivor_regions;
1174 1184 // List of survivor regions.
1175 1185 HeapRegion* _recorded_survivor_head;
1176 1186 HeapRegion* _recorded_survivor_tail;
1177 1187
1178 1188 ageTable _survivors_age_table;
1179 1189
1180 1190 public:
1181 1191
1182 1192 inline GCAllocPurpose
1183 1193 evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) {
1184 1194 if (age < _tenuring_threshold && src_region->is_young()) {
1185 1195 return GCAllocForSurvived;
1186 1196 } else {
1187 1197 return GCAllocForTenured;
1188 1198 }
1189 1199 }
1190 1200
1191 1201 inline bool track_object_age(GCAllocPurpose purpose) {
1192 1202 return purpose == GCAllocForSurvived;
1193 1203 }
1194 1204
1195 1205 static const size_t REGIONS_UNLIMITED = ~(size_t)0;
1196 1206
1197 1207 size_t max_regions(int purpose);
1198 1208
1199 1209 // The limit on regions for a particular purpose is reached.
1200 1210 void note_alloc_region_limit_reached(int purpose) {
1201 1211 if (purpose == GCAllocForSurvived) {
1202 1212 _tenuring_threshold = 0;
1203 1213 }
1204 1214 }
1205 1215
1206 1216 void note_start_adding_survivor_regions() {
1207 1217 _survivor_surv_rate_group->start_adding_regions();
1208 1218 }
1209 1219
1210 1220 void note_stop_adding_survivor_regions() {
1211 1221 _survivor_surv_rate_group->stop_adding_regions();
1212 1222 }
1213 1223
1214 1224 void record_survivor_regions(size_t regions,
1215 1225 HeapRegion* head,
1216 1226 HeapRegion* tail) {
1217 1227 _recorded_survivor_regions = regions;
1218 1228 _recorded_survivor_head = head;
1219 1229 _recorded_survivor_tail = tail;
1220 1230 }
1221 1231
1222 1232 size_t recorded_survivor_regions() {
1223 1233 return _recorded_survivor_regions;
1224 1234 }
1225 1235
1226 1236 void record_thread_age_table(ageTable* age_table)
1227 1237 {
1228 1238 _survivors_age_table.merge_par(age_table);
1229 1239 }
1230 1240
1231 1241 void calculate_max_gc_locker_expansion();
1232 1242
1233 1243 // Calculates survivor space parameters.
1234 1244 void calculate_survivors_policy();
1235 1245
1236 1246 };
1237 1247
1238 1248 // This encapsulates a particular strategy for a g1 Collector.
1239 1249 //
1240 1250 // Start a concurrent mark when our heap size is n bytes
1241 1251 // greater then our heap size was at the last concurrent
1242 1252 // mark. Where n is a function of the CMSTriggerRatio
1243 1253 // and the MinHeapFreeRatio.
1244 1254 //
1245 1255 // Start a g1 collection pause when we have allocated the
1246 1256 // average number of bytes currently being freed in
1247 1257 // a collection, but only if it is at least one region
1248 1258 // full
1249 1259 //
1250 1260 // Resize Heap based on desired
1251 1261 // allocation space, where desired allocation space is
1252 1262 // a function of survival rate and desired future to size.
1253 1263 //
1254 1264 // Choose collection set by first picking all older regions
1255 1265 // which have a survival rate which beats our projected young
1256 1266 // survival rate. Then fill out the number of needed regions
1257 1267 // with young regions.
1258 1268
1259 1269 class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy {
1260 1270 CollectionSetChooser* _collectionSetChooser;
1261 1271 // If the estimated is less then desirable, resize if possible.
1262 1272 void expand_if_possible(size_t numRegions);
1263 1273
1264 1274 virtual void choose_collection_set(double target_pause_time_ms);
1265 1275 virtual void record_collection_pause_start(double start_time_sec,
1266 1276 size_t start_used);
1267 1277 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
1268 1278 size_t max_live_bytes);
1269 1279 virtual void record_full_collection_end();
1270 1280
1271 1281 public:
1272 1282 G1CollectorPolicy_BestRegionsFirst() {
1273 1283 _collectionSetChooser = new CollectionSetChooser();
1274 1284 }
1275 1285 void record_collection_pause_end();
1276 1286 // This is not needed any more, after the CSet choosing code was
1277 1287 // changed to use the pause prediction work. But let's leave the
1278 1288 // hook in just in case.
1279 1289 void note_change_in_marked_bytes(HeapRegion* r) { }
1280 1290 #ifndef PRODUCT
1281 1291 bool assertMarkedBytesDataOK();
1282 1292 #endif
1283 1293 };
1284 1294
1285 1295 // This should move to some place more general...
1286 1296
1287 1297 // If we have "n" measurements, and we've kept track of their "sum" and the
1288 1298 // "sum_of_squares" of the measurements, this returns the variance of the
1289 1299 // sequence.
1290 1300 inline double variance(int n, double sum_of_squares, double sum) {
1291 1301 double n_d = (double)n;
1292 1302 double avg = sum/n_d;
1293 1303 return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d;
1294 1304 }
1295 1305
1296 1306 // Local Variables: ***
1297 1307 // c-indentation-style: gnu ***
1298 1308 // End: ***
1299 1309
1300 1310 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
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