Mercurial > hg > graal-compiler
comparison src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp @ 342:37f87013dfd8
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author | ysr |
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date | Thu, 05 Jun 2008 15:57:56 -0700 |
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children | e0c09f7ec5c4 |
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1 /* | |
2 * Copyright 2001-2007 Sun Microsystems, Inc. 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. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 #include "incls/_precompiled.incl" | |
26 #include "incls/_g1CollectedHeap.cpp.incl" | |
27 | |
28 // turn it on so that the contents of the young list (scan-only / | |
29 // to-be-collected) are printed at "strategic" points before / during | |
30 // / after the collection --- this is useful for debugging | |
31 #define SCAN_ONLY_VERBOSE 0 | |
32 // CURRENT STATUS | |
33 // This file is under construction. Search for "FIXME". | |
34 | |
35 // INVARIANTS/NOTES | |
36 // | |
37 // All allocation activity covered by the G1CollectedHeap interface is | |
38 // serialized by acquiring the HeapLock. This happens in | |
39 // mem_allocate_work, which all such allocation functions call. | |
40 // (Note that this does not apply to TLAB allocation, which is not part | |
41 // of this interface: it is done by clients of this interface.) | |
42 | |
43 // Local to this file. | |
44 | |
45 // Finds the first HeapRegion. | |
46 // No longer used, but might be handy someday. | |
47 | |
48 class FindFirstRegionClosure: public HeapRegionClosure { | |
49 HeapRegion* _a_region; | |
50 public: | |
51 FindFirstRegionClosure() : _a_region(NULL) {} | |
52 bool doHeapRegion(HeapRegion* r) { | |
53 _a_region = r; | |
54 return true; | |
55 } | |
56 HeapRegion* result() { return _a_region; } | |
57 }; | |
58 | |
59 | |
60 class RefineCardTableEntryClosure: public CardTableEntryClosure { | |
61 SuspendibleThreadSet* _sts; | |
62 G1RemSet* _g1rs; | |
63 ConcurrentG1Refine* _cg1r; | |
64 bool _concurrent; | |
65 public: | |
66 RefineCardTableEntryClosure(SuspendibleThreadSet* sts, | |
67 G1RemSet* g1rs, | |
68 ConcurrentG1Refine* cg1r) : | |
69 _sts(sts), _g1rs(g1rs), _cg1r(cg1r), _concurrent(true) | |
70 {} | |
71 bool do_card_ptr(jbyte* card_ptr, int worker_i) { | |
72 _g1rs->concurrentRefineOneCard(card_ptr, worker_i); | |
73 if (_concurrent && _sts->should_yield()) { | |
74 // Caller will actually yield. | |
75 return false; | |
76 } | |
77 // Otherwise, we finished successfully; return true. | |
78 return true; | |
79 } | |
80 void set_concurrent(bool b) { _concurrent = b; } | |
81 }; | |
82 | |
83 | |
84 class ClearLoggedCardTableEntryClosure: public CardTableEntryClosure { | |
85 int _calls; | |
86 G1CollectedHeap* _g1h; | |
87 CardTableModRefBS* _ctbs; | |
88 int _histo[256]; | |
89 public: | |
90 ClearLoggedCardTableEntryClosure() : | |
91 _calls(0) | |
92 { | |
93 _g1h = G1CollectedHeap::heap(); | |
94 _ctbs = (CardTableModRefBS*)_g1h->barrier_set(); | |
95 for (int i = 0; i < 256; i++) _histo[i] = 0; | |
96 } | |
97 bool do_card_ptr(jbyte* card_ptr, int worker_i) { | |
98 if (_g1h->is_in_reserved(_ctbs->addr_for(card_ptr))) { | |
99 _calls++; | |
100 unsigned char* ujb = (unsigned char*)card_ptr; | |
101 int ind = (int)(*ujb); | |
102 _histo[ind]++; | |
103 *card_ptr = -1; | |
104 } | |
105 return true; | |
106 } | |
107 int calls() { return _calls; } | |
108 void print_histo() { | |
109 gclog_or_tty->print_cr("Card table value histogram:"); | |
110 for (int i = 0; i < 256; i++) { | |
111 if (_histo[i] != 0) { | |
112 gclog_or_tty->print_cr(" %d: %d", i, _histo[i]); | |
113 } | |
114 } | |
115 } | |
116 }; | |
117 | |
118 class RedirtyLoggedCardTableEntryClosure: public CardTableEntryClosure { | |
119 int _calls; | |
120 G1CollectedHeap* _g1h; | |
121 CardTableModRefBS* _ctbs; | |
122 public: | |
123 RedirtyLoggedCardTableEntryClosure() : | |
124 _calls(0) | |
125 { | |
126 _g1h = G1CollectedHeap::heap(); | |
127 _ctbs = (CardTableModRefBS*)_g1h->barrier_set(); | |
128 } | |
129 bool do_card_ptr(jbyte* card_ptr, int worker_i) { | |
130 if (_g1h->is_in_reserved(_ctbs->addr_for(card_ptr))) { | |
131 _calls++; | |
132 *card_ptr = 0; | |
133 } | |
134 return true; | |
135 } | |
136 int calls() { return _calls; } | |
137 }; | |
138 | |
139 YoungList::YoungList(G1CollectedHeap* g1h) | |
140 : _g1h(g1h), _head(NULL), | |
141 _scan_only_head(NULL), _scan_only_tail(NULL), _curr_scan_only(NULL), | |
142 _length(0), _scan_only_length(0), | |
143 _last_sampled_rs_lengths(0), | |
144 _survivor_head(NULL), _survivors_tail(NULL), _survivor_length(0) | |
145 { | |
146 guarantee( check_list_empty(false), "just making sure..." ); | |
147 } | |
148 | |
149 void YoungList::push_region(HeapRegion *hr) { | |
150 assert(!hr->is_young(), "should not already be young"); | |
151 assert(hr->get_next_young_region() == NULL, "cause it should!"); | |
152 | |
153 hr->set_next_young_region(_head); | |
154 _head = hr; | |
155 | |
156 hr->set_young(); | |
157 double yg_surv_rate = _g1h->g1_policy()->predict_yg_surv_rate((int)_length); | |
158 ++_length; | |
159 } | |
160 | |
161 void YoungList::add_survivor_region(HeapRegion* hr) { | |
162 assert(!hr->is_survivor(), "should not already be for survived"); | |
163 assert(hr->get_next_young_region() == NULL, "cause it should!"); | |
164 | |
165 hr->set_next_young_region(_survivor_head); | |
166 if (_survivor_head == NULL) { | |
167 _survivors_tail = hr; | |
168 } | |
169 _survivor_head = hr; | |
170 | |
171 hr->set_survivor(); | |
172 ++_survivor_length; | |
173 } | |
174 | |
175 HeapRegion* YoungList::pop_region() { | |
176 while (_head != NULL) { | |
177 assert( length() > 0, "list should not be empty" ); | |
178 HeapRegion* ret = _head; | |
179 _head = ret->get_next_young_region(); | |
180 ret->set_next_young_region(NULL); | |
181 --_length; | |
182 assert(ret->is_young(), "region should be very young"); | |
183 | |
184 // Replace 'Survivor' region type with 'Young'. So the region will | |
185 // be treated as a young region and will not be 'confused' with | |
186 // newly created survivor regions. | |
187 if (ret->is_survivor()) { | |
188 ret->set_young(); | |
189 } | |
190 | |
191 if (!ret->is_scan_only()) { | |
192 return ret; | |
193 } | |
194 | |
195 // scan-only, we'll add it to the scan-only list | |
196 if (_scan_only_tail == NULL) { | |
197 guarantee( _scan_only_head == NULL, "invariant" ); | |
198 | |
199 _scan_only_head = ret; | |
200 _curr_scan_only = ret; | |
201 } else { | |
202 guarantee( _scan_only_head != NULL, "invariant" ); | |
203 _scan_only_tail->set_next_young_region(ret); | |
204 } | |
205 guarantee( ret->get_next_young_region() == NULL, "invariant" ); | |
206 _scan_only_tail = ret; | |
207 | |
208 // no need to be tagged as scan-only any more | |
209 ret->set_young(); | |
210 | |
211 ++_scan_only_length; | |
212 } | |
213 assert( length() == 0, "list should be empty" ); | |
214 return NULL; | |
215 } | |
216 | |
217 void YoungList::empty_list(HeapRegion* list) { | |
218 while (list != NULL) { | |
219 HeapRegion* next = list->get_next_young_region(); | |
220 list->set_next_young_region(NULL); | |
221 list->uninstall_surv_rate_group(); | |
222 list->set_not_young(); | |
223 list = next; | |
224 } | |
225 } | |
226 | |
227 void YoungList::empty_list() { | |
228 assert(check_list_well_formed(), "young list should be well formed"); | |
229 | |
230 empty_list(_head); | |
231 _head = NULL; | |
232 _length = 0; | |
233 | |
234 empty_list(_scan_only_head); | |
235 _scan_only_head = NULL; | |
236 _scan_only_tail = NULL; | |
237 _scan_only_length = 0; | |
238 _curr_scan_only = NULL; | |
239 | |
240 empty_list(_survivor_head); | |
241 _survivor_head = NULL; | |
242 _survivors_tail = NULL; | |
243 _survivor_length = 0; | |
244 | |
245 _last_sampled_rs_lengths = 0; | |
246 | |
247 assert(check_list_empty(false), "just making sure..."); | |
248 } | |
249 | |
250 bool YoungList::check_list_well_formed() { | |
251 bool ret = true; | |
252 | |
253 size_t length = 0; | |
254 HeapRegion* curr = _head; | |
255 HeapRegion* last = NULL; | |
256 while (curr != NULL) { | |
257 if (!curr->is_young() || curr->is_scan_only()) { | |
258 gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" " | |
259 "incorrectly tagged (%d, %d)", | |
260 curr->bottom(), curr->end(), | |
261 curr->is_young(), curr->is_scan_only()); | |
262 ret = false; | |
263 } | |
264 ++length; | |
265 last = curr; | |
266 curr = curr->get_next_young_region(); | |
267 } | |
268 ret = ret && (length == _length); | |
269 | |
270 if (!ret) { | |
271 gclog_or_tty->print_cr("### YOUNG LIST seems not well formed!"); | |
272 gclog_or_tty->print_cr("### list has %d entries, _length is %d", | |
273 length, _length); | |
274 } | |
275 | |
276 bool scan_only_ret = true; | |
277 length = 0; | |
278 curr = _scan_only_head; | |
279 last = NULL; | |
280 while (curr != NULL) { | |
281 if (!curr->is_young() || curr->is_scan_only()) { | |
282 gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" " | |
283 "incorrectly tagged (%d, %d)", | |
284 curr->bottom(), curr->end(), | |
285 curr->is_young(), curr->is_scan_only()); | |
286 scan_only_ret = false; | |
287 } | |
288 ++length; | |
289 last = curr; | |
290 curr = curr->get_next_young_region(); | |
291 } | |
292 scan_only_ret = scan_only_ret && (length == _scan_only_length); | |
293 | |
294 if ( (last != _scan_only_tail) || | |
295 (_scan_only_head == NULL && _scan_only_tail != NULL) || | |
296 (_scan_only_head != NULL && _scan_only_tail == NULL) ) { | |
297 gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly"); | |
298 scan_only_ret = false; | |
299 } | |
300 | |
301 if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) { | |
302 gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly"); | |
303 scan_only_ret = false; | |
304 } | |
305 | |
306 if (!scan_only_ret) { | |
307 gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!"); | |
308 gclog_or_tty->print_cr("### list has %d entries, _scan_only_length is %d", | |
309 length, _scan_only_length); | |
310 } | |
311 | |
312 return ret && scan_only_ret; | |
313 } | |
314 | |
315 bool YoungList::check_list_empty(bool ignore_scan_only_list, | |
316 bool check_sample) { | |
317 bool ret = true; | |
318 | |
319 if (_length != 0) { | |
320 gclog_or_tty->print_cr("### YOUNG LIST should have 0 length, not %d", | |
321 _length); | |
322 ret = false; | |
323 } | |
324 if (check_sample && _last_sampled_rs_lengths != 0) { | |
325 gclog_or_tty->print_cr("### YOUNG LIST has non-zero last sampled RS lengths"); | |
326 ret = false; | |
327 } | |
328 if (_head != NULL) { | |
329 gclog_or_tty->print_cr("### YOUNG LIST does not have a NULL head"); | |
330 ret = false; | |
331 } | |
332 if (!ret) { | |
333 gclog_or_tty->print_cr("### YOUNG LIST does not seem empty"); | |
334 } | |
335 | |
336 if (ignore_scan_only_list) | |
337 return ret; | |
338 | |
339 bool scan_only_ret = true; | |
340 if (_scan_only_length != 0) { | |
341 gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d", | |
342 _scan_only_length); | |
343 scan_only_ret = false; | |
344 } | |
345 if (_scan_only_head != NULL) { | |
346 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head"); | |
347 scan_only_ret = false; | |
348 } | |
349 if (_scan_only_tail != NULL) { | |
350 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail"); | |
351 scan_only_ret = false; | |
352 } | |
353 if (!scan_only_ret) { | |
354 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty"); | |
355 } | |
356 | |
357 return ret && scan_only_ret; | |
358 } | |
359 | |
360 void | |
361 YoungList::rs_length_sampling_init() { | |
362 _sampled_rs_lengths = 0; | |
363 _curr = _head; | |
364 } | |
365 | |
366 bool | |
367 YoungList::rs_length_sampling_more() { | |
368 return _curr != NULL; | |
369 } | |
370 | |
371 void | |
372 YoungList::rs_length_sampling_next() { | |
373 assert( _curr != NULL, "invariant" ); | |
374 _sampled_rs_lengths += _curr->rem_set()->occupied(); | |
375 _curr = _curr->get_next_young_region(); | |
376 if (_curr == NULL) { | |
377 _last_sampled_rs_lengths = _sampled_rs_lengths; | |
378 // gclog_or_tty->print_cr("last sampled RS lengths = %d", _last_sampled_rs_lengths); | |
379 } | |
380 } | |
381 | |
382 void | |
383 YoungList::reset_auxilary_lists() { | |
384 // We could have just "moved" the scan-only list to the young list. | |
385 // However, the scan-only list is ordered according to the region | |
386 // age in descending order, so, by moving one entry at a time, we | |
387 // ensure that it is recreated in ascending order. | |
388 | |
389 guarantee( is_empty(), "young list should be empty" ); | |
390 assert(check_list_well_formed(), "young list should be well formed"); | |
391 | |
392 // Add survivor regions to SurvRateGroup. | |
393 _g1h->g1_policy()->note_start_adding_survivor_regions(); | |
394 for (HeapRegion* curr = _survivor_head; | |
395 curr != NULL; | |
396 curr = curr->get_next_young_region()) { | |
397 _g1h->g1_policy()->set_region_survivors(curr); | |
398 } | |
399 _g1h->g1_policy()->note_stop_adding_survivor_regions(); | |
400 | |
401 if (_survivor_head != NULL) { | |
402 _head = _survivor_head; | |
403 _length = _survivor_length + _scan_only_length; | |
404 _survivors_tail->set_next_young_region(_scan_only_head); | |
405 } else { | |
406 _head = _scan_only_head; | |
407 _length = _scan_only_length; | |
408 } | |
409 | |
410 for (HeapRegion* curr = _scan_only_head; | |
411 curr != NULL; | |
412 curr = curr->get_next_young_region()) { | |
413 curr->recalculate_age_in_surv_rate_group(); | |
414 } | |
415 _scan_only_head = NULL; | |
416 _scan_only_tail = NULL; | |
417 _scan_only_length = 0; | |
418 _curr_scan_only = NULL; | |
419 | |
420 _survivor_head = NULL; | |
421 _survivors_tail = NULL; | |
422 _survivor_length = 0; | |
423 _g1h->g1_policy()->finished_recalculating_age_indexes(); | |
424 | |
425 assert(check_list_well_formed(), "young list should be well formed"); | |
426 } | |
427 | |
428 void YoungList::print() { | |
429 HeapRegion* lists[] = {_head, _scan_only_head, _survivor_head}; | |
430 const char* names[] = {"YOUNG", "SCAN-ONLY", "SURVIVOR"}; | |
431 | |
432 for (unsigned int list = 0; list < ARRAY_SIZE(lists); ++list) { | |
433 gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]); | |
434 HeapRegion *curr = lists[list]; | |
435 if (curr == NULL) | |
436 gclog_or_tty->print_cr(" empty"); | |
437 while (curr != NULL) { | |
438 gclog_or_tty->print_cr(" [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, " | |
439 "age: %4d, y: %d, s-o: %d, surv: %d", | |
440 curr->bottom(), curr->end(), | |
441 curr->top(), | |
442 curr->prev_top_at_mark_start(), | |
443 curr->next_top_at_mark_start(), | |
444 curr->top_at_conc_mark_count(), | |
445 curr->age_in_surv_rate_group_cond(), | |
446 curr->is_young(), | |
447 curr->is_scan_only(), | |
448 curr->is_survivor()); | |
449 curr = curr->get_next_young_region(); | |
450 } | |
451 } | |
452 | |
453 gclog_or_tty->print_cr(""); | |
454 } | |
455 | |
456 void G1CollectedHeap::stop_conc_gc_threads() { | |
457 _cg1r->cg1rThread()->stop(); | |
458 _czft->stop(); | |
459 _cmThread->stop(); | |
460 } | |
461 | |
462 | |
463 void G1CollectedHeap::check_ct_logs_at_safepoint() { | |
464 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
465 CardTableModRefBS* ct_bs = (CardTableModRefBS*)barrier_set(); | |
466 | |
467 // Count the dirty cards at the start. | |
468 CountNonCleanMemRegionClosure count1(this); | |
469 ct_bs->mod_card_iterate(&count1); | |
470 int orig_count = count1.n(); | |
471 | |
472 // First clear the logged cards. | |
473 ClearLoggedCardTableEntryClosure clear; | |
474 dcqs.set_closure(&clear); | |
475 dcqs.apply_closure_to_all_completed_buffers(); | |
476 dcqs.iterate_closure_all_threads(false); | |
477 clear.print_histo(); | |
478 | |
479 // Now ensure that there's no dirty cards. | |
480 CountNonCleanMemRegionClosure count2(this); | |
481 ct_bs->mod_card_iterate(&count2); | |
482 if (count2.n() != 0) { | |
483 gclog_or_tty->print_cr("Card table has %d entries; %d originally", | |
484 count2.n(), orig_count); | |
485 } | |
486 guarantee(count2.n() == 0, "Card table should be clean."); | |
487 | |
488 RedirtyLoggedCardTableEntryClosure redirty; | |
489 JavaThread::dirty_card_queue_set().set_closure(&redirty); | |
490 dcqs.apply_closure_to_all_completed_buffers(); | |
491 dcqs.iterate_closure_all_threads(false); | |
492 gclog_or_tty->print_cr("Log entries = %d, dirty cards = %d.", | |
493 clear.calls(), orig_count); | |
494 guarantee(redirty.calls() == clear.calls(), | |
495 "Or else mechanism is broken."); | |
496 | |
497 CountNonCleanMemRegionClosure count3(this); | |
498 ct_bs->mod_card_iterate(&count3); | |
499 if (count3.n() != orig_count) { | |
500 gclog_or_tty->print_cr("Should have restored them all: orig = %d, final = %d.", | |
501 orig_count, count3.n()); | |
502 guarantee(count3.n() >= orig_count, "Should have restored them all."); | |
503 } | |
504 | |
505 JavaThread::dirty_card_queue_set().set_closure(_refine_cte_cl); | |
506 } | |
507 | |
508 // Private class members. | |
509 | |
510 G1CollectedHeap* G1CollectedHeap::_g1h; | |
511 | |
512 // Private methods. | |
513 | |
514 // Finds a HeapRegion that can be used to allocate a given size of block. | |
515 | |
516 | |
517 HeapRegion* G1CollectedHeap::newAllocRegion_work(size_t word_size, | |
518 bool do_expand, | |
519 bool zero_filled) { | |
520 ConcurrentZFThread::note_region_alloc(); | |
521 HeapRegion* res = alloc_free_region_from_lists(zero_filled); | |
522 if (res == NULL && do_expand) { | |
523 expand(word_size * HeapWordSize); | |
524 res = alloc_free_region_from_lists(zero_filled); | |
525 assert(res == NULL || | |
526 (!res->isHumongous() && | |
527 (!zero_filled || | |
528 res->zero_fill_state() == HeapRegion::Allocated)), | |
529 "Alloc Regions must be zero filled (and non-H)"); | |
530 } | |
531 if (res != NULL && res->is_empty()) _free_regions--; | |
532 assert(res == NULL || | |
533 (!res->isHumongous() && | |
534 (!zero_filled || | |
535 res->zero_fill_state() == HeapRegion::Allocated)), | |
536 "Non-young alloc Regions must be zero filled (and non-H)"); | |
537 | |
538 if (G1TraceRegions) { | |
539 if (res != NULL) { | |
540 gclog_or_tty->print_cr("new alloc region %d:["PTR_FORMAT", "PTR_FORMAT"], " | |
541 "top "PTR_FORMAT, | |
542 res->hrs_index(), res->bottom(), res->end(), res->top()); | |
543 } | |
544 } | |
545 | |
546 return res; | |
547 } | |
548 | |
549 HeapRegion* G1CollectedHeap::newAllocRegionWithExpansion(int purpose, | |
550 size_t word_size, | |
551 bool zero_filled) { | |
552 HeapRegion* alloc_region = NULL; | |
553 if (_gc_alloc_region_counts[purpose] < g1_policy()->max_regions(purpose)) { | |
554 alloc_region = newAllocRegion_work(word_size, true, zero_filled); | |
555 if (purpose == GCAllocForSurvived && alloc_region != NULL) { | |
556 _young_list->add_survivor_region(alloc_region); | |
557 } | |
558 ++_gc_alloc_region_counts[purpose]; | |
559 } else { | |
560 g1_policy()->note_alloc_region_limit_reached(purpose); | |
561 } | |
562 return alloc_region; | |
563 } | |
564 | |
565 // If could fit into free regions w/o expansion, try. | |
566 // Otherwise, if can expand, do so. | |
567 // Otherwise, if using ex regions might help, try with ex given back. | |
568 HeapWord* G1CollectedHeap::humongousObjAllocate(size_t word_size) { | |
569 assert(regions_accounted_for(), "Region leakage!"); | |
570 | |
571 // We can't allocate H regions while cleanupComplete is running, since | |
572 // some of the regions we find to be empty might not yet be added to the | |
573 // unclean list. (If we're already at a safepoint, this call is | |
574 // unnecessary, not to mention wrong.) | |
575 if (!SafepointSynchronize::is_at_safepoint()) | |
576 wait_for_cleanup_complete(); | |
577 | |
578 size_t num_regions = | |
579 round_to(word_size, HeapRegion::GrainWords) / HeapRegion::GrainWords; | |
580 | |
581 // Special case if < one region??? | |
582 | |
583 // Remember the ft size. | |
584 size_t x_size = expansion_regions(); | |
585 | |
586 HeapWord* res = NULL; | |
587 bool eliminated_allocated_from_lists = false; | |
588 | |
589 // Can the allocation potentially fit in the free regions? | |
590 if (free_regions() >= num_regions) { | |
591 res = _hrs->obj_allocate(word_size); | |
592 } | |
593 if (res == NULL) { | |
594 // Try expansion. | |
595 size_t fs = _hrs->free_suffix(); | |
596 if (fs + x_size >= num_regions) { | |
597 expand((num_regions - fs) * HeapRegion::GrainBytes); | |
598 res = _hrs->obj_allocate(word_size); | |
599 assert(res != NULL, "This should have worked."); | |
600 } else { | |
601 // Expansion won't help. Are there enough free regions if we get rid | |
602 // of reservations? | |
603 size_t avail = free_regions(); | |
604 if (avail >= num_regions) { | |
605 res = _hrs->obj_allocate(word_size); | |
606 if (res != NULL) { | |
607 remove_allocated_regions_from_lists(); | |
608 eliminated_allocated_from_lists = true; | |
609 } | |
610 } | |
611 } | |
612 } | |
613 if (res != NULL) { | |
614 // Increment by the number of regions allocated. | |
615 // FIXME: Assumes regions all of size GrainBytes. | |
616 #ifndef PRODUCT | |
617 mr_bs()->verify_clean_region(MemRegion(res, res + num_regions * | |
618 HeapRegion::GrainWords)); | |
619 #endif | |
620 if (!eliminated_allocated_from_lists) | |
621 remove_allocated_regions_from_lists(); | |
622 _summary_bytes_used += word_size * HeapWordSize; | |
623 _free_regions -= num_regions; | |
624 _num_humongous_regions += (int) num_regions; | |
625 } | |
626 assert(regions_accounted_for(), "Region Leakage"); | |
627 return res; | |
628 } | |
629 | |
630 HeapWord* | |
631 G1CollectedHeap::attempt_allocation_slow(size_t word_size, | |
632 bool permit_collection_pause) { | |
633 HeapWord* res = NULL; | |
634 HeapRegion* allocated_young_region = NULL; | |
635 | |
636 assert( SafepointSynchronize::is_at_safepoint() || | |
637 Heap_lock->owned_by_self(), "pre condition of the call" ); | |
638 | |
639 if (isHumongous(word_size)) { | |
640 // Allocation of a humongous object can, in a sense, complete a | |
641 // partial region, if the previous alloc was also humongous, and | |
642 // caused the test below to succeed. | |
643 if (permit_collection_pause) | |
644 do_collection_pause_if_appropriate(word_size); | |
645 res = humongousObjAllocate(word_size); | |
646 assert(_cur_alloc_region == NULL | |
647 || !_cur_alloc_region->isHumongous(), | |
648 "Prevent a regression of this bug."); | |
649 | |
650 } else { | |
651 // If we do a collection pause, this will be reset to a non-NULL | |
652 // value. If we don't, nulling here ensures that we allocate a new | |
653 // region below. | |
654 if (_cur_alloc_region != NULL) { | |
655 // We're finished with the _cur_alloc_region. | |
656 _summary_bytes_used += _cur_alloc_region->used(); | |
657 _cur_alloc_region = NULL; | |
658 } | |
659 assert(_cur_alloc_region == NULL, "Invariant."); | |
660 // Completion of a heap region is perhaps a good point at which to do | |
661 // a collection pause. | |
662 if (permit_collection_pause) | |
663 do_collection_pause_if_appropriate(word_size); | |
664 // Make sure we have an allocation region available. | |
665 if (_cur_alloc_region == NULL) { | |
666 if (!SafepointSynchronize::is_at_safepoint()) | |
667 wait_for_cleanup_complete(); | |
668 bool next_is_young = should_set_young_locked(); | |
669 // If the next region is not young, make sure it's zero-filled. | |
670 _cur_alloc_region = newAllocRegion(word_size, !next_is_young); | |
671 if (_cur_alloc_region != NULL) { | |
672 _summary_bytes_used -= _cur_alloc_region->used(); | |
673 if (next_is_young) { | |
674 set_region_short_lived_locked(_cur_alloc_region); | |
675 allocated_young_region = _cur_alloc_region; | |
676 } | |
677 } | |
678 } | |
679 assert(_cur_alloc_region == NULL || !_cur_alloc_region->isHumongous(), | |
680 "Prevent a regression of this bug."); | |
681 | |
682 // Now retry the allocation. | |
683 if (_cur_alloc_region != NULL) { | |
684 res = _cur_alloc_region->allocate(word_size); | |
685 } | |
686 } | |
687 | |
688 // NOTE: fails frequently in PRT | |
689 assert(regions_accounted_for(), "Region leakage!"); | |
690 | |
691 if (res != NULL) { | |
692 if (!SafepointSynchronize::is_at_safepoint()) { | |
693 assert( permit_collection_pause, "invariant" ); | |
694 assert( Heap_lock->owned_by_self(), "invariant" ); | |
695 Heap_lock->unlock(); | |
696 } | |
697 | |
698 if (allocated_young_region != NULL) { | |
699 HeapRegion* hr = allocated_young_region; | |
700 HeapWord* bottom = hr->bottom(); | |
701 HeapWord* end = hr->end(); | |
702 MemRegion mr(bottom, end); | |
703 ((CardTableModRefBS*)_g1h->barrier_set())->dirty(mr); | |
704 } | |
705 } | |
706 | |
707 assert( SafepointSynchronize::is_at_safepoint() || | |
708 (res == NULL && Heap_lock->owned_by_self()) || | |
709 (res != NULL && !Heap_lock->owned_by_self()), | |
710 "post condition of the call" ); | |
711 | |
712 return res; | |
713 } | |
714 | |
715 HeapWord* | |
716 G1CollectedHeap::mem_allocate(size_t word_size, | |
717 bool is_noref, | |
718 bool is_tlab, | |
719 bool* gc_overhead_limit_was_exceeded) { | |
720 debug_only(check_for_valid_allocation_state()); | |
721 assert(no_gc_in_progress(), "Allocation during gc not allowed"); | |
722 HeapWord* result = NULL; | |
723 | |
724 // Loop until the allocation is satisified, | |
725 // or unsatisfied after GC. | |
726 for (int try_count = 1; /* return or throw */; try_count += 1) { | |
727 int gc_count_before; | |
728 { | |
729 Heap_lock->lock(); | |
730 result = attempt_allocation(word_size); | |
731 if (result != NULL) { | |
732 // attempt_allocation should have unlocked the heap lock | |
733 assert(is_in(result), "result not in heap"); | |
734 return result; | |
735 } | |
736 // Read the gc count while the heap lock is held. | |
737 gc_count_before = SharedHeap::heap()->total_collections(); | |
738 Heap_lock->unlock(); | |
739 } | |
740 | |
741 // Create the garbage collection operation... | |
742 VM_G1CollectForAllocation op(word_size, | |
743 gc_count_before); | |
744 | |
745 // ...and get the VM thread to execute it. | |
746 VMThread::execute(&op); | |
747 if (op.prologue_succeeded()) { | |
748 result = op.result(); | |
749 assert(result == NULL || is_in(result), "result not in heap"); | |
750 return result; | |
751 } | |
752 | |
753 // Give a warning if we seem to be looping forever. | |
754 if ((QueuedAllocationWarningCount > 0) && | |
755 (try_count % QueuedAllocationWarningCount == 0)) { | |
756 warning("G1CollectedHeap::mem_allocate_work retries %d times", | |
757 try_count); | |
758 } | |
759 } | |
760 } | |
761 | |
762 void G1CollectedHeap::abandon_cur_alloc_region() { | |
763 if (_cur_alloc_region != NULL) { | |
764 // We're finished with the _cur_alloc_region. | |
765 if (_cur_alloc_region->is_empty()) { | |
766 _free_regions++; | |
767 free_region(_cur_alloc_region); | |
768 } else { | |
769 _summary_bytes_used += _cur_alloc_region->used(); | |
770 } | |
771 _cur_alloc_region = NULL; | |
772 } | |
773 } | |
774 | |
775 class PostMCRemSetClearClosure: public HeapRegionClosure { | |
776 ModRefBarrierSet* _mr_bs; | |
777 public: | |
778 PostMCRemSetClearClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {} | |
779 bool doHeapRegion(HeapRegion* r) { | |
780 r->reset_gc_time_stamp(); | |
781 if (r->continuesHumongous()) | |
782 return false; | |
783 HeapRegionRemSet* hrrs = r->rem_set(); | |
784 if (hrrs != NULL) hrrs->clear(); | |
785 // You might think here that we could clear just the cards | |
786 // corresponding to the used region. But no: if we leave a dirty card | |
787 // in a region we might allocate into, then it would prevent that card | |
788 // from being enqueued, and cause it to be missed. | |
789 // Re: the performance cost: we shouldn't be doing full GC anyway! | |
790 _mr_bs->clear(MemRegion(r->bottom(), r->end())); | |
791 return false; | |
792 } | |
793 }; | |
794 | |
795 | |
796 class PostMCRemSetInvalidateClosure: public HeapRegionClosure { | |
797 ModRefBarrierSet* _mr_bs; | |
798 public: | |
799 PostMCRemSetInvalidateClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {} | |
800 bool doHeapRegion(HeapRegion* r) { | |
801 if (r->continuesHumongous()) return false; | |
802 if (r->used_region().word_size() != 0) { | |
803 _mr_bs->invalidate(r->used_region(), true /*whole heap*/); | |
804 } | |
805 return false; | |
806 } | |
807 }; | |
808 | |
809 void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs, | |
810 size_t word_size) { | |
811 ResourceMark rm; | |
812 | |
813 if (full && DisableExplicitGC) { | |
814 gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n"); | |
815 return; | |
816 } | |
817 | |
818 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
819 assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread"); | |
820 | |
821 if (GC_locker::is_active()) { | |
822 return; // GC is disabled (e.g. JNI GetXXXCritical operation) | |
823 } | |
824 | |
825 { | |
826 IsGCActiveMark x; | |
827 | |
828 // Timing | |
829 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
830 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
831 TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty); | |
832 | |
833 double start = os::elapsedTime(); | |
834 GCOverheadReporter::recordSTWStart(start); | |
835 g1_policy()->record_full_collection_start(); | |
836 | |
837 gc_prologue(true); | |
838 increment_total_collections(); | |
839 | |
840 size_t g1h_prev_used = used(); | |
841 assert(used() == recalculate_used(), "Should be equal"); | |
842 | |
843 if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) { | |
844 HandleMark hm; // Discard invalid handles created during verification | |
845 prepare_for_verify(); | |
846 gclog_or_tty->print(" VerifyBeforeGC:"); | |
847 Universe::verify(true); | |
848 } | |
849 assert(regions_accounted_for(), "Region leakage!"); | |
850 | |
851 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
852 | |
853 // We want to discover references, but not process them yet. | |
854 // This mode is disabled in | |
855 // instanceRefKlass::process_discovered_references if the | |
856 // generation does some collection work, or | |
857 // instanceRefKlass::enqueue_discovered_references if the | |
858 // generation returns without doing any work. | |
859 ref_processor()->disable_discovery(); | |
860 ref_processor()->abandon_partial_discovery(); | |
861 ref_processor()->verify_no_references_recorded(); | |
862 | |
863 // Abandon current iterations of concurrent marking and concurrent | |
864 // refinement, if any are in progress. | |
865 concurrent_mark()->abort(); | |
866 | |
867 // Make sure we'll choose a new allocation region afterwards. | |
868 abandon_cur_alloc_region(); | |
869 assert(_cur_alloc_region == NULL, "Invariant."); | |
870 g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS(); | |
871 tear_down_region_lists(); | |
872 set_used_regions_to_need_zero_fill(); | |
873 if (g1_policy()->in_young_gc_mode()) { | |
874 empty_young_list(); | |
875 g1_policy()->set_full_young_gcs(true); | |
876 } | |
877 | |
878 // Temporarily make reference _discovery_ single threaded (non-MT). | |
879 ReferenceProcessorMTMutator rp_disc_ser(ref_processor(), false); | |
880 | |
881 // Temporarily make refs discovery atomic | |
882 ReferenceProcessorAtomicMutator rp_disc_atomic(ref_processor(), true); | |
883 | |
884 // Temporarily clear _is_alive_non_header | |
885 ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL); | |
886 | |
887 ref_processor()->enable_discovery(); | |
888 | |
889 // Do collection work | |
890 { | |
891 HandleMark hm; // Discard invalid handles created during gc | |
892 G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs); | |
893 } | |
894 // Because freeing humongous regions may have added some unclean | |
895 // regions, it is necessary to tear down again before rebuilding. | |
896 tear_down_region_lists(); | |
897 rebuild_region_lists(); | |
898 | |
899 _summary_bytes_used = recalculate_used(); | |
900 | |
901 ref_processor()->enqueue_discovered_references(); | |
902 | |
903 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
904 | |
905 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) { | |
906 HandleMark hm; // Discard invalid handles created during verification | |
907 gclog_or_tty->print(" VerifyAfterGC:"); | |
908 Universe::verify(false); | |
909 } | |
910 NOT_PRODUCT(ref_processor()->verify_no_references_recorded()); | |
911 | |
912 reset_gc_time_stamp(); | |
913 // Since everything potentially moved, we will clear all remembered | |
914 // sets, and clear all cards. Later we will also cards in the used | |
915 // portion of the heap after the resizing (which could be a shrinking.) | |
916 // We will also reset the GC time stamps of the regions. | |
917 PostMCRemSetClearClosure rs_clear(mr_bs()); | |
918 heap_region_iterate(&rs_clear); | |
919 | |
920 // Resize the heap if necessary. | |
921 resize_if_necessary_after_full_collection(full ? 0 : word_size); | |
922 | |
923 // Since everything potentially moved, we will clear all remembered | |
924 // sets, but also dirty all cards corresponding to used regions. | |
925 PostMCRemSetInvalidateClosure rs_invalidate(mr_bs()); | |
926 heap_region_iterate(&rs_invalidate); | |
927 if (_cg1r->use_cache()) { | |
928 _cg1r->clear_and_record_card_counts(); | |
929 _cg1r->clear_hot_cache(); | |
930 } | |
931 | |
932 if (PrintGC) { | |
933 print_size_transition(gclog_or_tty, g1h_prev_used, used(), capacity()); | |
934 } | |
935 | |
936 if (true) { // FIXME | |
937 // Ask the permanent generation to adjust size for full collections | |
938 perm()->compute_new_size(); | |
939 } | |
940 | |
941 double end = os::elapsedTime(); | |
942 GCOverheadReporter::recordSTWEnd(end); | |
943 g1_policy()->record_full_collection_end(); | |
944 | |
945 gc_epilogue(true); | |
946 | |
947 // Abandon concurrent refinement. This must happen last: in the | |
948 // dirty-card logging system, some cards may be dirty by weak-ref | |
949 // processing, and may be enqueued. But the whole card table is | |
950 // dirtied, so this should abandon those logs, and set "do_traversal" | |
951 // to true. | |
952 concurrent_g1_refine()->set_pya_restart(); | |
953 | |
954 assert(regions_accounted_for(), "Region leakage!"); | |
955 } | |
956 | |
957 if (g1_policy()->in_young_gc_mode()) { | |
958 _young_list->reset_sampled_info(); | |
959 assert( check_young_list_empty(false, false), | |
960 "young list should be empty at this point"); | |
961 } | |
962 } | |
963 | |
964 void G1CollectedHeap::do_full_collection(bool clear_all_soft_refs) { | |
965 do_collection(true, clear_all_soft_refs, 0); | |
966 } | |
967 | |
968 // This code is mostly copied from TenuredGeneration. | |
969 void | |
970 G1CollectedHeap:: | |
971 resize_if_necessary_after_full_collection(size_t word_size) { | |
972 assert(MinHeapFreeRatio <= MaxHeapFreeRatio, "sanity check"); | |
973 | |
974 // Include the current allocation, if any, and bytes that will be | |
975 // pre-allocated to support collections, as "used". | |
976 const size_t used_after_gc = used(); | |
977 const size_t capacity_after_gc = capacity(); | |
978 const size_t free_after_gc = capacity_after_gc - used_after_gc; | |
979 | |
980 // We don't have floating point command-line arguments | |
981 const double minimum_free_percentage = (double) MinHeapFreeRatio / 100; | |
982 const double maximum_used_percentage = 1.0 - minimum_free_percentage; | |
983 const double maximum_free_percentage = (double) MaxHeapFreeRatio / 100; | |
984 const double minimum_used_percentage = 1.0 - maximum_free_percentage; | |
985 | |
986 size_t minimum_desired_capacity = (size_t) (used_after_gc / maximum_used_percentage); | |
987 size_t maximum_desired_capacity = (size_t) (used_after_gc / minimum_used_percentage); | |
988 | |
989 // Don't shrink less than the initial size. | |
990 minimum_desired_capacity = | |
991 MAX2(minimum_desired_capacity, | |
992 collector_policy()->initial_heap_byte_size()); | |
993 maximum_desired_capacity = | |
994 MAX2(maximum_desired_capacity, | |
995 collector_policy()->initial_heap_byte_size()); | |
996 | |
997 // We are failing here because minimum_desired_capacity is | |
998 assert(used_after_gc <= minimum_desired_capacity, "sanity check"); | |
999 assert(minimum_desired_capacity <= maximum_desired_capacity, "sanity check"); | |
1000 | |
1001 if (PrintGC && Verbose) { | |
1002 const double free_percentage = ((double)free_after_gc) / capacity(); | |
1003 gclog_or_tty->print_cr("Computing new size after full GC "); | |
1004 gclog_or_tty->print_cr(" " | |
1005 " minimum_free_percentage: %6.2f", | |
1006 minimum_free_percentage); | |
1007 gclog_or_tty->print_cr(" " | |
1008 " maximum_free_percentage: %6.2f", | |
1009 maximum_free_percentage); | |
1010 gclog_or_tty->print_cr(" " | |
1011 " capacity: %6.1fK" | |
1012 " minimum_desired_capacity: %6.1fK" | |
1013 " maximum_desired_capacity: %6.1fK", | |
1014 capacity() / (double) K, | |
1015 minimum_desired_capacity / (double) K, | |
1016 maximum_desired_capacity / (double) K); | |
1017 gclog_or_tty->print_cr(" " | |
1018 " free_after_gc : %6.1fK" | |
1019 " used_after_gc : %6.1fK", | |
1020 free_after_gc / (double) K, | |
1021 used_after_gc / (double) K); | |
1022 gclog_or_tty->print_cr(" " | |
1023 " free_percentage: %6.2f", | |
1024 free_percentage); | |
1025 } | |
1026 if (capacity() < minimum_desired_capacity) { | |
1027 // Don't expand unless it's significant | |
1028 size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; | |
1029 expand(expand_bytes); | |
1030 if (PrintGC && Verbose) { | |
1031 gclog_or_tty->print_cr(" expanding:" | |
1032 " minimum_desired_capacity: %6.1fK" | |
1033 " expand_bytes: %6.1fK", | |
1034 minimum_desired_capacity / (double) K, | |
1035 expand_bytes / (double) K); | |
1036 } | |
1037 | |
1038 // No expansion, now see if we want to shrink | |
1039 } else if (capacity() > maximum_desired_capacity) { | |
1040 // Capacity too large, compute shrinking size | |
1041 size_t shrink_bytes = capacity_after_gc - maximum_desired_capacity; | |
1042 shrink(shrink_bytes); | |
1043 if (PrintGC && Verbose) { | |
1044 gclog_or_tty->print_cr(" " | |
1045 " shrinking:" | |
1046 " initSize: %.1fK" | |
1047 " maximum_desired_capacity: %.1fK", | |
1048 collector_policy()->initial_heap_byte_size() / (double) K, | |
1049 maximum_desired_capacity / (double) K); | |
1050 gclog_or_tty->print_cr(" " | |
1051 " shrink_bytes: %.1fK", | |
1052 shrink_bytes / (double) K); | |
1053 } | |
1054 } | |
1055 } | |
1056 | |
1057 | |
1058 HeapWord* | |
1059 G1CollectedHeap::satisfy_failed_allocation(size_t word_size) { | |
1060 HeapWord* result = NULL; | |
1061 | |
1062 // In a G1 heap, we're supposed to keep allocation from failing by | |
1063 // incremental pauses. Therefore, at least for now, we'll favor | |
1064 // expansion over collection. (This might change in the future if we can | |
1065 // do something smarter than full collection to satisfy a failed alloc.) | |
1066 | |
1067 result = expand_and_allocate(word_size); | |
1068 if (result != NULL) { | |
1069 assert(is_in(result), "result not in heap"); | |
1070 return result; | |
1071 } | |
1072 | |
1073 // OK, I guess we have to try collection. | |
1074 | |
1075 do_collection(false, false, word_size); | |
1076 | |
1077 result = attempt_allocation(word_size, /*permit_collection_pause*/false); | |
1078 | |
1079 if (result != NULL) { | |
1080 assert(is_in(result), "result not in heap"); | |
1081 return result; | |
1082 } | |
1083 | |
1084 // Try collecting soft references. | |
1085 do_collection(false, true, word_size); | |
1086 result = attempt_allocation(word_size, /*permit_collection_pause*/false); | |
1087 if (result != NULL) { | |
1088 assert(is_in(result), "result not in heap"); | |
1089 return result; | |
1090 } | |
1091 | |
1092 // What else? We might try synchronous finalization later. If the total | |
1093 // space available is large enough for the allocation, then a more | |
1094 // complete compaction phase than we've tried so far might be | |
1095 // appropriate. | |
1096 return NULL; | |
1097 } | |
1098 | |
1099 // Attempting to expand the heap sufficiently | |
1100 // to support an allocation of the given "word_size". If | |
1101 // successful, perform the allocation and return the address of the | |
1102 // allocated block, or else "NULL". | |
1103 | |
1104 HeapWord* G1CollectedHeap::expand_and_allocate(size_t word_size) { | |
1105 size_t expand_bytes = word_size * HeapWordSize; | |
1106 if (expand_bytes < MinHeapDeltaBytes) { | |
1107 expand_bytes = MinHeapDeltaBytes; | |
1108 } | |
1109 expand(expand_bytes); | |
1110 assert(regions_accounted_for(), "Region leakage!"); | |
1111 HeapWord* result = attempt_allocation(word_size, false /* permit_collection_pause */); | |
1112 return result; | |
1113 } | |
1114 | |
1115 size_t G1CollectedHeap::free_region_if_totally_empty(HeapRegion* hr) { | |
1116 size_t pre_used = 0; | |
1117 size_t cleared_h_regions = 0; | |
1118 size_t freed_regions = 0; | |
1119 UncleanRegionList local_list; | |
1120 free_region_if_totally_empty_work(hr, pre_used, cleared_h_regions, | |
1121 freed_regions, &local_list); | |
1122 | |
1123 finish_free_region_work(pre_used, cleared_h_regions, freed_regions, | |
1124 &local_list); | |
1125 return pre_used; | |
1126 } | |
1127 | |
1128 void | |
1129 G1CollectedHeap::free_region_if_totally_empty_work(HeapRegion* hr, | |
1130 size_t& pre_used, | |
1131 size_t& cleared_h, | |
1132 size_t& freed_regions, | |
1133 UncleanRegionList* list, | |
1134 bool par) { | |
1135 assert(!hr->continuesHumongous(), "should have filtered these out"); | |
1136 size_t res = 0; | |
1137 if (!hr->popular() && hr->used() > 0 && hr->garbage_bytes() == hr->used()) { | |
1138 if (!hr->is_young()) { | |
1139 if (G1PolicyVerbose > 0) | |
1140 gclog_or_tty->print_cr("Freeing empty region "PTR_FORMAT "(" SIZE_FORMAT " bytes)" | |
1141 " during cleanup", hr, hr->used()); | |
1142 free_region_work(hr, pre_used, cleared_h, freed_regions, list, par); | |
1143 } | |
1144 } | |
1145 } | |
1146 | |
1147 // FIXME: both this and shrink could probably be more efficient by | |
1148 // doing one "VirtualSpace::expand_by" call rather than several. | |
1149 void G1CollectedHeap::expand(size_t expand_bytes) { | |
1150 size_t old_mem_size = _g1_storage.committed_size(); | |
1151 // We expand by a minimum of 1K. | |
1152 expand_bytes = MAX2(expand_bytes, (size_t)K); | |
1153 size_t aligned_expand_bytes = | |
1154 ReservedSpace::page_align_size_up(expand_bytes); | |
1155 aligned_expand_bytes = align_size_up(aligned_expand_bytes, | |
1156 HeapRegion::GrainBytes); | |
1157 expand_bytes = aligned_expand_bytes; | |
1158 while (expand_bytes > 0) { | |
1159 HeapWord* base = (HeapWord*)_g1_storage.high(); | |
1160 // Commit more storage. | |
1161 bool successful = _g1_storage.expand_by(HeapRegion::GrainBytes); | |
1162 if (!successful) { | |
1163 expand_bytes = 0; | |
1164 } else { | |
1165 expand_bytes -= HeapRegion::GrainBytes; | |
1166 // Expand the committed region. | |
1167 HeapWord* high = (HeapWord*) _g1_storage.high(); | |
1168 _g1_committed.set_end(high); | |
1169 // Create a new HeapRegion. | |
1170 MemRegion mr(base, high); | |
1171 bool is_zeroed = !_g1_max_committed.contains(base); | |
1172 HeapRegion* hr = new HeapRegion(_bot_shared, mr, is_zeroed); | |
1173 | |
1174 // Now update max_committed if necessary. | |
1175 _g1_max_committed.set_end(MAX2(_g1_max_committed.end(), high)); | |
1176 | |
1177 // Add it to the HeapRegionSeq. | |
1178 _hrs->insert(hr); | |
1179 // Set the zero-fill state, according to whether it's already | |
1180 // zeroed. | |
1181 { | |
1182 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
1183 if (is_zeroed) { | |
1184 hr->set_zero_fill_complete(); | |
1185 put_free_region_on_list_locked(hr); | |
1186 } else { | |
1187 hr->set_zero_fill_needed(); | |
1188 put_region_on_unclean_list_locked(hr); | |
1189 } | |
1190 } | |
1191 _free_regions++; | |
1192 // And we used up an expansion region to create it. | |
1193 _expansion_regions--; | |
1194 // Tell the cardtable about it. | |
1195 Universe::heap()->barrier_set()->resize_covered_region(_g1_committed); | |
1196 // And the offset table as well. | |
1197 _bot_shared->resize(_g1_committed.word_size()); | |
1198 } | |
1199 } | |
1200 if (Verbose && PrintGC) { | |
1201 size_t new_mem_size = _g1_storage.committed_size(); | |
1202 gclog_or_tty->print_cr("Expanding garbage-first heap from %ldK by %ldK to %ldK", | |
1203 old_mem_size/K, aligned_expand_bytes/K, | |
1204 new_mem_size/K); | |
1205 } | |
1206 } | |
1207 | |
1208 void G1CollectedHeap::shrink_helper(size_t shrink_bytes) | |
1209 { | |
1210 size_t old_mem_size = _g1_storage.committed_size(); | |
1211 size_t aligned_shrink_bytes = | |
1212 ReservedSpace::page_align_size_down(shrink_bytes); | |
1213 aligned_shrink_bytes = align_size_down(aligned_shrink_bytes, | |
1214 HeapRegion::GrainBytes); | |
1215 size_t num_regions_deleted = 0; | |
1216 MemRegion mr = _hrs->shrink_by(aligned_shrink_bytes, num_regions_deleted); | |
1217 | |
1218 assert(mr.end() == (HeapWord*)_g1_storage.high(), "Bad shrink!"); | |
1219 if (mr.byte_size() > 0) | |
1220 _g1_storage.shrink_by(mr.byte_size()); | |
1221 assert(mr.start() == (HeapWord*)_g1_storage.high(), "Bad shrink!"); | |
1222 | |
1223 _g1_committed.set_end(mr.start()); | |
1224 _free_regions -= num_regions_deleted; | |
1225 _expansion_regions += num_regions_deleted; | |
1226 | |
1227 // Tell the cardtable about it. | |
1228 Universe::heap()->barrier_set()->resize_covered_region(_g1_committed); | |
1229 | |
1230 // And the offset table as well. | |
1231 _bot_shared->resize(_g1_committed.word_size()); | |
1232 | |
1233 HeapRegionRemSet::shrink_heap(n_regions()); | |
1234 | |
1235 if (Verbose && PrintGC) { | |
1236 size_t new_mem_size = _g1_storage.committed_size(); | |
1237 gclog_or_tty->print_cr("Shrinking garbage-first heap from %ldK by %ldK to %ldK", | |
1238 old_mem_size/K, aligned_shrink_bytes/K, | |
1239 new_mem_size/K); | |
1240 } | |
1241 } | |
1242 | |
1243 void G1CollectedHeap::shrink(size_t shrink_bytes) { | |
1244 release_gc_alloc_regions(); | |
1245 tear_down_region_lists(); // We will rebuild them in a moment. | |
1246 shrink_helper(shrink_bytes); | |
1247 rebuild_region_lists(); | |
1248 } | |
1249 | |
1250 // Public methods. | |
1251 | |
1252 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away | |
1253 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list | |
1254 #endif // _MSC_VER | |
1255 | |
1256 | |
1257 G1CollectedHeap::G1CollectedHeap(G1CollectorPolicy* policy_) : | |
1258 SharedHeap(policy_), | |
1259 _g1_policy(policy_), | |
1260 _ref_processor(NULL), | |
1261 _process_strong_tasks(new SubTasksDone(G1H_PS_NumElements)), | |
1262 _bot_shared(NULL), | |
1263 _par_alloc_during_gc_lock(Mutex::leaf, "par alloc during GC lock"), | |
1264 _objs_with_preserved_marks(NULL), _preserved_marks_of_objs(NULL), | |
1265 _evac_failure_scan_stack(NULL) , | |
1266 _mark_in_progress(false), | |
1267 _cg1r(NULL), _czft(NULL), _summary_bytes_used(0), | |
1268 _cur_alloc_region(NULL), | |
1269 _refine_cte_cl(NULL), | |
1270 _free_region_list(NULL), _free_region_list_size(0), | |
1271 _free_regions(0), | |
1272 _popular_object_boundary(NULL), | |
1273 _cur_pop_hr_index(0), | |
1274 _popular_regions_to_be_evacuated(NULL), | |
1275 _pop_obj_rc_at_copy(), | |
1276 _full_collection(false), | |
1277 _unclean_region_list(), | |
1278 _unclean_regions_coming(false), | |
1279 _young_list(new YoungList(this)), | |
1280 _gc_time_stamp(0), | |
1281 _surviving_young_words(NULL) | |
1282 { | |
1283 _g1h = this; // To catch bugs. | |
1284 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) { | |
1285 vm_exit_during_initialization("Failed necessary allocation."); | |
1286 } | |
1287 int n_queues = MAX2((int)ParallelGCThreads, 1); | |
1288 _task_queues = new RefToScanQueueSet(n_queues); | |
1289 | |
1290 int n_rem_sets = HeapRegionRemSet::num_par_rem_sets(); | |
1291 assert(n_rem_sets > 0, "Invariant."); | |
1292 | |
1293 HeapRegionRemSetIterator** iter_arr = | |
1294 NEW_C_HEAP_ARRAY(HeapRegionRemSetIterator*, n_queues); | |
1295 for (int i = 0; i < n_queues; i++) { | |
1296 iter_arr[i] = new HeapRegionRemSetIterator(); | |
1297 } | |
1298 _rem_set_iterator = iter_arr; | |
1299 | |
1300 for (int i = 0; i < n_queues; i++) { | |
1301 RefToScanQueue* q = new RefToScanQueue(); | |
1302 q->initialize(); | |
1303 _task_queues->register_queue(i, q); | |
1304 } | |
1305 | |
1306 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
1307 _gc_alloc_regions[ap] = NULL; | |
1308 _gc_alloc_region_counts[ap] = 0; | |
1309 } | |
1310 guarantee(_task_queues != NULL, "task_queues allocation failure."); | |
1311 } | |
1312 | |
1313 jint G1CollectedHeap::initialize() { | |
1314 os::enable_vtime(); | |
1315 | |
1316 // Necessary to satisfy locking discipline assertions. | |
1317 | |
1318 MutexLocker x(Heap_lock); | |
1319 | |
1320 // While there are no constraints in the GC code that HeapWordSize | |
1321 // be any particular value, there are multiple other areas in the | |
1322 // system which believe this to be true (e.g. oop->object_size in some | |
1323 // cases incorrectly returns the size in wordSize units rather than | |
1324 // HeapWordSize). | |
1325 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize"); | |
1326 | |
1327 size_t init_byte_size = collector_policy()->initial_heap_byte_size(); | |
1328 size_t max_byte_size = collector_policy()->max_heap_byte_size(); | |
1329 | |
1330 // Ensure that the sizes are properly aligned. | |
1331 Universe::check_alignment(init_byte_size, HeapRegion::GrainBytes, "g1 heap"); | |
1332 Universe::check_alignment(max_byte_size, HeapRegion::GrainBytes, "g1 heap"); | |
1333 | |
1334 // We allocate this in any case, but only do no work if the command line | |
1335 // param is off. | |
1336 _cg1r = new ConcurrentG1Refine(); | |
1337 | |
1338 // Reserve the maximum. | |
1339 PermanentGenerationSpec* pgs = collector_policy()->permanent_generation(); | |
1340 // Includes the perm-gen. | |
1341 ReservedSpace heap_rs(max_byte_size + pgs->max_size(), | |
1342 HeapRegion::GrainBytes, | |
1343 false /*ism*/); | |
1344 | |
1345 if (!heap_rs.is_reserved()) { | |
1346 vm_exit_during_initialization("Could not reserve enough space for object heap"); | |
1347 return JNI_ENOMEM; | |
1348 } | |
1349 | |
1350 // It is important to do this in a way such that concurrent readers can't | |
1351 // temporarily think somethings in the heap. (I've actually seen this | |
1352 // happen in asserts: DLD.) | |
1353 _reserved.set_word_size(0); | |
1354 _reserved.set_start((HeapWord*)heap_rs.base()); | |
1355 _reserved.set_end((HeapWord*)(heap_rs.base() + heap_rs.size())); | |
1356 | |
1357 _expansion_regions = max_byte_size/HeapRegion::GrainBytes; | |
1358 | |
1359 _num_humongous_regions = 0; | |
1360 | |
1361 // Create the gen rem set (and barrier set) for the entire reserved region. | |
1362 _rem_set = collector_policy()->create_rem_set(_reserved, 2); | |
1363 set_barrier_set(rem_set()->bs()); | |
1364 if (barrier_set()->is_a(BarrierSet::ModRef)) { | |
1365 _mr_bs = (ModRefBarrierSet*)_barrier_set; | |
1366 } else { | |
1367 vm_exit_during_initialization("G1 requires a mod ref bs."); | |
1368 return JNI_ENOMEM; | |
1369 } | |
1370 | |
1371 // Also create a G1 rem set. | |
1372 if (G1UseHRIntoRS) { | |
1373 if (mr_bs()->is_a(BarrierSet::CardTableModRef)) { | |
1374 _g1_rem_set = new HRInto_G1RemSet(this, (CardTableModRefBS*)mr_bs()); | |
1375 } else { | |
1376 vm_exit_during_initialization("G1 requires a cardtable mod ref bs."); | |
1377 return JNI_ENOMEM; | |
1378 } | |
1379 } else { | |
1380 _g1_rem_set = new StupidG1RemSet(this); | |
1381 } | |
1382 | |
1383 // Carve out the G1 part of the heap. | |
1384 | |
1385 ReservedSpace g1_rs = heap_rs.first_part(max_byte_size); | |
1386 _g1_reserved = MemRegion((HeapWord*)g1_rs.base(), | |
1387 g1_rs.size()/HeapWordSize); | |
1388 ReservedSpace perm_gen_rs = heap_rs.last_part(max_byte_size); | |
1389 | |
1390 _perm_gen = pgs->init(perm_gen_rs, pgs->init_size(), rem_set()); | |
1391 | |
1392 _g1_storage.initialize(g1_rs, 0); | |
1393 _g1_committed = MemRegion((HeapWord*)_g1_storage.low(), (size_t) 0); | |
1394 _g1_max_committed = _g1_committed; | |
1395 _hrs = new HeapRegionSeq(); | |
1396 guarantee(_hrs != NULL, "Couldn't allocate HeapRegionSeq"); | |
1397 guarantee(_cur_alloc_region == NULL, "from constructor"); | |
1398 | |
1399 _bot_shared = new G1BlockOffsetSharedArray(_reserved, | |
1400 heap_word_size(init_byte_size)); | |
1401 | |
1402 _g1h = this; | |
1403 | |
1404 // Create the ConcurrentMark data structure and thread. | |
1405 // (Must do this late, so that "max_regions" is defined.) | |
1406 _cm = new ConcurrentMark(heap_rs, (int) max_regions()); | |
1407 _cmThread = _cm->cmThread(); | |
1408 | |
1409 // ...and the concurrent zero-fill thread, if necessary. | |
1410 if (G1ConcZeroFill) { | |
1411 _czft = new ConcurrentZFThread(); | |
1412 } | |
1413 | |
1414 | |
1415 | |
1416 // Allocate the popular regions; take them off free lists. | |
1417 size_t pop_byte_size = G1NumPopularRegions * HeapRegion::GrainBytes; | |
1418 expand(pop_byte_size); | |
1419 _popular_object_boundary = | |
1420 _g1_reserved.start() + (G1NumPopularRegions * HeapRegion::GrainWords); | |
1421 for (int i = 0; i < G1NumPopularRegions; i++) { | |
1422 HeapRegion* hr = newAllocRegion(HeapRegion::GrainWords); | |
1423 // assert(hr != NULL && hr->bottom() < _popular_object_boundary, | |
1424 // "Should be enough, and all should be below boundary."); | |
1425 hr->set_popular(true); | |
1426 } | |
1427 assert(_cur_pop_hr_index == 0, "Start allocating at the first region."); | |
1428 | |
1429 // Initialize the from_card cache structure of HeapRegionRemSet. | |
1430 HeapRegionRemSet::init_heap(max_regions()); | |
1431 | |
1432 // Now expand into the rest of the initial heap size. | |
1433 expand(init_byte_size - pop_byte_size); | |
1434 | |
1435 // Perform any initialization actions delegated to the policy. | |
1436 g1_policy()->init(); | |
1437 | |
1438 g1_policy()->note_start_of_mark_thread(); | |
1439 | |
1440 _refine_cte_cl = | |
1441 new RefineCardTableEntryClosure(ConcurrentG1RefineThread::sts(), | |
1442 g1_rem_set(), | |
1443 concurrent_g1_refine()); | |
1444 JavaThread::dirty_card_queue_set().set_closure(_refine_cte_cl); | |
1445 | |
1446 JavaThread::satb_mark_queue_set().initialize(SATB_Q_CBL_mon, | |
1447 SATB_Q_FL_lock, | |
1448 0, | |
1449 Shared_SATB_Q_lock); | |
1450 if (G1RSBarrierUseQueue) { | |
1451 JavaThread::dirty_card_queue_set().initialize(DirtyCardQ_CBL_mon, | |
1452 DirtyCardQ_FL_lock, | |
1453 G1DirtyCardQueueMax, | |
1454 Shared_DirtyCardQ_lock); | |
1455 } | |
1456 // In case we're keeping closure specialization stats, initialize those | |
1457 // counts and that mechanism. | |
1458 SpecializationStats::clear(); | |
1459 | |
1460 _gc_alloc_region_list = NULL; | |
1461 | |
1462 // Do later initialization work for concurrent refinement. | |
1463 _cg1r->init(); | |
1464 | |
1465 const char* group_names[] = { "CR", "ZF", "CM", "CL" }; | |
1466 GCOverheadReporter::initGCOverheadReporter(4, group_names); | |
1467 | |
1468 return JNI_OK; | |
1469 } | |
1470 | |
1471 void G1CollectedHeap::ref_processing_init() { | |
1472 SharedHeap::ref_processing_init(); | |
1473 MemRegion mr = reserved_region(); | |
1474 _ref_processor = ReferenceProcessor::create_ref_processor( | |
1475 mr, // span | |
1476 false, // Reference discovery is not atomic | |
1477 // (though it shouldn't matter here.) | |
1478 true, // mt_discovery | |
1479 NULL, // is alive closure: need to fill this in for efficiency | |
1480 ParallelGCThreads, | |
1481 ParallelRefProcEnabled, | |
1482 true); // Setting next fields of discovered | |
1483 // lists requires a barrier. | |
1484 } | |
1485 | |
1486 size_t G1CollectedHeap::capacity() const { | |
1487 return _g1_committed.byte_size(); | |
1488 } | |
1489 | |
1490 void G1CollectedHeap::iterate_dirty_card_closure(bool concurrent, | |
1491 int worker_i) { | |
1492 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
1493 int n_completed_buffers = 0; | |
1494 while (dcqs.apply_closure_to_completed_buffer(worker_i, 0, true)) { | |
1495 n_completed_buffers++; | |
1496 } | |
1497 g1_policy()->record_update_rs_processed_buffers(worker_i, | |
1498 (double) n_completed_buffers); | |
1499 dcqs.clear_n_completed_buffers(); | |
1500 // Finish up the queue... | |
1501 if (worker_i == 0) concurrent_g1_refine()->clean_up_cache(worker_i, | |
1502 g1_rem_set()); | |
1503 assert(!dcqs.completed_buffers_exist_dirty(), "Completed buffers exist!"); | |
1504 } | |
1505 | |
1506 | |
1507 // Computes the sum of the storage used by the various regions. | |
1508 | |
1509 size_t G1CollectedHeap::used() const { | |
1510 assert(Heap_lock->owner() != NULL, | |
1511 "Should be owned on this thread's behalf."); | |
1512 size_t result = _summary_bytes_used; | |
1513 if (_cur_alloc_region != NULL) | |
1514 result += _cur_alloc_region->used(); | |
1515 return result; | |
1516 } | |
1517 | |
1518 class SumUsedClosure: public HeapRegionClosure { | |
1519 size_t _used; | |
1520 public: | |
1521 SumUsedClosure() : _used(0) {} | |
1522 bool doHeapRegion(HeapRegion* r) { | |
1523 if (!r->continuesHumongous()) { | |
1524 _used += r->used(); | |
1525 } | |
1526 return false; | |
1527 } | |
1528 size_t result() { return _used; } | |
1529 }; | |
1530 | |
1531 size_t G1CollectedHeap::recalculate_used() const { | |
1532 SumUsedClosure blk; | |
1533 _hrs->iterate(&blk); | |
1534 return blk.result(); | |
1535 } | |
1536 | |
1537 #ifndef PRODUCT | |
1538 class SumUsedRegionsClosure: public HeapRegionClosure { | |
1539 size_t _num; | |
1540 public: | |
1541 // _num is set to 1 to account for the popular region | |
1542 SumUsedRegionsClosure() : _num(G1NumPopularRegions) {} | |
1543 bool doHeapRegion(HeapRegion* r) { | |
1544 if (r->continuesHumongous() || r->used() > 0 || r->is_gc_alloc_region()) { | |
1545 _num += 1; | |
1546 } | |
1547 return false; | |
1548 } | |
1549 size_t result() { return _num; } | |
1550 }; | |
1551 | |
1552 size_t G1CollectedHeap::recalculate_used_regions() const { | |
1553 SumUsedRegionsClosure blk; | |
1554 _hrs->iterate(&blk); | |
1555 return blk.result(); | |
1556 } | |
1557 #endif // PRODUCT | |
1558 | |
1559 size_t G1CollectedHeap::unsafe_max_alloc() { | |
1560 if (_free_regions > 0) return HeapRegion::GrainBytes; | |
1561 // otherwise, is there space in the current allocation region? | |
1562 | |
1563 // We need to store the current allocation region in a local variable | |
1564 // here. The problem is that this method doesn't take any locks and | |
1565 // there may be other threads which overwrite the current allocation | |
1566 // region field. attempt_allocation(), for example, sets it to NULL | |
1567 // and this can happen *after* the NULL check here but before the call | |
1568 // to free(), resulting in a SIGSEGV. Note that this doesn't appear | |
1569 // to be a problem in the optimized build, since the two loads of the | |
1570 // current allocation region field are optimized away. | |
1571 HeapRegion* car = _cur_alloc_region; | |
1572 | |
1573 // FIXME: should iterate over all regions? | |
1574 if (car == NULL) { | |
1575 return 0; | |
1576 } | |
1577 return car->free(); | |
1578 } | |
1579 | |
1580 void G1CollectedHeap::collect(GCCause::Cause cause) { | |
1581 // The caller doesn't have the Heap_lock | |
1582 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
1583 MutexLocker ml(Heap_lock); | |
1584 collect_locked(cause); | |
1585 } | |
1586 | |
1587 void G1CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { | |
1588 assert(Thread::current()->is_VM_thread(), "Precondition#1"); | |
1589 assert(Heap_lock->is_locked(), "Precondition#2"); | |
1590 GCCauseSetter gcs(this, cause); | |
1591 switch (cause) { | |
1592 case GCCause::_heap_inspection: | |
1593 case GCCause::_heap_dump: { | |
1594 HandleMark hm; | |
1595 do_full_collection(false); // don't clear all soft refs | |
1596 break; | |
1597 } | |
1598 default: // XXX FIX ME | |
1599 ShouldNotReachHere(); // Unexpected use of this function | |
1600 } | |
1601 } | |
1602 | |
1603 | |
1604 void G1CollectedHeap::collect_locked(GCCause::Cause cause) { | |
1605 // Don't want to do a GC until cleanup is completed. | |
1606 wait_for_cleanup_complete(); | |
1607 | |
1608 // Read the GC count while holding the Heap_lock | |
1609 int gc_count_before = SharedHeap::heap()->total_collections(); | |
1610 { | |
1611 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
1612 VM_G1CollectFull op(gc_count_before, cause); | |
1613 VMThread::execute(&op); | |
1614 } | |
1615 } | |
1616 | |
1617 bool G1CollectedHeap::is_in(const void* p) const { | |
1618 if (_g1_committed.contains(p)) { | |
1619 HeapRegion* hr = _hrs->addr_to_region(p); | |
1620 return hr->is_in(p); | |
1621 } else { | |
1622 return _perm_gen->as_gen()->is_in(p); | |
1623 } | |
1624 } | |
1625 | |
1626 // Iteration functions. | |
1627 | |
1628 // Iterates an OopClosure over all ref-containing fields of objects | |
1629 // within a HeapRegion. | |
1630 | |
1631 class IterateOopClosureRegionClosure: public HeapRegionClosure { | |
1632 MemRegion _mr; | |
1633 OopClosure* _cl; | |
1634 public: | |
1635 IterateOopClosureRegionClosure(MemRegion mr, OopClosure* cl) | |
1636 : _mr(mr), _cl(cl) {} | |
1637 bool doHeapRegion(HeapRegion* r) { | |
1638 if (! r->continuesHumongous()) { | |
1639 r->oop_iterate(_cl); | |
1640 } | |
1641 return false; | |
1642 } | |
1643 }; | |
1644 | |
1645 void G1CollectedHeap::oop_iterate(OopClosure* cl) { | |
1646 IterateOopClosureRegionClosure blk(_g1_committed, cl); | |
1647 _hrs->iterate(&blk); | |
1648 } | |
1649 | |
1650 void G1CollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) { | |
1651 IterateOopClosureRegionClosure blk(mr, cl); | |
1652 _hrs->iterate(&blk); | |
1653 } | |
1654 | |
1655 // Iterates an ObjectClosure over all objects within a HeapRegion. | |
1656 | |
1657 class IterateObjectClosureRegionClosure: public HeapRegionClosure { | |
1658 ObjectClosure* _cl; | |
1659 public: | |
1660 IterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {} | |
1661 bool doHeapRegion(HeapRegion* r) { | |
1662 if (! r->continuesHumongous()) { | |
1663 r->object_iterate(_cl); | |
1664 } | |
1665 return false; | |
1666 } | |
1667 }; | |
1668 | |
1669 void G1CollectedHeap::object_iterate(ObjectClosure* cl) { | |
1670 IterateObjectClosureRegionClosure blk(cl); | |
1671 _hrs->iterate(&blk); | |
1672 } | |
1673 | |
1674 void G1CollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) { | |
1675 // FIXME: is this right? | |
1676 guarantee(false, "object_iterate_since_last_GC not supported by G1 heap"); | |
1677 } | |
1678 | |
1679 // Calls a SpaceClosure on a HeapRegion. | |
1680 | |
1681 class SpaceClosureRegionClosure: public HeapRegionClosure { | |
1682 SpaceClosure* _cl; | |
1683 public: | |
1684 SpaceClosureRegionClosure(SpaceClosure* cl) : _cl(cl) {} | |
1685 bool doHeapRegion(HeapRegion* r) { | |
1686 _cl->do_space(r); | |
1687 return false; | |
1688 } | |
1689 }; | |
1690 | |
1691 void G1CollectedHeap::space_iterate(SpaceClosure* cl) { | |
1692 SpaceClosureRegionClosure blk(cl); | |
1693 _hrs->iterate(&blk); | |
1694 } | |
1695 | |
1696 void G1CollectedHeap::heap_region_iterate(HeapRegionClosure* cl) { | |
1697 _hrs->iterate(cl); | |
1698 } | |
1699 | |
1700 void G1CollectedHeap::heap_region_iterate_from(HeapRegion* r, | |
1701 HeapRegionClosure* cl) { | |
1702 _hrs->iterate_from(r, cl); | |
1703 } | |
1704 | |
1705 void | |
1706 G1CollectedHeap::heap_region_iterate_from(int idx, HeapRegionClosure* cl) { | |
1707 _hrs->iterate_from(idx, cl); | |
1708 } | |
1709 | |
1710 HeapRegion* G1CollectedHeap::region_at(size_t idx) { return _hrs->at(idx); } | |
1711 | |
1712 const int OverpartitionFactor = 4; | |
1713 void | |
1714 G1CollectedHeap::heap_region_par_iterate_chunked(HeapRegionClosure* cl, | |
1715 int worker, | |
1716 jint claim_value) { | |
1717 // We break up the heap regions into blocks of size ParallelGCThreads (to | |
1718 // decrease iteration costs). | |
1719 const size_t nregions = n_regions(); | |
1720 const size_t n_thrds = (ParallelGCThreads > 0 ? ParallelGCThreads : 1); | |
1721 const size_t partitions = n_thrds * OverpartitionFactor; | |
1722 const size_t BlkSize = MAX2(nregions/partitions, (size_t)1); | |
1723 const size_t n_blocks = (nregions + BlkSize - 1)/BlkSize; | |
1724 assert(ParallelGCThreads > 0 || worker == 0, "Precondition"); | |
1725 const int init_idx = (int) (n_blocks/n_thrds * worker); | |
1726 for (size_t blk = 0; blk < n_blocks; blk++) { | |
1727 size_t idx = init_idx + blk; | |
1728 if (idx >= n_blocks) idx = idx - n_blocks; | |
1729 size_t reg_idx = idx * BlkSize; | |
1730 assert(reg_idx < nregions, "Because we rounded blk up."); | |
1731 HeapRegion* r = region_at(reg_idx); | |
1732 if (r->claimHeapRegion(claim_value)) { | |
1733 for (size_t j = 0; j < BlkSize; j++) { | |
1734 size_t reg_idx2 = reg_idx + j; | |
1735 if (reg_idx2 == nregions) break; | |
1736 HeapRegion* r2 = region_at(reg_idx2); | |
1737 if (j > 0) r2->set_claim_value(claim_value); | |
1738 bool res = cl->doHeapRegion(r2); | |
1739 guarantee(!res, "Should not abort."); | |
1740 } | |
1741 } | |
1742 } | |
1743 } | |
1744 | |
1745 void G1CollectedHeap::collection_set_iterate(HeapRegionClosure* cl) { | |
1746 HeapRegion* r = g1_policy()->collection_set(); | |
1747 while (r != NULL) { | |
1748 HeapRegion* next = r->next_in_collection_set(); | |
1749 if (cl->doHeapRegion(r)) { | |
1750 cl->incomplete(); | |
1751 return; | |
1752 } | |
1753 r = next; | |
1754 } | |
1755 } | |
1756 | |
1757 void G1CollectedHeap::collection_set_iterate_from(HeapRegion* r, | |
1758 HeapRegionClosure *cl) { | |
1759 assert(r->in_collection_set(), | |
1760 "Start region must be a member of the collection set."); | |
1761 HeapRegion* cur = r; | |
1762 while (cur != NULL) { | |
1763 HeapRegion* next = cur->next_in_collection_set(); | |
1764 if (cl->doHeapRegion(cur) && false) { | |
1765 cl->incomplete(); | |
1766 return; | |
1767 } | |
1768 cur = next; | |
1769 } | |
1770 cur = g1_policy()->collection_set(); | |
1771 while (cur != r) { | |
1772 HeapRegion* next = cur->next_in_collection_set(); | |
1773 if (cl->doHeapRegion(cur) && false) { | |
1774 cl->incomplete(); | |
1775 return; | |
1776 } | |
1777 cur = next; | |
1778 } | |
1779 } | |
1780 | |
1781 CompactibleSpace* G1CollectedHeap::first_compactible_space() { | |
1782 return _hrs->length() > 0 ? _hrs->at(0) : NULL; | |
1783 } | |
1784 | |
1785 | |
1786 Space* G1CollectedHeap::space_containing(const void* addr) const { | |
1787 Space* res = heap_region_containing(addr); | |
1788 if (res == NULL) | |
1789 res = perm_gen()->space_containing(addr); | |
1790 return res; | |
1791 } | |
1792 | |
1793 HeapWord* G1CollectedHeap::block_start(const void* addr) const { | |
1794 Space* sp = space_containing(addr); | |
1795 if (sp != NULL) { | |
1796 return sp->block_start(addr); | |
1797 } | |
1798 return NULL; | |
1799 } | |
1800 | |
1801 size_t G1CollectedHeap::block_size(const HeapWord* addr) const { | |
1802 Space* sp = space_containing(addr); | |
1803 assert(sp != NULL, "block_size of address outside of heap"); | |
1804 return sp->block_size(addr); | |
1805 } | |
1806 | |
1807 bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const { | |
1808 Space* sp = space_containing(addr); | |
1809 return sp->block_is_obj(addr); | |
1810 } | |
1811 | |
1812 bool G1CollectedHeap::supports_tlab_allocation() const { | |
1813 return true; | |
1814 } | |
1815 | |
1816 size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const { | |
1817 return HeapRegion::GrainBytes; | |
1818 } | |
1819 | |
1820 size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const { | |
1821 // Return the remaining space in the cur alloc region, but not less than | |
1822 // the min TLAB size. | |
1823 // Also, no more than half the region size, since we can't allow tlabs to | |
1824 // grow big enough to accomodate humongous objects. | |
1825 | |
1826 // We need to story it locally, since it might change between when we | |
1827 // test for NULL and when we use it later. | |
1828 ContiguousSpace* cur_alloc_space = _cur_alloc_region; | |
1829 if (cur_alloc_space == NULL) { | |
1830 return HeapRegion::GrainBytes/2; | |
1831 } else { | |
1832 return MAX2(MIN2(cur_alloc_space->free(), | |
1833 (size_t)(HeapRegion::GrainBytes/2)), | |
1834 (size_t)MinTLABSize); | |
1835 } | |
1836 } | |
1837 | |
1838 HeapWord* G1CollectedHeap::allocate_new_tlab(size_t size) { | |
1839 bool dummy; | |
1840 return G1CollectedHeap::mem_allocate(size, false, true, &dummy); | |
1841 } | |
1842 | |
1843 bool G1CollectedHeap::allocs_are_zero_filled() { | |
1844 return false; | |
1845 } | |
1846 | |
1847 size_t G1CollectedHeap::large_typearray_limit() { | |
1848 // FIXME | |
1849 return HeapRegion::GrainBytes/HeapWordSize; | |
1850 } | |
1851 | |
1852 size_t G1CollectedHeap::max_capacity() const { | |
1853 return _g1_committed.byte_size(); | |
1854 } | |
1855 | |
1856 jlong G1CollectedHeap::millis_since_last_gc() { | |
1857 // assert(false, "NYI"); | |
1858 return 0; | |
1859 } | |
1860 | |
1861 | |
1862 void G1CollectedHeap::prepare_for_verify() { | |
1863 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { | |
1864 ensure_parsability(false); | |
1865 } | |
1866 g1_rem_set()->prepare_for_verify(); | |
1867 } | |
1868 | |
1869 class VerifyLivenessOopClosure: public OopClosure { | |
1870 G1CollectedHeap* g1h; | |
1871 public: | |
1872 VerifyLivenessOopClosure(G1CollectedHeap* _g1h) { | |
1873 g1h = _g1h; | |
1874 } | |
1875 void do_oop(narrowOop *p) { | |
1876 guarantee(false, "NYI"); | |
1877 } | |
1878 void do_oop(oop *p) { | |
1879 oop obj = *p; | |
1880 assert(obj == NULL || !g1h->is_obj_dead(obj), | |
1881 "Dead object referenced by a not dead object"); | |
1882 } | |
1883 }; | |
1884 | |
1885 class VerifyObjsInRegionClosure: public ObjectClosure { | |
1886 G1CollectedHeap* _g1h; | |
1887 size_t _live_bytes; | |
1888 HeapRegion *_hr; | |
1889 public: | |
1890 VerifyObjsInRegionClosure(HeapRegion *hr) : _live_bytes(0), _hr(hr) { | |
1891 _g1h = G1CollectedHeap::heap(); | |
1892 } | |
1893 void do_object(oop o) { | |
1894 VerifyLivenessOopClosure isLive(_g1h); | |
1895 assert(o != NULL, "Huh?"); | |
1896 if (!_g1h->is_obj_dead(o)) { | |
1897 o->oop_iterate(&isLive); | |
1898 if (!_hr->obj_allocated_since_prev_marking(o)) | |
1899 _live_bytes += (o->size() * HeapWordSize); | |
1900 } | |
1901 } | |
1902 size_t live_bytes() { return _live_bytes; } | |
1903 }; | |
1904 | |
1905 class PrintObjsInRegionClosure : public ObjectClosure { | |
1906 HeapRegion *_hr; | |
1907 G1CollectedHeap *_g1; | |
1908 public: | |
1909 PrintObjsInRegionClosure(HeapRegion *hr) : _hr(hr) { | |
1910 _g1 = G1CollectedHeap::heap(); | |
1911 }; | |
1912 | |
1913 void do_object(oop o) { | |
1914 if (o != NULL) { | |
1915 HeapWord *start = (HeapWord *) o; | |
1916 size_t word_sz = o->size(); | |
1917 gclog_or_tty->print("\nPrinting obj "PTR_FORMAT" of size " SIZE_FORMAT | |
1918 " isMarkedPrev %d isMarkedNext %d isAllocSince %d\n", | |
1919 (void*) o, word_sz, | |
1920 _g1->isMarkedPrev(o), | |
1921 _g1->isMarkedNext(o), | |
1922 _hr->obj_allocated_since_prev_marking(o)); | |
1923 HeapWord *end = start + word_sz; | |
1924 HeapWord *cur; | |
1925 int *val; | |
1926 for (cur = start; cur < end; cur++) { | |
1927 val = (int *) cur; | |
1928 gclog_or_tty->print("\t "PTR_FORMAT":"PTR_FORMAT"\n", val, *val); | |
1929 } | |
1930 } | |
1931 } | |
1932 }; | |
1933 | |
1934 class VerifyRegionClosure: public HeapRegionClosure { | |
1935 public: | |
1936 bool _allow_dirty; | |
1937 VerifyRegionClosure(bool allow_dirty) | |
1938 : _allow_dirty(allow_dirty) {} | |
1939 bool doHeapRegion(HeapRegion* r) { | |
1940 guarantee(r->claim_value() == 0, "Should be unclaimed at verify points."); | |
1941 if (r->isHumongous()) { | |
1942 if (r->startsHumongous()) { | |
1943 // Verify the single H object. | |
1944 oop(r->bottom())->verify(); | |
1945 size_t word_sz = oop(r->bottom())->size(); | |
1946 guarantee(r->top() == r->bottom() + word_sz, | |
1947 "Only one object in a humongous region"); | |
1948 } | |
1949 } else { | |
1950 VerifyObjsInRegionClosure not_dead_yet_cl(r); | |
1951 r->verify(_allow_dirty); | |
1952 r->object_iterate(¬_dead_yet_cl); | |
1953 guarantee(r->max_live_bytes() >= not_dead_yet_cl.live_bytes(), | |
1954 "More live objects than counted in last complete marking."); | |
1955 } | |
1956 return false; | |
1957 } | |
1958 }; | |
1959 | |
1960 class VerifyRootsClosure: public OopsInGenClosure { | |
1961 private: | |
1962 G1CollectedHeap* _g1h; | |
1963 bool _failures; | |
1964 | |
1965 public: | |
1966 VerifyRootsClosure() : | |
1967 _g1h(G1CollectedHeap::heap()), _failures(false) { } | |
1968 | |
1969 bool failures() { return _failures; } | |
1970 | |
1971 void do_oop(narrowOop* p) { | |
1972 guarantee(false, "NYI"); | |
1973 } | |
1974 | |
1975 void do_oop(oop* p) { | |
1976 oop obj = *p; | |
1977 if (obj != NULL) { | |
1978 if (_g1h->is_obj_dead(obj)) { | |
1979 gclog_or_tty->print_cr("Root location "PTR_FORMAT" " | |
1980 "points to dead obj "PTR_FORMAT, p, (void*) obj); | |
1981 obj->print_on(gclog_or_tty); | |
1982 _failures = true; | |
1983 } | |
1984 } | |
1985 } | |
1986 }; | |
1987 | |
1988 void G1CollectedHeap::verify(bool allow_dirty, bool silent) { | |
1989 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { | |
1990 if (!silent) { gclog_or_tty->print("roots "); } | |
1991 VerifyRootsClosure rootsCl; | |
1992 process_strong_roots(false, | |
1993 SharedHeap::SO_AllClasses, | |
1994 &rootsCl, | |
1995 &rootsCl); | |
1996 rem_set()->invalidate(perm_gen()->used_region(), false); | |
1997 if (!silent) { gclog_or_tty->print("heapRegions "); } | |
1998 VerifyRegionClosure blk(allow_dirty); | |
1999 _hrs->iterate(&blk); | |
2000 if (!silent) gclog_or_tty->print("remset "); | |
2001 rem_set()->verify(); | |
2002 guarantee(!rootsCl.failures(), "should not have had failures"); | |
2003 } else { | |
2004 if (!silent) gclog_or_tty->print("(SKIPPING roots, heapRegions, remset) "); | |
2005 } | |
2006 } | |
2007 | |
2008 class PrintRegionClosure: public HeapRegionClosure { | |
2009 outputStream* _st; | |
2010 public: | |
2011 PrintRegionClosure(outputStream* st) : _st(st) {} | |
2012 bool doHeapRegion(HeapRegion* r) { | |
2013 r->print_on(_st); | |
2014 return false; | |
2015 } | |
2016 }; | |
2017 | |
2018 void G1CollectedHeap::print() const { print_on(gclog_or_tty); } | |
2019 | |
2020 void G1CollectedHeap::print_on(outputStream* st) const { | |
2021 PrintRegionClosure blk(st); | |
2022 _hrs->iterate(&blk); | |
2023 } | |
2024 | |
2025 void G1CollectedHeap::print_gc_threads_on(outputStream* st) const { | |
2026 if (ParallelGCThreads > 0) { | |
2027 workers()->print_worker_threads(); | |
2028 } | |
2029 st->print("\"G1 concurrent mark GC Thread\" "); | |
2030 _cmThread->print(); | |
2031 st->cr(); | |
2032 st->print("\"G1 concurrent refinement GC Thread\" "); | |
2033 _cg1r->cg1rThread()->print_on(st); | |
2034 st->cr(); | |
2035 st->print("\"G1 zero-fill GC Thread\" "); | |
2036 _czft->print_on(st); | |
2037 st->cr(); | |
2038 } | |
2039 | |
2040 void G1CollectedHeap::gc_threads_do(ThreadClosure* tc) const { | |
2041 if (ParallelGCThreads > 0) { | |
2042 workers()->threads_do(tc); | |
2043 } | |
2044 tc->do_thread(_cmThread); | |
2045 tc->do_thread(_cg1r->cg1rThread()); | |
2046 tc->do_thread(_czft); | |
2047 } | |
2048 | |
2049 void G1CollectedHeap::print_tracing_info() const { | |
2050 concurrent_g1_refine()->print_final_card_counts(); | |
2051 | |
2052 // We'll overload this to mean "trace GC pause statistics." | |
2053 if (TraceGen0Time || TraceGen1Time) { | |
2054 // The "G1CollectorPolicy" is keeping track of these stats, so delegate | |
2055 // to that. | |
2056 g1_policy()->print_tracing_info(); | |
2057 } | |
2058 if (SummarizeG1RSStats) { | |
2059 g1_rem_set()->print_summary_info(); | |
2060 } | |
2061 if (SummarizeG1ConcMark) { | |
2062 concurrent_mark()->print_summary_info(); | |
2063 } | |
2064 if (SummarizeG1ZFStats) { | |
2065 ConcurrentZFThread::print_summary_info(); | |
2066 } | |
2067 if (G1SummarizePopularity) { | |
2068 print_popularity_summary_info(); | |
2069 } | |
2070 g1_policy()->print_yg_surv_rate_info(); | |
2071 | |
2072 GCOverheadReporter::printGCOverhead(); | |
2073 | |
2074 SpecializationStats::print(); | |
2075 } | |
2076 | |
2077 | |
2078 int G1CollectedHeap::addr_to_arena_id(void* addr) const { | |
2079 HeapRegion* hr = heap_region_containing(addr); | |
2080 if (hr == NULL) { | |
2081 return 0; | |
2082 } else { | |
2083 return 1; | |
2084 } | |
2085 } | |
2086 | |
2087 G1CollectedHeap* G1CollectedHeap::heap() { | |
2088 assert(_sh->kind() == CollectedHeap::G1CollectedHeap, | |
2089 "not a garbage-first heap"); | |
2090 return _g1h; | |
2091 } | |
2092 | |
2093 void G1CollectedHeap::gc_prologue(bool full /* Ignored */) { | |
2094 if (PrintHeapAtGC){ | |
2095 gclog_or_tty->print_cr(" {Heap before GC collections=%d:", total_collections()); | |
2096 Universe::print(); | |
2097 } | |
2098 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer"); | |
2099 // Call allocation profiler | |
2100 AllocationProfiler::iterate_since_last_gc(); | |
2101 // Fill TLAB's and such | |
2102 ensure_parsability(true); | |
2103 } | |
2104 | |
2105 void G1CollectedHeap::gc_epilogue(bool full /* Ignored */) { | |
2106 // FIXME: what is this about? | |
2107 // I'm ignoring the "fill_newgen()" call if "alloc_event_enabled" | |
2108 // is set. | |
2109 COMPILER2_PRESENT(assert(DerivedPointerTable::is_empty(), | |
2110 "derived pointer present")); | |
2111 | |
2112 if (PrintHeapAtGC){ | |
2113 gclog_or_tty->print_cr(" Heap after GC collections=%d:", total_collections()); | |
2114 Universe::print(); | |
2115 gclog_or_tty->print("} "); | |
2116 } | |
2117 } | |
2118 | |
2119 void G1CollectedHeap::do_collection_pause() { | |
2120 // Read the GC count while holding the Heap_lock | |
2121 // we need to do this _before_ wait_for_cleanup_complete(), to | |
2122 // ensure that we do not give up the heap lock and potentially | |
2123 // pick up the wrong count | |
2124 int gc_count_before = SharedHeap::heap()->total_collections(); | |
2125 | |
2126 // Don't want to do a GC pause while cleanup is being completed! | |
2127 wait_for_cleanup_complete(); | |
2128 | |
2129 g1_policy()->record_stop_world_start(); | |
2130 { | |
2131 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
2132 VM_G1IncCollectionPause op(gc_count_before); | |
2133 VMThread::execute(&op); | |
2134 } | |
2135 } | |
2136 | |
2137 void | |
2138 G1CollectedHeap::doConcurrentMark() { | |
2139 if (G1ConcMark) { | |
2140 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2141 if (!_cmThread->in_progress()) { | |
2142 _cmThread->set_started(); | |
2143 CGC_lock->notify(); | |
2144 } | |
2145 } | |
2146 } | |
2147 | |
2148 class VerifyMarkedObjsClosure: public ObjectClosure { | |
2149 G1CollectedHeap* _g1h; | |
2150 public: | |
2151 VerifyMarkedObjsClosure(G1CollectedHeap* g1h) : _g1h(g1h) {} | |
2152 void do_object(oop obj) { | |
2153 assert(obj->mark()->is_marked() ? !_g1h->is_obj_dead(obj) : true, | |
2154 "markandsweep mark should agree with concurrent deadness"); | |
2155 } | |
2156 }; | |
2157 | |
2158 void | |
2159 G1CollectedHeap::checkConcurrentMark() { | |
2160 VerifyMarkedObjsClosure verifycl(this); | |
2161 doConcurrentMark(); | |
2162 // MutexLockerEx x(getMarkBitMapLock(), | |
2163 // Mutex::_no_safepoint_check_flag); | |
2164 object_iterate(&verifycl); | |
2165 } | |
2166 | |
2167 void G1CollectedHeap::do_sync_mark() { | |
2168 _cm->checkpointRootsInitial(); | |
2169 _cm->markFromRoots(); | |
2170 _cm->checkpointRootsFinal(false); | |
2171 } | |
2172 | |
2173 // <NEW PREDICTION> | |
2174 | |
2175 double G1CollectedHeap::predict_region_elapsed_time_ms(HeapRegion *hr, | |
2176 bool young) { | |
2177 return _g1_policy->predict_region_elapsed_time_ms(hr, young); | |
2178 } | |
2179 | |
2180 void G1CollectedHeap::check_if_region_is_too_expensive(double | |
2181 predicted_time_ms) { | |
2182 _g1_policy->check_if_region_is_too_expensive(predicted_time_ms); | |
2183 } | |
2184 | |
2185 size_t G1CollectedHeap::pending_card_num() { | |
2186 size_t extra_cards = 0; | |
2187 JavaThread *curr = Threads::first(); | |
2188 while (curr != NULL) { | |
2189 DirtyCardQueue& dcq = curr->dirty_card_queue(); | |
2190 extra_cards += dcq.size(); | |
2191 curr = curr->next(); | |
2192 } | |
2193 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
2194 size_t buffer_size = dcqs.buffer_size(); | |
2195 size_t buffer_num = dcqs.completed_buffers_num(); | |
2196 return buffer_size * buffer_num + extra_cards; | |
2197 } | |
2198 | |
2199 size_t G1CollectedHeap::max_pending_card_num() { | |
2200 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
2201 size_t buffer_size = dcqs.buffer_size(); | |
2202 size_t buffer_num = dcqs.completed_buffers_num(); | |
2203 int thread_num = Threads::number_of_threads(); | |
2204 return (buffer_num + thread_num) * buffer_size; | |
2205 } | |
2206 | |
2207 size_t G1CollectedHeap::cards_scanned() { | |
2208 HRInto_G1RemSet* g1_rset = (HRInto_G1RemSet*) g1_rem_set(); | |
2209 return g1_rset->cardsScanned(); | |
2210 } | |
2211 | |
2212 void | |
2213 G1CollectedHeap::setup_surviving_young_words() { | |
2214 guarantee( _surviving_young_words == NULL, "pre-condition" ); | |
2215 size_t array_length = g1_policy()->young_cset_length(); | |
2216 _surviving_young_words = NEW_C_HEAP_ARRAY(size_t, array_length); | |
2217 if (_surviving_young_words == NULL) { | |
2218 vm_exit_out_of_memory(sizeof(size_t) * array_length, | |
2219 "Not enough space for young surv words summary."); | |
2220 } | |
2221 memset(_surviving_young_words, 0, array_length * sizeof(size_t)); | |
2222 for (size_t i = 0; i < array_length; ++i) { | |
2223 guarantee( _surviving_young_words[i] == 0, "invariant" ); | |
2224 } | |
2225 } | |
2226 | |
2227 void | |
2228 G1CollectedHeap::update_surviving_young_words(size_t* surv_young_words) { | |
2229 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
2230 size_t array_length = g1_policy()->young_cset_length(); | |
2231 for (size_t i = 0; i < array_length; ++i) | |
2232 _surviving_young_words[i] += surv_young_words[i]; | |
2233 } | |
2234 | |
2235 void | |
2236 G1CollectedHeap::cleanup_surviving_young_words() { | |
2237 guarantee( _surviving_young_words != NULL, "pre-condition" ); | |
2238 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words); | |
2239 _surviving_young_words = NULL; | |
2240 } | |
2241 | |
2242 // </NEW PREDICTION> | |
2243 | |
2244 void | |
2245 G1CollectedHeap::do_collection_pause_at_safepoint(HeapRegion* popular_region) { | |
2246 char verbose_str[128]; | |
2247 sprintf(verbose_str, "GC pause "); | |
2248 if (popular_region != NULL) | |
2249 strcat(verbose_str, "(popular)"); | |
2250 else if (g1_policy()->in_young_gc_mode()) { | |
2251 if (g1_policy()->full_young_gcs()) | |
2252 strcat(verbose_str, "(young)"); | |
2253 else | |
2254 strcat(verbose_str, "(partial)"); | |
2255 } | |
2256 bool reset_should_initiate_conc_mark = false; | |
2257 if (popular_region != NULL && g1_policy()->should_initiate_conc_mark()) { | |
2258 // we currently do not allow an initial mark phase to be piggy-backed | |
2259 // on a popular pause | |
2260 reset_should_initiate_conc_mark = true; | |
2261 g1_policy()->unset_should_initiate_conc_mark(); | |
2262 } | |
2263 if (g1_policy()->should_initiate_conc_mark()) | |
2264 strcat(verbose_str, " (initial-mark)"); | |
2265 | |
2266 GCCauseSetter x(this, (popular_region == NULL ? | |
2267 GCCause::_g1_inc_collection_pause : | |
2268 GCCause::_g1_pop_region_collection_pause)); | |
2269 | |
2270 // if PrintGCDetails is on, we'll print long statistics information | |
2271 // in the collector policy code, so let's not print this as the output | |
2272 // is messy if we do. | |
2273 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
2274 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
2275 TraceTime t(verbose_str, PrintGC && !PrintGCDetails, true, gclog_or_tty); | |
2276 | |
2277 ResourceMark rm; | |
2278 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
2279 assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread"); | |
2280 guarantee(!is_gc_active(), "collection is not reentrant"); | |
2281 assert(regions_accounted_for(), "Region leakage!"); | |
2282 ++_gc_time_stamp; | |
2283 | |
2284 if (g1_policy()->in_young_gc_mode()) { | |
2285 assert(check_young_list_well_formed(), | |
2286 "young list should be well formed"); | |
2287 } | |
2288 | |
2289 if (GC_locker::is_active()) { | |
2290 return; // GC is disabled (e.g. JNI GetXXXCritical operation) | |
2291 } | |
2292 | |
2293 bool abandoned = false; | |
2294 { // Call to jvmpi::post_class_unload_events must occur outside of active GC | |
2295 IsGCActiveMark x; | |
2296 | |
2297 gc_prologue(false); | |
2298 increment_total_collections(); | |
2299 | |
2300 #if G1_REM_SET_LOGGING | |
2301 gclog_or_tty->print_cr("\nJust chose CS, heap:"); | |
2302 print(); | |
2303 #endif | |
2304 | |
2305 if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) { | |
2306 HandleMark hm; // Discard invalid handles created during verification | |
2307 prepare_for_verify(); | |
2308 gclog_or_tty->print(" VerifyBeforeGC:"); | |
2309 Universe::verify(false); | |
2310 } | |
2311 | |
2312 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
2313 | |
2314 // We want to turn off ref discovere, if necessary, and turn it back on | |
2315 // on again later if we do. | |
2316 bool was_enabled = ref_processor()->discovery_enabled(); | |
2317 if (was_enabled) ref_processor()->disable_discovery(); | |
2318 | |
2319 // Forget the current alloc region (we might even choose it to be part | |
2320 // of the collection set!). | |
2321 abandon_cur_alloc_region(); | |
2322 | |
2323 // The elapsed time induced by the start time below deliberately elides | |
2324 // the possible verification above. | |
2325 double start_time_sec = os::elapsedTime(); | |
2326 GCOverheadReporter::recordSTWStart(start_time_sec); | |
2327 size_t start_used_bytes = used(); | |
2328 if (!G1ConcMark) { | |
2329 do_sync_mark(); | |
2330 } | |
2331 | |
2332 g1_policy()->record_collection_pause_start(start_time_sec, | |
2333 start_used_bytes); | |
2334 | |
2335 #if SCAN_ONLY_VERBOSE | |
2336 _young_list->print(); | |
2337 #endif // SCAN_ONLY_VERBOSE | |
2338 | |
2339 if (g1_policy()->should_initiate_conc_mark()) { | |
2340 concurrent_mark()->checkpointRootsInitialPre(); | |
2341 } | |
2342 save_marks(); | |
2343 | |
2344 // We must do this before any possible evacuation that should propogate | |
2345 // marks, including evacuation of popular objects in a popular pause. | |
2346 if (mark_in_progress()) { | |
2347 double start_time_sec = os::elapsedTime(); | |
2348 | |
2349 _cm->drainAllSATBBuffers(); | |
2350 double finish_mark_ms = (os::elapsedTime() - start_time_sec) * 1000.0; | |
2351 g1_policy()->record_satb_drain_time(finish_mark_ms); | |
2352 | |
2353 } | |
2354 // Record the number of elements currently on the mark stack, so we | |
2355 // only iterate over these. (Since evacuation may add to the mark | |
2356 // stack, doing more exposes race conditions.) If no mark is in | |
2357 // progress, this will be zero. | |
2358 _cm->set_oops_do_bound(); | |
2359 | |
2360 assert(regions_accounted_for(), "Region leakage."); | |
2361 | |
2362 bool abandoned = false; | |
2363 | |
2364 if (mark_in_progress()) | |
2365 concurrent_mark()->newCSet(); | |
2366 | |
2367 // Now choose the CS. | |
2368 if (popular_region == NULL) { | |
2369 g1_policy()->choose_collection_set(); | |
2370 } else { | |
2371 // We may be evacuating a single region (for popularity). | |
2372 g1_policy()->record_popular_pause_preamble_start(); | |
2373 popularity_pause_preamble(popular_region); | |
2374 g1_policy()->record_popular_pause_preamble_end(); | |
2375 abandoned = (g1_policy()->collection_set() == NULL); | |
2376 // Now we allow more regions to be added (we have to collect | |
2377 // all popular regions). | |
2378 if (!abandoned) { | |
2379 g1_policy()->choose_collection_set(popular_region); | |
2380 } | |
2381 } | |
2382 // We may abandon a pause if we find no region that will fit in the MMU | |
2383 // pause. | |
2384 abandoned = (g1_policy()->collection_set() == NULL); | |
2385 | |
2386 // Nothing to do if we were unable to choose a collection set. | |
2387 if (!abandoned) { | |
2388 #if G1_REM_SET_LOGGING | |
2389 gclog_or_tty->print_cr("\nAfter pause, heap:"); | |
2390 print(); | |
2391 #endif | |
2392 | |
2393 setup_surviving_young_words(); | |
2394 | |
2395 // Set up the gc allocation regions. | |
2396 get_gc_alloc_regions(); | |
2397 | |
2398 // Actually do the work... | |
2399 evacuate_collection_set(); | |
2400 free_collection_set(g1_policy()->collection_set()); | |
2401 g1_policy()->clear_collection_set(); | |
2402 | |
2403 if (popular_region != NULL) { | |
2404 // We have to wait until now, because we don't want the region to | |
2405 // be rescheduled for pop-evac during RS update. | |
2406 popular_region->set_popular_pending(false); | |
2407 } | |
2408 | |
2409 release_gc_alloc_regions(); | |
2410 | |
2411 cleanup_surviving_young_words(); | |
2412 | |
2413 if (g1_policy()->in_young_gc_mode()) { | |
2414 _young_list->reset_sampled_info(); | |
2415 assert(check_young_list_empty(true), | |
2416 "young list should be empty"); | |
2417 | |
2418 #if SCAN_ONLY_VERBOSE | |
2419 _young_list->print(); | |
2420 #endif // SCAN_ONLY_VERBOSE | |
2421 | |
2422 _young_list->reset_auxilary_lists(); | |
2423 } | |
2424 } else { | |
2425 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
2426 } | |
2427 | |
2428 if (evacuation_failed()) { | |
2429 _summary_bytes_used = recalculate_used(); | |
2430 } else { | |
2431 // The "used" of the the collection set have already been subtracted | |
2432 // when they were freed. Add in the bytes evacuated. | |
2433 _summary_bytes_used += g1_policy()->bytes_in_to_space(); | |
2434 } | |
2435 | |
2436 if (g1_policy()->in_young_gc_mode() && | |
2437 g1_policy()->should_initiate_conc_mark()) { | |
2438 concurrent_mark()->checkpointRootsInitialPost(); | |
2439 set_marking_started(); | |
2440 doConcurrentMark(); | |
2441 } | |
2442 | |
2443 #if SCAN_ONLY_VERBOSE | |
2444 _young_list->print(); | |
2445 #endif // SCAN_ONLY_VERBOSE | |
2446 | |
2447 double end_time_sec = os::elapsedTime(); | |
2448 g1_policy()->record_pause_time((end_time_sec - start_time_sec)*1000.0); | |
2449 GCOverheadReporter::recordSTWEnd(end_time_sec); | |
2450 g1_policy()->record_collection_pause_end(popular_region != NULL, | |
2451 abandoned); | |
2452 | |
2453 assert(regions_accounted_for(), "Region leakage."); | |
2454 | |
2455 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) { | |
2456 HandleMark hm; // Discard invalid handles created during verification | |
2457 gclog_or_tty->print(" VerifyAfterGC:"); | |
2458 Universe::verify(false); | |
2459 } | |
2460 | |
2461 if (was_enabled) ref_processor()->enable_discovery(); | |
2462 | |
2463 { | |
2464 size_t expand_bytes = g1_policy()->expansion_amount(); | |
2465 if (expand_bytes > 0) { | |
2466 size_t bytes_before = capacity(); | |
2467 expand(expand_bytes); | |
2468 } | |
2469 } | |
2470 | |
2471 if (mark_in_progress()) | |
2472 concurrent_mark()->update_g1_committed(); | |
2473 | |
2474 gc_epilogue(false); | |
2475 } | |
2476 | |
2477 assert(verify_region_lists(), "Bad region lists."); | |
2478 | |
2479 if (reset_should_initiate_conc_mark) | |
2480 g1_policy()->set_should_initiate_conc_mark(); | |
2481 | |
2482 if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) { | |
2483 gclog_or_tty->print_cr("Stopping after GC #%d", ExitAfterGCNum); | |
2484 print_tracing_info(); | |
2485 vm_exit(-1); | |
2486 } | |
2487 } | |
2488 | |
2489 void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) { | |
2490 assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose"); | |
2491 HeapWord* original_top = NULL; | |
2492 if (r != NULL) | |
2493 original_top = r->top(); | |
2494 | |
2495 // We will want to record the used space in r as being there before gc. | |
2496 // One we install it as a GC alloc region it's eligible for allocation. | |
2497 // So record it now and use it later. | |
2498 size_t r_used = 0; | |
2499 if (r != NULL) { | |
2500 r_used = r->used(); | |
2501 | |
2502 if (ParallelGCThreads > 0) { | |
2503 // need to take the lock to guard against two threads calling | |
2504 // get_gc_alloc_region concurrently (very unlikely but...) | |
2505 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
2506 r->save_marks(); | |
2507 } | |
2508 } | |
2509 HeapRegion* old_alloc_region = _gc_alloc_regions[purpose]; | |
2510 _gc_alloc_regions[purpose] = r; | |
2511 if (old_alloc_region != NULL) { | |
2512 // Replace aliases too. | |
2513 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2514 if (_gc_alloc_regions[ap] == old_alloc_region) { | |
2515 _gc_alloc_regions[ap] = r; | |
2516 } | |
2517 } | |
2518 } | |
2519 if (r != NULL) { | |
2520 push_gc_alloc_region(r); | |
2521 if (mark_in_progress() && original_top != r->next_top_at_mark_start()) { | |
2522 // We are using a region as a GC alloc region after it has been used | |
2523 // as a mutator allocation region during the current marking cycle. | |
2524 // The mutator-allocated objects are currently implicitly marked, but | |
2525 // when we move hr->next_top_at_mark_start() forward at the the end | |
2526 // of the GC pause, they won't be. We therefore mark all objects in | |
2527 // the "gap". We do this object-by-object, since marking densely | |
2528 // does not currently work right with marking bitmap iteration. This | |
2529 // means we rely on TLAB filling at the start of pauses, and no | |
2530 // "resuscitation" of filled TLAB's. If we want to do this, we need | |
2531 // to fix the marking bitmap iteration. | |
2532 HeapWord* curhw = r->next_top_at_mark_start(); | |
2533 HeapWord* t = original_top; | |
2534 | |
2535 while (curhw < t) { | |
2536 oop cur = (oop)curhw; | |
2537 // We'll assume parallel for generality. This is rare code. | |
2538 concurrent_mark()->markAndGrayObjectIfNecessary(cur); // can't we just mark them? | |
2539 curhw = curhw + cur->size(); | |
2540 } | |
2541 assert(curhw == t, "Should have parsed correctly."); | |
2542 } | |
2543 if (G1PolicyVerbose > 1) { | |
2544 gclog_or_tty->print("New alloc region ["PTR_FORMAT", "PTR_FORMAT", " PTR_FORMAT") " | |
2545 "for survivors:", r->bottom(), original_top, r->end()); | |
2546 r->print(); | |
2547 } | |
2548 g1_policy()->record_before_bytes(r_used); | |
2549 } | |
2550 } | |
2551 | |
2552 void G1CollectedHeap::push_gc_alloc_region(HeapRegion* hr) { | |
2553 assert(Thread::current()->is_VM_thread() || | |
2554 par_alloc_during_gc_lock()->owned_by_self(), "Precondition"); | |
2555 assert(!hr->is_gc_alloc_region() && !hr->in_collection_set(), | |
2556 "Precondition."); | |
2557 hr->set_is_gc_alloc_region(true); | |
2558 hr->set_next_gc_alloc_region(_gc_alloc_region_list); | |
2559 _gc_alloc_region_list = hr; | |
2560 } | |
2561 | |
2562 #ifdef G1_DEBUG | |
2563 class FindGCAllocRegion: public HeapRegionClosure { | |
2564 public: | |
2565 bool doHeapRegion(HeapRegion* r) { | |
2566 if (r->is_gc_alloc_region()) { | |
2567 gclog_or_tty->print_cr("Region %d ["PTR_FORMAT"...] is still a gc_alloc_region.", | |
2568 r->hrs_index(), r->bottom()); | |
2569 } | |
2570 return false; | |
2571 } | |
2572 }; | |
2573 #endif // G1_DEBUG | |
2574 | |
2575 void G1CollectedHeap::forget_alloc_region_list() { | |
2576 assert(Thread::current()->is_VM_thread(), "Precondition"); | |
2577 while (_gc_alloc_region_list != NULL) { | |
2578 HeapRegion* r = _gc_alloc_region_list; | |
2579 assert(r->is_gc_alloc_region(), "Invariant."); | |
2580 _gc_alloc_region_list = r->next_gc_alloc_region(); | |
2581 r->set_next_gc_alloc_region(NULL); | |
2582 r->set_is_gc_alloc_region(false); | |
2583 if (r->is_empty()) { | |
2584 ++_free_regions; | |
2585 } | |
2586 } | |
2587 #ifdef G1_DEBUG | |
2588 FindGCAllocRegion fa; | |
2589 heap_region_iterate(&fa); | |
2590 #endif // G1_DEBUG | |
2591 } | |
2592 | |
2593 | |
2594 bool G1CollectedHeap::check_gc_alloc_regions() { | |
2595 // TODO: allocation regions check | |
2596 return true; | |
2597 } | |
2598 | |
2599 void G1CollectedHeap::get_gc_alloc_regions() { | |
2600 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2601 // Create new GC alloc regions. | |
2602 HeapRegion* alloc_region = _gc_alloc_regions[ap]; | |
2603 // Clear this alloc region, so that in case it turns out to be | |
2604 // unacceptable, we end up with no allocation region, rather than a bad | |
2605 // one. | |
2606 _gc_alloc_regions[ap] = NULL; | |
2607 if (alloc_region == NULL || alloc_region->in_collection_set()) { | |
2608 // Can't re-use old one. Allocate a new one. | |
2609 alloc_region = newAllocRegionWithExpansion(ap, 0); | |
2610 } | |
2611 if (alloc_region != NULL) { | |
2612 set_gc_alloc_region(ap, alloc_region); | |
2613 } | |
2614 } | |
2615 // Set alternative regions for allocation purposes that have reached | |
2616 // thier limit. | |
2617 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2618 GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(ap); | |
2619 if (_gc_alloc_regions[ap] == NULL && alt_purpose != ap) { | |
2620 _gc_alloc_regions[ap] = _gc_alloc_regions[alt_purpose]; | |
2621 } | |
2622 } | |
2623 assert(check_gc_alloc_regions(), "alloc regions messed up"); | |
2624 } | |
2625 | |
2626 void G1CollectedHeap::release_gc_alloc_regions() { | |
2627 // We keep a separate list of all regions that have been alloc regions in | |
2628 // the current collection pause. Forget that now. | |
2629 forget_alloc_region_list(); | |
2630 | |
2631 // The current alloc regions contain objs that have survived | |
2632 // collection. Make them no longer GC alloc regions. | |
2633 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2634 HeapRegion* r = _gc_alloc_regions[ap]; | |
2635 if (r != NULL && r->is_empty()) { | |
2636 { | |
2637 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
2638 r->set_zero_fill_complete(); | |
2639 put_free_region_on_list_locked(r); | |
2640 } | |
2641 } | |
2642 // set_gc_alloc_region will also NULLify all aliases to the region | |
2643 set_gc_alloc_region(ap, NULL); | |
2644 _gc_alloc_region_counts[ap] = 0; | |
2645 } | |
2646 } | |
2647 | |
2648 void G1CollectedHeap::init_for_evac_failure(OopsInHeapRegionClosure* cl) { | |
2649 _drain_in_progress = false; | |
2650 set_evac_failure_closure(cl); | |
2651 _evac_failure_scan_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); | |
2652 } | |
2653 | |
2654 void G1CollectedHeap::finalize_for_evac_failure() { | |
2655 assert(_evac_failure_scan_stack != NULL && | |
2656 _evac_failure_scan_stack->length() == 0, | |
2657 "Postcondition"); | |
2658 assert(!_drain_in_progress, "Postcondition"); | |
2659 // Don't have to delete, since the scan stack is a resource object. | |
2660 _evac_failure_scan_stack = NULL; | |
2661 } | |
2662 | |
2663 | |
2664 | |
2665 // *** Sequential G1 Evacuation | |
2666 | |
2667 HeapWord* G1CollectedHeap::allocate_during_gc(GCAllocPurpose purpose, size_t word_size) { | |
2668 HeapRegion* alloc_region = _gc_alloc_regions[purpose]; | |
2669 // let the caller handle alloc failure | |
2670 if (alloc_region == NULL) return NULL; | |
2671 assert(isHumongous(word_size) || !alloc_region->isHumongous(), | |
2672 "Either the object is humongous or the region isn't"); | |
2673 HeapWord* block = alloc_region->allocate(word_size); | |
2674 if (block == NULL) { | |
2675 block = allocate_during_gc_slow(purpose, alloc_region, false, word_size); | |
2676 } | |
2677 return block; | |
2678 } | |
2679 | |
2680 class G1IsAliveClosure: public BoolObjectClosure { | |
2681 G1CollectedHeap* _g1; | |
2682 public: | |
2683 G1IsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} | |
2684 void do_object(oop p) { assert(false, "Do not call."); } | |
2685 bool do_object_b(oop p) { | |
2686 // It is reachable if it is outside the collection set, or is inside | |
2687 // and forwarded. | |
2688 | |
2689 #ifdef G1_DEBUG | |
2690 gclog_or_tty->print_cr("is alive "PTR_FORMAT" in CS %d forwarded %d overall %d", | |
2691 (void*) p, _g1->obj_in_cs(p), p->is_forwarded(), | |
2692 !_g1->obj_in_cs(p) || p->is_forwarded()); | |
2693 #endif // G1_DEBUG | |
2694 | |
2695 return !_g1->obj_in_cs(p) || p->is_forwarded(); | |
2696 } | |
2697 }; | |
2698 | |
2699 class G1KeepAliveClosure: public OopClosure { | |
2700 G1CollectedHeap* _g1; | |
2701 public: | |
2702 G1KeepAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} | |
2703 void do_oop(narrowOop* p) { | |
2704 guarantee(false, "NYI"); | |
2705 } | |
2706 void do_oop(oop* p) { | |
2707 oop obj = *p; | |
2708 #ifdef G1_DEBUG | |
2709 if (PrintGC && Verbose) { | |
2710 gclog_or_tty->print_cr("keep alive *"PTR_FORMAT" = "PTR_FORMAT" "PTR_FORMAT, | |
2711 p, (void*) obj, (void*) *p); | |
2712 } | |
2713 #endif // G1_DEBUG | |
2714 | |
2715 if (_g1->obj_in_cs(obj)) { | |
2716 assert( obj->is_forwarded(), "invariant" ); | |
2717 *p = obj->forwardee(); | |
2718 | |
2719 #ifdef G1_DEBUG | |
2720 gclog_or_tty->print_cr(" in CSet: moved "PTR_FORMAT" -> "PTR_FORMAT, | |
2721 (void*) obj, (void*) *p); | |
2722 #endif // G1_DEBUG | |
2723 } | |
2724 } | |
2725 }; | |
2726 | |
2727 class RecreateRSetEntriesClosure: public OopClosure { | |
2728 private: | |
2729 G1CollectedHeap* _g1; | |
2730 G1RemSet* _g1_rem_set; | |
2731 HeapRegion* _from; | |
2732 public: | |
2733 RecreateRSetEntriesClosure(G1CollectedHeap* g1, HeapRegion* from) : | |
2734 _g1(g1), _g1_rem_set(g1->g1_rem_set()), _from(from) | |
2735 {} | |
2736 | |
2737 void do_oop(narrowOop* p) { | |
2738 guarantee(false, "NYI"); | |
2739 } | |
2740 void do_oop(oop* p) { | |
2741 assert(_from->is_in_reserved(p), "paranoia"); | |
2742 if (*p != NULL) { | |
2743 _g1_rem_set->write_ref(_from, p); | |
2744 } | |
2745 } | |
2746 }; | |
2747 | |
2748 class RemoveSelfPointerClosure: public ObjectClosure { | |
2749 private: | |
2750 G1CollectedHeap* _g1; | |
2751 ConcurrentMark* _cm; | |
2752 HeapRegion* _hr; | |
2753 HeapWord* _last_self_forwarded_end; | |
2754 size_t _prev_marked_bytes; | |
2755 size_t _next_marked_bytes; | |
2756 public: | |
2757 RemoveSelfPointerClosure(G1CollectedHeap* g1, HeapRegion* hr) : | |
2758 _g1(g1), _cm(_g1->concurrent_mark()), _hr(hr), | |
2759 _last_self_forwarded_end(_hr->bottom()), | |
2760 _prev_marked_bytes(0), _next_marked_bytes(0) | |
2761 {} | |
2762 | |
2763 size_t prev_marked_bytes() { return _prev_marked_bytes; } | |
2764 size_t next_marked_bytes() { return _next_marked_bytes; } | |
2765 | |
2766 void fill_remainder() { | |
2767 HeapWord* limit = _hr->top(); | |
2768 MemRegion mr(_last_self_forwarded_end, limit); | |
2769 if (!mr.is_empty()) { | |
2770 SharedHeap::fill_region_with_object(mr); | |
2771 _cm->clearRangeBothMaps(mr); | |
2772 _hr->declare_filled_region_to_BOT(mr); | |
2773 } | |
2774 } | |
2775 | |
2776 void do_object(oop obj) { | |
2777 if (obj->is_forwarded()) { | |
2778 if (obj->forwardee() == obj) { | |
2779 assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs."); | |
2780 _cm->markPrev(obj); | |
2781 assert(_cm->isPrevMarked(obj), "Should be marked!"); | |
2782 _prev_marked_bytes += (obj->size() * HeapWordSize); | |
2783 if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) { | |
2784 _cm->markAndGrayObjectIfNecessary(obj); | |
2785 } | |
2786 HeapWord* obj_start = (HeapWord*)obj; | |
2787 if (obj_start > _last_self_forwarded_end) { | |
2788 MemRegion mr(_last_self_forwarded_end, obj_start); | |
2789 SharedHeap::fill_region_with_object(mr); | |
2790 assert(_cm->isPrevMarked(obj), "Should be marked!"); | |
2791 _cm->clearRangeBothMaps(mr); | |
2792 assert(_cm->isPrevMarked(obj), "Should be marked!"); | |
2793 _hr->declare_filled_region_to_BOT(mr); | |
2794 } | |
2795 _last_self_forwarded_end = obj_start + obj->size(); | |
2796 obj->set_mark(markOopDesc::prototype()); | |
2797 | |
2798 // While we were processing RSet buffers during the | |
2799 // collection, we actually didn't scan any cards on the | |
2800 // collection set, since we didn't want to update remebered | |
2801 // sets with entries that point into the collection set, given | |
2802 // that live objects fromthe collection set are about to move | |
2803 // and such entries will be stale very soon. This change also | |
2804 // dealt with a reliability issue which involved scanning a | |
2805 // card in the collection set and coming across an array that | |
2806 // was being chunked and looking malformed. The problem is | |
2807 // that, if evacuation fails, we might have remembered set | |
2808 // entries missing given that we skipped cards on the | |
2809 // collection set. So, we'll recreate such entries now. | |
2810 RecreateRSetEntriesClosure cl(_g1, _hr); | |
2811 obj->oop_iterate(&cl); | |
2812 | |
2813 assert(_cm->isPrevMarked(obj), "Should be marked!"); | |
2814 } | |
2815 } | |
2816 } | |
2817 }; | |
2818 | |
2819 void G1CollectedHeap::remove_self_forwarding_pointers() { | |
2820 HeapRegion* cur = g1_policy()->collection_set(); | |
2821 | |
2822 while (cur != NULL) { | |
2823 assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!"); | |
2824 | |
2825 if (cur->evacuation_failed()) { | |
2826 RemoveSelfPointerClosure rspc(_g1h, cur); | |
2827 assert(cur->in_collection_set(), "bad CS"); | |
2828 cur->object_iterate(&rspc); | |
2829 rspc.fill_remainder(); | |
2830 | |
2831 // A number of manipulations to make the TAMS be the current top, | |
2832 // and the marked bytes be the ones observed in the iteration. | |
2833 if (_g1h->concurrent_mark()->at_least_one_mark_complete()) { | |
2834 // The comments below are the postconditions achieved by the | |
2835 // calls. Note especially the last such condition, which says that | |
2836 // the count of marked bytes has been properly restored. | |
2837 cur->note_start_of_marking(false); | |
2838 // _next_top_at_mark_start == top, _next_marked_bytes == 0 | |
2839 cur->add_to_marked_bytes(rspc.prev_marked_bytes()); | |
2840 // _next_marked_bytes == prev_marked_bytes. | |
2841 cur->note_end_of_marking(); | |
2842 // _prev_top_at_mark_start == top(), | |
2843 // _prev_marked_bytes == prev_marked_bytes | |
2844 } | |
2845 // If there is no mark in progress, we modified the _next variables | |
2846 // above needlessly, but harmlessly. | |
2847 if (_g1h->mark_in_progress()) { | |
2848 cur->note_start_of_marking(false); | |
2849 // _next_top_at_mark_start == top, _next_marked_bytes == 0 | |
2850 // _next_marked_bytes == next_marked_bytes. | |
2851 } | |
2852 | |
2853 // Now make sure the region has the right index in the sorted array. | |
2854 g1_policy()->note_change_in_marked_bytes(cur); | |
2855 } | |
2856 cur = cur->next_in_collection_set(); | |
2857 } | |
2858 assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!"); | |
2859 | |
2860 // Now restore saved marks, if any. | |
2861 if (_objs_with_preserved_marks != NULL) { | |
2862 assert(_preserved_marks_of_objs != NULL, "Both or none."); | |
2863 assert(_objs_with_preserved_marks->length() == | |
2864 _preserved_marks_of_objs->length(), "Both or none."); | |
2865 guarantee(_objs_with_preserved_marks->length() == | |
2866 _preserved_marks_of_objs->length(), "Both or none."); | |
2867 for (int i = 0; i < _objs_with_preserved_marks->length(); i++) { | |
2868 oop obj = _objs_with_preserved_marks->at(i); | |
2869 markOop m = _preserved_marks_of_objs->at(i); | |
2870 obj->set_mark(m); | |
2871 } | |
2872 // Delete the preserved marks growable arrays (allocated on the C heap). | |
2873 delete _objs_with_preserved_marks; | |
2874 delete _preserved_marks_of_objs; | |
2875 _objs_with_preserved_marks = NULL; | |
2876 _preserved_marks_of_objs = NULL; | |
2877 } | |
2878 } | |
2879 | |
2880 void G1CollectedHeap::push_on_evac_failure_scan_stack(oop obj) { | |
2881 _evac_failure_scan_stack->push(obj); | |
2882 } | |
2883 | |
2884 void G1CollectedHeap::drain_evac_failure_scan_stack() { | |
2885 assert(_evac_failure_scan_stack != NULL, "precondition"); | |
2886 | |
2887 while (_evac_failure_scan_stack->length() > 0) { | |
2888 oop obj = _evac_failure_scan_stack->pop(); | |
2889 _evac_failure_closure->set_region(heap_region_containing(obj)); | |
2890 obj->oop_iterate_backwards(_evac_failure_closure); | |
2891 } | |
2892 } | |
2893 | |
2894 void G1CollectedHeap::handle_evacuation_failure(oop old) { | |
2895 markOop m = old->mark(); | |
2896 // forward to self | |
2897 assert(!old->is_forwarded(), "precondition"); | |
2898 | |
2899 old->forward_to(old); | |
2900 handle_evacuation_failure_common(old, m); | |
2901 } | |
2902 | |
2903 oop | |
2904 G1CollectedHeap::handle_evacuation_failure_par(OopsInHeapRegionClosure* cl, | |
2905 oop old) { | |
2906 markOop m = old->mark(); | |
2907 oop forward_ptr = old->forward_to_atomic(old); | |
2908 if (forward_ptr == NULL) { | |
2909 // Forward-to-self succeeded. | |
2910 if (_evac_failure_closure != cl) { | |
2911 MutexLockerEx x(EvacFailureStack_lock, Mutex::_no_safepoint_check_flag); | |
2912 assert(!_drain_in_progress, | |
2913 "Should only be true while someone holds the lock."); | |
2914 // Set the global evac-failure closure to the current thread's. | |
2915 assert(_evac_failure_closure == NULL, "Or locking has failed."); | |
2916 set_evac_failure_closure(cl); | |
2917 // Now do the common part. | |
2918 handle_evacuation_failure_common(old, m); | |
2919 // Reset to NULL. | |
2920 set_evac_failure_closure(NULL); | |
2921 } else { | |
2922 // The lock is already held, and this is recursive. | |
2923 assert(_drain_in_progress, "This should only be the recursive case."); | |
2924 handle_evacuation_failure_common(old, m); | |
2925 } | |
2926 return old; | |
2927 } else { | |
2928 // Someone else had a place to copy it. | |
2929 return forward_ptr; | |
2930 } | |
2931 } | |
2932 | |
2933 void G1CollectedHeap::handle_evacuation_failure_common(oop old, markOop m) { | |
2934 set_evacuation_failed(true); | |
2935 | |
2936 preserve_mark_if_necessary(old, m); | |
2937 | |
2938 HeapRegion* r = heap_region_containing(old); | |
2939 if (!r->evacuation_failed()) { | |
2940 r->set_evacuation_failed(true); | |
2941 if (G1TraceRegions) { | |
2942 gclog_or_tty->print("evacuation failed in heap region "PTR_FORMAT" " | |
2943 "["PTR_FORMAT","PTR_FORMAT")\n", | |
2944 r, r->bottom(), r->end()); | |
2945 } | |
2946 } | |
2947 | |
2948 push_on_evac_failure_scan_stack(old); | |
2949 | |
2950 if (!_drain_in_progress) { | |
2951 // prevent recursion in copy_to_survivor_space() | |
2952 _drain_in_progress = true; | |
2953 drain_evac_failure_scan_stack(); | |
2954 _drain_in_progress = false; | |
2955 } | |
2956 } | |
2957 | |
2958 void G1CollectedHeap::preserve_mark_if_necessary(oop obj, markOop m) { | |
2959 if (m != markOopDesc::prototype()) { | |
2960 if (_objs_with_preserved_marks == NULL) { | |
2961 assert(_preserved_marks_of_objs == NULL, "Both or none."); | |
2962 _objs_with_preserved_marks = | |
2963 new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); | |
2964 _preserved_marks_of_objs = | |
2965 new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true); | |
2966 } | |
2967 _objs_with_preserved_marks->push(obj); | |
2968 _preserved_marks_of_objs->push(m); | |
2969 } | |
2970 } | |
2971 | |
2972 // *** Parallel G1 Evacuation | |
2973 | |
2974 HeapWord* G1CollectedHeap::par_allocate_during_gc(GCAllocPurpose purpose, | |
2975 size_t word_size) { | |
2976 HeapRegion* alloc_region = _gc_alloc_regions[purpose]; | |
2977 // let the caller handle alloc failure | |
2978 if (alloc_region == NULL) return NULL; | |
2979 | |
2980 HeapWord* block = alloc_region->par_allocate(word_size); | |
2981 if (block == NULL) { | |
2982 MutexLockerEx x(par_alloc_during_gc_lock(), | |
2983 Mutex::_no_safepoint_check_flag); | |
2984 block = allocate_during_gc_slow(purpose, alloc_region, true, word_size); | |
2985 } | |
2986 return block; | |
2987 } | |
2988 | |
2989 HeapWord* | |
2990 G1CollectedHeap::allocate_during_gc_slow(GCAllocPurpose purpose, | |
2991 HeapRegion* alloc_region, | |
2992 bool par, | |
2993 size_t word_size) { | |
2994 HeapWord* block = NULL; | |
2995 // In the parallel case, a previous thread to obtain the lock may have | |
2996 // already assigned a new gc_alloc_region. | |
2997 if (alloc_region != _gc_alloc_regions[purpose]) { | |
2998 assert(par, "But should only happen in parallel case."); | |
2999 alloc_region = _gc_alloc_regions[purpose]; | |
3000 if (alloc_region == NULL) return NULL; | |
3001 block = alloc_region->par_allocate(word_size); | |
3002 if (block != NULL) return block; | |
3003 // Otherwise, continue; this new region is empty, too. | |
3004 } | |
3005 assert(alloc_region != NULL, "We better have an allocation region"); | |
3006 // Another thread might have obtained alloc_region for the given | |
3007 // purpose, and might be attempting to allocate in it, and might | |
3008 // succeed. Therefore, we can't do the "finalization" stuff on the | |
3009 // region below until we're sure the last allocation has happened. | |
3010 // We ensure this by allocating the remaining space with a garbage | |
3011 // object. | |
3012 if (par) par_allocate_remaining_space(alloc_region); | |
3013 // Now we can do the post-GC stuff on the region. | |
3014 alloc_region->note_end_of_copying(); | |
3015 g1_policy()->record_after_bytes(alloc_region->used()); | |
3016 | |
3017 if (_gc_alloc_region_counts[purpose] >= g1_policy()->max_regions(purpose)) { | |
3018 // Cannot allocate more regions for the given purpose. | |
3019 GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(purpose); | |
3020 // Is there an alternative? | |
3021 if (purpose != alt_purpose) { | |
3022 HeapRegion* alt_region = _gc_alloc_regions[alt_purpose]; | |
3023 // Has not the alternative region been aliased? | |
3024 if (alloc_region != alt_region) { | |
3025 // Try to allocate in the alternative region. | |
3026 if (par) { | |
3027 block = alt_region->par_allocate(word_size); | |
3028 } else { | |
3029 block = alt_region->allocate(word_size); | |
3030 } | |
3031 // Make an alias. | |
3032 _gc_alloc_regions[purpose] = _gc_alloc_regions[alt_purpose]; | |
3033 } | |
3034 if (block != NULL) { | |
3035 return block; | |
3036 } | |
3037 // Both the allocation region and the alternative one are full | |
3038 // and aliased, replace them with a new allocation region. | |
3039 purpose = alt_purpose; | |
3040 } else { | |
3041 set_gc_alloc_region(purpose, NULL); | |
3042 return NULL; | |
3043 } | |
3044 } | |
3045 | |
3046 // Now allocate a new region for allocation. | |
3047 alloc_region = newAllocRegionWithExpansion(purpose, word_size, false /*zero_filled*/); | |
3048 | |
3049 // let the caller handle alloc failure | |
3050 if (alloc_region != NULL) { | |
3051 | |
3052 assert(check_gc_alloc_regions(), "alloc regions messed up"); | |
3053 assert(alloc_region->saved_mark_at_top(), | |
3054 "Mark should have been saved already."); | |
3055 // We used to assert that the region was zero-filled here, but no | |
3056 // longer. | |
3057 | |
3058 // This must be done last: once it's installed, other regions may | |
3059 // allocate in it (without holding the lock.) | |
3060 set_gc_alloc_region(purpose, alloc_region); | |
3061 | |
3062 if (par) { | |
3063 block = alloc_region->par_allocate(word_size); | |
3064 } else { | |
3065 block = alloc_region->allocate(word_size); | |
3066 } | |
3067 // Caller handles alloc failure. | |
3068 } else { | |
3069 // This sets other apis using the same old alloc region to NULL, also. | |
3070 set_gc_alloc_region(purpose, NULL); | |
3071 } | |
3072 return block; // May be NULL. | |
3073 } | |
3074 | |
3075 void G1CollectedHeap::par_allocate_remaining_space(HeapRegion* r) { | |
3076 HeapWord* block = NULL; | |
3077 size_t free_words; | |
3078 do { | |
3079 free_words = r->free()/HeapWordSize; | |
3080 // If there's too little space, no one can allocate, so we're done. | |
3081 if (free_words < (size_t)oopDesc::header_size()) return; | |
3082 // Otherwise, try to claim it. | |
3083 block = r->par_allocate(free_words); | |
3084 } while (block == NULL); | |
3085 SharedHeap::fill_region_with_object(MemRegion(block, free_words)); | |
3086 } | |
3087 | |
3088 #define use_local_bitmaps 1 | |
3089 #define verify_local_bitmaps 0 | |
3090 | |
3091 #ifndef PRODUCT | |
3092 | |
3093 class GCLabBitMap; | |
3094 class GCLabBitMapClosure: public BitMapClosure { | |
3095 private: | |
3096 ConcurrentMark* _cm; | |
3097 GCLabBitMap* _bitmap; | |
3098 | |
3099 public: | |
3100 GCLabBitMapClosure(ConcurrentMark* cm, | |
3101 GCLabBitMap* bitmap) { | |
3102 _cm = cm; | |
3103 _bitmap = bitmap; | |
3104 } | |
3105 | |
3106 virtual bool do_bit(size_t offset); | |
3107 }; | |
3108 | |
3109 #endif // PRODUCT | |
3110 | |
3111 #define oop_buffer_length 256 | |
3112 | |
3113 class GCLabBitMap: public BitMap { | |
3114 private: | |
3115 ConcurrentMark* _cm; | |
3116 | |
3117 int _shifter; | |
3118 size_t _bitmap_word_covers_words; | |
3119 | |
3120 // beginning of the heap | |
3121 HeapWord* _heap_start; | |
3122 | |
3123 // this is the actual start of the GCLab | |
3124 HeapWord* _real_start_word; | |
3125 | |
3126 // this is the actual end of the GCLab | |
3127 HeapWord* _real_end_word; | |
3128 | |
3129 // this is the first word, possibly located before the actual start | |
3130 // of the GCLab, that corresponds to the first bit of the bitmap | |
3131 HeapWord* _start_word; | |
3132 | |
3133 // size of a GCLab in words | |
3134 size_t _gclab_word_size; | |
3135 | |
3136 static int shifter() { | |
3137 return MinObjAlignment - 1; | |
3138 } | |
3139 | |
3140 // how many heap words does a single bitmap word corresponds to? | |
3141 static size_t bitmap_word_covers_words() { | |
3142 return BitsPerWord << shifter(); | |
3143 } | |
3144 | |
3145 static size_t gclab_word_size() { | |
3146 return ParallelGCG1AllocBufferSize / HeapWordSize; | |
3147 } | |
3148 | |
3149 static size_t bitmap_size_in_bits() { | |
3150 size_t bits_in_bitmap = gclab_word_size() >> shifter(); | |
3151 // We are going to ensure that the beginning of a word in this | |
3152 // bitmap also corresponds to the beginning of a word in the | |
3153 // global marking bitmap. To handle the case where a GCLab | |
3154 // starts from the middle of the bitmap, we need to add enough | |
3155 // space (i.e. up to a bitmap word) to ensure that we have | |
3156 // enough bits in the bitmap. | |
3157 return bits_in_bitmap + BitsPerWord - 1; | |
3158 } | |
3159 public: | |
3160 GCLabBitMap(HeapWord* heap_start) | |
3161 : BitMap(bitmap_size_in_bits()), | |
3162 _cm(G1CollectedHeap::heap()->concurrent_mark()), | |
3163 _shifter(shifter()), | |
3164 _bitmap_word_covers_words(bitmap_word_covers_words()), | |
3165 _heap_start(heap_start), | |
3166 _gclab_word_size(gclab_word_size()), | |
3167 _real_start_word(NULL), | |
3168 _real_end_word(NULL), | |
3169 _start_word(NULL) | |
3170 { | |
3171 guarantee( size_in_words() >= bitmap_size_in_words(), | |
3172 "just making sure"); | |
3173 } | |
3174 | |
3175 inline unsigned heapWordToOffset(HeapWord* addr) { | |
3176 unsigned offset = (unsigned) pointer_delta(addr, _start_word) >> _shifter; | |
3177 assert(offset < size(), "offset should be within bounds"); | |
3178 return offset; | |
3179 } | |
3180 | |
3181 inline HeapWord* offsetToHeapWord(size_t offset) { | |
3182 HeapWord* addr = _start_word + (offset << _shifter); | |
3183 assert(_real_start_word <= addr && addr < _real_end_word, "invariant"); | |
3184 return addr; | |
3185 } | |
3186 | |
3187 bool fields_well_formed() { | |
3188 bool ret1 = (_real_start_word == NULL) && | |
3189 (_real_end_word == NULL) && | |
3190 (_start_word == NULL); | |
3191 if (ret1) | |
3192 return true; | |
3193 | |
3194 bool ret2 = _real_start_word >= _start_word && | |
3195 _start_word < _real_end_word && | |
3196 (_real_start_word + _gclab_word_size) == _real_end_word && | |
3197 (_start_word + _gclab_word_size + _bitmap_word_covers_words) | |
3198 > _real_end_word; | |
3199 return ret2; | |
3200 } | |
3201 | |
3202 inline bool mark(HeapWord* addr) { | |
3203 guarantee(use_local_bitmaps, "invariant"); | |
3204 assert(fields_well_formed(), "invariant"); | |
3205 | |
3206 if (addr >= _real_start_word && addr < _real_end_word) { | |
3207 assert(!isMarked(addr), "should not have already been marked"); | |
3208 | |
3209 // first mark it on the bitmap | |
3210 at_put(heapWordToOffset(addr), true); | |
3211 | |
3212 return true; | |
3213 } else { | |
3214 return false; | |
3215 } | |
3216 } | |
3217 | |
3218 inline bool isMarked(HeapWord* addr) { | |
3219 guarantee(use_local_bitmaps, "invariant"); | |
3220 assert(fields_well_formed(), "invariant"); | |
3221 | |
3222 return at(heapWordToOffset(addr)); | |
3223 } | |
3224 | |
3225 void set_buffer(HeapWord* start) { | |
3226 guarantee(use_local_bitmaps, "invariant"); | |
3227 clear(); | |
3228 | |
3229 assert(start != NULL, "invariant"); | |
3230 _real_start_word = start; | |
3231 _real_end_word = start + _gclab_word_size; | |
3232 | |
3233 size_t diff = | |
3234 pointer_delta(start, _heap_start) % _bitmap_word_covers_words; | |
3235 _start_word = start - diff; | |
3236 | |
3237 assert(fields_well_formed(), "invariant"); | |
3238 } | |
3239 | |
3240 #ifndef PRODUCT | |
3241 void verify() { | |
3242 // verify that the marks have been propagated | |
3243 GCLabBitMapClosure cl(_cm, this); | |
3244 iterate(&cl); | |
3245 } | |
3246 #endif // PRODUCT | |
3247 | |
3248 void retire() { | |
3249 guarantee(use_local_bitmaps, "invariant"); | |
3250 assert(fields_well_formed(), "invariant"); | |
3251 | |
3252 if (_start_word != NULL) { | |
3253 CMBitMap* mark_bitmap = _cm->nextMarkBitMap(); | |
3254 | |
3255 // this means that the bitmap was set up for the GCLab | |
3256 assert(_real_start_word != NULL && _real_end_word != NULL, "invariant"); | |
3257 | |
3258 mark_bitmap->mostly_disjoint_range_union(this, | |
3259 0, // always start from the start of the bitmap | |
3260 _start_word, | |
3261 size_in_words()); | |
3262 _cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word)); | |
3263 | |
3264 #ifndef PRODUCT | |
3265 if (use_local_bitmaps && verify_local_bitmaps) | |
3266 verify(); | |
3267 #endif // PRODUCT | |
3268 } else { | |
3269 assert(_real_start_word == NULL && _real_end_word == NULL, "invariant"); | |
3270 } | |
3271 } | |
3272 | |
3273 static size_t bitmap_size_in_words() { | |
3274 return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord; | |
3275 } | |
3276 }; | |
3277 | |
3278 #ifndef PRODUCT | |
3279 | |
3280 bool GCLabBitMapClosure::do_bit(size_t offset) { | |
3281 HeapWord* addr = _bitmap->offsetToHeapWord(offset); | |
3282 guarantee(_cm->isMarked(oop(addr)), "it should be!"); | |
3283 return true; | |
3284 } | |
3285 | |
3286 #endif // PRODUCT | |
3287 | |
3288 class G1ParGCAllocBuffer: public ParGCAllocBuffer { | |
3289 private: | |
3290 bool _retired; | |
3291 bool _during_marking; | |
3292 GCLabBitMap _bitmap; | |
3293 | |
3294 public: | |
3295 G1ParGCAllocBuffer() : | |
3296 ParGCAllocBuffer(ParallelGCG1AllocBufferSize / HeapWordSize), | |
3297 _during_marking(G1CollectedHeap::heap()->mark_in_progress()), | |
3298 _bitmap(G1CollectedHeap::heap()->reserved_region().start()), | |
3299 _retired(false) | |
3300 { } | |
3301 | |
3302 inline bool mark(HeapWord* addr) { | |
3303 guarantee(use_local_bitmaps, "invariant"); | |
3304 assert(_during_marking, "invariant"); | |
3305 return _bitmap.mark(addr); | |
3306 } | |
3307 | |
3308 inline void set_buf(HeapWord* buf) { | |
3309 if (use_local_bitmaps && _during_marking) | |
3310 _bitmap.set_buffer(buf); | |
3311 ParGCAllocBuffer::set_buf(buf); | |
3312 _retired = false; | |
3313 } | |
3314 | |
3315 inline void retire(bool end_of_gc, bool retain) { | |
3316 if (_retired) | |
3317 return; | |
3318 if (use_local_bitmaps && _during_marking) { | |
3319 _bitmap.retire(); | |
3320 } | |
3321 ParGCAllocBuffer::retire(end_of_gc, retain); | |
3322 _retired = true; | |
3323 } | |
3324 }; | |
3325 | |
3326 | |
3327 class G1ParScanThreadState : public StackObj { | |
3328 protected: | |
3329 G1CollectedHeap* _g1h; | |
3330 RefToScanQueue* _refs; | |
3331 | |
3332 typedef GrowableArray<oop*> OverflowQueue; | |
3333 OverflowQueue* _overflowed_refs; | |
3334 | |
3335 G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount]; | |
3336 | |
3337 size_t _alloc_buffer_waste; | |
3338 size_t _undo_waste; | |
3339 | |
3340 OopsInHeapRegionClosure* _evac_failure_cl; | |
3341 G1ParScanHeapEvacClosure* _evac_cl; | |
3342 G1ParScanPartialArrayClosure* _partial_scan_cl; | |
3343 | |
3344 int _hash_seed; | |
3345 int _queue_num; | |
3346 | |
3347 int _term_attempts; | |
3348 #if G1_DETAILED_STATS | |
3349 int _pushes, _pops, _steals, _steal_attempts; | |
3350 int _overflow_pushes; | |
3351 #endif | |
3352 | |
3353 double _start; | |
3354 double _start_strong_roots; | |
3355 double _strong_roots_time; | |
3356 double _start_term; | |
3357 double _term_time; | |
3358 | |
3359 // Map from young-age-index (0 == not young, 1 is youngest) to | |
3360 // surviving words. base is what we get back from the malloc call | |
3361 size_t* _surviving_young_words_base; | |
3362 // this points into the array, as we use the first few entries for padding | |
3363 size_t* _surviving_young_words; | |
3364 | |
3365 #define PADDING_ELEM_NUM (64 / sizeof(size_t)) | |
3366 | |
3367 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } | |
3368 | |
3369 void add_to_undo_waste(size_t waste) { _undo_waste += waste; } | |
3370 | |
3371 public: | |
3372 G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num) | |
3373 : _g1h(g1h), | |
3374 _refs(g1h->task_queue(queue_num)), | |
3375 _hash_seed(17), _queue_num(queue_num), | |
3376 _term_attempts(0), | |
3377 #if G1_DETAILED_STATS | |
3378 _pushes(0), _pops(0), _steals(0), | |
3379 _steal_attempts(0), _overflow_pushes(0), | |
3380 #endif | |
3381 _strong_roots_time(0), _term_time(0), | |
3382 _alloc_buffer_waste(0), _undo_waste(0) | |
3383 { | |
3384 // we allocate G1YoungSurvRateNumRegions plus one entries, since | |
3385 // we "sacrifice" entry 0 to keep track of surviving bytes for | |
3386 // non-young regions (where the age is -1) | |
3387 // We also add a few elements at the beginning and at the end in | |
3388 // an attempt to eliminate cache contention | |
3389 size_t real_length = 1 + _g1h->g1_policy()->young_cset_length(); | |
3390 size_t array_length = PADDING_ELEM_NUM + | |
3391 real_length + | |
3392 PADDING_ELEM_NUM; | |
3393 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length); | |
3394 if (_surviving_young_words_base == NULL) | |
3395 vm_exit_out_of_memory(array_length * sizeof(size_t), | |
3396 "Not enough space for young surv histo."); | |
3397 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM; | |
3398 memset(_surviving_young_words, 0, real_length * sizeof(size_t)); | |
3399 | |
3400 _overflowed_refs = new OverflowQueue(10); | |
3401 | |
3402 _start = os::elapsedTime(); | |
3403 } | |
3404 | |
3405 ~G1ParScanThreadState() { | |
3406 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); | |
3407 } | |
3408 | |
3409 RefToScanQueue* refs() { return _refs; } | |
3410 OverflowQueue* overflowed_refs() { return _overflowed_refs; } | |
3411 | |
3412 inline G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) { | |
3413 return &_alloc_buffers[purpose]; | |
3414 } | |
3415 | |
3416 size_t alloc_buffer_waste() { return _alloc_buffer_waste; } | |
3417 size_t undo_waste() { return _undo_waste; } | |
3418 | |
3419 void push_on_queue(oop* ref) { | |
3420 if (!refs()->push(ref)) { | |
3421 overflowed_refs()->push(ref); | |
3422 IF_G1_DETAILED_STATS(note_overflow_push()); | |
3423 } else { | |
3424 IF_G1_DETAILED_STATS(note_push()); | |
3425 } | |
3426 } | |
3427 | |
3428 void pop_from_queue(oop*& ref) { | |
3429 if (!refs()->pop_local(ref)) { | |
3430 ref = NULL; | |
3431 } else { | |
3432 IF_G1_DETAILED_STATS(note_pop()); | |
3433 } | |
3434 } | |
3435 | |
3436 void pop_from_overflow_queue(oop*& ref) { | |
3437 ref = overflowed_refs()->pop(); | |
3438 } | |
3439 | |
3440 int refs_to_scan() { return refs()->size(); } | |
3441 int overflowed_refs_to_scan() { return overflowed_refs()->length(); } | |
3442 | |
3443 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) { | |
3444 | |
3445 HeapWord* obj = NULL; | |
3446 if (word_sz * 100 < | |
3447 (size_t)(ParallelGCG1AllocBufferSize / HeapWordSize) * | |
3448 ParallelGCBufferWastePct) { | |
3449 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); | |
3450 add_to_alloc_buffer_waste(alloc_buf->words_remaining()); | |
3451 alloc_buf->retire(false, false); | |
3452 | |
3453 HeapWord* buf = | |
3454 _g1h->par_allocate_during_gc(purpose, ParallelGCG1AllocBufferSize / HeapWordSize); | |
3455 if (buf == NULL) return NULL; // Let caller handle allocation failure. | |
3456 // Otherwise. | |
3457 alloc_buf->set_buf(buf); | |
3458 | |
3459 obj = alloc_buf->allocate(word_sz); | |
3460 assert(obj != NULL, "buffer was definitely big enough..."); | |
3461 } | |
3462 else { | |
3463 obj = _g1h->par_allocate_during_gc(purpose, word_sz); | |
3464 } | |
3465 return obj; | |
3466 } | |
3467 | |
3468 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) { | |
3469 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); | |
3470 if (obj != NULL) return obj; | |
3471 return allocate_slow(purpose, word_sz); | |
3472 } | |
3473 | |
3474 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { | |
3475 if (alloc_buffer(purpose)->contains(obj)) { | |
3476 guarantee(alloc_buffer(purpose)->contains(obj + word_sz - 1), | |
3477 "should contain whole object"); | |
3478 alloc_buffer(purpose)->undo_allocation(obj, word_sz); | |
3479 } | |
3480 else { | |
3481 SharedHeap::fill_region_with_object(MemRegion(obj, word_sz)); | |
3482 add_to_undo_waste(word_sz); | |
3483 } | |
3484 } | |
3485 | |
3486 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) { | |
3487 _evac_failure_cl = evac_failure_cl; | |
3488 } | |
3489 OopsInHeapRegionClosure* evac_failure_closure() { | |
3490 return _evac_failure_cl; | |
3491 } | |
3492 | |
3493 void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) { | |
3494 _evac_cl = evac_cl; | |
3495 } | |
3496 | |
3497 void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) { | |
3498 _partial_scan_cl = partial_scan_cl; | |
3499 } | |
3500 | |
3501 int* hash_seed() { return &_hash_seed; } | |
3502 int queue_num() { return _queue_num; } | |
3503 | |
3504 int term_attempts() { return _term_attempts; } | |
3505 void note_term_attempt() { _term_attempts++; } | |
3506 | |
3507 #if G1_DETAILED_STATS | |
3508 int pushes() { return _pushes; } | |
3509 int pops() { return _pops; } | |
3510 int steals() { return _steals; } | |
3511 int steal_attempts() { return _steal_attempts; } | |
3512 int overflow_pushes() { return _overflow_pushes; } | |
3513 | |
3514 void note_push() { _pushes++; } | |
3515 void note_pop() { _pops++; } | |
3516 void note_steal() { _steals++; } | |
3517 void note_steal_attempt() { _steal_attempts++; } | |
3518 void note_overflow_push() { _overflow_pushes++; } | |
3519 #endif | |
3520 | |
3521 void start_strong_roots() { | |
3522 _start_strong_roots = os::elapsedTime(); | |
3523 } | |
3524 void end_strong_roots() { | |
3525 _strong_roots_time += (os::elapsedTime() - _start_strong_roots); | |
3526 } | |
3527 double strong_roots_time() { return _strong_roots_time; } | |
3528 | |
3529 void start_term_time() { | |
3530 note_term_attempt(); | |
3531 _start_term = os::elapsedTime(); | |
3532 } | |
3533 void end_term_time() { | |
3534 _term_time += (os::elapsedTime() - _start_term); | |
3535 } | |
3536 double term_time() { return _term_time; } | |
3537 | |
3538 double elapsed() { | |
3539 return os::elapsedTime() - _start; | |
3540 } | |
3541 | |
3542 size_t* surviving_young_words() { | |
3543 // We add on to hide entry 0 which accumulates surviving words for | |
3544 // age -1 regions (i.e. non-young ones) | |
3545 return _surviving_young_words; | |
3546 } | |
3547 | |
3548 void retire_alloc_buffers() { | |
3549 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
3550 size_t waste = _alloc_buffers[ap].words_remaining(); | |
3551 add_to_alloc_buffer_waste(waste); | |
3552 _alloc_buffers[ap].retire(true, false); | |
3553 } | |
3554 } | |
3555 | |
3556 void trim_queue() { | |
3557 while (refs_to_scan() > 0 || overflowed_refs_to_scan() > 0) { | |
3558 oop *ref_to_scan = NULL; | |
3559 if (overflowed_refs_to_scan() == 0) { | |
3560 pop_from_queue(ref_to_scan); | |
3561 } else { | |
3562 pop_from_overflow_queue(ref_to_scan); | |
3563 } | |
3564 if (ref_to_scan != NULL) { | |
3565 if ((intptr_t)ref_to_scan & G1_PARTIAL_ARRAY_MASK) { | |
3566 _partial_scan_cl->do_oop_nv(ref_to_scan); | |
3567 } else { | |
3568 // Note: we can use "raw" versions of "region_containing" because | |
3569 // "obj_to_scan" is definitely in the heap, and is not in a | |
3570 // humongous region. | |
3571 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan); | |
3572 _evac_cl->set_region(r); | |
3573 _evac_cl->do_oop_nv(ref_to_scan); | |
3574 } | |
3575 } | |
3576 } | |
3577 } | |
3578 }; | |
3579 | |
3580 | |
3581 G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state) : | |
3582 _g1(g1), _g1_rem(_g1->g1_rem_set()), _cm(_g1->concurrent_mark()), | |
3583 _par_scan_state(par_scan_state) { } | |
3584 | |
3585 // This closure is applied to the fields of the objects that have just been copied. | |
3586 // Should probably be made inline and moved in g1OopClosures.inline.hpp. | |
3587 void G1ParScanClosure::do_oop_nv(oop* p) { | |
3588 oop obj = *p; | |
3589 if (obj != NULL) { | |
3590 if (_g1->obj_in_cs(obj)) { | |
3591 if (obj->is_forwarded()) { | |
3592 *p = obj->forwardee(); | |
3593 } else { | |
3594 _par_scan_state->push_on_queue(p); | |
3595 return; | |
3596 } | |
3597 } | |
3598 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); | |
3599 } | |
3600 } | |
3601 | |
3602 void G1ParCopyHelper::mark_forwardee(oop* p) { | |
3603 // This is called _after_ do_oop_work has been called, hence after | |
3604 // the object has been relocated to its new location and *p points | |
3605 // to its new location. | |
3606 | |
3607 oop thisOop = *p; | |
3608 if (thisOop != NULL) { | |
3609 assert((_g1->evacuation_failed()) || (!_g1->obj_in_cs(thisOop)), | |
3610 "shouldn't still be in the CSet if evacuation didn't fail."); | |
3611 HeapWord* addr = (HeapWord*)thisOop; | |
3612 if (_g1->is_in_g1_reserved(addr)) | |
3613 _cm->grayRoot(oop(addr)); | |
3614 } | |
3615 } | |
3616 | |
3617 oop G1ParCopyHelper::copy_to_survivor_space(oop old) { | |
3618 size_t word_sz = old->size(); | |
3619 HeapRegion* from_region = _g1->heap_region_containing_raw(old); | |
3620 // +1 to make the -1 indexes valid... | |
3621 int young_index = from_region->young_index_in_cset()+1; | |
3622 assert( (from_region->is_young() && young_index > 0) || | |
3623 (!from_region->is_young() && young_index == 0), "invariant" ); | |
3624 G1CollectorPolicy* g1p = _g1->g1_policy(); | |
3625 markOop m = old->mark(); | |
3626 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, m->age(), | |
3627 word_sz); | |
3628 HeapWord* obj_ptr = _par_scan_state->allocate(alloc_purpose, word_sz); | |
3629 oop obj = oop(obj_ptr); | |
3630 | |
3631 if (obj_ptr == NULL) { | |
3632 // This will either forward-to-self, or detect that someone else has | |
3633 // installed a forwarding pointer. | |
3634 OopsInHeapRegionClosure* cl = _par_scan_state->evac_failure_closure(); | |
3635 return _g1->handle_evacuation_failure_par(cl, old); | |
3636 } | |
3637 | |
3638 oop forward_ptr = old->forward_to_atomic(obj); | |
3639 if (forward_ptr == NULL) { | |
3640 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz); | |
3641 obj->set_mark(m); | |
3642 if (g1p->track_object_age(alloc_purpose)) { | |
3643 obj->incr_age(); | |
3644 } | |
3645 // preserve "next" mark bit | |
3646 if (_g1->mark_in_progress() && !_g1->is_obj_ill(old)) { | |
3647 if (!use_local_bitmaps || | |
3648 !_par_scan_state->alloc_buffer(alloc_purpose)->mark(obj_ptr)) { | |
3649 // if we couldn't mark it on the local bitmap (this happens when | |
3650 // the object was not allocated in the GCLab), we have to bite | |
3651 // the bullet and do the standard parallel mark | |
3652 _cm->markAndGrayObjectIfNecessary(obj); | |
3653 } | |
3654 #if 1 | |
3655 if (_g1->isMarkedNext(old)) { | |
3656 _cm->nextMarkBitMap()->parClear((HeapWord*)old); | |
3657 } | |
3658 #endif | |
3659 } | |
3660 | |
3661 size_t* surv_young_words = _par_scan_state->surviving_young_words(); | |
3662 surv_young_words[young_index] += word_sz; | |
3663 | |
3664 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) { | |
3665 arrayOop(old)->set_length(0); | |
3666 _par_scan_state->push_on_queue((oop*) ((intptr_t)old | G1_PARTIAL_ARRAY_MASK)); | |
3667 } else { | |
3668 _scanner->set_region(_g1->heap_region_containing(obj)); | |
3669 obj->oop_iterate_backwards(_scanner); | |
3670 } | |
3671 } else { | |
3672 _par_scan_state->undo_allocation(alloc_purpose, obj_ptr, word_sz); | |
3673 obj = forward_ptr; | |
3674 } | |
3675 return obj; | |
3676 } | |
3677 | |
3678 template<bool do_gen_barrier, G1Barrier barrier, bool do_mark_forwardee> | |
3679 void G1ParCopyClosure<do_gen_barrier, barrier, do_mark_forwardee>::do_oop_work(oop* p) { | |
3680 oop obj = *p; | |
3681 assert(barrier != G1BarrierRS || obj != NULL, | |
3682 "Precondition: G1BarrierRS implies obj is nonNull"); | |
3683 | |
3684 if (obj != NULL) { | |
3685 if (_g1->obj_in_cs(obj)) { | |
3686 #if G1_REM_SET_LOGGING | |
3687 gclog_or_tty->print_cr("Loc "PTR_FORMAT" contains pointer "PTR_FORMAT" into CS.", | |
3688 p, (void*) obj); | |
3689 #endif | |
3690 if (obj->is_forwarded()) { | |
3691 *p = obj->forwardee(); | |
3692 } else { | |
3693 *p = copy_to_survivor_space(obj); | |
3694 } | |
3695 // When scanning the RS, we only care about objs in CS. | |
3696 if (barrier == G1BarrierRS) { | |
3697 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); | |
3698 } | |
3699 } | |
3700 // When scanning moved objs, must look at all oops. | |
3701 if (barrier == G1BarrierEvac) { | |
3702 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); | |
3703 } | |
3704 | |
3705 if (do_gen_barrier) { | |
3706 par_do_barrier(p); | |
3707 } | |
3708 } | |
3709 } | |
3710 | |
3711 template void G1ParCopyClosure<false, G1BarrierEvac, false>::do_oop_work(oop* p); | |
3712 | |
3713 template <class T> void G1ParScanPartialArrayClosure::process_array_chunk( | |
3714 oop obj, int start, int end) { | |
3715 // process our set of indices (include header in first chunk) | |
3716 assert(start < end, "invariant"); | |
3717 T* const base = (T*)objArrayOop(obj)->base(); | |
3718 T* const start_addr = base + start; | |
3719 T* const end_addr = base + end; | |
3720 MemRegion mr((HeapWord*)start_addr, (HeapWord*)end_addr); | |
3721 _scanner.set_region(_g1->heap_region_containing(obj)); | |
3722 obj->oop_iterate(&_scanner, mr); | |
3723 } | |
3724 | |
3725 void G1ParScanPartialArrayClosure::do_oop_nv(oop* p) { | |
3726 assert(!UseCompressedOops, "Needs to be fixed to work with compressed oops"); | |
3727 oop old = oop((intptr_t)p & ~G1_PARTIAL_ARRAY_MASK); | |
3728 assert(old->is_objArray(), "must be obj array"); | |
3729 assert(old->is_forwarded(), "must be forwarded"); | |
3730 assert(Universe::heap()->is_in_reserved(old), "must be in heap."); | |
3731 | |
3732 objArrayOop obj = objArrayOop(old->forwardee()); | |
3733 assert((void*)old != (void*)old->forwardee(), "self forwarding here?"); | |
3734 // Process ParGCArrayScanChunk elements now | |
3735 // and push the remainder back onto queue | |
3736 int start = arrayOop(old)->length(); | |
3737 int end = obj->length(); | |
3738 int remainder = end - start; | |
3739 assert(start <= end, "just checking"); | |
3740 if (remainder > 2 * ParGCArrayScanChunk) { | |
3741 // Test above combines last partial chunk with a full chunk | |
3742 end = start + ParGCArrayScanChunk; | |
3743 arrayOop(old)->set_length(end); | |
3744 // Push remainder. | |
3745 _par_scan_state->push_on_queue((oop*) ((intptr_t) old | G1_PARTIAL_ARRAY_MASK)); | |
3746 } else { | |
3747 // Restore length so that the heap remains parsable in | |
3748 // case of evacuation failure. | |
3749 arrayOop(old)->set_length(end); | |
3750 } | |
3751 | |
3752 // process our set of indices (include header in first chunk) | |
3753 process_array_chunk<oop>(obj, start, end); | |
3754 oop* start_addr = start == 0 ? (oop*)obj : obj->obj_at_addr<oop>(start); | |
3755 oop* end_addr = (oop*)(obj->base()) + end; // obj_at_addr(end) asserts end < length | |
3756 MemRegion mr((HeapWord*)start_addr, (HeapWord*)end_addr); | |
3757 _scanner.set_region(_g1->heap_region_containing(obj)); | |
3758 obj->oop_iterate(&_scanner, mr); | |
3759 } | |
3760 | |
3761 int G1ScanAndBalanceClosure::_nq = 0; | |
3762 | |
3763 class G1ParEvacuateFollowersClosure : public VoidClosure { | |
3764 protected: | |
3765 G1CollectedHeap* _g1h; | |
3766 G1ParScanThreadState* _par_scan_state; | |
3767 RefToScanQueueSet* _queues; | |
3768 ParallelTaskTerminator* _terminator; | |
3769 | |
3770 G1ParScanThreadState* par_scan_state() { return _par_scan_state; } | |
3771 RefToScanQueueSet* queues() { return _queues; } | |
3772 ParallelTaskTerminator* terminator() { return _terminator; } | |
3773 | |
3774 public: | |
3775 G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h, | |
3776 G1ParScanThreadState* par_scan_state, | |
3777 RefToScanQueueSet* queues, | |
3778 ParallelTaskTerminator* terminator) | |
3779 : _g1h(g1h), _par_scan_state(par_scan_state), | |
3780 _queues(queues), _terminator(terminator) {} | |
3781 | |
3782 void do_void() { | |
3783 G1ParScanThreadState* pss = par_scan_state(); | |
3784 while (true) { | |
3785 oop* ref_to_scan; | |
3786 pss->trim_queue(); | |
3787 IF_G1_DETAILED_STATS(pss->note_steal_attempt()); | |
3788 if (queues()->steal(pss->queue_num(), | |
3789 pss->hash_seed(), | |
3790 ref_to_scan)) { | |
3791 IF_G1_DETAILED_STATS(pss->note_steal()); | |
3792 pss->push_on_queue(ref_to_scan); | |
3793 continue; | |
3794 } | |
3795 pss->start_term_time(); | |
3796 if (terminator()->offer_termination()) break; | |
3797 pss->end_term_time(); | |
3798 } | |
3799 pss->end_term_time(); | |
3800 pss->retire_alloc_buffers(); | |
3801 } | |
3802 }; | |
3803 | |
3804 class G1ParTask : public AbstractGangTask { | |
3805 protected: | |
3806 G1CollectedHeap* _g1h; | |
3807 RefToScanQueueSet *_queues; | |
3808 ParallelTaskTerminator _terminator; | |
3809 | |
3810 Mutex _stats_lock; | |
3811 Mutex* stats_lock() { return &_stats_lock; } | |
3812 | |
3813 size_t getNCards() { | |
3814 return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1) | |
3815 / G1BlockOffsetSharedArray::N_bytes; | |
3816 } | |
3817 | |
3818 public: | |
3819 G1ParTask(G1CollectedHeap* g1h, int workers, RefToScanQueueSet *task_queues) | |
3820 : AbstractGangTask("G1 collection"), | |
3821 _g1h(g1h), | |
3822 _queues(task_queues), | |
3823 _terminator(workers, _queues), | |
3824 _stats_lock(Mutex::leaf, "parallel G1 stats lock", true) | |
3825 {} | |
3826 | |
3827 RefToScanQueueSet* queues() { return _queues; } | |
3828 | |
3829 RefToScanQueue *work_queue(int i) { | |
3830 return queues()->queue(i); | |
3831 } | |
3832 | |
3833 void work(int i) { | |
3834 ResourceMark rm; | |
3835 HandleMark hm; | |
3836 | |
3837 G1ParScanThreadState pss(_g1h, i); | |
3838 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss); | |
3839 G1ParScanHeapEvacClosure evac_failure_cl(_g1h, &pss); | |
3840 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss); | |
3841 | |
3842 pss.set_evac_closure(&scan_evac_cl); | |
3843 pss.set_evac_failure_closure(&evac_failure_cl); | |
3844 pss.set_partial_scan_closure(&partial_scan_cl); | |
3845 | |
3846 G1ParScanExtRootClosure only_scan_root_cl(_g1h, &pss); | |
3847 G1ParScanPermClosure only_scan_perm_cl(_g1h, &pss); | |
3848 G1ParScanHeapRSClosure only_scan_heap_rs_cl(_g1h, &pss); | |
3849 G1ParScanAndMarkExtRootClosure scan_mark_root_cl(_g1h, &pss); | |
3850 G1ParScanAndMarkPermClosure scan_mark_perm_cl(_g1h, &pss); | |
3851 G1ParScanAndMarkHeapRSClosure scan_mark_heap_rs_cl(_g1h, &pss); | |
3852 | |
3853 OopsInHeapRegionClosure *scan_root_cl; | |
3854 OopsInHeapRegionClosure *scan_perm_cl; | |
3855 OopsInHeapRegionClosure *scan_so_cl; | |
3856 | |
3857 if (_g1h->g1_policy()->should_initiate_conc_mark()) { | |
3858 scan_root_cl = &scan_mark_root_cl; | |
3859 scan_perm_cl = &scan_mark_perm_cl; | |
3860 scan_so_cl = &scan_mark_heap_rs_cl; | |
3861 } else { | |
3862 scan_root_cl = &only_scan_root_cl; | |
3863 scan_perm_cl = &only_scan_perm_cl; | |
3864 scan_so_cl = &only_scan_heap_rs_cl; | |
3865 } | |
3866 | |
3867 pss.start_strong_roots(); | |
3868 _g1h->g1_process_strong_roots(/* not collecting perm */ false, | |
3869 SharedHeap::SO_AllClasses, | |
3870 scan_root_cl, | |
3871 &only_scan_heap_rs_cl, | |
3872 scan_so_cl, | |
3873 scan_perm_cl, | |
3874 i); | |
3875 pss.end_strong_roots(); | |
3876 { | |
3877 double start = os::elapsedTime(); | |
3878 G1ParEvacuateFollowersClosure evac(_g1h, &pss, _queues, &_terminator); | |
3879 evac.do_void(); | |
3880 double elapsed_ms = (os::elapsedTime()-start)*1000.0; | |
3881 double term_ms = pss.term_time()*1000.0; | |
3882 _g1h->g1_policy()->record_obj_copy_time(i, elapsed_ms-term_ms); | |
3883 _g1h->g1_policy()->record_termination_time(i, term_ms); | |
3884 } | |
3885 _g1h->update_surviving_young_words(pss.surviving_young_words()+1); | |
3886 | |
3887 // Clean up any par-expanded rem sets. | |
3888 HeapRegionRemSet::par_cleanup(); | |
3889 | |
3890 MutexLocker x(stats_lock()); | |
3891 if (ParallelGCVerbose) { | |
3892 gclog_or_tty->print("Thread %d complete:\n", i); | |
3893 #if G1_DETAILED_STATS | |
3894 gclog_or_tty->print(" Pushes: %7d Pops: %7d Overflows: %7d Steals %7d (in %d attempts)\n", | |
3895 pss.pushes(), | |
3896 pss.pops(), | |
3897 pss.overflow_pushes(), | |
3898 pss.steals(), | |
3899 pss.steal_attempts()); | |
3900 #endif | |
3901 double elapsed = pss.elapsed(); | |
3902 double strong_roots = pss.strong_roots_time(); | |
3903 double term = pss.term_time(); | |
3904 gclog_or_tty->print(" Elapsed: %7.2f ms.\n" | |
3905 " Strong roots: %7.2f ms (%6.2f%%)\n" | |
3906 " Termination: %7.2f ms (%6.2f%%) (in %d entries)\n", | |
3907 elapsed * 1000.0, | |
3908 strong_roots * 1000.0, (strong_roots*100.0/elapsed), | |
3909 term * 1000.0, (term*100.0/elapsed), | |
3910 pss.term_attempts()); | |
3911 size_t total_waste = pss.alloc_buffer_waste() + pss.undo_waste(); | |
3912 gclog_or_tty->print(" Waste: %8dK\n" | |
3913 " Alloc Buffer: %8dK\n" | |
3914 " Undo: %8dK\n", | |
3915 (total_waste * HeapWordSize) / K, | |
3916 (pss.alloc_buffer_waste() * HeapWordSize) / K, | |
3917 (pss.undo_waste() * HeapWordSize) / K); | |
3918 } | |
3919 | |
3920 assert(pss.refs_to_scan() == 0, "Task queue should be empty"); | |
3921 assert(pss.overflowed_refs_to_scan() == 0, "Overflow queue should be empty"); | |
3922 } | |
3923 }; | |
3924 | |
3925 // *** Common G1 Evacuation Stuff | |
3926 | |
3927 class G1CountClosure: public OopsInHeapRegionClosure { | |
3928 public: | |
3929 int n; | |
3930 G1CountClosure() : n(0) {} | |
3931 void do_oop(narrowOop* p) { | |
3932 guarantee(false, "NYI"); | |
3933 } | |
3934 void do_oop(oop* p) { | |
3935 oop obj = *p; | |
3936 assert(obj != NULL && G1CollectedHeap::heap()->obj_in_cs(obj), | |
3937 "Rem set closure called on non-rem-set pointer."); | |
3938 n++; | |
3939 } | |
3940 }; | |
3941 | |
3942 static G1CountClosure count_closure; | |
3943 | |
3944 void | |
3945 G1CollectedHeap:: | |
3946 g1_process_strong_roots(bool collecting_perm_gen, | |
3947 SharedHeap::ScanningOption so, | |
3948 OopClosure* scan_non_heap_roots, | |
3949 OopsInHeapRegionClosure* scan_rs, | |
3950 OopsInHeapRegionClosure* scan_so, | |
3951 OopsInGenClosure* scan_perm, | |
3952 int worker_i) { | |
3953 // First scan the strong roots, including the perm gen. | |
3954 double ext_roots_start = os::elapsedTime(); | |
3955 double closure_app_time_sec = 0.0; | |
3956 | |
3957 BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots); | |
3958 BufferingOopsInGenClosure buf_scan_perm(scan_perm); | |
3959 buf_scan_perm.set_generation(perm_gen()); | |
3960 | |
3961 process_strong_roots(collecting_perm_gen, so, | |
3962 &buf_scan_non_heap_roots, | |
3963 &buf_scan_perm); | |
3964 // Finish up any enqueued closure apps. | |
3965 buf_scan_non_heap_roots.done(); | |
3966 buf_scan_perm.done(); | |
3967 double ext_roots_end = os::elapsedTime(); | |
3968 g1_policy()->reset_obj_copy_time(worker_i); | |
3969 double obj_copy_time_sec = | |
3970 buf_scan_non_heap_roots.closure_app_seconds() + | |
3971 buf_scan_perm.closure_app_seconds(); | |
3972 g1_policy()->record_obj_copy_time(worker_i, obj_copy_time_sec * 1000.0); | |
3973 double ext_root_time_ms = | |
3974 ((ext_roots_end - ext_roots_start) - obj_copy_time_sec) * 1000.0; | |
3975 g1_policy()->record_ext_root_scan_time(worker_i, ext_root_time_ms); | |
3976 | |
3977 // Scan strong roots in mark stack. | |
3978 if (!_process_strong_tasks->is_task_claimed(G1H_PS_mark_stack_oops_do)) { | |
3979 concurrent_mark()->oops_do(scan_non_heap_roots); | |
3980 } | |
3981 double mark_stack_scan_ms = (os::elapsedTime() - ext_roots_end) * 1000.0; | |
3982 g1_policy()->record_mark_stack_scan_time(worker_i, mark_stack_scan_ms); | |
3983 | |
3984 // XXX What should this be doing in the parallel case? | |
3985 g1_policy()->record_collection_pause_end_CH_strong_roots(); | |
3986 if (G1VerifyRemSet) { | |
3987 // :::: FIXME :::: | |
3988 // The stupid remembered set doesn't know how to filter out dead | |
3989 // objects, which the smart one does, and so when it is created | |
3990 // and then compared the number of entries in each differs and | |
3991 // the verification code fails. | |
3992 guarantee(false, "verification code is broken, see note"); | |
3993 | |
3994 // Let's make sure that the current rem set agrees with the stupidest | |
3995 // one possible! | |
3996 bool refs_enabled = ref_processor()->discovery_enabled(); | |
3997 if (refs_enabled) ref_processor()->disable_discovery(); | |
3998 StupidG1RemSet stupid(this); | |
3999 count_closure.n = 0; | |
4000 stupid.oops_into_collection_set_do(&count_closure, worker_i); | |
4001 int stupid_n = count_closure.n; | |
4002 count_closure.n = 0; | |
4003 g1_rem_set()->oops_into_collection_set_do(&count_closure, worker_i); | |
4004 guarantee(count_closure.n == stupid_n, "Old and new rem sets differ."); | |
4005 gclog_or_tty->print_cr("\nFound %d pointers in heap RS.", count_closure.n); | |
4006 if (refs_enabled) ref_processor()->enable_discovery(); | |
4007 } | |
4008 if (scan_so != NULL) { | |
4009 scan_scan_only_set(scan_so, worker_i); | |
4010 } | |
4011 // Now scan the complement of the collection set. | |
4012 if (scan_rs != NULL) { | |
4013 g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i); | |
4014 } | |
4015 // Finish with the ref_processor roots. | |
4016 if (!_process_strong_tasks->is_task_claimed(G1H_PS_refProcessor_oops_do)) { | |
4017 ref_processor()->oops_do(scan_non_heap_roots); | |
4018 } | |
4019 g1_policy()->record_collection_pause_end_G1_strong_roots(); | |
4020 _process_strong_tasks->all_tasks_completed(); | |
4021 } | |
4022 | |
4023 void | |
4024 G1CollectedHeap::scan_scan_only_region(HeapRegion* r, | |
4025 OopsInHeapRegionClosure* oc, | |
4026 int worker_i) { | |
4027 HeapWord* startAddr = r->bottom(); | |
4028 HeapWord* endAddr = r->used_region().end(); | |
4029 | |
4030 oc->set_region(r); | |
4031 | |
4032 HeapWord* p = r->bottom(); | |
4033 HeapWord* t = r->top(); | |
4034 guarantee( p == r->next_top_at_mark_start(), "invariant" ); | |
4035 while (p < t) { | |
4036 oop obj = oop(p); | |
4037 p += obj->oop_iterate(oc); | |
4038 } | |
4039 } | |
4040 | |
4041 void | |
4042 G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc, | |
4043 int worker_i) { | |
4044 double start = os::elapsedTime(); | |
4045 | |
4046 BufferingOopsInHeapRegionClosure boc(oc); | |
4047 | |
4048 FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc); | |
4049 FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark()); | |
4050 | |
4051 OopsInHeapRegionClosure *foc; | |
4052 if (g1_policy()->should_initiate_conc_mark()) | |
4053 foc = &scan_and_mark; | |
4054 else | |
4055 foc = &scan_only; | |
4056 | |
4057 HeapRegion* hr; | |
4058 int n = 0; | |
4059 while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) { | |
4060 scan_scan_only_region(hr, foc, worker_i); | |
4061 ++n; | |
4062 } | |
4063 boc.done(); | |
4064 | |
4065 double closure_app_s = boc.closure_app_seconds(); | |
4066 g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0); | |
4067 double ms = (os::elapsedTime() - start - closure_app_s)*1000.0; | |
4068 g1_policy()->record_scan_only_time(worker_i, ms, n); | |
4069 } | |
4070 | |
4071 void | |
4072 G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure, | |
4073 OopClosure* non_root_closure) { | |
4074 SharedHeap::process_weak_roots(root_closure, non_root_closure); | |
4075 } | |
4076 | |
4077 | |
4078 class SaveMarksClosure: public HeapRegionClosure { | |
4079 public: | |
4080 bool doHeapRegion(HeapRegion* r) { | |
4081 r->save_marks(); | |
4082 return false; | |
4083 } | |
4084 }; | |
4085 | |
4086 void G1CollectedHeap::save_marks() { | |
4087 if (ParallelGCThreads == 0) { | |
4088 SaveMarksClosure sm; | |
4089 heap_region_iterate(&sm); | |
4090 } | |
4091 // We do this even in the parallel case | |
4092 perm_gen()->save_marks(); | |
4093 } | |
4094 | |
4095 void G1CollectedHeap::evacuate_collection_set() { | |
4096 set_evacuation_failed(false); | |
4097 | |
4098 g1_rem_set()->prepare_for_oops_into_collection_set_do(); | |
4099 concurrent_g1_refine()->set_use_cache(false); | |
4100 int n_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1); | |
4101 | |
4102 set_par_threads(n_workers); | |
4103 G1ParTask g1_par_task(this, n_workers, _task_queues); | |
4104 | |
4105 init_for_evac_failure(NULL); | |
4106 | |
4107 change_strong_roots_parity(); // In preparation for parallel strong roots. | |
4108 rem_set()->prepare_for_younger_refs_iterate(true); | |
4109 double start_par = os::elapsedTime(); | |
4110 | |
4111 if (ParallelGCThreads > 0) { | |
4112 // The individual threads will set their evac-failure closures. | |
4113 workers()->run_task(&g1_par_task); | |
4114 } else { | |
4115 g1_par_task.work(0); | |
4116 } | |
4117 | |
4118 double par_time = (os::elapsedTime() - start_par) * 1000.0; | |
4119 g1_policy()->record_par_time(par_time); | |
4120 set_par_threads(0); | |
4121 // Is this the right thing to do here? We don't save marks | |
4122 // on individual heap regions when we allocate from | |
4123 // them in parallel, so this seems like the correct place for this. | |
4124 all_alloc_regions_note_end_of_copying(); | |
4125 { | |
4126 G1IsAliveClosure is_alive(this); | |
4127 G1KeepAliveClosure keep_alive(this); | |
4128 JNIHandles::weak_oops_do(&is_alive, &keep_alive); | |
4129 } | |
4130 | |
4131 g1_rem_set()->cleanup_after_oops_into_collection_set_do(); | |
4132 concurrent_g1_refine()->set_use_cache(true); | |
4133 | |
4134 finalize_for_evac_failure(); | |
4135 | |
4136 // Must do this before removing self-forwarding pointers, which clears | |
4137 // the per-region evac-failure flags. | |
4138 concurrent_mark()->complete_marking_in_collection_set(); | |
4139 | |
4140 if (evacuation_failed()) { | |
4141 remove_self_forwarding_pointers(); | |
4142 | |
4143 if (PrintGCDetails) { | |
4144 gclog_or_tty->print(" (evacuation failed)"); | |
4145 } else if (PrintGC) { | |
4146 gclog_or_tty->print("--"); | |
4147 } | |
4148 } | |
4149 | |
4150 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
4151 } | |
4152 | |
4153 void G1CollectedHeap::free_region(HeapRegion* hr) { | |
4154 size_t pre_used = 0; | |
4155 size_t cleared_h_regions = 0; | |
4156 size_t freed_regions = 0; | |
4157 UncleanRegionList local_list; | |
4158 | |
4159 HeapWord* start = hr->bottom(); | |
4160 HeapWord* end = hr->prev_top_at_mark_start(); | |
4161 size_t used_bytes = hr->used(); | |
4162 size_t live_bytes = hr->max_live_bytes(); | |
4163 if (used_bytes > 0) { | |
4164 guarantee( live_bytes <= used_bytes, "invariant" ); | |
4165 } else { | |
4166 guarantee( live_bytes == 0, "invariant" ); | |
4167 } | |
4168 | |
4169 size_t garbage_bytes = used_bytes - live_bytes; | |
4170 if (garbage_bytes > 0) | |
4171 g1_policy()->decrease_known_garbage_bytes(garbage_bytes); | |
4172 | |
4173 free_region_work(hr, pre_used, cleared_h_regions, freed_regions, | |
4174 &local_list); | |
4175 finish_free_region_work(pre_used, cleared_h_regions, freed_regions, | |
4176 &local_list); | |
4177 } | |
4178 | |
4179 void | |
4180 G1CollectedHeap::free_region_work(HeapRegion* hr, | |
4181 size_t& pre_used, | |
4182 size_t& cleared_h_regions, | |
4183 size_t& freed_regions, | |
4184 UncleanRegionList* list, | |
4185 bool par) { | |
4186 assert(!hr->popular(), "should not free popular regions"); | |
4187 pre_used += hr->used(); | |
4188 if (hr->isHumongous()) { | |
4189 assert(hr->startsHumongous(), | |
4190 "Only the start of a humongous region should be freed."); | |
4191 int ind = _hrs->find(hr); | |
4192 assert(ind != -1, "Should have an index."); | |
4193 // Clear the start region. | |
4194 hr->hr_clear(par, true /*clear_space*/); | |
4195 list->insert_before_head(hr); | |
4196 cleared_h_regions++; | |
4197 freed_regions++; | |
4198 // Clear any continued regions. | |
4199 ind++; | |
4200 while ((size_t)ind < n_regions()) { | |
4201 HeapRegion* hrc = _hrs->at(ind); | |
4202 if (!hrc->continuesHumongous()) break; | |
4203 // Otherwise, does continue the H region. | |
4204 assert(hrc->humongous_start_region() == hr, "Huh?"); | |
4205 hrc->hr_clear(par, true /*clear_space*/); | |
4206 cleared_h_regions++; | |
4207 freed_regions++; | |
4208 list->insert_before_head(hrc); | |
4209 ind++; | |
4210 } | |
4211 } else { | |
4212 hr->hr_clear(par, true /*clear_space*/); | |
4213 list->insert_before_head(hr); | |
4214 freed_regions++; | |
4215 // If we're using clear2, this should not be enabled. | |
4216 // assert(!hr->in_cohort(), "Can't be both free and in a cohort."); | |
4217 } | |
4218 } | |
4219 | |
4220 void G1CollectedHeap::finish_free_region_work(size_t pre_used, | |
4221 size_t cleared_h_regions, | |
4222 size_t freed_regions, | |
4223 UncleanRegionList* list) { | |
4224 if (list != NULL && list->sz() > 0) { | |
4225 prepend_region_list_on_unclean_list(list); | |
4226 } | |
4227 // Acquire a lock, if we're parallel, to update possibly-shared | |
4228 // variables. | |
4229 Mutex* lock = (n_par_threads() > 0) ? ParGCRareEvent_lock : NULL; | |
4230 { | |
4231 MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); | |
4232 _summary_bytes_used -= pre_used; | |
4233 _num_humongous_regions -= (int) cleared_h_regions; | |
4234 _free_regions += freed_regions; | |
4235 } | |
4236 } | |
4237 | |
4238 | |
4239 void G1CollectedHeap::dirtyCardsForYoungRegions(CardTableModRefBS* ct_bs, HeapRegion* list) { | |
4240 while (list != NULL) { | |
4241 guarantee( list->is_young(), "invariant" ); | |
4242 | |
4243 HeapWord* bottom = list->bottom(); | |
4244 HeapWord* end = list->end(); | |
4245 MemRegion mr(bottom, end); | |
4246 ct_bs->dirty(mr); | |
4247 | |
4248 list = list->get_next_young_region(); | |
4249 } | |
4250 } | |
4251 | |
4252 void G1CollectedHeap::cleanUpCardTable() { | |
4253 CardTableModRefBS* ct_bs = (CardTableModRefBS*) (barrier_set()); | |
4254 double start = os::elapsedTime(); | |
4255 | |
4256 ct_bs->clear(_g1_committed); | |
4257 | |
4258 // now, redirty the cards of the scan-only and survivor regions | |
4259 // (it seemed faster to do it this way, instead of iterating over | |
4260 // all regions and then clearing / dirtying as approprite) | |
4261 dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region()); | |
4262 dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region()); | |
4263 | |
4264 double elapsed = os::elapsedTime() - start; | |
4265 g1_policy()->record_clear_ct_time( elapsed * 1000.0); | |
4266 } | |
4267 | |
4268 | |
4269 void G1CollectedHeap::do_collection_pause_if_appropriate(size_t word_size) { | |
4270 // First do any popular regions. | |
4271 HeapRegion* hr; | |
4272 while ((hr = popular_region_to_evac()) != NULL) { | |
4273 evac_popular_region(hr); | |
4274 } | |
4275 // Now do heuristic pauses. | |
4276 if (g1_policy()->should_do_collection_pause(word_size)) { | |
4277 do_collection_pause(); | |
4278 } | |
4279 } | |
4280 | |
4281 void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) { | |
4282 double young_time_ms = 0.0; | |
4283 double non_young_time_ms = 0.0; | |
4284 | |
4285 G1CollectorPolicy* policy = g1_policy(); | |
4286 | |
4287 double start_sec = os::elapsedTime(); | |
4288 bool non_young = true; | |
4289 | |
4290 HeapRegion* cur = cs_head; | |
4291 int age_bound = -1; | |
4292 size_t rs_lengths = 0; | |
4293 | |
4294 while (cur != NULL) { | |
4295 if (non_young) { | |
4296 if (cur->is_young()) { | |
4297 double end_sec = os::elapsedTime(); | |
4298 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4299 non_young_time_ms += elapsed_ms; | |
4300 | |
4301 start_sec = os::elapsedTime(); | |
4302 non_young = false; | |
4303 } | |
4304 } else { | |
4305 if (!cur->is_on_free_list()) { | |
4306 double end_sec = os::elapsedTime(); | |
4307 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4308 young_time_ms += elapsed_ms; | |
4309 | |
4310 start_sec = os::elapsedTime(); | |
4311 non_young = true; | |
4312 } | |
4313 } | |
4314 | |
4315 rs_lengths += cur->rem_set()->occupied(); | |
4316 | |
4317 HeapRegion* next = cur->next_in_collection_set(); | |
4318 assert(cur->in_collection_set(), "bad CS"); | |
4319 cur->set_next_in_collection_set(NULL); | |
4320 cur->set_in_collection_set(false); | |
4321 | |
4322 if (cur->is_young()) { | |
4323 int index = cur->young_index_in_cset(); | |
4324 guarantee( index != -1, "invariant" ); | |
4325 guarantee( (size_t)index < policy->young_cset_length(), "invariant" ); | |
4326 size_t words_survived = _surviving_young_words[index]; | |
4327 cur->record_surv_words_in_group(words_survived); | |
4328 } else { | |
4329 int index = cur->young_index_in_cset(); | |
4330 guarantee( index == -1, "invariant" ); | |
4331 } | |
4332 | |
4333 assert( (cur->is_young() && cur->young_index_in_cset() > -1) || | |
4334 (!cur->is_young() && cur->young_index_in_cset() == -1), | |
4335 "invariant" ); | |
4336 | |
4337 if (!cur->evacuation_failed()) { | |
4338 // And the region is empty. | |
4339 assert(!cur->is_empty(), | |
4340 "Should not have empty regions in a CS."); | |
4341 free_region(cur); | |
4342 } else { | |
4343 guarantee( !cur->is_scan_only(), "should not be scan only" ); | |
4344 cur->uninstall_surv_rate_group(); | |
4345 if (cur->is_young()) | |
4346 cur->set_young_index_in_cset(-1); | |
4347 cur->set_not_young(); | |
4348 cur->set_evacuation_failed(false); | |
4349 } | |
4350 cur = next; | |
4351 } | |
4352 | |
4353 policy->record_max_rs_lengths(rs_lengths); | |
4354 policy->cset_regions_freed(); | |
4355 | |
4356 double end_sec = os::elapsedTime(); | |
4357 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4358 if (non_young) | |
4359 non_young_time_ms += elapsed_ms; | |
4360 else | |
4361 young_time_ms += elapsed_ms; | |
4362 | |
4363 policy->record_young_free_cset_time_ms(young_time_ms); | |
4364 policy->record_non_young_free_cset_time_ms(non_young_time_ms); | |
4365 } | |
4366 | |
4367 HeapRegion* | |
4368 G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) { | |
4369 assert(ZF_mon->owned_by_self(), "Precondition"); | |
4370 HeapRegion* res = pop_unclean_region_list_locked(); | |
4371 if (res != NULL) { | |
4372 assert(!res->continuesHumongous() && | |
4373 res->zero_fill_state() != HeapRegion::Allocated, | |
4374 "Only free regions on unclean list."); | |
4375 if (zero_filled) { | |
4376 res->ensure_zero_filled_locked(); | |
4377 res->set_zero_fill_allocated(); | |
4378 } | |
4379 } | |
4380 return res; | |
4381 } | |
4382 | |
4383 HeapRegion* G1CollectedHeap::alloc_region_from_unclean_list(bool zero_filled) { | |
4384 MutexLockerEx zx(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4385 return alloc_region_from_unclean_list_locked(zero_filled); | |
4386 } | |
4387 | |
4388 void G1CollectedHeap::put_region_on_unclean_list(HeapRegion* r) { | |
4389 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4390 put_region_on_unclean_list_locked(r); | |
4391 if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread. | |
4392 } | |
4393 | |
4394 void G1CollectedHeap::set_unclean_regions_coming(bool b) { | |
4395 MutexLockerEx x(Cleanup_mon); | |
4396 set_unclean_regions_coming_locked(b); | |
4397 } | |
4398 | |
4399 void G1CollectedHeap::set_unclean_regions_coming_locked(bool b) { | |
4400 assert(Cleanup_mon->owned_by_self(), "Precondition"); | |
4401 _unclean_regions_coming = b; | |
4402 // Wake up mutator threads that might be waiting for completeCleanup to | |
4403 // finish. | |
4404 if (!b) Cleanup_mon->notify_all(); | |
4405 } | |
4406 | |
4407 void G1CollectedHeap::wait_for_cleanup_complete() { | |
4408 MutexLockerEx x(Cleanup_mon); | |
4409 wait_for_cleanup_complete_locked(); | |
4410 } | |
4411 | |
4412 void G1CollectedHeap::wait_for_cleanup_complete_locked() { | |
4413 assert(Cleanup_mon->owned_by_self(), "precondition"); | |
4414 while (_unclean_regions_coming) { | |
4415 Cleanup_mon->wait(); | |
4416 } | |
4417 } | |
4418 | |
4419 void | |
4420 G1CollectedHeap::put_region_on_unclean_list_locked(HeapRegion* r) { | |
4421 assert(ZF_mon->owned_by_self(), "precondition."); | |
4422 _unclean_region_list.insert_before_head(r); | |
4423 } | |
4424 | |
4425 void | |
4426 G1CollectedHeap::prepend_region_list_on_unclean_list(UncleanRegionList* list) { | |
4427 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4428 prepend_region_list_on_unclean_list_locked(list); | |
4429 if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread. | |
4430 } | |
4431 | |
4432 void | |
4433 G1CollectedHeap:: | |
4434 prepend_region_list_on_unclean_list_locked(UncleanRegionList* list) { | |
4435 assert(ZF_mon->owned_by_self(), "precondition."); | |
4436 _unclean_region_list.prepend_list(list); | |
4437 } | |
4438 | |
4439 HeapRegion* G1CollectedHeap::pop_unclean_region_list_locked() { | |
4440 assert(ZF_mon->owned_by_self(), "precondition."); | |
4441 HeapRegion* res = _unclean_region_list.pop(); | |
4442 if (res != NULL) { | |
4443 // Inform ZF thread that there's a new unclean head. | |
4444 if (_unclean_region_list.hd() != NULL && should_zf()) | |
4445 ZF_mon->notify_all(); | |
4446 } | |
4447 return res; | |
4448 } | |
4449 | |
4450 HeapRegion* G1CollectedHeap::peek_unclean_region_list_locked() { | |
4451 assert(ZF_mon->owned_by_self(), "precondition."); | |
4452 return _unclean_region_list.hd(); | |
4453 } | |
4454 | |
4455 | |
4456 bool G1CollectedHeap::move_cleaned_region_to_free_list_locked() { | |
4457 assert(ZF_mon->owned_by_self(), "Precondition"); | |
4458 HeapRegion* r = peek_unclean_region_list_locked(); | |
4459 if (r != NULL && r->zero_fill_state() == HeapRegion::ZeroFilled) { | |
4460 // Result of below must be equal to "r", since we hold the lock. | |
4461 (void)pop_unclean_region_list_locked(); | |
4462 put_free_region_on_list_locked(r); | |
4463 return true; | |
4464 } else { | |
4465 return false; | |
4466 } | |
4467 } | |
4468 | |
4469 bool G1CollectedHeap::move_cleaned_region_to_free_list() { | |
4470 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4471 return move_cleaned_region_to_free_list_locked(); | |
4472 } | |
4473 | |
4474 | |
4475 void G1CollectedHeap::put_free_region_on_list_locked(HeapRegion* r) { | |
4476 assert(ZF_mon->owned_by_self(), "precondition."); | |
4477 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4478 assert(r->zero_fill_state() == HeapRegion::ZeroFilled, | |
4479 "Regions on free list must be zero filled"); | |
4480 assert(!r->isHumongous(), "Must not be humongous."); | |
4481 assert(r->is_empty(), "Better be empty"); | |
4482 assert(!r->is_on_free_list(), | |
4483 "Better not already be on free list"); | |
4484 assert(!r->is_on_unclean_list(), | |
4485 "Better not already be on unclean list"); | |
4486 r->set_on_free_list(true); | |
4487 r->set_next_on_free_list(_free_region_list); | |
4488 _free_region_list = r; | |
4489 _free_region_list_size++; | |
4490 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4491 } | |
4492 | |
4493 void G1CollectedHeap::put_free_region_on_list(HeapRegion* r) { | |
4494 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4495 put_free_region_on_list_locked(r); | |
4496 } | |
4497 | |
4498 HeapRegion* G1CollectedHeap::pop_free_region_list_locked() { | |
4499 assert(ZF_mon->owned_by_self(), "precondition."); | |
4500 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4501 HeapRegion* res = _free_region_list; | |
4502 if (res != NULL) { | |
4503 _free_region_list = res->next_from_free_list(); | |
4504 _free_region_list_size--; | |
4505 res->set_on_free_list(false); | |
4506 res->set_next_on_free_list(NULL); | |
4507 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4508 } | |
4509 return res; | |
4510 } | |
4511 | |
4512 | |
4513 HeapRegion* G1CollectedHeap::alloc_free_region_from_lists(bool zero_filled) { | |
4514 // By self, or on behalf of self. | |
4515 assert(Heap_lock->is_locked(), "Precondition"); | |
4516 HeapRegion* res = NULL; | |
4517 bool first = true; | |
4518 while (res == NULL) { | |
4519 if (zero_filled || !first) { | |
4520 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4521 res = pop_free_region_list_locked(); | |
4522 if (res != NULL) { | |
4523 assert(!res->zero_fill_is_allocated(), | |
4524 "No allocated regions on free list."); | |
4525 res->set_zero_fill_allocated(); | |
4526 } else if (!first) { | |
4527 break; // We tried both, time to return NULL. | |
4528 } | |
4529 } | |
4530 | |
4531 if (res == NULL) { | |
4532 res = alloc_region_from_unclean_list(zero_filled); | |
4533 } | |
4534 assert(res == NULL || | |
4535 !zero_filled || | |
4536 res->zero_fill_is_allocated(), | |
4537 "We must have allocated the region we're returning"); | |
4538 first = false; | |
4539 } | |
4540 return res; | |
4541 } | |
4542 | |
4543 void G1CollectedHeap::remove_allocated_regions_from_lists() { | |
4544 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4545 { | |
4546 HeapRegion* prev = NULL; | |
4547 HeapRegion* cur = _unclean_region_list.hd(); | |
4548 while (cur != NULL) { | |
4549 HeapRegion* next = cur->next_from_unclean_list(); | |
4550 if (cur->zero_fill_is_allocated()) { | |
4551 // Remove from the list. | |
4552 if (prev == NULL) { | |
4553 (void)_unclean_region_list.pop(); | |
4554 } else { | |
4555 _unclean_region_list.delete_after(prev); | |
4556 } | |
4557 cur->set_on_unclean_list(false); | |
4558 cur->set_next_on_unclean_list(NULL); | |
4559 } else { | |
4560 prev = cur; | |
4561 } | |
4562 cur = next; | |
4563 } | |
4564 assert(_unclean_region_list.sz() == unclean_region_list_length(), | |
4565 "Inv"); | |
4566 } | |
4567 | |
4568 { | |
4569 HeapRegion* prev = NULL; | |
4570 HeapRegion* cur = _free_region_list; | |
4571 while (cur != NULL) { | |
4572 HeapRegion* next = cur->next_from_free_list(); | |
4573 if (cur->zero_fill_is_allocated()) { | |
4574 // Remove from the list. | |
4575 if (prev == NULL) { | |
4576 _free_region_list = cur->next_from_free_list(); | |
4577 } else { | |
4578 prev->set_next_on_free_list(cur->next_from_free_list()); | |
4579 } | |
4580 cur->set_on_free_list(false); | |
4581 cur->set_next_on_free_list(NULL); | |
4582 _free_region_list_size--; | |
4583 } else { | |
4584 prev = cur; | |
4585 } | |
4586 cur = next; | |
4587 } | |
4588 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4589 } | |
4590 } | |
4591 | |
4592 bool G1CollectedHeap::verify_region_lists() { | |
4593 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4594 return verify_region_lists_locked(); | |
4595 } | |
4596 | |
4597 bool G1CollectedHeap::verify_region_lists_locked() { | |
4598 HeapRegion* unclean = _unclean_region_list.hd(); | |
4599 while (unclean != NULL) { | |
4600 guarantee(unclean->is_on_unclean_list(), "Well, it is!"); | |
4601 guarantee(!unclean->is_on_free_list(), "Well, it shouldn't be!"); | |
4602 guarantee(unclean->zero_fill_state() != HeapRegion::Allocated, | |
4603 "Everything else is possible."); | |
4604 unclean = unclean->next_from_unclean_list(); | |
4605 } | |
4606 guarantee(_unclean_region_list.sz() == unclean_region_list_length(), "Inv"); | |
4607 | |
4608 HeapRegion* free_r = _free_region_list; | |
4609 while (free_r != NULL) { | |
4610 assert(free_r->is_on_free_list(), "Well, it is!"); | |
4611 assert(!free_r->is_on_unclean_list(), "Well, it shouldn't be!"); | |
4612 switch (free_r->zero_fill_state()) { | |
4613 case HeapRegion::NotZeroFilled: | |
4614 case HeapRegion::ZeroFilling: | |
4615 guarantee(false, "Should not be on free list."); | |
4616 break; | |
4617 default: | |
4618 // Everything else is possible. | |
4619 break; | |
4620 } | |
4621 free_r = free_r->next_from_free_list(); | |
4622 } | |
4623 guarantee(_free_region_list_size == free_region_list_length(), "Inv"); | |
4624 // If we didn't do an assertion... | |
4625 return true; | |
4626 } | |
4627 | |
4628 size_t G1CollectedHeap::free_region_list_length() { | |
4629 assert(ZF_mon->owned_by_self(), "precondition."); | |
4630 size_t len = 0; | |
4631 HeapRegion* cur = _free_region_list; | |
4632 while (cur != NULL) { | |
4633 len++; | |
4634 cur = cur->next_from_free_list(); | |
4635 } | |
4636 return len; | |
4637 } | |
4638 | |
4639 size_t G1CollectedHeap::unclean_region_list_length() { | |
4640 assert(ZF_mon->owned_by_self(), "precondition."); | |
4641 return _unclean_region_list.length(); | |
4642 } | |
4643 | |
4644 size_t G1CollectedHeap::n_regions() { | |
4645 return _hrs->length(); | |
4646 } | |
4647 | |
4648 size_t G1CollectedHeap::max_regions() { | |
4649 return | |
4650 (size_t)align_size_up(g1_reserved_obj_bytes(), HeapRegion::GrainBytes) / | |
4651 HeapRegion::GrainBytes; | |
4652 } | |
4653 | |
4654 size_t G1CollectedHeap::free_regions() { | |
4655 /* Possibly-expensive assert. | |
4656 assert(_free_regions == count_free_regions(), | |
4657 "_free_regions is off."); | |
4658 */ | |
4659 return _free_regions; | |
4660 } | |
4661 | |
4662 bool G1CollectedHeap::should_zf() { | |
4663 return _free_region_list_size < (size_t) G1ConcZFMaxRegions; | |
4664 } | |
4665 | |
4666 class RegionCounter: public HeapRegionClosure { | |
4667 size_t _n; | |
4668 public: | |
4669 RegionCounter() : _n(0) {} | |
4670 bool doHeapRegion(HeapRegion* r) { | |
4671 if (r->is_empty() && !r->popular()) { | |
4672 assert(!r->isHumongous(), "H regions should not be empty."); | |
4673 _n++; | |
4674 } | |
4675 return false; | |
4676 } | |
4677 int res() { return (int) _n; } | |
4678 }; | |
4679 | |
4680 size_t G1CollectedHeap::count_free_regions() { | |
4681 RegionCounter rc; | |
4682 heap_region_iterate(&rc); | |
4683 size_t n = rc.res(); | |
4684 if (_cur_alloc_region != NULL && _cur_alloc_region->is_empty()) | |
4685 n--; | |
4686 return n; | |
4687 } | |
4688 | |
4689 size_t G1CollectedHeap::count_free_regions_list() { | |
4690 size_t n = 0; | |
4691 size_t o = 0; | |
4692 ZF_mon->lock_without_safepoint_check(); | |
4693 HeapRegion* cur = _free_region_list; | |
4694 while (cur != NULL) { | |
4695 cur = cur->next_from_free_list(); | |
4696 n++; | |
4697 } | |
4698 size_t m = unclean_region_list_length(); | |
4699 ZF_mon->unlock(); | |
4700 return n + m; | |
4701 } | |
4702 | |
4703 bool G1CollectedHeap::should_set_young_locked() { | |
4704 assert(heap_lock_held_for_gc(), | |
4705 "the heap lock should already be held by or for this thread"); | |
4706 return (g1_policy()->in_young_gc_mode() && | |
4707 g1_policy()->should_add_next_region_to_young_list()); | |
4708 } | |
4709 | |
4710 void G1CollectedHeap::set_region_short_lived_locked(HeapRegion* hr) { | |
4711 assert(heap_lock_held_for_gc(), | |
4712 "the heap lock should already be held by or for this thread"); | |
4713 _young_list->push_region(hr); | |
4714 g1_policy()->set_region_short_lived(hr); | |
4715 } | |
4716 | |
4717 class NoYoungRegionsClosure: public HeapRegionClosure { | |
4718 private: | |
4719 bool _success; | |
4720 public: | |
4721 NoYoungRegionsClosure() : _success(true) { } | |
4722 bool doHeapRegion(HeapRegion* r) { | |
4723 if (r->is_young()) { | |
4724 gclog_or_tty->print_cr("Region ["PTR_FORMAT", "PTR_FORMAT") tagged as young", | |
4725 r->bottom(), r->end()); | |
4726 _success = false; | |
4727 } | |
4728 return false; | |
4729 } | |
4730 bool success() { return _success; } | |
4731 }; | |
4732 | |
4733 bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list, | |
4734 bool check_sample) { | |
4735 bool ret = true; | |
4736 | |
4737 ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample); | |
4738 if (!ignore_scan_only_list) { | |
4739 NoYoungRegionsClosure closure; | |
4740 heap_region_iterate(&closure); | |
4741 ret = ret && closure.success(); | |
4742 } | |
4743 | |
4744 return ret; | |
4745 } | |
4746 | |
4747 void G1CollectedHeap::empty_young_list() { | |
4748 assert(heap_lock_held_for_gc(), | |
4749 "the heap lock should already be held by or for this thread"); | |
4750 assert(g1_policy()->in_young_gc_mode(), "should be in young GC mode"); | |
4751 | |
4752 _young_list->empty_list(); | |
4753 } | |
4754 | |
4755 bool G1CollectedHeap::all_alloc_regions_no_allocs_since_save_marks() { | |
4756 bool no_allocs = true; | |
4757 for (int ap = 0; ap < GCAllocPurposeCount && no_allocs; ++ap) { | |
4758 HeapRegion* r = _gc_alloc_regions[ap]; | |
4759 no_allocs = r == NULL || r->saved_mark_at_top(); | |
4760 } | |
4761 return no_allocs; | |
4762 } | |
4763 | |
4764 void G1CollectedHeap::all_alloc_regions_note_end_of_copying() { | |
4765 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
4766 HeapRegion* r = _gc_alloc_regions[ap]; | |
4767 if (r != NULL) { | |
4768 // Check for aliases. | |
4769 bool has_processed_alias = false; | |
4770 for (int i = 0; i < ap; ++i) { | |
4771 if (_gc_alloc_regions[i] == r) { | |
4772 has_processed_alias = true; | |
4773 break; | |
4774 } | |
4775 } | |
4776 if (!has_processed_alias) { | |
4777 r->note_end_of_copying(); | |
4778 g1_policy()->record_after_bytes(r->used()); | |
4779 } | |
4780 } | |
4781 } | |
4782 } | |
4783 | |
4784 | |
4785 // Done at the start of full GC. | |
4786 void G1CollectedHeap::tear_down_region_lists() { | |
4787 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4788 while (pop_unclean_region_list_locked() != NULL) ; | |
4789 assert(_unclean_region_list.hd() == NULL && _unclean_region_list.sz() == 0, | |
4790 "Postconditions of loop.") | |
4791 while (pop_free_region_list_locked() != NULL) ; | |
4792 assert(_free_region_list == NULL, "Postcondition of loop."); | |
4793 if (_free_region_list_size != 0) { | |
4794 gclog_or_tty->print_cr("Size is %d.", _free_region_list_size); | |
4795 print(); | |
4796 } | |
4797 assert(_free_region_list_size == 0, "Postconditions of loop."); | |
4798 } | |
4799 | |
4800 | |
4801 class RegionResetter: public HeapRegionClosure { | |
4802 G1CollectedHeap* _g1; | |
4803 int _n; | |
4804 public: | |
4805 RegionResetter() : _g1(G1CollectedHeap::heap()), _n(0) {} | |
4806 bool doHeapRegion(HeapRegion* r) { | |
4807 if (r->continuesHumongous()) return false; | |
4808 if (r->top() > r->bottom()) { | |
4809 if (r->top() < r->end()) { | |
4810 Copy::fill_to_words(r->top(), | |
4811 pointer_delta(r->end(), r->top())); | |
4812 } | |
4813 r->set_zero_fill_allocated(); | |
4814 } else { | |
4815 assert(r->is_empty(), "tautology"); | |
4816 if (r->popular()) { | |
4817 if (r->zero_fill_state() != HeapRegion::Allocated) { | |
4818 r->ensure_zero_filled_locked(); | |
4819 r->set_zero_fill_allocated(); | |
4820 } | |
4821 } else { | |
4822 _n++; | |
4823 switch (r->zero_fill_state()) { | |
4824 case HeapRegion::NotZeroFilled: | |
4825 case HeapRegion::ZeroFilling: | |
4826 _g1->put_region_on_unclean_list_locked(r); | |
4827 break; | |
4828 case HeapRegion::Allocated: | |
4829 r->set_zero_fill_complete(); | |
4830 // no break; go on to put on free list. | |
4831 case HeapRegion::ZeroFilled: | |
4832 _g1->put_free_region_on_list_locked(r); | |
4833 break; | |
4834 } | |
4835 } | |
4836 } | |
4837 return false; | |
4838 } | |
4839 | |
4840 int getFreeRegionCount() {return _n;} | |
4841 }; | |
4842 | |
4843 // Done at the end of full GC. | |
4844 void G1CollectedHeap::rebuild_region_lists() { | |
4845 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4846 // This needs to go at the end of the full GC. | |
4847 RegionResetter rs; | |
4848 heap_region_iterate(&rs); | |
4849 _free_regions = rs.getFreeRegionCount(); | |
4850 // Tell the ZF thread it may have work to do. | |
4851 if (should_zf()) ZF_mon->notify_all(); | |
4852 } | |
4853 | |
4854 class UsedRegionsNeedZeroFillSetter: public HeapRegionClosure { | |
4855 G1CollectedHeap* _g1; | |
4856 int _n; | |
4857 public: | |
4858 UsedRegionsNeedZeroFillSetter() : _g1(G1CollectedHeap::heap()), _n(0) {} | |
4859 bool doHeapRegion(HeapRegion* r) { | |
4860 if (r->continuesHumongous()) return false; | |
4861 if (r->top() > r->bottom()) { | |
4862 // There are assertions in "set_zero_fill_needed()" below that | |
4863 // require top() == bottom(), so this is technically illegal. | |
4864 // We'll skirt the law here, by making that true temporarily. | |
4865 DEBUG_ONLY(HeapWord* save_top = r->top(); | |
4866 r->set_top(r->bottom())); | |
4867 r->set_zero_fill_needed(); | |
4868 DEBUG_ONLY(r->set_top(save_top)); | |
4869 } | |
4870 return false; | |
4871 } | |
4872 }; | |
4873 | |
4874 // Done at the start of full GC. | |
4875 void G1CollectedHeap::set_used_regions_to_need_zero_fill() { | |
4876 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4877 // This needs to go at the end of the full GC. | |
4878 UsedRegionsNeedZeroFillSetter rs; | |
4879 heap_region_iterate(&rs); | |
4880 } | |
4881 | |
4882 class CountObjClosure: public ObjectClosure { | |
4883 size_t _n; | |
4884 public: | |
4885 CountObjClosure() : _n(0) {} | |
4886 void do_object(oop obj) { _n++; } | |
4887 size_t n() { return _n; } | |
4888 }; | |
4889 | |
4890 size_t G1CollectedHeap::pop_object_used_objs() { | |
4891 size_t sum_objs = 0; | |
4892 for (int i = 0; i < G1NumPopularRegions; i++) { | |
4893 CountObjClosure cl; | |
4894 _hrs->at(i)->object_iterate(&cl); | |
4895 sum_objs += cl.n(); | |
4896 } | |
4897 return sum_objs; | |
4898 } | |
4899 | |
4900 size_t G1CollectedHeap::pop_object_used_bytes() { | |
4901 size_t sum_bytes = 0; | |
4902 for (int i = 0; i < G1NumPopularRegions; i++) { | |
4903 sum_bytes += _hrs->at(i)->used(); | |
4904 } | |
4905 return sum_bytes; | |
4906 } | |
4907 | |
4908 | |
4909 static int nq = 0; | |
4910 | |
4911 HeapWord* G1CollectedHeap::allocate_popular_object(size_t word_size) { | |
4912 while (_cur_pop_hr_index < G1NumPopularRegions) { | |
4913 HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index); | |
4914 HeapWord* res = cur_pop_region->allocate(word_size); | |
4915 if (res != NULL) { | |
4916 // We account for popular objs directly in the used summary: | |
4917 _summary_bytes_used += (word_size * HeapWordSize); | |
4918 return res; | |
4919 } | |
4920 // Otherwise, try the next region (first making sure that we remember | |
4921 // the last "top" value as the "next_top_at_mark_start", so that | |
4922 // objects made popular during markings aren't automatically considered | |
4923 // live). | |
4924 cur_pop_region->note_end_of_copying(); | |
4925 // Otherwise, try the next region. | |
4926 _cur_pop_hr_index++; | |
4927 } | |
4928 // XXX: For now !!! | |
4929 vm_exit_out_of_memory(word_size, | |
4930 "Not enough pop obj space (To Be Fixed)"); | |
4931 return NULL; | |
4932 } | |
4933 | |
4934 class HeapRegionList: public CHeapObj { | |
4935 public: | |
4936 HeapRegion* hr; | |
4937 HeapRegionList* next; | |
4938 }; | |
4939 | |
4940 void G1CollectedHeap::schedule_popular_region_evac(HeapRegion* r) { | |
4941 // This might happen during parallel GC, so protect by this lock. | |
4942 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
4943 // We don't schedule regions whose evacuations are already pending, or | |
4944 // are already being evacuated. | |
4945 if (!r->popular_pending() && !r->in_collection_set()) { | |
4946 r->set_popular_pending(true); | |
4947 if (G1TracePopularity) { | |
4948 gclog_or_tty->print_cr("Scheduling region "PTR_FORMAT" " | |
4949 "["PTR_FORMAT", "PTR_FORMAT") for pop-object evacuation.", | |
4950 r, r->bottom(), r->end()); | |
4951 } | |
4952 HeapRegionList* hrl = new HeapRegionList; | |
4953 hrl->hr = r; | |
4954 hrl->next = _popular_regions_to_be_evacuated; | |
4955 _popular_regions_to_be_evacuated = hrl; | |
4956 } | |
4957 } | |
4958 | |
4959 HeapRegion* G1CollectedHeap::popular_region_to_evac() { | |
4960 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
4961 HeapRegion* res = NULL; | |
4962 while (_popular_regions_to_be_evacuated != NULL && res == NULL) { | |
4963 HeapRegionList* hrl = _popular_regions_to_be_evacuated; | |
4964 _popular_regions_to_be_evacuated = hrl->next; | |
4965 res = hrl->hr; | |
4966 // The G1RSPopLimit may have increased, so recheck here... | |
4967 if (res->rem_set()->occupied() < (size_t) G1RSPopLimit) { | |
4968 // Hah: don't need to schedule. | |
4969 if (G1TracePopularity) { | |
4970 gclog_or_tty->print_cr("Unscheduling region "PTR_FORMAT" " | |
4971 "["PTR_FORMAT", "PTR_FORMAT") " | |
4972 "for pop-object evacuation (size %d < limit %d)", | |
4973 res, res->bottom(), res->end(), | |
4974 res->rem_set()->occupied(), G1RSPopLimit); | |
4975 } | |
4976 res->set_popular_pending(false); | |
4977 res = NULL; | |
4978 } | |
4979 // We do not reset res->popular() here; if we did so, it would allow | |
4980 // the region to be "rescheduled" for popularity evacuation. Instead, | |
4981 // this is done in the collection pause, with the world stopped. | |
4982 // So the invariant is that the regions in the list have the popularity | |
4983 // boolean set, but having the boolean set does not imply membership | |
4984 // on the list (though there can at most one such pop-pending region | |
4985 // not on the list at any time). | |
4986 delete hrl; | |
4987 } | |
4988 return res; | |
4989 } | |
4990 | |
4991 void G1CollectedHeap::evac_popular_region(HeapRegion* hr) { | |
4992 while (true) { | |
4993 // Don't want to do a GC pause while cleanup is being completed! | |
4994 wait_for_cleanup_complete(); | |
4995 | |
4996 // Read the GC count while holding the Heap_lock | |
4997 int gc_count_before = SharedHeap::heap()->total_collections(); | |
4998 g1_policy()->record_stop_world_start(); | |
4999 | |
5000 { | |
5001 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
5002 VM_G1PopRegionCollectionPause op(gc_count_before, hr); | |
5003 VMThread::execute(&op); | |
5004 | |
5005 // If the prolog succeeded, we didn't do a GC for this. | |
5006 if (op.prologue_succeeded()) break; | |
5007 } | |
5008 // Otherwise we didn't. We should recheck the size, though, since | |
5009 // the limit may have increased... | |
5010 if (hr->rem_set()->occupied() < (size_t) G1RSPopLimit) { | |
5011 hr->set_popular_pending(false); | |
5012 break; | |
5013 } | |
5014 } | |
5015 } | |
5016 | |
5017 void G1CollectedHeap::atomic_inc_obj_rc(oop obj) { | |
5018 Atomic::inc(obj_rc_addr(obj)); | |
5019 } | |
5020 | |
5021 class CountRCClosure: public OopsInHeapRegionClosure { | |
5022 G1CollectedHeap* _g1h; | |
5023 bool _parallel; | |
5024 public: | |
5025 CountRCClosure(G1CollectedHeap* g1h) : | |
5026 _g1h(g1h), _parallel(ParallelGCThreads > 0) | |
5027 {} | |
5028 void do_oop(narrowOop* p) { | |
5029 guarantee(false, "NYI"); | |
5030 } | |
5031 void do_oop(oop* p) { | |
5032 oop obj = *p; | |
5033 assert(obj != NULL, "Precondition."); | |
5034 if (_parallel) { | |
5035 // We go sticky at the limit to avoid excess contention. | |
5036 // If we want to track the actual RC's further, we'll need to keep a | |
5037 // per-thread hash table or something for the popular objects. | |
5038 if (_g1h->obj_rc(obj) < G1ObjPopLimit) { | |
5039 _g1h->atomic_inc_obj_rc(obj); | |
5040 } | |
5041 } else { | |
5042 _g1h->inc_obj_rc(obj); | |
5043 } | |
5044 } | |
5045 }; | |
5046 | |
5047 class EvacPopObjClosure: public ObjectClosure { | |
5048 G1CollectedHeap* _g1h; | |
5049 size_t _pop_objs; | |
5050 size_t _max_rc; | |
5051 public: | |
5052 EvacPopObjClosure(G1CollectedHeap* g1h) : | |
5053 _g1h(g1h), _pop_objs(0), _max_rc(0) {} | |
5054 | |
5055 void do_object(oop obj) { | |
5056 size_t rc = _g1h->obj_rc(obj); | |
5057 _max_rc = MAX2(rc, _max_rc); | |
5058 if (rc >= (size_t) G1ObjPopLimit) { | |
5059 _g1h->_pop_obj_rc_at_copy.add((double)rc); | |
5060 size_t word_sz = obj->size(); | |
5061 HeapWord* new_pop_loc = _g1h->allocate_popular_object(word_sz); | |
5062 oop new_pop_obj = (oop)new_pop_loc; | |
5063 Copy::aligned_disjoint_words((HeapWord*)obj, new_pop_loc, word_sz); | |
5064 obj->forward_to(new_pop_obj); | |
5065 G1ScanAndBalanceClosure scan_and_balance(_g1h); | |
5066 new_pop_obj->oop_iterate_backwards(&scan_and_balance); | |
5067 // preserve "next" mark bit if marking is in progress. | |
5068 if (_g1h->mark_in_progress() && !_g1h->is_obj_ill(obj)) { | |
5069 _g1h->concurrent_mark()->markAndGrayObjectIfNecessary(new_pop_obj); | |
5070 } | |
5071 | |
5072 if (G1TracePopularity) { | |
5073 gclog_or_tty->print_cr("Found obj " PTR_FORMAT " of word size " SIZE_FORMAT | |
5074 " pop (%d), move to " PTR_FORMAT, | |
5075 (void*) obj, word_sz, | |
5076 _g1h->obj_rc(obj), (void*) new_pop_obj); | |
5077 } | |
5078 _pop_objs++; | |
5079 } | |
5080 } | |
5081 size_t pop_objs() { return _pop_objs; } | |
5082 size_t max_rc() { return _max_rc; } | |
5083 }; | |
5084 | |
5085 class G1ParCountRCTask : public AbstractGangTask { | |
5086 G1CollectedHeap* _g1h; | |
5087 BitMap _bm; | |
5088 | |
5089 size_t getNCards() { | |
5090 return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1) | |
5091 / G1BlockOffsetSharedArray::N_bytes; | |
5092 } | |
5093 CountRCClosure _count_rc_closure; | |
5094 public: | |
5095 G1ParCountRCTask(G1CollectedHeap* g1h) : | |
5096 AbstractGangTask("G1 Par RC Count task"), | |
5097 _g1h(g1h), _bm(getNCards()), _count_rc_closure(g1h) | |
5098 {} | |
5099 | |
5100 void work(int i) { | |
5101 ResourceMark rm; | |
5102 HandleMark hm; | |
5103 _g1h->g1_rem_set()->oops_into_collection_set_do(&_count_rc_closure, i); | |
5104 } | |
5105 }; | |
5106 | |
5107 void G1CollectedHeap::popularity_pause_preamble(HeapRegion* popular_region) { | |
5108 // We're evacuating a single region (for popularity). | |
5109 if (G1TracePopularity) { | |
5110 gclog_or_tty->print_cr("Doing pop region pause for ["PTR_FORMAT", "PTR_FORMAT")", | |
5111 popular_region->bottom(), popular_region->end()); | |
5112 } | |
5113 g1_policy()->set_single_region_collection_set(popular_region); | |
5114 size_t max_rc; | |
5115 if (!compute_reference_counts_and_evac_popular(popular_region, | |
5116 &max_rc)) { | |
5117 // We didn't evacuate any popular objects. | |
5118 // We increase the RS popularity limit, to prevent this from | |
5119 // happening in the future. | |
5120 if (G1RSPopLimit < (1 << 30)) { | |
5121 G1RSPopLimit *= 2; | |
5122 } | |
5123 // For now, interesting enough for a message: | |
5124 #if 1 | |
5125 gclog_or_tty->print_cr("In pop region pause for ["PTR_FORMAT", "PTR_FORMAT"), " | |
5126 "failed to find a pop object (max = %d).", | |
5127 popular_region->bottom(), popular_region->end(), | |
5128 max_rc); | |
5129 gclog_or_tty->print_cr("Increased G1RSPopLimit to %d.", G1RSPopLimit); | |
5130 #endif // 0 | |
5131 // Also, we reset the collection set to NULL, to make the rest of | |
5132 // the collection do nothing. | |
5133 assert(popular_region->next_in_collection_set() == NULL, | |
5134 "should be single-region."); | |
5135 popular_region->set_in_collection_set(false); | |
5136 popular_region->set_popular_pending(false); | |
5137 g1_policy()->clear_collection_set(); | |
5138 } | |
5139 } | |
5140 | |
5141 bool G1CollectedHeap:: | |
5142 compute_reference_counts_and_evac_popular(HeapRegion* popular_region, | |
5143 size_t* max_rc) { | |
5144 HeapWord* rc_region_bot; | |
5145 HeapWord* rc_region_end; | |
5146 | |
5147 // Set up the reference count region. | |
5148 HeapRegion* rc_region = newAllocRegion(HeapRegion::GrainWords); | |
5149 if (rc_region != NULL) { | |
5150 rc_region_bot = rc_region->bottom(); | |
5151 rc_region_end = rc_region->end(); | |
5152 } else { | |
5153 rc_region_bot = NEW_C_HEAP_ARRAY(HeapWord, HeapRegion::GrainWords); | |
5154 if (rc_region_bot == NULL) { | |
5155 vm_exit_out_of_memory(HeapRegion::GrainWords, | |
5156 "No space for RC region."); | |
5157 } | |
5158 rc_region_end = rc_region_bot + HeapRegion::GrainWords; | |
5159 } | |
5160 | |
5161 if (G1TracePopularity) | |
5162 gclog_or_tty->print_cr("RC region is ["PTR_FORMAT", "PTR_FORMAT")", | |
5163 rc_region_bot, rc_region_end); | |
5164 if (rc_region_bot > popular_region->bottom()) { | |
5165 _rc_region_above = true; | |
5166 _rc_region_diff = | |
5167 pointer_delta(rc_region_bot, popular_region->bottom(), 1); | |
5168 } else { | |
5169 assert(rc_region_bot < popular_region->bottom(), "Can't be equal."); | |
5170 _rc_region_above = false; | |
5171 _rc_region_diff = | |
5172 pointer_delta(popular_region->bottom(), rc_region_bot, 1); | |
5173 } | |
5174 g1_policy()->record_pop_compute_rc_start(); | |
5175 // Count external references. | |
5176 g1_rem_set()->prepare_for_oops_into_collection_set_do(); | |
5177 if (ParallelGCThreads > 0) { | |
5178 | |
5179 set_par_threads(workers()->total_workers()); | |
5180 G1ParCountRCTask par_count_rc_task(this); | |
5181 workers()->run_task(&par_count_rc_task); | |
5182 set_par_threads(0); | |
5183 | |
5184 } else { | |
5185 CountRCClosure count_rc_closure(this); | |
5186 g1_rem_set()->oops_into_collection_set_do(&count_rc_closure, 0); | |
5187 } | |
5188 g1_rem_set()->cleanup_after_oops_into_collection_set_do(); | |
5189 g1_policy()->record_pop_compute_rc_end(); | |
5190 | |
5191 // Now evacuate popular objects. | |
5192 g1_policy()->record_pop_evac_start(); | |
5193 EvacPopObjClosure evac_pop_obj_cl(this); | |
5194 popular_region->object_iterate(&evac_pop_obj_cl); | |
5195 *max_rc = evac_pop_obj_cl.max_rc(); | |
5196 | |
5197 // Make sure the last "top" value of the current popular region is copied | |
5198 // as the "next_top_at_mark_start", so that objects made popular during | |
5199 // markings aren't automatically considered live. | |
5200 HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index); | |
5201 cur_pop_region->note_end_of_copying(); | |
5202 | |
5203 if (rc_region != NULL) { | |
5204 free_region(rc_region); | |
5205 } else { | |
5206 FREE_C_HEAP_ARRAY(HeapWord, rc_region_bot); | |
5207 } | |
5208 g1_policy()->record_pop_evac_end(); | |
5209 | |
5210 return evac_pop_obj_cl.pop_objs() > 0; | |
5211 } | |
5212 | |
5213 class CountPopObjInfoClosure: public HeapRegionClosure { | |
5214 size_t _objs; | |
5215 size_t _bytes; | |
5216 | |
5217 class CountObjClosure: public ObjectClosure { | |
5218 int _n; | |
5219 public: | |
5220 CountObjClosure() : _n(0) {} | |
5221 void do_object(oop obj) { _n++; } | |
5222 size_t n() { return _n; } | |
5223 }; | |
5224 | |
5225 public: | |
5226 CountPopObjInfoClosure() : _objs(0), _bytes(0) {} | |
5227 bool doHeapRegion(HeapRegion* r) { | |
5228 _bytes += r->used(); | |
5229 CountObjClosure blk; | |
5230 r->object_iterate(&blk); | |
5231 _objs += blk.n(); | |
5232 return false; | |
5233 } | |
5234 size_t objs() { return _objs; } | |
5235 size_t bytes() { return _bytes; } | |
5236 }; | |
5237 | |
5238 | |
5239 void G1CollectedHeap::print_popularity_summary_info() const { | |
5240 CountPopObjInfoClosure blk; | |
5241 for (int i = 0; i <= _cur_pop_hr_index; i++) { | |
5242 blk.doHeapRegion(_hrs->at(i)); | |
5243 } | |
5244 gclog_or_tty->print_cr("\nPopular objects: %d objs, %d bytes.", | |
5245 blk.objs(), blk.bytes()); | |
5246 gclog_or_tty->print_cr(" RC at copy = [avg = %5.2f, max = %5.2f, sd = %5.2f].", | |
5247 _pop_obj_rc_at_copy.avg(), | |
5248 _pop_obj_rc_at_copy.maximum(), | |
5249 _pop_obj_rc_at_copy.sd()); | |
5250 } | |
5251 | |
5252 void G1CollectedHeap::set_refine_cte_cl_concurrency(bool concurrent) { | |
5253 _refine_cte_cl->set_concurrent(concurrent); | |
5254 } | |
5255 | |
5256 #ifndef PRODUCT | |
5257 | |
5258 class PrintHeapRegionClosure: public HeapRegionClosure { | |
5259 public: | |
5260 bool doHeapRegion(HeapRegion *r) { | |
5261 gclog_or_tty->print("Region: "PTR_FORMAT":", r); | |
5262 if (r != NULL) { | |
5263 if (r->is_on_free_list()) | |
5264 gclog_or_tty->print("Free "); | |
5265 if (r->is_young()) | |
5266 gclog_or_tty->print("Young "); | |
5267 if (r->isHumongous()) | |
5268 gclog_or_tty->print("Is Humongous "); | |
5269 r->print(); | |
5270 } | |
5271 return false; | |
5272 } | |
5273 }; | |
5274 | |
5275 class SortHeapRegionClosure : public HeapRegionClosure { | |
5276 size_t young_regions,free_regions, unclean_regions; | |
5277 size_t hum_regions, count; | |
5278 size_t unaccounted, cur_unclean, cur_alloc; | |
5279 size_t total_free; | |
5280 HeapRegion* cur; | |
5281 public: | |
5282 SortHeapRegionClosure(HeapRegion *_cur) : cur(_cur), young_regions(0), | |
5283 free_regions(0), unclean_regions(0), | |
5284 hum_regions(0), | |
5285 count(0), unaccounted(0), | |
5286 cur_alloc(0), total_free(0) | |
5287 {} | |
5288 bool doHeapRegion(HeapRegion *r) { | |
5289 count++; | |
5290 if (r->is_on_free_list()) free_regions++; | |
5291 else if (r->is_on_unclean_list()) unclean_regions++; | |
5292 else if (r->isHumongous()) hum_regions++; | |
5293 else if (r->is_young()) young_regions++; | |
5294 else if (r == cur) cur_alloc++; | |
5295 else unaccounted++; | |
5296 return false; | |
5297 } | |
5298 void print() { | |
5299 total_free = free_regions + unclean_regions; | |
5300 gclog_or_tty->print("%d regions\n", count); | |
5301 gclog_or_tty->print("%d free: free_list = %d unclean = %d\n", | |
5302 total_free, free_regions, unclean_regions); | |
5303 gclog_or_tty->print("%d humongous %d young\n", | |
5304 hum_regions, young_regions); | |
5305 gclog_or_tty->print("%d cur_alloc\n", cur_alloc); | |
5306 gclog_or_tty->print("UHOH unaccounted = %d\n", unaccounted); | |
5307 } | |
5308 }; | |
5309 | |
5310 void G1CollectedHeap::print_region_counts() { | |
5311 SortHeapRegionClosure sc(_cur_alloc_region); | |
5312 PrintHeapRegionClosure cl; | |
5313 heap_region_iterate(&cl); | |
5314 heap_region_iterate(&sc); | |
5315 sc.print(); | |
5316 print_region_accounting_info(); | |
5317 }; | |
5318 | |
5319 bool G1CollectedHeap::regions_accounted_for() { | |
5320 // TODO: regions accounting for young/survivor/tenured | |
5321 return true; | |
5322 } | |
5323 | |
5324 bool G1CollectedHeap::print_region_accounting_info() { | |
5325 gclog_or_tty->print_cr("P regions: %d.", G1NumPopularRegions); | |
5326 gclog_or_tty->print_cr("Free regions: %d (count: %d count list %d) (clean: %d unclean: %d).", | |
5327 free_regions(), | |
5328 count_free_regions(), count_free_regions_list(), | |
5329 _free_region_list_size, _unclean_region_list.sz()); | |
5330 gclog_or_tty->print_cr("cur_alloc: %d.", | |
5331 (_cur_alloc_region == NULL ? 0 : 1)); | |
5332 gclog_or_tty->print_cr("H regions: %d.", _num_humongous_regions); | |
5333 | |
5334 // TODO: check regions accounting for young/survivor/tenured | |
5335 return true; | |
5336 } | |
5337 | |
5338 bool G1CollectedHeap::is_in_closed_subset(const void* p) const { | |
5339 HeapRegion* hr = heap_region_containing(p); | |
5340 if (hr == NULL) { | |
5341 return is_in_permanent(p); | |
5342 } else { | |
5343 return hr->is_in(p); | |
5344 } | |
5345 } | |
5346 #endif // PRODUCT | |
5347 | |
5348 void G1CollectedHeap::g1_unimplemented() { | |
5349 // Unimplemented(); | |
5350 } | |
5351 | |
5352 | |
5353 // Local Variables: *** | |
5354 // c-indentation-style: gnu *** | |
5355 // End: *** |