Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp @ 546:05c6d52fa7a9
6690928: Use spinning in combination with yields for workstealing termination.
Summary: Substitute a spin loop for most calls to yield() to reduce the stress on the system.
Reviewed-by: tonyp
author | jmasa |
---|---|
date | Sun, 08 Feb 2009 13:18:01 -0800 |
parents | 58054a18d735 |
children | 0fbdb4381b99 3698e8f47799 98cb887364d3 |
rev | line source |
---|---|
342 | 1 /* |
470 | 2 * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved. |
342 | 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), | |
545 | 144 _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0) |
342 | 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) { | |
545 | 162 assert(hr->is_survivor(), "should be flagged as survivor region"); |
342 | 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) { | |
545 | 167 _survivor_tail = hr; |
342 | 168 } |
169 _survivor_head = hr; | |
170 | |
171 ++_survivor_length; | |
172 } | |
173 | |
174 HeapRegion* YoungList::pop_region() { | |
175 while (_head != NULL) { | |
176 assert( length() > 0, "list should not be empty" ); | |
177 HeapRegion* ret = _head; | |
178 _head = ret->get_next_young_region(); | |
179 ret->set_next_young_region(NULL); | |
180 --_length; | |
181 assert(ret->is_young(), "region should be very young"); | |
182 | |
183 // Replace 'Survivor' region type with 'Young'. So the region will | |
184 // be treated as a young region and will not be 'confused' with | |
185 // newly created survivor regions. | |
186 if (ret->is_survivor()) { | |
187 ret->set_young(); | |
188 } | |
189 | |
190 if (!ret->is_scan_only()) { | |
191 return ret; | |
192 } | |
193 | |
194 // scan-only, we'll add it to the scan-only list | |
195 if (_scan_only_tail == NULL) { | |
196 guarantee( _scan_only_head == NULL, "invariant" ); | |
197 | |
198 _scan_only_head = ret; | |
199 _curr_scan_only = ret; | |
200 } else { | |
201 guarantee( _scan_only_head != NULL, "invariant" ); | |
202 _scan_only_tail->set_next_young_region(ret); | |
203 } | |
204 guarantee( ret->get_next_young_region() == NULL, "invariant" ); | |
205 _scan_only_tail = ret; | |
206 | |
207 // no need to be tagged as scan-only any more | |
208 ret->set_young(); | |
209 | |
210 ++_scan_only_length; | |
211 } | |
212 assert( length() == 0, "list should be empty" ); | |
213 return NULL; | |
214 } | |
215 | |
216 void YoungList::empty_list(HeapRegion* list) { | |
217 while (list != NULL) { | |
218 HeapRegion* next = list->get_next_young_region(); | |
219 list->set_next_young_region(NULL); | |
220 list->uninstall_surv_rate_group(); | |
221 list->set_not_young(); | |
222 list = next; | |
223 } | |
224 } | |
225 | |
226 void YoungList::empty_list() { | |
227 assert(check_list_well_formed(), "young list should be well formed"); | |
228 | |
229 empty_list(_head); | |
230 _head = NULL; | |
231 _length = 0; | |
232 | |
233 empty_list(_scan_only_head); | |
234 _scan_only_head = NULL; | |
235 _scan_only_tail = NULL; | |
236 _scan_only_length = 0; | |
237 _curr_scan_only = NULL; | |
238 | |
239 empty_list(_survivor_head); | |
240 _survivor_head = NULL; | |
545 | 241 _survivor_tail = NULL; |
342 | 242 _survivor_length = 0; |
243 | |
244 _last_sampled_rs_lengths = 0; | |
245 | |
246 assert(check_list_empty(false), "just making sure..."); | |
247 } | |
248 | |
249 bool YoungList::check_list_well_formed() { | |
250 bool ret = true; | |
251 | |
252 size_t length = 0; | |
253 HeapRegion* curr = _head; | |
254 HeapRegion* last = NULL; | |
255 while (curr != NULL) { | |
256 if (!curr->is_young() || curr->is_scan_only()) { | |
257 gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" " | |
258 "incorrectly tagged (%d, %d)", | |
259 curr->bottom(), curr->end(), | |
260 curr->is_young(), curr->is_scan_only()); | |
261 ret = false; | |
262 } | |
263 ++length; | |
264 last = curr; | |
265 curr = curr->get_next_young_region(); | |
266 } | |
267 ret = ret && (length == _length); | |
268 | |
269 if (!ret) { | |
270 gclog_or_tty->print_cr("### YOUNG LIST seems not well formed!"); | |
271 gclog_or_tty->print_cr("### list has %d entries, _length is %d", | |
272 length, _length); | |
273 } | |
274 | |
275 bool scan_only_ret = true; | |
276 length = 0; | |
277 curr = _scan_only_head; | |
278 last = NULL; | |
279 while (curr != NULL) { | |
280 if (!curr->is_young() || curr->is_scan_only()) { | |
281 gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" " | |
282 "incorrectly tagged (%d, %d)", | |
283 curr->bottom(), curr->end(), | |
284 curr->is_young(), curr->is_scan_only()); | |
285 scan_only_ret = false; | |
286 } | |
287 ++length; | |
288 last = curr; | |
289 curr = curr->get_next_young_region(); | |
290 } | |
291 scan_only_ret = scan_only_ret && (length == _scan_only_length); | |
292 | |
293 if ( (last != _scan_only_tail) || | |
294 (_scan_only_head == NULL && _scan_only_tail != NULL) || | |
295 (_scan_only_head != NULL && _scan_only_tail == NULL) ) { | |
296 gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly"); | |
297 scan_only_ret = false; | |
298 } | |
299 | |
300 if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) { | |
301 gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly"); | |
302 scan_only_ret = false; | |
303 } | |
304 | |
305 if (!scan_only_ret) { | |
306 gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!"); | |
307 gclog_or_tty->print_cr("### list has %d entries, _scan_only_length is %d", | |
308 length, _scan_only_length); | |
309 } | |
310 | |
311 return ret && scan_only_ret; | |
312 } | |
313 | |
314 bool YoungList::check_list_empty(bool ignore_scan_only_list, | |
315 bool check_sample) { | |
316 bool ret = true; | |
317 | |
318 if (_length != 0) { | |
319 gclog_or_tty->print_cr("### YOUNG LIST should have 0 length, not %d", | |
320 _length); | |
321 ret = false; | |
322 } | |
323 if (check_sample && _last_sampled_rs_lengths != 0) { | |
324 gclog_or_tty->print_cr("### YOUNG LIST has non-zero last sampled RS lengths"); | |
325 ret = false; | |
326 } | |
327 if (_head != NULL) { | |
328 gclog_or_tty->print_cr("### YOUNG LIST does not have a NULL head"); | |
329 ret = false; | |
330 } | |
331 if (!ret) { | |
332 gclog_or_tty->print_cr("### YOUNG LIST does not seem empty"); | |
333 } | |
334 | |
335 if (ignore_scan_only_list) | |
336 return ret; | |
337 | |
338 bool scan_only_ret = true; | |
339 if (_scan_only_length != 0) { | |
340 gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d", | |
341 _scan_only_length); | |
342 scan_only_ret = false; | |
343 } | |
344 if (_scan_only_head != NULL) { | |
345 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head"); | |
346 scan_only_ret = false; | |
347 } | |
348 if (_scan_only_tail != NULL) { | |
349 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail"); | |
350 scan_only_ret = false; | |
351 } | |
352 if (!scan_only_ret) { | |
353 gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty"); | |
354 } | |
355 | |
356 return ret && scan_only_ret; | |
357 } | |
358 | |
359 void | |
360 YoungList::rs_length_sampling_init() { | |
361 _sampled_rs_lengths = 0; | |
362 _curr = _head; | |
363 } | |
364 | |
365 bool | |
366 YoungList::rs_length_sampling_more() { | |
367 return _curr != NULL; | |
368 } | |
369 | |
370 void | |
371 YoungList::rs_length_sampling_next() { | |
372 assert( _curr != NULL, "invariant" ); | |
373 _sampled_rs_lengths += _curr->rem_set()->occupied(); | |
374 _curr = _curr->get_next_young_region(); | |
375 if (_curr == NULL) { | |
376 _last_sampled_rs_lengths = _sampled_rs_lengths; | |
377 // gclog_or_tty->print_cr("last sampled RS lengths = %d", _last_sampled_rs_lengths); | |
378 } | |
379 } | |
380 | |
381 void | |
382 YoungList::reset_auxilary_lists() { | |
383 // We could have just "moved" the scan-only list to the young list. | |
384 // However, the scan-only list is ordered according to the region | |
385 // age in descending order, so, by moving one entry at a time, we | |
386 // ensure that it is recreated in ascending order. | |
387 | |
388 guarantee( is_empty(), "young list should be empty" ); | |
389 assert(check_list_well_formed(), "young list should be well formed"); | |
390 | |
391 // Add survivor regions to SurvRateGroup. | |
392 _g1h->g1_policy()->note_start_adding_survivor_regions(); | |
545 | 393 _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */); |
342 | 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; | |
545 | 404 _survivor_tail->set_next_young_region(_scan_only_head); |
342 | 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; | |
545 | 421 _survivor_tail = NULL; |
342 | 422 _survivor_length = 0; |
545 | 423 _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */); |
342 | 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) { | |
545 | 556 alloc_region->set_survivor(); |
342 | 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 { | |
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651 // We may have concurrent cleanup working at the time. Wait for it |
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652 // to complete. In the future we would probably want to make the |
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653 // concurrent cleanup truly concurrent by decoupling it from the |
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654 // allocation. |
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655 if (!SafepointSynchronize::is_at_safepoint()) |
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656 wait_for_cleanup_complete(); |
342 | 657 // If we do a collection pause, this will be reset to a non-NULL |
658 // value. If we don't, nulling here ensures that we allocate a new | |
659 // region below. | |
660 if (_cur_alloc_region != NULL) { | |
661 // We're finished with the _cur_alloc_region. | |
662 _summary_bytes_used += _cur_alloc_region->used(); | |
663 _cur_alloc_region = NULL; | |
664 } | |
665 assert(_cur_alloc_region == NULL, "Invariant."); | |
666 // Completion of a heap region is perhaps a good point at which to do | |
667 // a collection pause. | |
668 if (permit_collection_pause) | |
669 do_collection_pause_if_appropriate(word_size); | |
670 // Make sure we have an allocation region available. | |
671 if (_cur_alloc_region == NULL) { | |
672 if (!SafepointSynchronize::is_at_safepoint()) | |
673 wait_for_cleanup_complete(); | |
674 bool next_is_young = should_set_young_locked(); | |
675 // If the next region is not young, make sure it's zero-filled. | |
676 _cur_alloc_region = newAllocRegion(word_size, !next_is_young); | |
677 if (_cur_alloc_region != NULL) { | |
678 _summary_bytes_used -= _cur_alloc_region->used(); | |
679 if (next_is_young) { | |
680 set_region_short_lived_locked(_cur_alloc_region); | |
681 allocated_young_region = _cur_alloc_region; | |
682 } | |
683 } | |
684 } | |
685 assert(_cur_alloc_region == NULL || !_cur_alloc_region->isHumongous(), | |
686 "Prevent a regression of this bug."); | |
687 | |
688 // Now retry the allocation. | |
689 if (_cur_alloc_region != NULL) { | |
690 res = _cur_alloc_region->allocate(word_size); | |
691 } | |
692 } | |
693 | |
694 // NOTE: fails frequently in PRT | |
695 assert(regions_accounted_for(), "Region leakage!"); | |
696 | |
697 if (res != NULL) { | |
698 if (!SafepointSynchronize::is_at_safepoint()) { | |
699 assert( permit_collection_pause, "invariant" ); | |
700 assert( Heap_lock->owned_by_self(), "invariant" ); | |
701 Heap_lock->unlock(); | |
702 } | |
703 | |
704 if (allocated_young_region != NULL) { | |
705 HeapRegion* hr = allocated_young_region; | |
706 HeapWord* bottom = hr->bottom(); | |
707 HeapWord* end = hr->end(); | |
708 MemRegion mr(bottom, end); | |
709 ((CardTableModRefBS*)_g1h->barrier_set())->dirty(mr); | |
710 } | |
711 } | |
712 | |
713 assert( SafepointSynchronize::is_at_safepoint() || | |
714 (res == NULL && Heap_lock->owned_by_self()) || | |
715 (res != NULL && !Heap_lock->owned_by_self()), | |
716 "post condition of the call" ); | |
717 | |
718 return res; | |
719 } | |
720 | |
721 HeapWord* | |
722 G1CollectedHeap::mem_allocate(size_t word_size, | |
723 bool is_noref, | |
724 bool is_tlab, | |
725 bool* gc_overhead_limit_was_exceeded) { | |
726 debug_only(check_for_valid_allocation_state()); | |
727 assert(no_gc_in_progress(), "Allocation during gc not allowed"); | |
728 HeapWord* result = NULL; | |
729 | |
730 // Loop until the allocation is satisified, | |
731 // or unsatisfied after GC. | |
732 for (int try_count = 1; /* return or throw */; try_count += 1) { | |
733 int gc_count_before; | |
734 { | |
735 Heap_lock->lock(); | |
736 result = attempt_allocation(word_size); | |
737 if (result != NULL) { | |
738 // attempt_allocation should have unlocked the heap lock | |
739 assert(is_in(result), "result not in heap"); | |
740 return result; | |
741 } | |
742 // Read the gc count while the heap lock is held. | |
743 gc_count_before = SharedHeap::heap()->total_collections(); | |
744 Heap_lock->unlock(); | |
745 } | |
746 | |
747 // Create the garbage collection operation... | |
748 VM_G1CollectForAllocation op(word_size, | |
749 gc_count_before); | |
750 | |
751 // ...and get the VM thread to execute it. | |
752 VMThread::execute(&op); | |
753 if (op.prologue_succeeded()) { | |
754 result = op.result(); | |
755 assert(result == NULL || is_in(result), "result not in heap"); | |
756 return result; | |
757 } | |
758 | |
759 // Give a warning if we seem to be looping forever. | |
760 if ((QueuedAllocationWarningCount > 0) && | |
761 (try_count % QueuedAllocationWarningCount == 0)) { | |
762 warning("G1CollectedHeap::mem_allocate_work retries %d times", | |
763 try_count); | |
764 } | |
765 } | |
766 } | |
767 | |
768 void G1CollectedHeap::abandon_cur_alloc_region() { | |
769 if (_cur_alloc_region != NULL) { | |
770 // We're finished with the _cur_alloc_region. | |
771 if (_cur_alloc_region->is_empty()) { | |
772 _free_regions++; | |
773 free_region(_cur_alloc_region); | |
774 } else { | |
775 _summary_bytes_used += _cur_alloc_region->used(); | |
776 } | |
777 _cur_alloc_region = NULL; | |
778 } | |
779 } | |
780 | |
781 class PostMCRemSetClearClosure: public HeapRegionClosure { | |
782 ModRefBarrierSet* _mr_bs; | |
783 public: | |
784 PostMCRemSetClearClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {} | |
785 bool doHeapRegion(HeapRegion* r) { | |
786 r->reset_gc_time_stamp(); | |
787 if (r->continuesHumongous()) | |
788 return false; | |
789 HeapRegionRemSet* hrrs = r->rem_set(); | |
790 if (hrrs != NULL) hrrs->clear(); | |
791 // You might think here that we could clear just the cards | |
792 // corresponding to the used region. But no: if we leave a dirty card | |
793 // in a region we might allocate into, then it would prevent that card | |
794 // from being enqueued, and cause it to be missed. | |
795 // Re: the performance cost: we shouldn't be doing full GC anyway! | |
796 _mr_bs->clear(MemRegion(r->bottom(), r->end())); | |
797 return false; | |
798 } | |
799 }; | |
800 | |
801 | |
802 class PostMCRemSetInvalidateClosure: public HeapRegionClosure { | |
803 ModRefBarrierSet* _mr_bs; | |
804 public: | |
805 PostMCRemSetInvalidateClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {} | |
806 bool doHeapRegion(HeapRegion* r) { | |
807 if (r->continuesHumongous()) return false; | |
808 if (r->used_region().word_size() != 0) { | |
809 _mr_bs->invalidate(r->used_region(), true /*whole heap*/); | |
810 } | |
811 return false; | |
812 } | |
813 }; | |
814 | |
815 void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs, | |
816 size_t word_size) { | |
817 ResourceMark rm; | |
818 | |
819 if (full && DisableExplicitGC) { | |
820 gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n"); | |
821 return; | |
822 } | |
823 | |
824 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
825 assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread"); | |
826 | |
827 if (GC_locker::is_active()) { | |
828 return; // GC is disabled (e.g. JNI GetXXXCritical operation) | |
829 } | |
830 | |
831 { | |
832 IsGCActiveMark x; | |
833 | |
834 // Timing | |
835 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
836 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
837 TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty); | |
838 | |
839 double start = os::elapsedTime(); | |
840 GCOverheadReporter::recordSTWStart(start); | |
841 g1_policy()->record_full_collection_start(); | |
842 | |
843 gc_prologue(true); | |
844 increment_total_collections(); | |
845 | |
846 size_t g1h_prev_used = used(); | |
847 assert(used() == recalculate_used(), "Should be equal"); | |
848 | |
849 if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) { | |
850 HandleMark hm; // Discard invalid handles created during verification | |
851 prepare_for_verify(); | |
852 gclog_or_tty->print(" VerifyBeforeGC:"); | |
853 Universe::verify(true); | |
854 } | |
855 assert(regions_accounted_for(), "Region leakage!"); | |
856 | |
857 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
858 | |
859 // We want to discover references, but not process them yet. | |
860 // This mode is disabled in | |
861 // instanceRefKlass::process_discovered_references if the | |
862 // generation does some collection work, or | |
863 // instanceRefKlass::enqueue_discovered_references if the | |
864 // generation returns without doing any work. | |
865 ref_processor()->disable_discovery(); | |
866 ref_processor()->abandon_partial_discovery(); | |
867 ref_processor()->verify_no_references_recorded(); | |
868 | |
869 // Abandon current iterations of concurrent marking and concurrent | |
870 // refinement, if any are in progress. | |
871 concurrent_mark()->abort(); | |
872 | |
873 // Make sure we'll choose a new allocation region afterwards. | |
874 abandon_cur_alloc_region(); | |
875 assert(_cur_alloc_region == NULL, "Invariant."); | |
876 g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS(); | |
877 tear_down_region_lists(); | |
878 set_used_regions_to_need_zero_fill(); | |
879 if (g1_policy()->in_young_gc_mode()) { | |
880 empty_young_list(); | |
881 g1_policy()->set_full_young_gcs(true); | |
882 } | |
883 | |
884 // Temporarily make reference _discovery_ single threaded (non-MT). | |
885 ReferenceProcessorMTMutator rp_disc_ser(ref_processor(), false); | |
886 | |
887 // Temporarily make refs discovery atomic | |
888 ReferenceProcessorAtomicMutator rp_disc_atomic(ref_processor(), true); | |
889 | |
890 // Temporarily clear _is_alive_non_header | |
891 ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL); | |
892 | |
893 ref_processor()->enable_discovery(); | |
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894 ref_processor()->setup_policy(clear_all_soft_refs); |
342 | 895 |
896 // Do collection work | |
897 { | |
898 HandleMark hm; // Discard invalid handles created during gc | |
899 G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs); | |
900 } | |
901 // Because freeing humongous regions may have added some unclean | |
902 // regions, it is necessary to tear down again before rebuilding. | |
903 tear_down_region_lists(); | |
904 rebuild_region_lists(); | |
905 | |
906 _summary_bytes_used = recalculate_used(); | |
907 | |
908 ref_processor()->enqueue_discovered_references(); | |
909 | |
910 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
911 | |
912 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) { | |
913 HandleMark hm; // Discard invalid handles created during verification | |
914 gclog_or_tty->print(" VerifyAfterGC:"); | |
915 Universe::verify(false); | |
916 } | |
917 NOT_PRODUCT(ref_processor()->verify_no_references_recorded()); | |
918 | |
919 reset_gc_time_stamp(); | |
920 // Since everything potentially moved, we will clear all remembered | |
921 // sets, and clear all cards. Later we will also cards in the used | |
922 // portion of the heap after the resizing (which could be a shrinking.) | |
923 // We will also reset the GC time stamps of the regions. | |
924 PostMCRemSetClearClosure rs_clear(mr_bs()); | |
925 heap_region_iterate(&rs_clear); | |
926 | |
927 // Resize the heap if necessary. | |
928 resize_if_necessary_after_full_collection(full ? 0 : word_size); | |
929 | |
930 // Since everything potentially moved, we will clear all remembered | |
931 // sets, but also dirty all cards corresponding to used regions. | |
932 PostMCRemSetInvalidateClosure rs_invalidate(mr_bs()); | |
933 heap_region_iterate(&rs_invalidate); | |
934 if (_cg1r->use_cache()) { | |
935 _cg1r->clear_and_record_card_counts(); | |
936 _cg1r->clear_hot_cache(); | |
937 } | |
938 | |
939 if (PrintGC) { | |
940 print_size_transition(gclog_or_tty, g1h_prev_used, used(), capacity()); | |
941 } | |
942 | |
943 if (true) { // FIXME | |
944 // Ask the permanent generation to adjust size for full collections | |
945 perm()->compute_new_size(); | |
946 } | |
947 | |
948 double end = os::elapsedTime(); | |
949 GCOverheadReporter::recordSTWEnd(end); | |
950 g1_policy()->record_full_collection_end(); | |
951 | |
546
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952 #ifdef TRACESPINNING |
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953 ParallelTaskTerminator::print_termination_counts(); |
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954 #endif |
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955 |
342 | 956 gc_epilogue(true); |
957 | |
958 // Abandon concurrent refinement. This must happen last: in the | |
959 // dirty-card logging system, some cards may be dirty by weak-ref | |
960 // processing, and may be enqueued. But the whole card table is | |
961 // dirtied, so this should abandon those logs, and set "do_traversal" | |
962 // to true. | |
963 concurrent_g1_refine()->set_pya_restart(); | |
964 | |
965 assert(regions_accounted_for(), "Region leakage!"); | |
966 } | |
967 | |
968 if (g1_policy()->in_young_gc_mode()) { | |
969 _young_list->reset_sampled_info(); | |
970 assert( check_young_list_empty(false, false), | |
971 "young list should be empty at this point"); | |
972 } | |
973 } | |
974 | |
975 void G1CollectedHeap::do_full_collection(bool clear_all_soft_refs) { | |
976 do_collection(true, clear_all_soft_refs, 0); | |
977 } | |
978 | |
979 // This code is mostly copied from TenuredGeneration. | |
980 void | |
981 G1CollectedHeap:: | |
982 resize_if_necessary_after_full_collection(size_t word_size) { | |
983 assert(MinHeapFreeRatio <= MaxHeapFreeRatio, "sanity check"); | |
984 | |
985 // Include the current allocation, if any, and bytes that will be | |
986 // pre-allocated to support collections, as "used". | |
987 const size_t used_after_gc = used(); | |
988 const size_t capacity_after_gc = capacity(); | |
989 const size_t free_after_gc = capacity_after_gc - used_after_gc; | |
990 | |
991 // We don't have floating point command-line arguments | |
992 const double minimum_free_percentage = (double) MinHeapFreeRatio / 100; | |
993 const double maximum_used_percentage = 1.0 - minimum_free_percentage; | |
994 const double maximum_free_percentage = (double) MaxHeapFreeRatio / 100; | |
995 const double minimum_used_percentage = 1.0 - maximum_free_percentage; | |
996 | |
997 size_t minimum_desired_capacity = (size_t) (used_after_gc / maximum_used_percentage); | |
998 size_t maximum_desired_capacity = (size_t) (used_after_gc / minimum_used_percentage); | |
999 | |
1000 // Don't shrink less than the initial size. | |
1001 minimum_desired_capacity = | |
1002 MAX2(minimum_desired_capacity, | |
1003 collector_policy()->initial_heap_byte_size()); | |
1004 maximum_desired_capacity = | |
1005 MAX2(maximum_desired_capacity, | |
1006 collector_policy()->initial_heap_byte_size()); | |
1007 | |
1008 // We are failing here because minimum_desired_capacity is | |
1009 assert(used_after_gc <= minimum_desired_capacity, "sanity check"); | |
1010 assert(minimum_desired_capacity <= maximum_desired_capacity, "sanity check"); | |
1011 | |
1012 if (PrintGC && Verbose) { | |
1013 const double free_percentage = ((double)free_after_gc) / capacity(); | |
1014 gclog_or_tty->print_cr("Computing new size after full GC "); | |
1015 gclog_or_tty->print_cr(" " | |
1016 " minimum_free_percentage: %6.2f", | |
1017 minimum_free_percentage); | |
1018 gclog_or_tty->print_cr(" " | |
1019 " maximum_free_percentage: %6.2f", | |
1020 maximum_free_percentage); | |
1021 gclog_or_tty->print_cr(" " | |
1022 " capacity: %6.1fK" | |
1023 " minimum_desired_capacity: %6.1fK" | |
1024 " maximum_desired_capacity: %6.1fK", | |
1025 capacity() / (double) K, | |
1026 minimum_desired_capacity / (double) K, | |
1027 maximum_desired_capacity / (double) K); | |
1028 gclog_or_tty->print_cr(" " | |
1029 " free_after_gc : %6.1fK" | |
1030 " used_after_gc : %6.1fK", | |
1031 free_after_gc / (double) K, | |
1032 used_after_gc / (double) K); | |
1033 gclog_or_tty->print_cr(" " | |
1034 " free_percentage: %6.2f", | |
1035 free_percentage); | |
1036 } | |
1037 if (capacity() < minimum_desired_capacity) { | |
1038 // Don't expand unless it's significant | |
1039 size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; | |
1040 expand(expand_bytes); | |
1041 if (PrintGC && Verbose) { | |
1042 gclog_or_tty->print_cr(" expanding:" | |
1043 " minimum_desired_capacity: %6.1fK" | |
1044 " expand_bytes: %6.1fK", | |
1045 minimum_desired_capacity / (double) K, | |
1046 expand_bytes / (double) K); | |
1047 } | |
1048 | |
1049 // No expansion, now see if we want to shrink | |
1050 } else if (capacity() > maximum_desired_capacity) { | |
1051 // Capacity too large, compute shrinking size | |
1052 size_t shrink_bytes = capacity_after_gc - maximum_desired_capacity; | |
1053 shrink(shrink_bytes); | |
1054 if (PrintGC && Verbose) { | |
1055 gclog_or_tty->print_cr(" " | |
1056 " shrinking:" | |
1057 " initSize: %.1fK" | |
1058 " maximum_desired_capacity: %.1fK", | |
1059 collector_policy()->initial_heap_byte_size() / (double) K, | |
1060 maximum_desired_capacity / (double) K); | |
1061 gclog_or_tty->print_cr(" " | |
1062 " shrink_bytes: %.1fK", | |
1063 shrink_bytes / (double) K); | |
1064 } | |
1065 } | |
1066 } | |
1067 | |
1068 | |
1069 HeapWord* | |
1070 G1CollectedHeap::satisfy_failed_allocation(size_t word_size) { | |
1071 HeapWord* result = NULL; | |
1072 | |
1073 // In a G1 heap, we're supposed to keep allocation from failing by | |
1074 // incremental pauses. Therefore, at least for now, we'll favor | |
1075 // expansion over collection. (This might change in the future if we can | |
1076 // do something smarter than full collection to satisfy a failed alloc.) | |
1077 | |
1078 result = expand_and_allocate(word_size); | |
1079 if (result != NULL) { | |
1080 assert(is_in(result), "result not in heap"); | |
1081 return result; | |
1082 } | |
1083 | |
1084 // OK, I guess we have to try collection. | |
1085 | |
1086 do_collection(false, false, word_size); | |
1087 | |
1088 result = attempt_allocation(word_size, /*permit_collection_pause*/false); | |
1089 | |
1090 if (result != NULL) { | |
1091 assert(is_in(result), "result not in heap"); | |
1092 return result; | |
1093 } | |
1094 | |
1095 // Try collecting soft references. | |
1096 do_collection(false, true, word_size); | |
1097 result = attempt_allocation(word_size, /*permit_collection_pause*/false); | |
1098 if (result != NULL) { | |
1099 assert(is_in(result), "result not in heap"); | |
1100 return result; | |
1101 } | |
1102 | |
1103 // What else? We might try synchronous finalization later. If the total | |
1104 // space available is large enough for the allocation, then a more | |
1105 // complete compaction phase than we've tried so far might be | |
1106 // appropriate. | |
1107 return NULL; | |
1108 } | |
1109 | |
1110 // Attempting to expand the heap sufficiently | |
1111 // to support an allocation of the given "word_size". If | |
1112 // successful, perform the allocation and return the address of the | |
1113 // allocated block, or else "NULL". | |
1114 | |
1115 HeapWord* G1CollectedHeap::expand_and_allocate(size_t word_size) { | |
1116 size_t expand_bytes = word_size * HeapWordSize; | |
1117 if (expand_bytes < MinHeapDeltaBytes) { | |
1118 expand_bytes = MinHeapDeltaBytes; | |
1119 } | |
1120 expand(expand_bytes); | |
1121 assert(regions_accounted_for(), "Region leakage!"); | |
1122 HeapWord* result = attempt_allocation(word_size, false /* permit_collection_pause */); | |
1123 return result; | |
1124 } | |
1125 | |
1126 size_t G1CollectedHeap::free_region_if_totally_empty(HeapRegion* hr) { | |
1127 size_t pre_used = 0; | |
1128 size_t cleared_h_regions = 0; | |
1129 size_t freed_regions = 0; | |
1130 UncleanRegionList local_list; | |
1131 free_region_if_totally_empty_work(hr, pre_used, cleared_h_regions, | |
1132 freed_regions, &local_list); | |
1133 | |
1134 finish_free_region_work(pre_used, cleared_h_regions, freed_regions, | |
1135 &local_list); | |
1136 return pre_used; | |
1137 } | |
1138 | |
1139 void | |
1140 G1CollectedHeap::free_region_if_totally_empty_work(HeapRegion* hr, | |
1141 size_t& pre_used, | |
1142 size_t& cleared_h, | |
1143 size_t& freed_regions, | |
1144 UncleanRegionList* list, | |
1145 bool par) { | |
1146 assert(!hr->continuesHumongous(), "should have filtered these out"); | |
1147 size_t res = 0; | |
1148 if (!hr->popular() && hr->used() > 0 && hr->garbage_bytes() == hr->used()) { | |
1149 if (!hr->is_young()) { | |
1150 if (G1PolicyVerbose > 0) | |
1151 gclog_or_tty->print_cr("Freeing empty region "PTR_FORMAT "(" SIZE_FORMAT " bytes)" | |
1152 " during cleanup", hr, hr->used()); | |
1153 free_region_work(hr, pre_used, cleared_h, freed_regions, list, par); | |
1154 } | |
1155 } | |
1156 } | |
1157 | |
1158 // FIXME: both this and shrink could probably be more efficient by | |
1159 // doing one "VirtualSpace::expand_by" call rather than several. | |
1160 void G1CollectedHeap::expand(size_t expand_bytes) { | |
1161 size_t old_mem_size = _g1_storage.committed_size(); | |
1162 // We expand by a minimum of 1K. | |
1163 expand_bytes = MAX2(expand_bytes, (size_t)K); | |
1164 size_t aligned_expand_bytes = | |
1165 ReservedSpace::page_align_size_up(expand_bytes); | |
1166 aligned_expand_bytes = align_size_up(aligned_expand_bytes, | |
1167 HeapRegion::GrainBytes); | |
1168 expand_bytes = aligned_expand_bytes; | |
1169 while (expand_bytes > 0) { | |
1170 HeapWord* base = (HeapWord*)_g1_storage.high(); | |
1171 // Commit more storage. | |
1172 bool successful = _g1_storage.expand_by(HeapRegion::GrainBytes); | |
1173 if (!successful) { | |
1174 expand_bytes = 0; | |
1175 } else { | |
1176 expand_bytes -= HeapRegion::GrainBytes; | |
1177 // Expand the committed region. | |
1178 HeapWord* high = (HeapWord*) _g1_storage.high(); | |
1179 _g1_committed.set_end(high); | |
1180 // Create a new HeapRegion. | |
1181 MemRegion mr(base, high); | |
1182 bool is_zeroed = !_g1_max_committed.contains(base); | |
1183 HeapRegion* hr = new HeapRegion(_bot_shared, mr, is_zeroed); | |
1184 | |
1185 // Now update max_committed if necessary. | |
1186 _g1_max_committed.set_end(MAX2(_g1_max_committed.end(), high)); | |
1187 | |
1188 // Add it to the HeapRegionSeq. | |
1189 _hrs->insert(hr); | |
1190 // Set the zero-fill state, according to whether it's already | |
1191 // zeroed. | |
1192 { | |
1193 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
1194 if (is_zeroed) { | |
1195 hr->set_zero_fill_complete(); | |
1196 put_free_region_on_list_locked(hr); | |
1197 } else { | |
1198 hr->set_zero_fill_needed(); | |
1199 put_region_on_unclean_list_locked(hr); | |
1200 } | |
1201 } | |
1202 _free_regions++; | |
1203 // And we used up an expansion region to create it. | |
1204 _expansion_regions--; | |
1205 // Tell the cardtable about it. | |
1206 Universe::heap()->barrier_set()->resize_covered_region(_g1_committed); | |
1207 // And the offset table as well. | |
1208 _bot_shared->resize(_g1_committed.word_size()); | |
1209 } | |
1210 } | |
1211 if (Verbose && PrintGC) { | |
1212 size_t new_mem_size = _g1_storage.committed_size(); | |
1213 gclog_or_tty->print_cr("Expanding garbage-first heap from %ldK by %ldK to %ldK", | |
1214 old_mem_size/K, aligned_expand_bytes/K, | |
1215 new_mem_size/K); | |
1216 } | |
1217 } | |
1218 | |
1219 void G1CollectedHeap::shrink_helper(size_t shrink_bytes) | |
1220 { | |
1221 size_t old_mem_size = _g1_storage.committed_size(); | |
1222 size_t aligned_shrink_bytes = | |
1223 ReservedSpace::page_align_size_down(shrink_bytes); | |
1224 aligned_shrink_bytes = align_size_down(aligned_shrink_bytes, | |
1225 HeapRegion::GrainBytes); | |
1226 size_t num_regions_deleted = 0; | |
1227 MemRegion mr = _hrs->shrink_by(aligned_shrink_bytes, num_regions_deleted); | |
1228 | |
1229 assert(mr.end() == (HeapWord*)_g1_storage.high(), "Bad shrink!"); | |
1230 if (mr.byte_size() > 0) | |
1231 _g1_storage.shrink_by(mr.byte_size()); | |
1232 assert(mr.start() == (HeapWord*)_g1_storage.high(), "Bad shrink!"); | |
1233 | |
1234 _g1_committed.set_end(mr.start()); | |
1235 _free_regions -= num_regions_deleted; | |
1236 _expansion_regions += num_regions_deleted; | |
1237 | |
1238 // Tell the cardtable about it. | |
1239 Universe::heap()->barrier_set()->resize_covered_region(_g1_committed); | |
1240 | |
1241 // And the offset table as well. | |
1242 _bot_shared->resize(_g1_committed.word_size()); | |
1243 | |
1244 HeapRegionRemSet::shrink_heap(n_regions()); | |
1245 | |
1246 if (Verbose && PrintGC) { | |
1247 size_t new_mem_size = _g1_storage.committed_size(); | |
1248 gclog_or_tty->print_cr("Shrinking garbage-first heap from %ldK by %ldK to %ldK", | |
1249 old_mem_size/K, aligned_shrink_bytes/K, | |
1250 new_mem_size/K); | |
1251 } | |
1252 } | |
1253 | |
1254 void G1CollectedHeap::shrink(size_t shrink_bytes) { | |
1255 release_gc_alloc_regions(); | |
1256 tear_down_region_lists(); // We will rebuild them in a moment. | |
1257 shrink_helper(shrink_bytes); | |
1258 rebuild_region_lists(); | |
1259 } | |
1260 | |
1261 // Public methods. | |
1262 | |
1263 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away | |
1264 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list | |
1265 #endif // _MSC_VER | |
1266 | |
1267 | |
1268 G1CollectedHeap::G1CollectedHeap(G1CollectorPolicy* policy_) : | |
1269 SharedHeap(policy_), | |
1270 _g1_policy(policy_), | |
1271 _ref_processor(NULL), | |
1272 _process_strong_tasks(new SubTasksDone(G1H_PS_NumElements)), | |
1273 _bot_shared(NULL), | |
1274 _par_alloc_during_gc_lock(Mutex::leaf, "par alloc during GC lock"), | |
1275 _objs_with_preserved_marks(NULL), _preserved_marks_of_objs(NULL), | |
1276 _evac_failure_scan_stack(NULL) , | |
1277 _mark_in_progress(false), | |
1278 _cg1r(NULL), _czft(NULL), _summary_bytes_used(0), | |
1279 _cur_alloc_region(NULL), | |
1280 _refine_cte_cl(NULL), | |
1281 _free_region_list(NULL), _free_region_list_size(0), | |
1282 _free_regions(0), | |
1283 _popular_object_boundary(NULL), | |
1284 _cur_pop_hr_index(0), | |
1285 _popular_regions_to_be_evacuated(NULL), | |
1286 _pop_obj_rc_at_copy(), | |
1287 _full_collection(false), | |
1288 _unclean_region_list(), | |
1289 _unclean_regions_coming(false), | |
1290 _young_list(new YoungList(this)), | |
1291 _gc_time_stamp(0), | |
526 | 1292 _surviving_young_words(NULL), |
1293 _in_cset_fast_test(NULL), | |
1294 _in_cset_fast_test_base(NULL) | |
342 | 1295 { |
1296 _g1h = this; // To catch bugs. | |
1297 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) { | |
1298 vm_exit_during_initialization("Failed necessary allocation."); | |
1299 } | |
1300 int n_queues = MAX2((int)ParallelGCThreads, 1); | |
1301 _task_queues = new RefToScanQueueSet(n_queues); | |
1302 | |
1303 int n_rem_sets = HeapRegionRemSet::num_par_rem_sets(); | |
1304 assert(n_rem_sets > 0, "Invariant."); | |
1305 | |
1306 HeapRegionRemSetIterator** iter_arr = | |
1307 NEW_C_HEAP_ARRAY(HeapRegionRemSetIterator*, n_queues); | |
1308 for (int i = 0; i < n_queues; i++) { | |
1309 iter_arr[i] = new HeapRegionRemSetIterator(); | |
1310 } | |
1311 _rem_set_iterator = iter_arr; | |
1312 | |
1313 for (int i = 0; i < n_queues; i++) { | |
1314 RefToScanQueue* q = new RefToScanQueue(); | |
1315 q->initialize(); | |
1316 _task_queues->register_queue(i, q); | |
1317 } | |
1318 | |
1319 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
1320 _gc_alloc_regions[ap] = NULL; | |
1321 _gc_alloc_region_counts[ap] = 0; | |
1322 } | |
1323 guarantee(_task_queues != NULL, "task_queues allocation failure."); | |
1324 } | |
1325 | |
1326 jint G1CollectedHeap::initialize() { | |
1327 os::enable_vtime(); | |
1328 | |
1329 // Necessary to satisfy locking discipline assertions. | |
1330 | |
1331 MutexLocker x(Heap_lock); | |
1332 | |
1333 // While there are no constraints in the GC code that HeapWordSize | |
1334 // be any particular value, there are multiple other areas in the | |
1335 // system which believe this to be true (e.g. oop->object_size in some | |
1336 // cases incorrectly returns the size in wordSize units rather than | |
1337 // HeapWordSize). | |
1338 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize"); | |
1339 | |
1340 size_t init_byte_size = collector_policy()->initial_heap_byte_size(); | |
1341 size_t max_byte_size = collector_policy()->max_heap_byte_size(); | |
1342 | |
1343 // Ensure that the sizes are properly aligned. | |
1344 Universe::check_alignment(init_byte_size, HeapRegion::GrainBytes, "g1 heap"); | |
1345 Universe::check_alignment(max_byte_size, HeapRegion::GrainBytes, "g1 heap"); | |
1346 | |
1347 // We allocate this in any case, but only do no work if the command line | |
1348 // param is off. | |
1349 _cg1r = new ConcurrentG1Refine(); | |
1350 | |
1351 // Reserve the maximum. | |
1352 PermanentGenerationSpec* pgs = collector_policy()->permanent_generation(); | |
1353 // Includes the perm-gen. | |
1354 ReservedSpace heap_rs(max_byte_size + pgs->max_size(), | |
1355 HeapRegion::GrainBytes, | |
1356 false /*ism*/); | |
1357 | |
1358 if (!heap_rs.is_reserved()) { | |
1359 vm_exit_during_initialization("Could not reserve enough space for object heap"); | |
1360 return JNI_ENOMEM; | |
1361 } | |
1362 | |
1363 // It is important to do this in a way such that concurrent readers can't | |
1364 // temporarily think somethings in the heap. (I've actually seen this | |
1365 // happen in asserts: DLD.) | |
1366 _reserved.set_word_size(0); | |
1367 _reserved.set_start((HeapWord*)heap_rs.base()); | |
1368 _reserved.set_end((HeapWord*)(heap_rs.base() + heap_rs.size())); | |
1369 | |
1370 _expansion_regions = max_byte_size/HeapRegion::GrainBytes; | |
1371 | |
1372 _num_humongous_regions = 0; | |
1373 | |
1374 // Create the gen rem set (and barrier set) for the entire reserved region. | |
1375 _rem_set = collector_policy()->create_rem_set(_reserved, 2); | |
1376 set_barrier_set(rem_set()->bs()); | |
1377 if (barrier_set()->is_a(BarrierSet::ModRef)) { | |
1378 _mr_bs = (ModRefBarrierSet*)_barrier_set; | |
1379 } else { | |
1380 vm_exit_during_initialization("G1 requires a mod ref bs."); | |
1381 return JNI_ENOMEM; | |
1382 } | |
1383 | |
1384 // Also create a G1 rem set. | |
1385 if (G1UseHRIntoRS) { | |
1386 if (mr_bs()->is_a(BarrierSet::CardTableModRef)) { | |
1387 _g1_rem_set = new HRInto_G1RemSet(this, (CardTableModRefBS*)mr_bs()); | |
1388 } else { | |
1389 vm_exit_during_initialization("G1 requires a cardtable mod ref bs."); | |
1390 return JNI_ENOMEM; | |
1391 } | |
1392 } else { | |
1393 _g1_rem_set = new StupidG1RemSet(this); | |
1394 } | |
1395 | |
1396 // Carve out the G1 part of the heap. | |
1397 | |
1398 ReservedSpace g1_rs = heap_rs.first_part(max_byte_size); | |
1399 _g1_reserved = MemRegion((HeapWord*)g1_rs.base(), | |
1400 g1_rs.size()/HeapWordSize); | |
1401 ReservedSpace perm_gen_rs = heap_rs.last_part(max_byte_size); | |
1402 | |
1403 _perm_gen = pgs->init(perm_gen_rs, pgs->init_size(), rem_set()); | |
1404 | |
1405 _g1_storage.initialize(g1_rs, 0); | |
1406 _g1_committed = MemRegion((HeapWord*)_g1_storage.low(), (size_t) 0); | |
1407 _g1_max_committed = _g1_committed; | |
393 | 1408 _hrs = new HeapRegionSeq(_expansion_regions); |
342 | 1409 guarantee(_hrs != NULL, "Couldn't allocate HeapRegionSeq"); |
1410 guarantee(_cur_alloc_region == NULL, "from constructor"); | |
1411 | |
1412 _bot_shared = new G1BlockOffsetSharedArray(_reserved, | |
1413 heap_word_size(init_byte_size)); | |
1414 | |
1415 _g1h = this; | |
1416 | |
1417 // Create the ConcurrentMark data structure and thread. | |
1418 // (Must do this late, so that "max_regions" is defined.) | |
1419 _cm = new ConcurrentMark(heap_rs, (int) max_regions()); | |
1420 _cmThread = _cm->cmThread(); | |
1421 | |
1422 // ...and the concurrent zero-fill thread, if necessary. | |
1423 if (G1ConcZeroFill) { | |
1424 _czft = new ConcurrentZFThread(); | |
1425 } | |
1426 | |
1427 | |
1428 | |
1429 // Allocate the popular regions; take them off free lists. | |
1430 size_t pop_byte_size = G1NumPopularRegions * HeapRegion::GrainBytes; | |
1431 expand(pop_byte_size); | |
1432 _popular_object_boundary = | |
1433 _g1_reserved.start() + (G1NumPopularRegions * HeapRegion::GrainWords); | |
1434 for (int i = 0; i < G1NumPopularRegions; i++) { | |
1435 HeapRegion* hr = newAllocRegion(HeapRegion::GrainWords); | |
1436 // assert(hr != NULL && hr->bottom() < _popular_object_boundary, | |
1437 // "Should be enough, and all should be below boundary."); | |
1438 hr->set_popular(true); | |
1439 } | |
1440 assert(_cur_pop_hr_index == 0, "Start allocating at the first region."); | |
1441 | |
1442 // Initialize the from_card cache structure of HeapRegionRemSet. | |
1443 HeapRegionRemSet::init_heap(max_regions()); | |
1444 | |
1445 // Now expand into the rest of the initial heap size. | |
1446 expand(init_byte_size - pop_byte_size); | |
1447 | |
1448 // Perform any initialization actions delegated to the policy. | |
1449 g1_policy()->init(); | |
1450 | |
1451 g1_policy()->note_start_of_mark_thread(); | |
1452 | |
1453 _refine_cte_cl = | |
1454 new RefineCardTableEntryClosure(ConcurrentG1RefineThread::sts(), | |
1455 g1_rem_set(), | |
1456 concurrent_g1_refine()); | |
1457 JavaThread::dirty_card_queue_set().set_closure(_refine_cte_cl); | |
1458 | |
1459 JavaThread::satb_mark_queue_set().initialize(SATB_Q_CBL_mon, | |
1460 SATB_Q_FL_lock, | |
1461 0, | |
1462 Shared_SATB_Q_lock); | |
1463 if (G1RSBarrierUseQueue) { | |
1464 JavaThread::dirty_card_queue_set().initialize(DirtyCardQ_CBL_mon, | |
1465 DirtyCardQ_FL_lock, | |
1466 G1DirtyCardQueueMax, | |
1467 Shared_DirtyCardQ_lock); | |
1468 } | |
1469 // In case we're keeping closure specialization stats, initialize those | |
1470 // counts and that mechanism. | |
1471 SpecializationStats::clear(); | |
1472 | |
1473 _gc_alloc_region_list = NULL; | |
1474 | |
1475 // Do later initialization work for concurrent refinement. | |
1476 _cg1r->init(); | |
1477 | |
1478 const char* group_names[] = { "CR", "ZF", "CM", "CL" }; | |
1479 GCOverheadReporter::initGCOverheadReporter(4, group_names); | |
1480 | |
1481 return JNI_OK; | |
1482 } | |
1483 | |
1484 void G1CollectedHeap::ref_processing_init() { | |
1485 SharedHeap::ref_processing_init(); | |
1486 MemRegion mr = reserved_region(); | |
1487 _ref_processor = ReferenceProcessor::create_ref_processor( | |
1488 mr, // span | |
1489 false, // Reference discovery is not atomic | |
1490 // (though it shouldn't matter here.) | |
1491 true, // mt_discovery | |
1492 NULL, // is alive closure: need to fill this in for efficiency | |
1493 ParallelGCThreads, | |
1494 ParallelRefProcEnabled, | |
1495 true); // Setting next fields of discovered | |
1496 // lists requires a barrier. | |
1497 } | |
1498 | |
1499 size_t G1CollectedHeap::capacity() const { | |
1500 return _g1_committed.byte_size(); | |
1501 } | |
1502 | |
1503 void G1CollectedHeap::iterate_dirty_card_closure(bool concurrent, | |
1504 int worker_i) { | |
1505 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
1506 int n_completed_buffers = 0; | |
1507 while (dcqs.apply_closure_to_completed_buffer(worker_i, 0, true)) { | |
1508 n_completed_buffers++; | |
1509 } | |
1510 g1_policy()->record_update_rs_processed_buffers(worker_i, | |
1511 (double) n_completed_buffers); | |
1512 dcqs.clear_n_completed_buffers(); | |
1513 // Finish up the queue... | |
1514 if (worker_i == 0) concurrent_g1_refine()->clean_up_cache(worker_i, | |
1515 g1_rem_set()); | |
1516 assert(!dcqs.completed_buffers_exist_dirty(), "Completed buffers exist!"); | |
1517 } | |
1518 | |
1519 | |
1520 // Computes the sum of the storage used by the various regions. | |
1521 | |
1522 size_t G1CollectedHeap::used() const { | |
1523 assert(Heap_lock->owner() != NULL, | |
1524 "Should be owned on this thread's behalf."); | |
1525 size_t result = _summary_bytes_used; | |
1526 if (_cur_alloc_region != NULL) | |
1527 result += _cur_alloc_region->used(); | |
1528 return result; | |
1529 } | |
1530 | |
1531 class SumUsedClosure: public HeapRegionClosure { | |
1532 size_t _used; | |
1533 public: | |
1534 SumUsedClosure() : _used(0) {} | |
1535 bool doHeapRegion(HeapRegion* r) { | |
1536 if (!r->continuesHumongous()) { | |
1537 _used += r->used(); | |
1538 } | |
1539 return false; | |
1540 } | |
1541 size_t result() { return _used; } | |
1542 }; | |
1543 | |
1544 size_t G1CollectedHeap::recalculate_used() const { | |
1545 SumUsedClosure blk; | |
1546 _hrs->iterate(&blk); | |
1547 return blk.result(); | |
1548 } | |
1549 | |
1550 #ifndef PRODUCT | |
1551 class SumUsedRegionsClosure: public HeapRegionClosure { | |
1552 size_t _num; | |
1553 public: | |
1554 // _num is set to 1 to account for the popular region | |
1555 SumUsedRegionsClosure() : _num(G1NumPopularRegions) {} | |
1556 bool doHeapRegion(HeapRegion* r) { | |
1557 if (r->continuesHumongous() || r->used() > 0 || r->is_gc_alloc_region()) { | |
1558 _num += 1; | |
1559 } | |
1560 return false; | |
1561 } | |
1562 size_t result() { return _num; } | |
1563 }; | |
1564 | |
1565 size_t G1CollectedHeap::recalculate_used_regions() const { | |
1566 SumUsedRegionsClosure blk; | |
1567 _hrs->iterate(&blk); | |
1568 return blk.result(); | |
1569 } | |
1570 #endif // PRODUCT | |
1571 | |
1572 size_t G1CollectedHeap::unsafe_max_alloc() { | |
1573 if (_free_regions > 0) return HeapRegion::GrainBytes; | |
1574 // otherwise, is there space in the current allocation region? | |
1575 | |
1576 // We need to store the current allocation region in a local variable | |
1577 // here. The problem is that this method doesn't take any locks and | |
1578 // there may be other threads which overwrite the current allocation | |
1579 // region field. attempt_allocation(), for example, sets it to NULL | |
1580 // and this can happen *after* the NULL check here but before the call | |
1581 // to free(), resulting in a SIGSEGV. Note that this doesn't appear | |
1582 // to be a problem in the optimized build, since the two loads of the | |
1583 // current allocation region field are optimized away. | |
1584 HeapRegion* car = _cur_alloc_region; | |
1585 | |
1586 // FIXME: should iterate over all regions? | |
1587 if (car == NULL) { | |
1588 return 0; | |
1589 } | |
1590 return car->free(); | |
1591 } | |
1592 | |
1593 void G1CollectedHeap::collect(GCCause::Cause cause) { | |
1594 // The caller doesn't have the Heap_lock | |
1595 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
1596 MutexLocker ml(Heap_lock); | |
1597 collect_locked(cause); | |
1598 } | |
1599 | |
1600 void G1CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) { | |
1601 assert(Thread::current()->is_VM_thread(), "Precondition#1"); | |
1602 assert(Heap_lock->is_locked(), "Precondition#2"); | |
1603 GCCauseSetter gcs(this, cause); | |
1604 switch (cause) { | |
1605 case GCCause::_heap_inspection: | |
1606 case GCCause::_heap_dump: { | |
1607 HandleMark hm; | |
1608 do_full_collection(false); // don't clear all soft refs | |
1609 break; | |
1610 } | |
1611 default: // XXX FIX ME | |
1612 ShouldNotReachHere(); // Unexpected use of this function | |
1613 } | |
1614 } | |
1615 | |
1616 | |
1617 void G1CollectedHeap::collect_locked(GCCause::Cause cause) { | |
1618 // Don't want to do a GC until cleanup is completed. | |
1619 wait_for_cleanup_complete(); | |
1620 | |
1621 // Read the GC count while holding the Heap_lock | |
1622 int gc_count_before = SharedHeap::heap()->total_collections(); | |
1623 { | |
1624 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
1625 VM_G1CollectFull op(gc_count_before, cause); | |
1626 VMThread::execute(&op); | |
1627 } | |
1628 } | |
1629 | |
1630 bool G1CollectedHeap::is_in(const void* p) const { | |
1631 if (_g1_committed.contains(p)) { | |
1632 HeapRegion* hr = _hrs->addr_to_region(p); | |
1633 return hr->is_in(p); | |
1634 } else { | |
1635 return _perm_gen->as_gen()->is_in(p); | |
1636 } | |
1637 } | |
1638 | |
1639 // Iteration functions. | |
1640 | |
1641 // Iterates an OopClosure over all ref-containing fields of objects | |
1642 // within a HeapRegion. | |
1643 | |
1644 class IterateOopClosureRegionClosure: public HeapRegionClosure { | |
1645 MemRegion _mr; | |
1646 OopClosure* _cl; | |
1647 public: | |
1648 IterateOopClosureRegionClosure(MemRegion mr, OopClosure* cl) | |
1649 : _mr(mr), _cl(cl) {} | |
1650 bool doHeapRegion(HeapRegion* r) { | |
1651 if (! r->continuesHumongous()) { | |
1652 r->oop_iterate(_cl); | |
1653 } | |
1654 return false; | |
1655 } | |
1656 }; | |
1657 | |
1658 void G1CollectedHeap::oop_iterate(OopClosure* cl) { | |
1659 IterateOopClosureRegionClosure blk(_g1_committed, cl); | |
1660 _hrs->iterate(&blk); | |
1661 } | |
1662 | |
1663 void G1CollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) { | |
1664 IterateOopClosureRegionClosure blk(mr, cl); | |
1665 _hrs->iterate(&blk); | |
1666 } | |
1667 | |
1668 // Iterates an ObjectClosure over all objects within a HeapRegion. | |
1669 | |
1670 class IterateObjectClosureRegionClosure: public HeapRegionClosure { | |
1671 ObjectClosure* _cl; | |
1672 public: | |
1673 IterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {} | |
1674 bool doHeapRegion(HeapRegion* r) { | |
1675 if (! r->continuesHumongous()) { | |
1676 r->object_iterate(_cl); | |
1677 } | |
1678 return false; | |
1679 } | |
1680 }; | |
1681 | |
1682 void G1CollectedHeap::object_iterate(ObjectClosure* cl) { | |
1683 IterateObjectClosureRegionClosure blk(cl); | |
1684 _hrs->iterate(&blk); | |
1685 } | |
1686 | |
1687 void G1CollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) { | |
1688 // FIXME: is this right? | |
1689 guarantee(false, "object_iterate_since_last_GC not supported by G1 heap"); | |
1690 } | |
1691 | |
1692 // Calls a SpaceClosure on a HeapRegion. | |
1693 | |
1694 class SpaceClosureRegionClosure: public HeapRegionClosure { | |
1695 SpaceClosure* _cl; | |
1696 public: | |
1697 SpaceClosureRegionClosure(SpaceClosure* cl) : _cl(cl) {} | |
1698 bool doHeapRegion(HeapRegion* r) { | |
1699 _cl->do_space(r); | |
1700 return false; | |
1701 } | |
1702 }; | |
1703 | |
1704 void G1CollectedHeap::space_iterate(SpaceClosure* cl) { | |
1705 SpaceClosureRegionClosure blk(cl); | |
1706 _hrs->iterate(&blk); | |
1707 } | |
1708 | |
1709 void G1CollectedHeap::heap_region_iterate(HeapRegionClosure* cl) { | |
1710 _hrs->iterate(cl); | |
1711 } | |
1712 | |
1713 void G1CollectedHeap::heap_region_iterate_from(HeapRegion* r, | |
1714 HeapRegionClosure* cl) { | |
1715 _hrs->iterate_from(r, cl); | |
1716 } | |
1717 | |
1718 void | |
1719 G1CollectedHeap::heap_region_iterate_from(int idx, HeapRegionClosure* cl) { | |
1720 _hrs->iterate_from(idx, cl); | |
1721 } | |
1722 | |
1723 HeapRegion* G1CollectedHeap::region_at(size_t idx) { return _hrs->at(idx); } | |
1724 | |
1725 void | |
1726 G1CollectedHeap::heap_region_par_iterate_chunked(HeapRegionClosure* cl, | |
1727 int worker, | |
1728 jint claim_value) { | |
355 | 1729 const size_t regions = n_regions(); |
1730 const size_t worker_num = (ParallelGCThreads > 0 ? ParallelGCThreads : 1); | |
1731 // try to spread out the starting points of the workers | |
1732 const size_t start_index = regions / worker_num * (size_t) worker; | |
1733 | |
1734 // each worker will actually look at all regions | |
1735 for (size_t count = 0; count < regions; ++count) { | |
1736 const size_t index = (start_index + count) % regions; | |
1737 assert(0 <= index && index < regions, "sanity"); | |
1738 HeapRegion* r = region_at(index); | |
1739 // we'll ignore "continues humongous" regions (we'll process them | |
1740 // when we come across their corresponding "start humongous" | |
1741 // region) and regions already claimed | |
1742 if (r->claim_value() == claim_value || r->continuesHumongous()) { | |
1743 continue; | |
1744 } | |
1745 // OK, try to claim it | |
342 | 1746 if (r->claimHeapRegion(claim_value)) { |
355 | 1747 // success! |
1748 assert(!r->continuesHumongous(), "sanity"); | |
1749 if (r->startsHumongous()) { | |
1750 // If the region is "starts humongous" we'll iterate over its | |
1751 // "continues humongous" first; in fact we'll do them | |
1752 // first. The order is important. In on case, calling the | |
1753 // closure on the "starts humongous" region might de-allocate | |
1754 // and clear all its "continues humongous" regions and, as a | |
1755 // result, we might end up processing them twice. So, we'll do | |
1756 // them first (notice: most closures will ignore them anyway) and | |
1757 // then we'll do the "starts humongous" region. | |
1758 for (size_t ch_index = index + 1; ch_index < regions; ++ch_index) { | |
1759 HeapRegion* chr = region_at(ch_index); | |
1760 | |
1761 // if the region has already been claimed or it's not | |
1762 // "continues humongous" we're done | |
1763 if (chr->claim_value() == claim_value || | |
1764 !chr->continuesHumongous()) { | |
1765 break; | |
1766 } | |
1767 | |
1768 // Noone should have claimed it directly. We can given | |
1769 // that we claimed its "starts humongous" region. | |
1770 assert(chr->claim_value() != claim_value, "sanity"); | |
1771 assert(chr->humongous_start_region() == r, "sanity"); | |
1772 | |
1773 if (chr->claimHeapRegion(claim_value)) { | |
1774 // we should always be able to claim it; noone else should | |
1775 // be trying to claim this region | |
1776 | |
1777 bool res2 = cl->doHeapRegion(chr); | |
1778 assert(!res2, "Should not abort"); | |
1779 | |
1780 // Right now, this holds (i.e., no closure that actually | |
1781 // does something with "continues humongous" regions | |
1782 // clears them). We might have to weaken it in the future, | |
1783 // but let's leave these two asserts here for extra safety. | |
1784 assert(chr->continuesHumongous(), "should still be the case"); | |
1785 assert(chr->humongous_start_region() == r, "sanity"); | |
1786 } else { | |
1787 guarantee(false, "we should not reach here"); | |
1788 } | |
1789 } | |
1790 } | |
1791 | |
1792 assert(!r->continuesHumongous(), "sanity"); | |
1793 bool res = cl->doHeapRegion(r); | |
1794 assert(!res, "Should not abort"); | |
1795 } | |
1796 } | |
1797 } | |
1798 | |
390 | 1799 class ResetClaimValuesClosure: public HeapRegionClosure { |
1800 public: | |
1801 bool doHeapRegion(HeapRegion* r) { | |
1802 r->set_claim_value(HeapRegion::InitialClaimValue); | |
1803 return false; | |
1804 } | |
1805 }; | |
1806 | |
1807 void | |
1808 G1CollectedHeap::reset_heap_region_claim_values() { | |
1809 ResetClaimValuesClosure blk; | |
1810 heap_region_iterate(&blk); | |
1811 } | |
1812 | |
355 | 1813 #ifdef ASSERT |
1814 // This checks whether all regions in the heap have the correct claim | |
1815 // value. I also piggy-backed on this a check to ensure that the | |
1816 // humongous_start_region() information on "continues humongous" | |
1817 // regions is correct. | |
1818 | |
1819 class CheckClaimValuesClosure : public HeapRegionClosure { | |
1820 private: | |
1821 jint _claim_value; | |
1822 size_t _failures; | |
1823 HeapRegion* _sh_region; | |
1824 public: | |
1825 CheckClaimValuesClosure(jint claim_value) : | |
1826 _claim_value(claim_value), _failures(0), _sh_region(NULL) { } | |
1827 bool doHeapRegion(HeapRegion* r) { | |
1828 if (r->claim_value() != _claim_value) { | |
1829 gclog_or_tty->print_cr("Region ["PTR_FORMAT","PTR_FORMAT"), " | |
1830 "claim value = %d, should be %d", | |
1831 r->bottom(), r->end(), r->claim_value(), | |
1832 _claim_value); | |
1833 ++_failures; | |
1834 } | |
1835 if (!r->isHumongous()) { | |
1836 _sh_region = NULL; | |
1837 } else if (r->startsHumongous()) { | |
1838 _sh_region = r; | |
1839 } else if (r->continuesHumongous()) { | |
1840 if (r->humongous_start_region() != _sh_region) { | |
1841 gclog_or_tty->print_cr("Region ["PTR_FORMAT","PTR_FORMAT"), " | |
1842 "HS = "PTR_FORMAT", should be "PTR_FORMAT, | |
1843 r->bottom(), r->end(), | |
1844 r->humongous_start_region(), | |
1845 _sh_region); | |
1846 ++_failures; | |
342 | 1847 } |
1848 } | |
355 | 1849 return false; |
1850 } | |
1851 size_t failures() { | |
1852 return _failures; | |
1853 } | |
1854 }; | |
1855 | |
1856 bool G1CollectedHeap::check_heap_region_claim_values(jint claim_value) { | |
1857 CheckClaimValuesClosure cl(claim_value); | |
1858 heap_region_iterate(&cl); | |
1859 return cl.failures() == 0; | |
1860 } | |
1861 #endif // ASSERT | |
342 | 1862 |
1863 void G1CollectedHeap::collection_set_iterate(HeapRegionClosure* cl) { | |
1864 HeapRegion* r = g1_policy()->collection_set(); | |
1865 while (r != NULL) { | |
1866 HeapRegion* next = r->next_in_collection_set(); | |
1867 if (cl->doHeapRegion(r)) { | |
1868 cl->incomplete(); | |
1869 return; | |
1870 } | |
1871 r = next; | |
1872 } | |
1873 } | |
1874 | |
1875 void G1CollectedHeap::collection_set_iterate_from(HeapRegion* r, | |
1876 HeapRegionClosure *cl) { | |
1877 assert(r->in_collection_set(), | |
1878 "Start region must be a member of the collection set."); | |
1879 HeapRegion* cur = r; | |
1880 while (cur != NULL) { | |
1881 HeapRegion* next = cur->next_in_collection_set(); | |
1882 if (cl->doHeapRegion(cur) && false) { | |
1883 cl->incomplete(); | |
1884 return; | |
1885 } | |
1886 cur = next; | |
1887 } | |
1888 cur = g1_policy()->collection_set(); | |
1889 while (cur != r) { | |
1890 HeapRegion* next = cur->next_in_collection_set(); | |
1891 if (cl->doHeapRegion(cur) && false) { | |
1892 cl->incomplete(); | |
1893 return; | |
1894 } | |
1895 cur = next; | |
1896 } | |
1897 } | |
1898 | |
1899 CompactibleSpace* G1CollectedHeap::first_compactible_space() { | |
1900 return _hrs->length() > 0 ? _hrs->at(0) : NULL; | |
1901 } | |
1902 | |
1903 | |
1904 Space* G1CollectedHeap::space_containing(const void* addr) const { | |
1905 Space* res = heap_region_containing(addr); | |
1906 if (res == NULL) | |
1907 res = perm_gen()->space_containing(addr); | |
1908 return res; | |
1909 } | |
1910 | |
1911 HeapWord* G1CollectedHeap::block_start(const void* addr) const { | |
1912 Space* sp = space_containing(addr); | |
1913 if (sp != NULL) { | |
1914 return sp->block_start(addr); | |
1915 } | |
1916 return NULL; | |
1917 } | |
1918 | |
1919 size_t G1CollectedHeap::block_size(const HeapWord* addr) const { | |
1920 Space* sp = space_containing(addr); | |
1921 assert(sp != NULL, "block_size of address outside of heap"); | |
1922 return sp->block_size(addr); | |
1923 } | |
1924 | |
1925 bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const { | |
1926 Space* sp = space_containing(addr); | |
1927 return sp->block_is_obj(addr); | |
1928 } | |
1929 | |
1930 bool G1CollectedHeap::supports_tlab_allocation() const { | |
1931 return true; | |
1932 } | |
1933 | |
1934 size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const { | |
1935 return HeapRegion::GrainBytes; | |
1936 } | |
1937 | |
1938 size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const { | |
1939 // Return the remaining space in the cur alloc region, but not less than | |
1940 // the min TLAB size. | |
1941 // Also, no more than half the region size, since we can't allow tlabs to | |
1942 // grow big enough to accomodate humongous objects. | |
1943 | |
1944 // We need to story it locally, since it might change between when we | |
1945 // test for NULL and when we use it later. | |
1946 ContiguousSpace* cur_alloc_space = _cur_alloc_region; | |
1947 if (cur_alloc_space == NULL) { | |
1948 return HeapRegion::GrainBytes/2; | |
1949 } else { | |
1950 return MAX2(MIN2(cur_alloc_space->free(), | |
1951 (size_t)(HeapRegion::GrainBytes/2)), | |
1952 (size_t)MinTLABSize); | |
1953 } | |
1954 } | |
1955 | |
1956 HeapWord* G1CollectedHeap::allocate_new_tlab(size_t size) { | |
1957 bool dummy; | |
1958 return G1CollectedHeap::mem_allocate(size, false, true, &dummy); | |
1959 } | |
1960 | |
1961 bool G1CollectedHeap::allocs_are_zero_filled() { | |
1962 return false; | |
1963 } | |
1964 | |
1965 size_t G1CollectedHeap::large_typearray_limit() { | |
1966 // FIXME | |
1967 return HeapRegion::GrainBytes/HeapWordSize; | |
1968 } | |
1969 | |
1970 size_t G1CollectedHeap::max_capacity() const { | |
1971 return _g1_committed.byte_size(); | |
1972 } | |
1973 | |
1974 jlong G1CollectedHeap::millis_since_last_gc() { | |
1975 // assert(false, "NYI"); | |
1976 return 0; | |
1977 } | |
1978 | |
1979 | |
1980 void G1CollectedHeap::prepare_for_verify() { | |
1981 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { | |
1982 ensure_parsability(false); | |
1983 } | |
1984 g1_rem_set()->prepare_for_verify(); | |
1985 } | |
1986 | |
1987 class VerifyLivenessOopClosure: public OopClosure { | |
1988 G1CollectedHeap* g1h; | |
1989 public: | |
1990 VerifyLivenessOopClosure(G1CollectedHeap* _g1h) { | |
1991 g1h = _g1h; | |
1992 } | |
1993 void do_oop(narrowOop *p) { | |
1994 guarantee(false, "NYI"); | |
1995 } | |
1996 void do_oop(oop *p) { | |
1997 oop obj = *p; | |
1998 assert(obj == NULL || !g1h->is_obj_dead(obj), | |
1999 "Dead object referenced by a not dead object"); | |
2000 } | |
2001 }; | |
2002 | |
2003 class VerifyObjsInRegionClosure: public ObjectClosure { | |
2004 G1CollectedHeap* _g1h; | |
2005 size_t _live_bytes; | |
2006 HeapRegion *_hr; | |
2007 public: | |
2008 VerifyObjsInRegionClosure(HeapRegion *hr) : _live_bytes(0), _hr(hr) { | |
2009 _g1h = G1CollectedHeap::heap(); | |
2010 } | |
2011 void do_object(oop o) { | |
2012 VerifyLivenessOopClosure isLive(_g1h); | |
2013 assert(o != NULL, "Huh?"); | |
2014 if (!_g1h->is_obj_dead(o)) { | |
2015 o->oop_iterate(&isLive); | |
2016 if (!_hr->obj_allocated_since_prev_marking(o)) | |
2017 _live_bytes += (o->size() * HeapWordSize); | |
2018 } | |
2019 } | |
2020 size_t live_bytes() { return _live_bytes; } | |
2021 }; | |
2022 | |
2023 class PrintObjsInRegionClosure : public ObjectClosure { | |
2024 HeapRegion *_hr; | |
2025 G1CollectedHeap *_g1; | |
2026 public: | |
2027 PrintObjsInRegionClosure(HeapRegion *hr) : _hr(hr) { | |
2028 _g1 = G1CollectedHeap::heap(); | |
2029 }; | |
2030 | |
2031 void do_object(oop o) { | |
2032 if (o != NULL) { | |
2033 HeapWord *start = (HeapWord *) o; | |
2034 size_t word_sz = o->size(); | |
2035 gclog_or_tty->print("\nPrinting obj "PTR_FORMAT" of size " SIZE_FORMAT | |
2036 " isMarkedPrev %d isMarkedNext %d isAllocSince %d\n", | |
2037 (void*) o, word_sz, | |
2038 _g1->isMarkedPrev(o), | |
2039 _g1->isMarkedNext(o), | |
2040 _hr->obj_allocated_since_prev_marking(o)); | |
2041 HeapWord *end = start + word_sz; | |
2042 HeapWord *cur; | |
2043 int *val; | |
2044 for (cur = start; cur < end; cur++) { | |
2045 val = (int *) cur; | |
2046 gclog_or_tty->print("\t "PTR_FORMAT":"PTR_FORMAT"\n", val, *val); | |
2047 } | |
2048 } | |
2049 } | |
2050 }; | |
2051 | |
2052 class VerifyRegionClosure: public HeapRegionClosure { | |
2053 public: | |
2054 bool _allow_dirty; | |
390 | 2055 bool _par; |
2056 VerifyRegionClosure(bool allow_dirty, bool par = false) | |
2057 : _allow_dirty(allow_dirty), _par(par) {} | |
342 | 2058 bool doHeapRegion(HeapRegion* r) { |
390 | 2059 guarantee(_par || r->claim_value() == HeapRegion::InitialClaimValue, |
2060 "Should be unclaimed at verify points."); | |
342 | 2061 if (r->isHumongous()) { |
2062 if (r->startsHumongous()) { | |
2063 // Verify the single H object. | |
2064 oop(r->bottom())->verify(); | |
2065 size_t word_sz = oop(r->bottom())->size(); | |
2066 guarantee(r->top() == r->bottom() + word_sz, | |
2067 "Only one object in a humongous region"); | |
2068 } | |
2069 } else { | |
2070 VerifyObjsInRegionClosure not_dead_yet_cl(r); | |
2071 r->verify(_allow_dirty); | |
2072 r->object_iterate(¬_dead_yet_cl); | |
2073 guarantee(r->max_live_bytes() >= not_dead_yet_cl.live_bytes(), | |
2074 "More live objects than counted in last complete marking."); | |
2075 } | |
2076 return false; | |
2077 } | |
2078 }; | |
2079 | |
2080 class VerifyRootsClosure: public OopsInGenClosure { | |
2081 private: | |
2082 G1CollectedHeap* _g1h; | |
2083 bool _failures; | |
2084 | |
2085 public: | |
2086 VerifyRootsClosure() : | |
2087 _g1h(G1CollectedHeap::heap()), _failures(false) { } | |
2088 | |
2089 bool failures() { return _failures; } | |
2090 | |
2091 void do_oop(narrowOop* p) { | |
2092 guarantee(false, "NYI"); | |
2093 } | |
2094 | |
2095 void do_oop(oop* p) { | |
2096 oop obj = *p; | |
2097 if (obj != NULL) { | |
2098 if (_g1h->is_obj_dead(obj)) { | |
2099 gclog_or_tty->print_cr("Root location "PTR_FORMAT" " | |
2100 "points to dead obj "PTR_FORMAT, p, (void*) obj); | |
2101 obj->print_on(gclog_or_tty); | |
2102 _failures = true; | |
2103 } | |
2104 } | |
2105 } | |
2106 }; | |
2107 | |
390 | 2108 // This is the task used for parallel heap verification. |
2109 | |
2110 class G1ParVerifyTask: public AbstractGangTask { | |
2111 private: | |
2112 G1CollectedHeap* _g1h; | |
2113 bool _allow_dirty; | |
2114 | |
2115 public: | |
2116 G1ParVerifyTask(G1CollectedHeap* g1h, bool allow_dirty) : | |
2117 AbstractGangTask("Parallel verify task"), | |
2118 _g1h(g1h), _allow_dirty(allow_dirty) { } | |
2119 | |
2120 void work(int worker_i) { | |
2121 VerifyRegionClosure blk(_allow_dirty, true); | |
2122 _g1h->heap_region_par_iterate_chunked(&blk, worker_i, | |
2123 HeapRegion::ParVerifyClaimValue); | |
2124 } | |
2125 }; | |
2126 | |
342 | 2127 void G1CollectedHeap::verify(bool allow_dirty, bool silent) { |
2128 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) { | |
2129 if (!silent) { gclog_or_tty->print("roots "); } | |
2130 VerifyRootsClosure rootsCl; | |
2131 process_strong_roots(false, | |
2132 SharedHeap::SO_AllClasses, | |
2133 &rootsCl, | |
2134 &rootsCl); | |
2135 rem_set()->invalidate(perm_gen()->used_region(), false); | |
2136 if (!silent) { gclog_or_tty->print("heapRegions "); } | |
390 | 2137 if (GCParallelVerificationEnabled && ParallelGCThreads > 1) { |
2138 assert(check_heap_region_claim_values(HeapRegion::InitialClaimValue), | |
2139 "sanity check"); | |
2140 | |
2141 G1ParVerifyTask task(this, allow_dirty); | |
2142 int n_workers = workers()->total_workers(); | |
2143 set_par_threads(n_workers); | |
2144 workers()->run_task(&task); | |
2145 set_par_threads(0); | |
2146 | |
2147 assert(check_heap_region_claim_values(HeapRegion::ParVerifyClaimValue), | |
2148 "sanity check"); | |
2149 | |
2150 reset_heap_region_claim_values(); | |
2151 | |
2152 assert(check_heap_region_claim_values(HeapRegion::InitialClaimValue), | |
2153 "sanity check"); | |
2154 } else { | |
2155 VerifyRegionClosure blk(allow_dirty); | |
2156 _hrs->iterate(&blk); | |
2157 } | |
342 | 2158 if (!silent) gclog_or_tty->print("remset "); |
2159 rem_set()->verify(); | |
2160 guarantee(!rootsCl.failures(), "should not have had failures"); | |
2161 } else { | |
2162 if (!silent) gclog_or_tty->print("(SKIPPING roots, heapRegions, remset) "); | |
2163 } | |
2164 } | |
2165 | |
2166 class PrintRegionClosure: public HeapRegionClosure { | |
2167 outputStream* _st; | |
2168 public: | |
2169 PrintRegionClosure(outputStream* st) : _st(st) {} | |
2170 bool doHeapRegion(HeapRegion* r) { | |
2171 r->print_on(_st); | |
2172 return false; | |
2173 } | |
2174 }; | |
2175 | |
2176 void G1CollectedHeap::print() const { print_on(gclog_or_tty); } | |
2177 | |
2178 void G1CollectedHeap::print_on(outputStream* st) const { | |
2179 PrintRegionClosure blk(st); | |
2180 _hrs->iterate(&blk); | |
2181 } | |
2182 | |
2183 void G1CollectedHeap::print_gc_threads_on(outputStream* st) const { | |
2184 if (ParallelGCThreads > 0) { | |
2185 workers()->print_worker_threads(); | |
2186 } | |
2187 st->print("\"G1 concurrent mark GC Thread\" "); | |
2188 _cmThread->print(); | |
2189 st->cr(); | |
2190 st->print("\"G1 concurrent refinement GC Thread\" "); | |
2191 _cg1r->cg1rThread()->print_on(st); | |
2192 st->cr(); | |
2193 st->print("\"G1 zero-fill GC Thread\" "); | |
2194 _czft->print_on(st); | |
2195 st->cr(); | |
2196 } | |
2197 | |
2198 void G1CollectedHeap::gc_threads_do(ThreadClosure* tc) const { | |
2199 if (ParallelGCThreads > 0) { | |
2200 workers()->threads_do(tc); | |
2201 } | |
2202 tc->do_thread(_cmThread); | |
2203 tc->do_thread(_cg1r->cg1rThread()); | |
2204 tc->do_thread(_czft); | |
2205 } | |
2206 | |
2207 void G1CollectedHeap::print_tracing_info() const { | |
2208 concurrent_g1_refine()->print_final_card_counts(); | |
2209 | |
2210 // We'll overload this to mean "trace GC pause statistics." | |
2211 if (TraceGen0Time || TraceGen1Time) { | |
2212 // The "G1CollectorPolicy" is keeping track of these stats, so delegate | |
2213 // to that. | |
2214 g1_policy()->print_tracing_info(); | |
2215 } | |
2216 if (SummarizeG1RSStats) { | |
2217 g1_rem_set()->print_summary_info(); | |
2218 } | |
2219 if (SummarizeG1ConcMark) { | |
2220 concurrent_mark()->print_summary_info(); | |
2221 } | |
2222 if (SummarizeG1ZFStats) { | |
2223 ConcurrentZFThread::print_summary_info(); | |
2224 } | |
2225 if (G1SummarizePopularity) { | |
2226 print_popularity_summary_info(); | |
2227 } | |
2228 g1_policy()->print_yg_surv_rate_info(); | |
2229 | |
2230 GCOverheadReporter::printGCOverhead(); | |
2231 | |
2232 SpecializationStats::print(); | |
2233 } | |
2234 | |
2235 | |
2236 int G1CollectedHeap::addr_to_arena_id(void* addr) const { | |
2237 HeapRegion* hr = heap_region_containing(addr); | |
2238 if (hr == NULL) { | |
2239 return 0; | |
2240 } else { | |
2241 return 1; | |
2242 } | |
2243 } | |
2244 | |
2245 G1CollectedHeap* G1CollectedHeap::heap() { | |
2246 assert(_sh->kind() == CollectedHeap::G1CollectedHeap, | |
2247 "not a garbage-first heap"); | |
2248 return _g1h; | |
2249 } | |
2250 | |
2251 void G1CollectedHeap::gc_prologue(bool full /* Ignored */) { | |
2252 if (PrintHeapAtGC){ | |
2253 gclog_or_tty->print_cr(" {Heap before GC collections=%d:", total_collections()); | |
2254 Universe::print(); | |
2255 } | |
2256 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer"); | |
2257 // Call allocation profiler | |
2258 AllocationProfiler::iterate_since_last_gc(); | |
2259 // Fill TLAB's and such | |
2260 ensure_parsability(true); | |
2261 } | |
2262 | |
2263 void G1CollectedHeap::gc_epilogue(bool full /* Ignored */) { | |
2264 // FIXME: what is this about? | |
2265 // I'm ignoring the "fill_newgen()" call if "alloc_event_enabled" | |
2266 // is set. | |
2267 COMPILER2_PRESENT(assert(DerivedPointerTable::is_empty(), | |
2268 "derived pointer present")); | |
2269 | |
2270 if (PrintHeapAtGC){ | |
2271 gclog_or_tty->print_cr(" Heap after GC collections=%d:", total_collections()); | |
2272 Universe::print(); | |
2273 gclog_or_tty->print("} "); | |
2274 } | |
2275 } | |
2276 | |
2277 void G1CollectedHeap::do_collection_pause() { | |
2278 // Read the GC count while holding the Heap_lock | |
2279 // we need to do this _before_ wait_for_cleanup_complete(), to | |
2280 // ensure that we do not give up the heap lock and potentially | |
2281 // pick up the wrong count | |
2282 int gc_count_before = SharedHeap::heap()->total_collections(); | |
2283 | |
2284 // Don't want to do a GC pause while cleanup is being completed! | |
2285 wait_for_cleanup_complete(); | |
2286 | |
2287 g1_policy()->record_stop_world_start(); | |
2288 { | |
2289 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
2290 VM_G1IncCollectionPause op(gc_count_before); | |
2291 VMThread::execute(&op); | |
2292 } | |
2293 } | |
2294 | |
2295 void | |
2296 G1CollectedHeap::doConcurrentMark() { | |
2297 if (G1ConcMark) { | |
2298 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2299 if (!_cmThread->in_progress()) { | |
2300 _cmThread->set_started(); | |
2301 CGC_lock->notify(); | |
2302 } | |
2303 } | |
2304 } | |
2305 | |
2306 class VerifyMarkedObjsClosure: public ObjectClosure { | |
2307 G1CollectedHeap* _g1h; | |
2308 public: | |
2309 VerifyMarkedObjsClosure(G1CollectedHeap* g1h) : _g1h(g1h) {} | |
2310 void do_object(oop obj) { | |
2311 assert(obj->mark()->is_marked() ? !_g1h->is_obj_dead(obj) : true, | |
2312 "markandsweep mark should agree with concurrent deadness"); | |
2313 } | |
2314 }; | |
2315 | |
2316 void | |
2317 G1CollectedHeap::checkConcurrentMark() { | |
2318 VerifyMarkedObjsClosure verifycl(this); | |
2319 doConcurrentMark(); | |
2320 // MutexLockerEx x(getMarkBitMapLock(), | |
2321 // Mutex::_no_safepoint_check_flag); | |
2322 object_iterate(&verifycl); | |
2323 } | |
2324 | |
2325 void G1CollectedHeap::do_sync_mark() { | |
2326 _cm->checkpointRootsInitial(); | |
2327 _cm->markFromRoots(); | |
2328 _cm->checkpointRootsFinal(false); | |
2329 } | |
2330 | |
2331 // <NEW PREDICTION> | |
2332 | |
2333 double G1CollectedHeap::predict_region_elapsed_time_ms(HeapRegion *hr, | |
2334 bool young) { | |
2335 return _g1_policy->predict_region_elapsed_time_ms(hr, young); | |
2336 } | |
2337 | |
2338 void G1CollectedHeap::check_if_region_is_too_expensive(double | |
2339 predicted_time_ms) { | |
2340 _g1_policy->check_if_region_is_too_expensive(predicted_time_ms); | |
2341 } | |
2342 | |
2343 size_t G1CollectedHeap::pending_card_num() { | |
2344 size_t extra_cards = 0; | |
2345 JavaThread *curr = Threads::first(); | |
2346 while (curr != NULL) { | |
2347 DirtyCardQueue& dcq = curr->dirty_card_queue(); | |
2348 extra_cards += dcq.size(); | |
2349 curr = curr->next(); | |
2350 } | |
2351 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
2352 size_t buffer_size = dcqs.buffer_size(); | |
2353 size_t buffer_num = dcqs.completed_buffers_num(); | |
2354 return buffer_size * buffer_num + extra_cards; | |
2355 } | |
2356 | |
2357 size_t G1CollectedHeap::max_pending_card_num() { | |
2358 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); | |
2359 size_t buffer_size = dcqs.buffer_size(); | |
2360 size_t buffer_num = dcqs.completed_buffers_num(); | |
2361 int thread_num = Threads::number_of_threads(); | |
2362 return (buffer_num + thread_num) * buffer_size; | |
2363 } | |
2364 | |
2365 size_t G1CollectedHeap::cards_scanned() { | |
2366 HRInto_G1RemSet* g1_rset = (HRInto_G1RemSet*) g1_rem_set(); | |
2367 return g1_rset->cardsScanned(); | |
2368 } | |
2369 | |
2370 void | |
2371 G1CollectedHeap::setup_surviving_young_words() { | |
2372 guarantee( _surviving_young_words == NULL, "pre-condition" ); | |
2373 size_t array_length = g1_policy()->young_cset_length(); | |
2374 _surviving_young_words = NEW_C_HEAP_ARRAY(size_t, array_length); | |
2375 if (_surviving_young_words == NULL) { | |
2376 vm_exit_out_of_memory(sizeof(size_t) * array_length, | |
2377 "Not enough space for young surv words summary."); | |
2378 } | |
2379 memset(_surviving_young_words, 0, array_length * sizeof(size_t)); | |
2380 for (size_t i = 0; i < array_length; ++i) { | |
2381 guarantee( _surviving_young_words[i] == 0, "invariant" ); | |
2382 } | |
2383 } | |
2384 | |
2385 void | |
2386 G1CollectedHeap::update_surviving_young_words(size_t* surv_young_words) { | |
2387 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
2388 size_t array_length = g1_policy()->young_cset_length(); | |
2389 for (size_t i = 0; i < array_length; ++i) | |
2390 _surviving_young_words[i] += surv_young_words[i]; | |
2391 } | |
2392 | |
2393 void | |
2394 G1CollectedHeap::cleanup_surviving_young_words() { | |
2395 guarantee( _surviving_young_words != NULL, "pre-condition" ); | |
2396 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words); | |
2397 _surviving_young_words = NULL; | |
2398 } | |
2399 | |
2400 // </NEW PREDICTION> | |
2401 | |
2402 void | |
2403 G1CollectedHeap::do_collection_pause_at_safepoint(HeapRegion* popular_region) { | |
2404 char verbose_str[128]; | |
2405 sprintf(verbose_str, "GC pause "); | |
2406 if (popular_region != NULL) | |
2407 strcat(verbose_str, "(popular)"); | |
2408 else if (g1_policy()->in_young_gc_mode()) { | |
2409 if (g1_policy()->full_young_gcs()) | |
2410 strcat(verbose_str, "(young)"); | |
2411 else | |
2412 strcat(verbose_str, "(partial)"); | |
2413 } | |
2414 bool reset_should_initiate_conc_mark = false; | |
2415 if (popular_region != NULL && g1_policy()->should_initiate_conc_mark()) { | |
2416 // we currently do not allow an initial mark phase to be piggy-backed | |
2417 // on a popular pause | |
2418 reset_should_initiate_conc_mark = true; | |
2419 g1_policy()->unset_should_initiate_conc_mark(); | |
2420 } | |
2421 if (g1_policy()->should_initiate_conc_mark()) | |
2422 strcat(verbose_str, " (initial-mark)"); | |
2423 | |
2424 GCCauseSetter x(this, (popular_region == NULL ? | |
2425 GCCause::_g1_inc_collection_pause : | |
2426 GCCause::_g1_pop_region_collection_pause)); | |
2427 | |
2428 // if PrintGCDetails is on, we'll print long statistics information | |
2429 // in the collector policy code, so let's not print this as the output | |
2430 // is messy if we do. | |
2431 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
2432 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
2433 TraceTime t(verbose_str, PrintGC && !PrintGCDetails, true, gclog_or_tty); | |
2434 | |
2435 ResourceMark rm; | |
2436 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
2437 assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread"); | |
2438 guarantee(!is_gc_active(), "collection is not reentrant"); | |
2439 assert(regions_accounted_for(), "Region leakage!"); | |
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6723570: G1: assertion failure: p == current_top or oop(p)->is_oop(),"p is not a block start" (revisited!)
iveresov
parents:
352
diff
changeset
|
2440 |
9bb2c10ac07b
6723570: G1: assertion failure: p == current_top or oop(p)->is_oop(),"p is not a block start" (revisited!)
iveresov
parents:
352
diff
changeset
|
2441 increment_gc_time_stamp(); |
342 | 2442 |
2443 if (g1_policy()->in_young_gc_mode()) { | |
2444 assert(check_young_list_well_formed(), | |
2445 "young list should be well formed"); | |
2446 } | |
2447 | |
2448 if (GC_locker::is_active()) { | |
2449 return; // GC is disabled (e.g. JNI GetXXXCritical operation) | |
2450 } | |
2451 | |
2452 bool abandoned = false; | |
2453 { // Call to jvmpi::post_class_unload_events must occur outside of active GC | |
2454 IsGCActiveMark x; | |
2455 | |
2456 gc_prologue(false); | |
2457 increment_total_collections(); | |
2458 | |
2459 #if G1_REM_SET_LOGGING | |
2460 gclog_or_tty->print_cr("\nJust chose CS, heap:"); | |
2461 print(); | |
2462 #endif | |
2463 | |
2464 if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) { | |
2465 HandleMark hm; // Discard invalid handles created during verification | |
2466 prepare_for_verify(); | |
2467 gclog_or_tty->print(" VerifyBeforeGC:"); | |
2468 Universe::verify(false); | |
2469 } | |
2470 | |
2471 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
2472 | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
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parents:
393
diff
changeset
|
2473 // We want to turn off ref discovery, if necessary, and turn it back on |
342 | 2474 // on again later if we do. |
2475 bool was_enabled = ref_processor()->discovery_enabled(); | |
2476 if (was_enabled) ref_processor()->disable_discovery(); | |
2477 | |
2478 // Forget the current alloc region (we might even choose it to be part | |
2479 // of the collection set!). | |
2480 abandon_cur_alloc_region(); | |
2481 | |
2482 // The elapsed time induced by the start time below deliberately elides | |
2483 // the possible verification above. | |
2484 double start_time_sec = os::elapsedTime(); | |
2485 GCOverheadReporter::recordSTWStart(start_time_sec); | |
2486 size_t start_used_bytes = used(); | |
2487 if (!G1ConcMark) { | |
2488 do_sync_mark(); | |
2489 } | |
2490 | |
2491 g1_policy()->record_collection_pause_start(start_time_sec, | |
2492 start_used_bytes); | |
2493 | |
526 | 2494 guarantee(_in_cset_fast_test == NULL, "invariant"); |
2495 guarantee(_in_cset_fast_test_base == NULL, "invariant"); | |
2496 _in_cset_fast_test_length = n_regions(); | |
2497 _in_cset_fast_test_base = | |
2498 NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length); | |
2499 memset(_in_cset_fast_test_base, false, | |
2500 _in_cset_fast_test_length * sizeof(bool)); | |
2501 // We're biasing _in_cset_fast_test to avoid subtracting the | |
2502 // beginning of the heap every time we want to index; basically | |
2503 // it's the same with what we do with the card table. | |
2504 _in_cset_fast_test = _in_cset_fast_test_base - | |
2505 ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes); | |
2506 | |
342 | 2507 #if SCAN_ONLY_VERBOSE |
2508 _young_list->print(); | |
2509 #endif // SCAN_ONLY_VERBOSE | |
2510 | |
2511 if (g1_policy()->should_initiate_conc_mark()) { | |
2512 concurrent_mark()->checkpointRootsInitialPre(); | |
2513 } | |
2514 save_marks(); | |
2515 | |
2516 // We must do this before any possible evacuation that should propogate | |
2517 // marks, including evacuation of popular objects in a popular pause. | |
2518 if (mark_in_progress()) { | |
2519 double start_time_sec = os::elapsedTime(); | |
2520 | |
2521 _cm->drainAllSATBBuffers(); | |
2522 double finish_mark_ms = (os::elapsedTime() - start_time_sec) * 1000.0; | |
2523 g1_policy()->record_satb_drain_time(finish_mark_ms); | |
2524 | |
2525 } | |
2526 // Record the number of elements currently on the mark stack, so we | |
2527 // only iterate over these. (Since evacuation may add to the mark | |
2528 // stack, doing more exposes race conditions.) If no mark is in | |
2529 // progress, this will be zero. | |
2530 _cm->set_oops_do_bound(); | |
2531 | |
2532 assert(regions_accounted_for(), "Region leakage."); | |
2533 | |
2534 bool abandoned = false; | |
2535 | |
2536 if (mark_in_progress()) | |
2537 concurrent_mark()->newCSet(); | |
2538 | |
2539 // Now choose the CS. | |
2540 if (popular_region == NULL) { | |
2541 g1_policy()->choose_collection_set(); | |
2542 } else { | |
2543 // We may be evacuating a single region (for popularity). | |
2544 g1_policy()->record_popular_pause_preamble_start(); | |
2545 popularity_pause_preamble(popular_region); | |
2546 g1_policy()->record_popular_pause_preamble_end(); | |
2547 abandoned = (g1_policy()->collection_set() == NULL); | |
2548 // Now we allow more regions to be added (we have to collect | |
2549 // all popular regions). | |
2550 if (!abandoned) { | |
2551 g1_policy()->choose_collection_set(popular_region); | |
2552 } | |
2553 } | |
2554 // We may abandon a pause if we find no region that will fit in the MMU | |
2555 // pause. | |
2556 abandoned = (g1_policy()->collection_set() == NULL); | |
2557 | |
2558 // Nothing to do if we were unable to choose a collection set. | |
2559 if (!abandoned) { | |
2560 #if G1_REM_SET_LOGGING | |
2561 gclog_or_tty->print_cr("\nAfter pause, heap:"); | |
2562 print(); | |
2563 #endif | |
2564 | |
2565 setup_surviving_young_words(); | |
2566 | |
2567 // Set up the gc allocation regions. | |
2568 get_gc_alloc_regions(); | |
2569 | |
2570 // Actually do the work... | |
2571 evacuate_collection_set(); | |
2572 free_collection_set(g1_policy()->collection_set()); | |
2573 g1_policy()->clear_collection_set(); | |
2574 | |
526 | 2575 FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base); |
2576 // this is more for peace of mind; we're nulling them here and | |
2577 // we're expecting them to be null at the beginning of the next GC | |
2578 _in_cset_fast_test = NULL; | |
2579 _in_cset_fast_test_base = NULL; | |
2580 | |
342 | 2581 if (popular_region != NULL) { |
2582 // We have to wait until now, because we don't want the region to | |
2583 // be rescheduled for pop-evac during RS update. | |
2584 popular_region->set_popular_pending(false); | |
2585 } | |
2586 | |
2587 release_gc_alloc_regions(); | |
2588 | |
2589 cleanup_surviving_young_words(); | |
2590 | |
2591 if (g1_policy()->in_young_gc_mode()) { | |
2592 _young_list->reset_sampled_info(); | |
2593 assert(check_young_list_empty(true), | |
2594 "young list should be empty"); | |
2595 | |
2596 #if SCAN_ONLY_VERBOSE | |
2597 _young_list->print(); | |
2598 #endif // SCAN_ONLY_VERBOSE | |
2599 | |
545 | 2600 g1_policy()->record_survivor_regions(_young_list->survivor_length(), |
2601 _young_list->first_survivor_region(), | |
2602 _young_list->last_survivor_region()); | |
342 | 2603 _young_list->reset_auxilary_lists(); |
2604 } | |
2605 } else { | |
2606 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
2607 } | |
2608 | |
2609 if (evacuation_failed()) { | |
2610 _summary_bytes_used = recalculate_used(); | |
2611 } else { | |
2612 // The "used" of the the collection set have already been subtracted | |
2613 // when they were freed. Add in the bytes evacuated. | |
2614 _summary_bytes_used += g1_policy()->bytes_in_to_space(); | |
2615 } | |
2616 | |
2617 if (g1_policy()->in_young_gc_mode() && | |
2618 g1_policy()->should_initiate_conc_mark()) { | |
2619 concurrent_mark()->checkpointRootsInitialPost(); | |
2620 set_marking_started(); | |
2621 doConcurrentMark(); | |
2622 } | |
2623 | |
2624 #if SCAN_ONLY_VERBOSE | |
2625 _young_list->print(); | |
2626 #endif // SCAN_ONLY_VERBOSE | |
2627 | |
2628 double end_time_sec = os::elapsedTime(); | |
545 | 2629 if (!evacuation_failed()) { |
2630 g1_policy()->record_pause_time((end_time_sec - start_time_sec)*1000.0); | |
2631 } | |
342 | 2632 GCOverheadReporter::recordSTWEnd(end_time_sec); |
2633 g1_policy()->record_collection_pause_end(popular_region != NULL, | |
2634 abandoned); | |
2635 | |
2636 assert(regions_accounted_for(), "Region leakage."); | |
2637 | |
2638 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) { | |
2639 HandleMark hm; // Discard invalid handles created during verification | |
2640 gclog_or_tty->print(" VerifyAfterGC:"); | |
2641 Universe::verify(false); | |
2642 } | |
2643 | |
2644 if (was_enabled) ref_processor()->enable_discovery(); | |
2645 | |
2646 { | |
2647 size_t expand_bytes = g1_policy()->expansion_amount(); | |
2648 if (expand_bytes > 0) { | |
2649 size_t bytes_before = capacity(); | |
2650 expand(expand_bytes); | |
2651 } | |
2652 } | |
2653 | |
546
05c6d52fa7a9
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2654 if (mark_in_progress()) { |
342 | 2655 concurrent_mark()->update_g1_committed(); |
546
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2656 } |
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2657 |
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2658 #ifdef TRACESPINNING |
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2659 ParallelTaskTerminator::print_termination_counts(); |
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2660 #endif |
342 | 2661 |
2662 gc_epilogue(false); | |
2663 } | |
2664 | |
2665 assert(verify_region_lists(), "Bad region lists."); | |
2666 | |
2667 if (reset_should_initiate_conc_mark) | |
2668 g1_policy()->set_should_initiate_conc_mark(); | |
2669 | |
2670 if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) { | |
2671 gclog_or_tty->print_cr("Stopping after GC #%d", ExitAfterGCNum); | |
2672 print_tracing_info(); | |
2673 vm_exit(-1); | |
2674 } | |
2675 } | |
2676 | |
2677 void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) { | |
2678 assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose"); | |
2679 HeapWord* original_top = NULL; | |
2680 if (r != NULL) | |
2681 original_top = r->top(); | |
2682 | |
2683 // We will want to record the used space in r as being there before gc. | |
2684 // One we install it as a GC alloc region it's eligible for allocation. | |
2685 // So record it now and use it later. | |
2686 size_t r_used = 0; | |
2687 if (r != NULL) { | |
2688 r_used = r->used(); | |
2689 | |
2690 if (ParallelGCThreads > 0) { | |
2691 // need to take the lock to guard against two threads calling | |
2692 // get_gc_alloc_region concurrently (very unlikely but...) | |
2693 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
2694 r->save_marks(); | |
2695 } | |
2696 } | |
2697 HeapRegion* old_alloc_region = _gc_alloc_regions[purpose]; | |
2698 _gc_alloc_regions[purpose] = r; | |
2699 if (old_alloc_region != NULL) { | |
2700 // Replace aliases too. | |
2701 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2702 if (_gc_alloc_regions[ap] == old_alloc_region) { | |
2703 _gc_alloc_regions[ap] = r; | |
2704 } | |
2705 } | |
2706 } | |
2707 if (r != NULL) { | |
2708 push_gc_alloc_region(r); | |
2709 if (mark_in_progress() && original_top != r->next_top_at_mark_start()) { | |
2710 // We are using a region as a GC alloc region after it has been used | |
2711 // as a mutator allocation region during the current marking cycle. | |
2712 // The mutator-allocated objects are currently implicitly marked, but | |
2713 // when we move hr->next_top_at_mark_start() forward at the the end | |
2714 // of the GC pause, they won't be. We therefore mark all objects in | |
2715 // the "gap". We do this object-by-object, since marking densely | |
2716 // does not currently work right with marking bitmap iteration. This | |
2717 // means we rely on TLAB filling at the start of pauses, and no | |
2718 // "resuscitation" of filled TLAB's. If we want to do this, we need | |
2719 // to fix the marking bitmap iteration. | |
2720 HeapWord* curhw = r->next_top_at_mark_start(); | |
2721 HeapWord* t = original_top; | |
2722 | |
2723 while (curhw < t) { | |
2724 oop cur = (oop)curhw; | |
2725 // We'll assume parallel for generality. This is rare code. | |
2726 concurrent_mark()->markAndGrayObjectIfNecessary(cur); // can't we just mark them? | |
2727 curhw = curhw + cur->size(); | |
2728 } | |
2729 assert(curhw == t, "Should have parsed correctly."); | |
2730 } | |
2731 if (G1PolicyVerbose > 1) { | |
2732 gclog_or_tty->print("New alloc region ["PTR_FORMAT", "PTR_FORMAT", " PTR_FORMAT") " | |
2733 "for survivors:", r->bottom(), original_top, r->end()); | |
2734 r->print(); | |
2735 } | |
2736 g1_policy()->record_before_bytes(r_used); | |
2737 } | |
2738 } | |
2739 | |
2740 void G1CollectedHeap::push_gc_alloc_region(HeapRegion* hr) { | |
2741 assert(Thread::current()->is_VM_thread() || | |
2742 par_alloc_during_gc_lock()->owned_by_self(), "Precondition"); | |
2743 assert(!hr->is_gc_alloc_region() && !hr->in_collection_set(), | |
2744 "Precondition."); | |
2745 hr->set_is_gc_alloc_region(true); | |
2746 hr->set_next_gc_alloc_region(_gc_alloc_region_list); | |
2747 _gc_alloc_region_list = hr; | |
2748 } | |
2749 | |
2750 #ifdef G1_DEBUG | |
2751 class FindGCAllocRegion: public HeapRegionClosure { | |
2752 public: | |
2753 bool doHeapRegion(HeapRegion* r) { | |
2754 if (r->is_gc_alloc_region()) { | |
2755 gclog_or_tty->print_cr("Region %d ["PTR_FORMAT"...] is still a gc_alloc_region.", | |
2756 r->hrs_index(), r->bottom()); | |
2757 } | |
2758 return false; | |
2759 } | |
2760 }; | |
2761 #endif // G1_DEBUG | |
2762 | |
2763 void G1CollectedHeap::forget_alloc_region_list() { | |
2764 assert(Thread::current()->is_VM_thread(), "Precondition"); | |
2765 while (_gc_alloc_region_list != NULL) { | |
2766 HeapRegion* r = _gc_alloc_region_list; | |
2767 assert(r->is_gc_alloc_region(), "Invariant."); | |
2768 _gc_alloc_region_list = r->next_gc_alloc_region(); | |
2769 r->set_next_gc_alloc_region(NULL); | |
2770 r->set_is_gc_alloc_region(false); | |
545 | 2771 if (r->is_survivor()) { |
2772 if (r->is_empty()) { | |
2773 r->set_not_young(); | |
2774 } else { | |
2775 _young_list->add_survivor_region(r); | |
2776 } | |
2777 } | |
342 | 2778 if (r->is_empty()) { |
2779 ++_free_regions; | |
2780 } | |
2781 } | |
2782 #ifdef G1_DEBUG | |
2783 FindGCAllocRegion fa; | |
2784 heap_region_iterate(&fa); | |
2785 #endif // G1_DEBUG | |
2786 } | |
2787 | |
2788 | |
2789 bool G1CollectedHeap::check_gc_alloc_regions() { | |
2790 // TODO: allocation regions check | |
2791 return true; | |
2792 } | |
2793 | |
2794 void G1CollectedHeap::get_gc_alloc_regions() { | |
2795 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2796 // Create new GC alloc regions. | |
2797 HeapRegion* alloc_region = _gc_alloc_regions[ap]; | |
2798 // Clear this alloc region, so that in case it turns out to be | |
2799 // unacceptable, we end up with no allocation region, rather than a bad | |
2800 // one. | |
2801 _gc_alloc_regions[ap] = NULL; | |
2802 if (alloc_region == NULL || alloc_region->in_collection_set()) { | |
2803 // Can't re-use old one. Allocate a new one. | |
2804 alloc_region = newAllocRegionWithExpansion(ap, 0); | |
2805 } | |
2806 if (alloc_region != NULL) { | |
2807 set_gc_alloc_region(ap, alloc_region); | |
2808 } | |
2809 } | |
2810 // Set alternative regions for allocation purposes that have reached | |
2811 // thier limit. | |
2812 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2813 GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(ap); | |
2814 if (_gc_alloc_regions[ap] == NULL && alt_purpose != ap) { | |
2815 _gc_alloc_regions[ap] = _gc_alloc_regions[alt_purpose]; | |
2816 } | |
2817 } | |
2818 assert(check_gc_alloc_regions(), "alloc regions messed up"); | |
2819 } | |
2820 | |
2821 void G1CollectedHeap::release_gc_alloc_regions() { | |
2822 // We keep a separate list of all regions that have been alloc regions in | |
2823 // the current collection pause. Forget that now. | |
2824 forget_alloc_region_list(); | |
2825 | |
2826 // The current alloc regions contain objs that have survived | |
2827 // collection. Make them no longer GC alloc regions. | |
2828 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
2829 HeapRegion* r = _gc_alloc_regions[ap]; | |
2830 if (r != NULL && r->is_empty()) { | |
2831 { | |
2832 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
2833 r->set_zero_fill_complete(); | |
2834 put_free_region_on_list_locked(r); | |
2835 } | |
2836 } | |
2837 // set_gc_alloc_region will also NULLify all aliases to the region | |
2838 set_gc_alloc_region(ap, NULL); | |
2839 _gc_alloc_region_counts[ap] = 0; | |
2840 } | |
2841 } | |
2842 | |
2843 void G1CollectedHeap::init_for_evac_failure(OopsInHeapRegionClosure* cl) { | |
2844 _drain_in_progress = false; | |
2845 set_evac_failure_closure(cl); | |
2846 _evac_failure_scan_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); | |
2847 } | |
2848 | |
2849 void G1CollectedHeap::finalize_for_evac_failure() { | |
2850 assert(_evac_failure_scan_stack != NULL && | |
2851 _evac_failure_scan_stack->length() == 0, | |
2852 "Postcondition"); | |
2853 assert(!_drain_in_progress, "Postcondition"); | |
2854 // Don't have to delete, since the scan stack is a resource object. | |
2855 _evac_failure_scan_stack = NULL; | |
2856 } | |
2857 | |
2858 | |
2859 | |
2860 // *** Sequential G1 Evacuation | |
2861 | |
2862 HeapWord* G1CollectedHeap::allocate_during_gc(GCAllocPurpose purpose, size_t word_size) { | |
2863 HeapRegion* alloc_region = _gc_alloc_regions[purpose]; | |
2864 // let the caller handle alloc failure | |
2865 if (alloc_region == NULL) return NULL; | |
2866 assert(isHumongous(word_size) || !alloc_region->isHumongous(), | |
2867 "Either the object is humongous or the region isn't"); | |
2868 HeapWord* block = alloc_region->allocate(word_size); | |
2869 if (block == NULL) { | |
2870 block = allocate_during_gc_slow(purpose, alloc_region, false, word_size); | |
2871 } | |
2872 return block; | |
2873 } | |
2874 | |
2875 class G1IsAliveClosure: public BoolObjectClosure { | |
2876 G1CollectedHeap* _g1; | |
2877 public: | |
2878 G1IsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} | |
2879 void do_object(oop p) { assert(false, "Do not call."); } | |
2880 bool do_object_b(oop p) { | |
2881 // It is reachable if it is outside the collection set, or is inside | |
2882 // and forwarded. | |
2883 | |
2884 #ifdef G1_DEBUG | |
2885 gclog_or_tty->print_cr("is alive "PTR_FORMAT" in CS %d forwarded %d overall %d", | |
2886 (void*) p, _g1->obj_in_cs(p), p->is_forwarded(), | |
2887 !_g1->obj_in_cs(p) || p->is_forwarded()); | |
2888 #endif // G1_DEBUG | |
2889 | |
2890 return !_g1->obj_in_cs(p) || p->is_forwarded(); | |
2891 } | |
2892 }; | |
2893 | |
2894 class G1KeepAliveClosure: public OopClosure { | |
2895 G1CollectedHeap* _g1; | |
2896 public: | |
2897 G1KeepAliveClosure(G1CollectedHeap* g1) : _g1(g1) {} | |
2898 void do_oop(narrowOop* p) { | |
2899 guarantee(false, "NYI"); | |
2900 } | |
2901 void do_oop(oop* p) { | |
2902 oop obj = *p; | |
2903 #ifdef G1_DEBUG | |
2904 if (PrintGC && Verbose) { | |
2905 gclog_or_tty->print_cr("keep alive *"PTR_FORMAT" = "PTR_FORMAT" "PTR_FORMAT, | |
2906 p, (void*) obj, (void*) *p); | |
2907 } | |
2908 #endif // G1_DEBUG | |
2909 | |
2910 if (_g1->obj_in_cs(obj)) { | |
2911 assert( obj->is_forwarded(), "invariant" ); | |
2912 *p = obj->forwardee(); | |
2913 | |
2914 #ifdef G1_DEBUG | |
2915 gclog_or_tty->print_cr(" in CSet: moved "PTR_FORMAT" -> "PTR_FORMAT, | |
2916 (void*) obj, (void*) *p); | |
2917 #endif // G1_DEBUG | |
2918 } | |
2919 } | |
2920 }; | |
2921 | |
2922 class RecreateRSetEntriesClosure: public OopClosure { | |
2923 private: | |
2924 G1CollectedHeap* _g1; | |
2925 G1RemSet* _g1_rem_set; | |
2926 HeapRegion* _from; | |
2927 public: | |
2928 RecreateRSetEntriesClosure(G1CollectedHeap* g1, HeapRegion* from) : | |
2929 _g1(g1), _g1_rem_set(g1->g1_rem_set()), _from(from) | |
2930 {} | |
2931 | |
2932 void do_oop(narrowOop* p) { | |
2933 guarantee(false, "NYI"); | |
2934 } | |
2935 void do_oop(oop* p) { | |
2936 assert(_from->is_in_reserved(p), "paranoia"); | |
2937 if (*p != NULL) { | |
2938 _g1_rem_set->write_ref(_from, p); | |
2939 } | |
2940 } | |
2941 }; | |
2942 | |
2943 class RemoveSelfPointerClosure: public ObjectClosure { | |
2944 private: | |
2945 G1CollectedHeap* _g1; | |
2946 ConcurrentMark* _cm; | |
2947 HeapRegion* _hr; | |
2948 size_t _prev_marked_bytes; | |
2949 size_t _next_marked_bytes; | |
2950 public: | |
2951 RemoveSelfPointerClosure(G1CollectedHeap* g1, HeapRegion* hr) : | |
2952 _g1(g1), _cm(_g1->concurrent_mark()), _hr(hr), | |
2953 _prev_marked_bytes(0), _next_marked_bytes(0) | |
2954 {} | |
2955 | |
2956 size_t prev_marked_bytes() { return _prev_marked_bytes; } | |
2957 size_t next_marked_bytes() { return _next_marked_bytes; } | |
2958 | |
352
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2959 // The original idea here was to coalesce evacuated and dead objects. |
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2960 // However that caused complications with the block offset table (BOT). |
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2961 // In particular if there were two TLABs, one of them partially refined. |
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2962 // |----- TLAB_1--------|----TLAB_2-~~~(partially refined part)~~~| |
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2963 // The BOT entries of the unrefined part of TLAB_2 point to the start |
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2964 // of TLAB_2. If the last object of the TLAB_1 and the first object |
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2965 // of TLAB_2 are coalesced, then the cards of the unrefined part |
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2966 // would point into middle of the filler object. |
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2967 // |
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2968 // The current approach is to not coalesce and leave the BOT contents intact. |
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2969 void do_object(oop obj) { |
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2970 if (obj->is_forwarded() && obj->forwardee() == obj) { |
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2971 // The object failed to move. |
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2972 assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs."); |
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2973 _cm->markPrev(obj); |
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2974 assert(_cm->isPrevMarked(obj), "Should be marked!"); |
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2975 _prev_marked_bytes += (obj->size() * HeapWordSize); |
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2976 if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) { |
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2977 _cm->markAndGrayObjectIfNecessary(obj); |
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2978 } |
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2979 obj->set_mark(markOopDesc::prototype()); |
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2980 // While we were processing RSet buffers during the |
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2981 // collection, we actually didn't scan any cards on the |
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2982 // collection set, since we didn't want to update remebered |
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2983 // sets with entries that point into the collection set, given |
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2984 // that live objects fromthe collection set are about to move |
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2985 // and such entries will be stale very soon. This change also |
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2986 // dealt with a reliability issue which involved scanning a |
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2987 // card in the collection set and coming across an array that |
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2988 // was being chunked and looking malformed. The problem is |
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2989 // that, if evacuation fails, we might have remembered set |
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2990 // entries missing given that we skipped cards on the |
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2991 // collection set. So, we'll recreate such entries now. |
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2992 RecreateRSetEntriesClosure cl(_g1, _hr); |
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2993 obj->oop_iterate(&cl); |
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2994 assert(_cm->isPrevMarked(obj), "Should be marked!"); |
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2995 } else { |
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2996 // The object has been either evacuated or is dead. Fill it with a |
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2997 // dummy object. |
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2998 MemRegion mr((HeapWord*)obj, obj->size()); |
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2999 CollectedHeap::fill_with_object(mr); |
342 | 3000 _cm->clearRangeBothMaps(mr); |
3001 } | |
3002 } | |
3003 }; | |
3004 | |
3005 void G1CollectedHeap::remove_self_forwarding_pointers() { | |
3006 HeapRegion* cur = g1_policy()->collection_set(); | |
3007 | |
3008 while (cur != NULL) { | |
3009 assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!"); | |
3010 | |
3011 if (cur->evacuation_failed()) { | |
3012 RemoveSelfPointerClosure rspc(_g1h, cur); | |
3013 assert(cur->in_collection_set(), "bad CS"); | |
3014 cur->object_iterate(&rspc); | |
3015 | |
3016 // A number of manipulations to make the TAMS be the current top, | |
3017 // and the marked bytes be the ones observed in the iteration. | |
3018 if (_g1h->concurrent_mark()->at_least_one_mark_complete()) { | |
3019 // The comments below are the postconditions achieved by the | |
3020 // calls. Note especially the last such condition, which says that | |
3021 // the count of marked bytes has been properly restored. | |
3022 cur->note_start_of_marking(false); | |
3023 // _next_top_at_mark_start == top, _next_marked_bytes == 0 | |
3024 cur->add_to_marked_bytes(rspc.prev_marked_bytes()); | |
3025 // _next_marked_bytes == prev_marked_bytes. | |
3026 cur->note_end_of_marking(); | |
3027 // _prev_top_at_mark_start == top(), | |
3028 // _prev_marked_bytes == prev_marked_bytes | |
3029 } | |
3030 // If there is no mark in progress, we modified the _next variables | |
3031 // above needlessly, but harmlessly. | |
3032 if (_g1h->mark_in_progress()) { | |
3033 cur->note_start_of_marking(false); | |
3034 // _next_top_at_mark_start == top, _next_marked_bytes == 0 | |
3035 // _next_marked_bytes == next_marked_bytes. | |
3036 } | |
3037 | |
3038 // Now make sure the region has the right index in the sorted array. | |
3039 g1_policy()->note_change_in_marked_bytes(cur); | |
3040 } | |
3041 cur = cur->next_in_collection_set(); | |
3042 } | |
3043 assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!"); | |
3044 | |
3045 // Now restore saved marks, if any. | |
3046 if (_objs_with_preserved_marks != NULL) { | |
3047 assert(_preserved_marks_of_objs != NULL, "Both or none."); | |
3048 assert(_objs_with_preserved_marks->length() == | |
3049 _preserved_marks_of_objs->length(), "Both or none."); | |
3050 guarantee(_objs_with_preserved_marks->length() == | |
3051 _preserved_marks_of_objs->length(), "Both or none."); | |
3052 for (int i = 0; i < _objs_with_preserved_marks->length(); i++) { | |
3053 oop obj = _objs_with_preserved_marks->at(i); | |
3054 markOop m = _preserved_marks_of_objs->at(i); | |
3055 obj->set_mark(m); | |
3056 } | |
3057 // Delete the preserved marks growable arrays (allocated on the C heap). | |
3058 delete _objs_with_preserved_marks; | |
3059 delete _preserved_marks_of_objs; | |
3060 _objs_with_preserved_marks = NULL; | |
3061 _preserved_marks_of_objs = NULL; | |
3062 } | |
3063 } | |
3064 | |
3065 void G1CollectedHeap::push_on_evac_failure_scan_stack(oop obj) { | |
3066 _evac_failure_scan_stack->push(obj); | |
3067 } | |
3068 | |
3069 void G1CollectedHeap::drain_evac_failure_scan_stack() { | |
3070 assert(_evac_failure_scan_stack != NULL, "precondition"); | |
3071 | |
3072 while (_evac_failure_scan_stack->length() > 0) { | |
3073 oop obj = _evac_failure_scan_stack->pop(); | |
3074 _evac_failure_closure->set_region(heap_region_containing(obj)); | |
3075 obj->oop_iterate_backwards(_evac_failure_closure); | |
3076 } | |
3077 } | |
3078 | |
3079 void G1CollectedHeap::handle_evacuation_failure(oop old) { | |
3080 markOop m = old->mark(); | |
3081 // forward to self | |
3082 assert(!old->is_forwarded(), "precondition"); | |
3083 | |
3084 old->forward_to(old); | |
3085 handle_evacuation_failure_common(old, m); | |
3086 } | |
3087 | |
3088 oop | |
3089 G1CollectedHeap::handle_evacuation_failure_par(OopsInHeapRegionClosure* cl, | |
3090 oop old) { | |
3091 markOop m = old->mark(); | |
3092 oop forward_ptr = old->forward_to_atomic(old); | |
3093 if (forward_ptr == NULL) { | |
3094 // Forward-to-self succeeded. | |
3095 if (_evac_failure_closure != cl) { | |
3096 MutexLockerEx x(EvacFailureStack_lock, Mutex::_no_safepoint_check_flag); | |
3097 assert(!_drain_in_progress, | |
3098 "Should only be true while someone holds the lock."); | |
3099 // Set the global evac-failure closure to the current thread's. | |
3100 assert(_evac_failure_closure == NULL, "Or locking has failed."); | |
3101 set_evac_failure_closure(cl); | |
3102 // Now do the common part. | |
3103 handle_evacuation_failure_common(old, m); | |
3104 // Reset to NULL. | |
3105 set_evac_failure_closure(NULL); | |
3106 } else { | |
3107 // The lock is already held, and this is recursive. | |
3108 assert(_drain_in_progress, "This should only be the recursive case."); | |
3109 handle_evacuation_failure_common(old, m); | |
3110 } | |
3111 return old; | |
3112 } else { | |
3113 // Someone else had a place to copy it. | |
3114 return forward_ptr; | |
3115 } | |
3116 } | |
3117 | |
3118 void G1CollectedHeap::handle_evacuation_failure_common(oop old, markOop m) { | |
3119 set_evacuation_failed(true); | |
3120 | |
3121 preserve_mark_if_necessary(old, m); | |
3122 | |
3123 HeapRegion* r = heap_region_containing(old); | |
3124 if (!r->evacuation_failed()) { | |
3125 r->set_evacuation_failed(true); | |
3126 if (G1TraceRegions) { | |
3127 gclog_or_tty->print("evacuation failed in heap region "PTR_FORMAT" " | |
3128 "["PTR_FORMAT","PTR_FORMAT")\n", | |
3129 r, r->bottom(), r->end()); | |
3130 } | |
3131 } | |
3132 | |
3133 push_on_evac_failure_scan_stack(old); | |
3134 | |
3135 if (!_drain_in_progress) { | |
3136 // prevent recursion in copy_to_survivor_space() | |
3137 _drain_in_progress = true; | |
3138 drain_evac_failure_scan_stack(); | |
3139 _drain_in_progress = false; | |
3140 } | |
3141 } | |
3142 | |
3143 void G1CollectedHeap::preserve_mark_if_necessary(oop obj, markOop m) { | |
3144 if (m != markOopDesc::prototype()) { | |
3145 if (_objs_with_preserved_marks == NULL) { | |
3146 assert(_preserved_marks_of_objs == NULL, "Both or none."); | |
3147 _objs_with_preserved_marks = | |
3148 new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); | |
3149 _preserved_marks_of_objs = | |
3150 new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true); | |
3151 } | |
3152 _objs_with_preserved_marks->push(obj); | |
3153 _preserved_marks_of_objs->push(m); | |
3154 } | |
3155 } | |
3156 | |
3157 // *** Parallel G1 Evacuation | |
3158 | |
3159 HeapWord* G1CollectedHeap::par_allocate_during_gc(GCAllocPurpose purpose, | |
3160 size_t word_size) { | |
3161 HeapRegion* alloc_region = _gc_alloc_regions[purpose]; | |
3162 // let the caller handle alloc failure | |
3163 if (alloc_region == NULL) return NULL; | |
3164 | |
3165 HeapWord* block = alloc_region->par_allocate(word_size); | |
3166 if (block == NULL) { | |
3167 MutexLockerEx x(par_alloc_during_gc_lock(), | |
3168 Mutex::_no_safepoint_check_flag); | |
3169 block = allocate_during_gc_slow(purpose, alloc_region, true, word_size); | |
3170 } | |
3171 return block; | |
3172 } | |
3173 | |
545 | 3174 void G1CollectedHeap::retire_alloc_region(HeapRegion* alloc_region, |
3175 bool par) { | |
3176 // Another thread might have obtained alloc_region for the given | |
3177 // purpose, and might be attempting to allocate in it, and might | |
3178 // succeed. Therefore, we can't do the "finalization" stuff on the | |
3179 // region below until we're sure the last allocation has happened. | |
3180 // We ensure this by allocating the remaining space with a garbage | |
3181 // object. | |
3182 if (par) par_allocate_remaining_space(alloc_region); | |
3183 // Now we can do the post-GC stuff on the region. | |
3184 alloc_region->note_end_of_copying(); | |
3185 g1_policy()->record_after_bytes(alloc_region->used()); | |
3186 } | |
3187 | |
342 | 3188 HeapWord* |
3189 G1CollectedHeap::allocate_during_gc_slow(GCAllocPurpose purpose, | |
3190 HeapRegion* alloc_region, | |
3191 bool par, | |
3192 size_t word_size) { | |
3193 HeapWord* block = NULL; | |
3194 // In the parallel case, a previous thread to obtain the lock may have | |
3195 // already assigned a new gc_alloc_region. | |
3196 if (alloc_region != _gc_alloc_regions[purpose]) { | |
3197 assert(par, "But should only happen in parallel case."); | |
3198 alloc_region = _gc_alloc_regions[purpose]; | |
3199 if (alloc_region == NULL) return NULL; | |
3200 block = alloc_region->par_allocate(word_size); | |
3201 if (block != NULL) return block; | |
3202 // Otherwise, continue; this new region is empty, too. | |
3203 } | |
3204 assert(alloc_region != NULL, "We better have an allocation region"); | |
545 | 3205 retire_alloc_region(alloc_region, par); |
342 | 3206 |
3207 if (_gc_alloc_region_counts[purpose] >= g1_policy()->max_regions(purpose)) { | |
3208 // Cannot allocate more regions for the given purpose. | |
3209 GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(purpose); | |
3210 // Is there an alternative? | |
3211 if (purpose != alt_purpose) { | |
3212 HeapRegion* alt_region = _gc_alloc_regions[alt_purpose]; | |
3213 // Has not the alternative region been aliased? | |
545 | 3214 if (alloc_region != alt_region && alt_region != NULL) { |
342 | 3215 // Try to allocate in the alternative region. |
3216 if (par) { | |
3217 block = alt_region->par_allocate(word_size); | |
3218 } else { | |
3219 block = alt_region->allocate(word_size); | |
3220 } | |
3221 // Make an alias. | |
3222 _gc_alloc_regions[purpose] = _gc_alloc_regions[alt_purpose]; | |
545 | 3223 if (block != NULL) { |
3224 return block; | |
3225 } | |
3226 retire_alloc_region(alt_region, par); | |
342 | 3227 } |
3228 // Both the allocation region and the alternative one are full | |
3229 // and aliased, replace them with a new allocation region. | |
3230 purpose = alt_purpose; | |
3231 } else { | |
3232 set_gc_alloc_region(purpose, NULL); | |
3233 return NULL; | |
3234 } | |
3235 } | |
3236 | |
3237 // Now allocate a new region for allocation. | |
3238 alloc_region = newAllocRegionWithExpansion(purpose, word_size, false /*zero_filled*/); | |
3239 | |
3240 // let the caller handle alloc failure | |
3241 if (alloc_region != NULL) { | |
3242 | |
3243 assert(check_gc_alloc_regions(), "alloc regions messed up"); | |
3244 assert(alloc_region->saved_mark_at_top(), | |
3245 "Mark should have been saved already."); | |
3246 // We used to assert that the region was zero-filled here, but no | |
3247 // longer. | |
3248 | |
3249 // This must be done last: once it's installed, other regions may | |
3250 // allocate in it (without holding the lock.) | |
3251 set_gc_alloc_region(purpose, alloc_region); | |
3252 | |
3253 if (par) { | |
3254 block = alloc_region->par_allocate(word_size); | |
3255 } else { | |
3256 block = alloc_region->allocate(word_size); | |
3257 } | |
3258 // Caller handles alloc failure. | |
3259 } else { | |
3260 // This sets other apis using the same old alloc region to NULL, also. | |
3261 set_gc_alloc_region(purpose, NULL); | |
3262 } | |
3263 return block; // May be NULL. | |
3264 } | |
3265 | |
3266 void G1CollectedHeap::par_allocate_remaining_space(HeapRegion* r) { | |
3267 HeapWord* block = NULL; | |
3268 size_t free_words; | |
3269 do { | |
3270 free_words = r->free()/HeapWordSize; | |
3271 // If there's too little space, no one can allocate, so we're done. | |
3272 if (free_words < (size_t)oopDesc::header_size()) return; | |
3273 // Otherwise, try to claim it. | |
3274 block = r->par_allocate(free_words); | |
3275 } while (block == NULL); | |
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3276 fill_with_object(block, free_words); |
342 | 3277 } |
3278 | |
3279 #define use_local_bitmaps 1 | |
3280 #define verify_local_bitmaps 0 | |
3281 | |
3282 #ifndef PRODUCT | |
3283 | |
3284 class GCLabBitMap; | |
3285 class GCLabBitMapClosure: public BitMapClosure { | |
3286 private: | |
3287 ConcurrentMark* _cm; | |
3288 GCLabBitMap* _bitmap; | |
3289 | |
3290 public: | |
3291 GCLabBitMapClosure(ConcurrentMark* cm, | |
3292 GCLabBitMap* bitmap) { | |
3293 _cm = cm; | |
3294 _bitmap = bitmap; | |
3295 } | |
3296 | |
3297 virtual bool do_bit(size_t offset); | |
3298 }; | |
3299 | |
3300 #endif // PRODUCT | |
3301 | |
3302 #define oop_buffer_length 256 | |
3303 | |
3304 class GCLabBitMap: public BitMap { | |
3305 private: | |
3306 ConcurrentMark* _cm; | |
3307 | |
3308 int _shifter; | |
3309 size_t _bitmap_word_covers_words; | |
3310 | |
3311 // beginning of the heap | |
3312 HeapWord* _heap_start; | |
3313 | |
3314 // this is the actual start of the GCLab | |
3315 HeapWord* _real_start_word; | |
3316 | |
3317 // this is the actual end of the GCLab | |
3318 HeapWord* _real_end_word; | |
3319 | |
3320 // this is the first word, possibly located before the actual start | |
3321 // of the GCLab, that corresponds to the first bit of the bitmap | |
3322 HeapWord* _start_word; | |
3323 | |
3324 // size of a GCLab in words | |
3325 size_t _gclab_word_size; | |
3326 | |
3327 static int shifter() { | |
3328 return MinObjAlignment - 1; | |
3329 } | |
3330 | |
3331 // how many heap words does a single bitmap word corresponds to? | |
3332 static size_t bitmap_word_covers_words() { | |
3333 return BitsPerWord << shifter(); | |
3334 } | |
3335 | |
3336 static size_t gclab_word_size() { | |
3337 return ParallelGCG1AllocBufferSize / HeapWordSize; | |
3338 } | |
3339 | |
3340 static size_t bitmap_size_in_bits() { | |
3341 size_t bits_in_bitmap = gclab_word_size() >> shifter(); | |
3342 // We are going to ensure that the beginning of a word in this | |
3343 // bitmap also corresponds to the beginning of a word in the | |
3344 // global marking bitmap. To handle the case where a GCLab | |
3345 // starts from the middle of the bitmap, we need to add enough | |
3346 // space (i.e. up to a bitmap word) to ensure that we have | |
3347 // enough bits in the bitmap. | |
3348 return bits_in_bitmap + BitsPerWord - 1; | |
3349 } | |
3350 public: | |
3351 GCLabBitMap(HeapWord* heap_start) | |
3352 : BitMap(bitmap_size_in_bits()), | |
3353 _cm(G1CollectedHeap::heap()->concurrent_mark()), | |
3354 _shifter(shifter()), | |
3355 _bitmap_word_covers_words(bitmap_word_covers_words()), | |
3356 _heap_start(heap_start), | |
3357 _gclab_word_size(gclab_word_size()), | |
3358 _real_start_word(NULL), | |
3359 _real_end_word(NULL), | |
3360 _start_word(NULL) | |
3361 { | |
3362 guarantee( size_in_words() >= bitmap_size_in_words(), | |
3363 "just making sure"); | |
3364 } | |
3365 | |
3366 inline unsigned heapWordToOffset(HeapWord* addr) { | |
3367 unsigned offset = (unsigned) pointer_delta(addr, _start_word) >> _shifter; | |
3368 assert(offset < size(), "offset should be within bounds"); | |
3369 return offset; | |
3370 } | |
3371 | |
3372 inline HeapWord* offsetToHeapWord(size_t offset) { | |
3373 HeapWord* addr = _start_word + (offset << _shifter); | |
3374 assert(_real_start_word <= addr && addr < _real_end_word, "invariant"); | |
3375 return addr; | |
3376 } | |
3377 | |
3378 bool fields_well_formed() { | |
3379 bool ret1 = (_real_start_word == NULL) && | |
3380 (_real_end_word == NULL) && | |
3381 (_start_word == NULL); | |
3382 if (ret1) | |
3383 return true; | |
3384 | |
3385 bool ret2 = _real_start_word >= _start_word && | |
3386 _start_word < _real_end_word && | |
3387 (_real_start_word + _gclab_word_size) == _real_end_word && | |
3388 (_start_word + _gclab_word_size + _bitmap_word_covers_words) | |
3389 > _real_end_word; | |
3390 return ret2; | |
3391 } | |
3392 | |
3393 inline bool mark(HeapWord* addr) { | |
3394 guarantee(use_local_bitmaps, "invariant"); | |
3395 assert(fields_well_formed(), "invariant"); | |
3396 | |
3397 if (addr >= _real_start_word && addr < _real_end_word) { | |
3398 assert(!isMarked(addr), "should not have already been marked"); | |
3399 | |
3400 // first mark it on the bitmap | |
3401 at_put(heapWordToOffset(addr), true); | |
3402 | |
3403 return true; | |
3404 } else { | |
3405 return false; | |
3406 } | |
3407 } | |
3408 | |
3409 inline bool isMarked(HeapWord* addr) { | |
3410 guarantee(use_local_bitmaps, "invariant"); | |
3411 assert(fields_well_formed(), "invariant"); | |
3412 | |
3413 return at(heapWordToOffset(addr)); | |
3414 } | |
3415 | |
3416 void set_buffer(HeapWord* start) { | |
3417 guarantee(use_local_bitmaps, "invariant"); | |
3418 clear(); | |
3419 | |
3420 assert(start != NULL, "invariant"); | |
3421 _real_start_word = start; | |
3422 _real_end_word = start + _gclab_word_size; | |
3423 | |
3424 size_t diff = | |
3425 pointer_delta(start, _heap_start) % _bitmap_word_covers_words; | |
3426 _start_word = start - diff; | |
3427 | |
3428 assert(fields_well_formed(), "invariant"); | |
3429 } | |
3430 | |
3431 #ifndef PRODUCT | |
3432 void verify() { | |
3433 // verify that the marks have been propagated | |
3434 GCLabBitMapClosure cl(_cm, this); | |
3435 iterate(&cl); | |
3436 } | |
3437 #endif // PRODUCT | |
3438 | |
3439 void retire() { | |
3440 guarantee(use_local_bitmaps, "invariant"); | |
3441 assert(fields_well_formed(), "invariant"); | |
3442 | |
3443 if (_start_word != NULL) { | |
3444 CMBitMap* mark_bitmap = _cm->nextMarkBitMap(); | |
3445 | |
3446 // this means that the bitmap was set up for the GCLab | |
3447 assert(_real_start_word != NULL && _real_end_word != NULL, "invariant"); | |
3448 | |
3449 mark_bitmap->mostly_disjoint_range_union(this, | |
3450 0, // always start from the start of the bitmap | |
3451 _start_word, | |
3452 size_in_words()); | |
3453 _cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word)); | |
3454 | |
3455 #ifndef PRODUCT | |
3456 if (use_local_bitmaps && verify_local_bitmaps) | |
3457 verify(); | |
3458 #endif // PRODUCT | |
3459 } else { | |
3460 assert(_real_start_word == NULL && _real_end_word == NULL, "invariant"); | |
3461 } | |
3462 } | |
3463 | |
3464 static size_t bitmap_size_in_words() { | |
3465 return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord; | |
3466 } | |
3467 }; | |
3468 | |
3469 #ifndef PRODUCT | |
3470 | |
3471 bool GCLabBitMapClosure::do_bit(size_t offset) { | |
3472 HeapWord* addr = _bitmap->offsetToHeapWord(offset); | |
3473 guarantee(_cm->isMarked(oop(addr)), "it should be!"); | |
3474 return true; | |
3475 } | |
3476 | |
3477 #endif // PRODUCT | |
3478 | |
3479 class G1ParGCAllocBuffer: public ParGCAllocBuffer { | |
3480 private: | |
3481 bool _retired; | |
3482 bool _during_marking; | |
3483 GCLabBitMap _bitmap; | |
3484 | |
3485 public: | |
3486 G1ParGCAllocBuffer() : | |
3487 ParGCAllocBuffer(ParallelGCG1AllocBufferSize / HeapWordSize), | |
3488 _during_marking(G1CollectedHeap::heap()->mark_in_progress()), | |
3489 _bitmap(G1CollectedHeap::heap()->reserved_region().start()), | |
3490 _retired(false) | |
3491 { } | |
3492 | |
3493 inline bool mark(HeapWord* addr) { | |
3494 guarantee(use_local_bitmaps, "invariant"); | |
3495 assert(_during_marking, "invariant"); | |
3496 return _bitmap.mark(addr); | |
3497 } | |
3498 | |
3499 inline void set_buf(HeapWord* buf) { | |
3500 if (use_local_bitmaps && _during_marking) | |
3501 _bitmap.set_buffer(buf); | |
3502 ParGCAllocBuffer::set_buf(buf); | |
3503 _retired = false; | |
3504 } | |
3505 | |
3506 inline void retire(bool end_of_gc, bool retain) { | |
3507 if (_retired) | |
3508 return; | |
3509 if (use_local_bitmaps && _during_marking) { | |
3510 _bitmap.retire(); | |
3511 } | |
3512 ParGCAllocBuffer::retire(end_of_gc, retain); | |
3513 _retired = true; | |
3514 } | |
3515 }; | |
3516 | |
3517 | |
3518 class G1ParScanThreadState : public StackObj { | |
3519 protected: | |
3520 G1CollectedHeap* _g1h; | |
3521 RefToScanQueue* _refs; | |
3522 | |
3523 typedef GrowableArray<oop*> OverflowQueue; | |
3524 OverflowQueue* _overflowed_refs; | |
3525 | |
3526 G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount]; | |
545 | 3527 ageTable _age_table; |
342 | 3528 |
3529 size_t _alloc_buffer_waste; | |
3530 size_t _undo_waste; | |
3531 | |
3532 OopsInHeapRegionClosure* _evac_failure_cl; | |
3533 G1ParScanHeapEvacClosure* _evac_cl; | |
3534 G1ParScanPartialArrayClosure* _partial_scan_cl; | |
3535 | |
3536 int _hash_seed; | |
3537 int _queue_num; | |
3538 | |
3539 int _term_attempts; | |
3540 #if G1_DETAILED_STATS | |
3541 int _pushes, _pops, _steals, _steal_attempts; | |
3542 int _overflow_pushes; | |
3543 #endif | |
3544 | |
3545 double _start; | |
3546 double _start_strong_roots; | |
3547 double _strong_roots_time; | |
3548 double _start_term; | |
3549 double _term_time; | |
3550 | |
3551 // Map from young-age-index (0 == not young, 1 is youngest) to | |
3552 // surviving words. base is what we get back from the malloc call | |
3553 size_t* _surviving_young_words_base; | |
3554 // this points into the array, as we use the first few entries for padding | |
3555 size_t* _surviving_young_words; | |
3556 | |
3557 #define PADDING_ELEM_NUM (64 / sizeof(size_t)) | |
3558 | |
3559 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } | |
3560 | |
3561 void add_to_undo_waste(size_t waste) { _undo_waste += waste; } | |
3562 | |
3563 public: | |
3564 G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num) | |
3565 : _g1h(g1h), | |
3566 _refs(g1h->task_queue(queue_num)), | |
3567 _hash_seed(17), _queue_num(queue_num), | |
3568 _term_attempts(0), | |
545 | 3569 _age_table(false), |
342 | 3570 #if G1_DETAILED_STATS |
3571 _pushes(0), _pops(0), _steals(0), | |
3572 _steal_attempts(0), _overflow_pushes(0), | |
3573 #endif | |
3574 _strong_roots_time(0), _term_time(0), | |
3575 _alloc_buffer_waste(0), _undo_waste(0) | |
3576 { | |
3577 // we allocate G1YoungSurvRateNumRegions plus one entries, since | |
3578 // we "sacrifice" entry 0 to keep track of surviving bytes for | |
3579 // non-young regions (where the age is -1) | |
3580 // We also add a few elements at the beginning and at the end in | |
3581 // an attempt to eliminate cache contention | |
3582 size_t real_length = 1 + _g1h->g1_policy()->young_cset_length(); | |
3583 size_t array_length = PADDING_ELEM_NUM + | |
3584 real_length + | |
3585 PADDING_ELEM_NUM; | |
3586 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length); | |
3587 if (_surviving_young_words_base == NULL) | |
3588 vm_exit_out_of_memory(array_length * sizeof(size_t), | |
3589 "Not enough space for young surv histo."); | |
3590 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM; | |
3591 memset(_surviving_young_words, 0, real_length * sizeof(size_t)); | |
3592 | |
3593 _overflowed_refs = new OverflowQueue(10); | |
3594 | |
3595 _start = os::elapsedTime(); | |
3596 } | |
3597 | |
3598 ~G1ParScanThreadState() { | |
3599 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base); | |
3600 } | |
3601 | |
3602 RefToScanQueue* refs() { return _refs; } | |
3603 OverflowQueue* overflowed_refs() { return _overflowed_refs; } | |
545 | 3604 ageTable* age_table() { return &_age_table; } |
3605 | |
3606 G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) { | |
342 | 3607 return &_alloc_buffers[purpose]; |
3608 } | |
3609 | |
3610 size_t alloc_buffer_waste() { return _alloc_buffer_waste; } | |
3611 size_t undo_waste() { return _undo_waste; } | |
3612 | |
3613 void push_on_queue(oop* ref) { | |
526 | 3614 assert(ref != NULL, "invariant"); |
3615 assert(has_partial_array_mask(ref) || _g1h->obj_in_cs(*ref), "invariant"); | |
3616 | |
342 | 3617 if (!refs()->push(ref)) { |
3618 overflowed_refs()->push(ref); | |
3619 IF_G1_DETAILED_STATS(note_overflow_push()); | |
3620 } else { | |
3621 IF_G1_DETAILED_STATS(note_push()); | |
3622 } | |
3623 } | |
3624 | |
3625 void pop_from_queue(oop*& ref) { | |
3626 if (!refs()->pop_local(ref)) { | |
3627 ref = NULL; | |
3628 } else { | |
526 | 3629 assert(ref != NULL, "invariant"); |
3630 assert(has_partial_array_mask(ref) || _g1h->obj_in_cs(*ref), | |
3631 "invariant"); | |
3632 | |
342 | 3633 IF_G1_DETAILED_STATS(note_pop()); |
3634 } | |
3635 } | |
3636 | |
3637 void pop_from_overflow_queue(oop*& ref) { | |
3638 ref = overflowed_refs()->pop(); | |
3639 } | |
3640 | |
3641 int refs_to_scan() { return refs()->size(); } | |
3642 int overflowed_refs_to_scan() { return overflowed_refs()->length(); } | |
3643 | |
3644 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) { | |
3645 | |
3646 HeapWord* obj = NULL; | |
3647 if (word_sz * 100 < | |
3648 (size_t)(ParallelGCG1AllocBufferSize / HeapWordSize) * | |
3649 ParallelGCBufferWastePct) { | |
3650 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); | |
3651 add_to_alloc_buffer_waste(alloc_buf->words_remaining()); | |
3652 alloc_buf->retire(false, false); | |
3653 | |
3654 HeapWord* buf = | |
3655 _g1h->par_allocate_during_gc(purpose, ParallelGCG1AllocBufferSize / HeapWordSize); | |
3656 if (buf == NULL) return NULL; // Let caller handle allocation failure. | |
3657 // Otherwise. | |
3658 alloc_buf->set_buf(buf); | |
3659 | |
3660 obj = alloc_buf->allocate(word_sz); | |
3661 assert(obj != NULL, "buffer was definitely big enough..."); | |
526 | 3662 } else { |
342 | 3663 obj = _g1h->par_allocate_during_gc(purpose, word_sz); |
3664 } | |
3665 return obj; | |
3666 } | |
3667 | |
3668 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) { | |
3669 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); | |
3670 if (obj != NULL) return obj; | |
3671 return allocate_slow(purpose, word_sz); | |
3672 } | |
3673 | |
3674 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { | |
3675 if (alloc_buffer(purpose)->contains(obj)) { | |
3676 guarantee(alloc_buffer(purpose)->contains(obj + word_sz - 1), | |
3677 "should contain whole object"); | |
3678 alloc_buffer(purpose)->undo_allocation(obj, word_sz); | |
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|
3679 } else { |
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diff
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|
3680 CollectedHeap::fill_with_object(obj, word_sz); |
342 | 3681 add_to_undo_waste(word_sz); |
3682 } | |
3683 } | |
3684 | |
3685 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) { | |
3686 _evac_failure_cl = evac_failure_cl; | |
3687 } | |
3688 OopsInHeapRegionClosure* evac_failure_closure() { | |
3689 return _evac_failure_cl; | |
3690 } | |
3691 | |
3692 void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) { | |
3693 _evac_cl = evac_cl; | |
3694 } | |
3695 | |
3696 void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) { | |
3697 _partial_scan_cl = partial_scan_cl; | |
3698 } | |
3699 | |
3700 int* hash_seed() { return &_hash_seed; } | |
3701 int queue_num() { return _queue_num; } | |
3702 | |
3703 int term_attempts() { return _term_attempts; } | |
3704 void note_term_attempt() { _term_attempts++; } | |
3705 | |
3706 #if G1_DETAILED_STATS | |
3707 int pushes() { return _pushes; } | |
3708 int pops() { return _pops; } | |
3709 int steals() { return _steals; } | |
3710 int steal_attempts() { return _steal_attempts; } | |
3711 int overflow_pushes() { return _overflow_pushes; } | |
3712 | |
3713 void note_push() { _pushes++; } | |
3714 void note_pop() { _pops++; } | |
3715 void note_steal() { _steals++; } | |
3716 void note_steal_attempt() { _steal_attempts++; } | |
3717 void note_overflow_push() { _overflow_pushes++; } | |
3718 #endif | |
3719 | |
3720 void start_strong_roots() { | |
3721 _start_strong_roots = os::elapsedTime(); | |
3722 } | |
3723 void end_strong_roots() { | |
3724 _strong_roots_time += (os::elapsedTime() - _start_strong_roots); | |
3725 } | |
3726 double strong_roots_time() { return _strong_roots_time; } | |
3727 | |
3728 void start_term_time() { | |
3729 note_term_attempt(); | |
3730 _start_term = os::elapsedTime(); | |
3731 } | |
3732 void end_term_time() { | |
3733 _term_time += (os::elapsedTime() - _start_term); | |
3734 } | |
3735 double term_time() { return _term_time; } | |
3736 | |
3737 double elapsed() { | |
3738 return os::elapsedTime() - _start; | |
3739 } | |
3740 | |
3741 size_t* surviving_young_words() { | |
3742 // We add on to hide entry 0 which accumulates surviving words for | |
3743 // age -1 regions (i.e. non-young ones) | |
3744 return _surviving_young_words; | |
3745 } | |
3746 | |
3747 void retire_alloc_buffers() { | |
3748 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { | |
3749 size_t waste = _alloc_buffers[ap].words_remaining(); | |
3750 add_to_alloc_buffer_waste(waste); | |
3751 _alloc_buffers[ap].retire(true, false); | |
3752 } | |
3753 } | |
3754 | |
526 | 3755 private: |
3756 void deal_with_reference(oop* ref_to_scan) { | |
3757 if (has_partial_array_mask(ref_to_scan)) { | |
3758 _partial_scan_cl->do_oop_nv(ref_to_scan); | |
3759 } else { | |
3760 // Note: we can use "raw" versions of "region_containing" because | |
3761 // "obj_to_scan" is definitely in the heap, and is not in a | |
3762 // humongous region. | |
3763 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan); | |
3764 _evac_cl->set_region(r); | |
3765 _evac_cl->do_oop_nv(ref_to_scan); | |
3766 } | |
3767 } | |
3768 | |
3769 public: | |
342 | 3770 void trim_queue() { |
526 | 3771 // I've replicated the loop twice, first to drain the overflow |
3772 // queue, second to drain the task queue. This is better than | |
3773 // having a single loop, which checks both conditions and, inside | |
3774 // it, either pops the overflow queue or the task queue, as each | |
3775 // loop is tighter. Also, the decision to drain the overflow queue | |
3776 // first is not arbitrary, as the overflow queue is not visible | |
3777 // to the other workers, whereas the task queue is. So, we want to | |
3778 // drain the "invisible" entries first, while allowing the other | |
3779 // workers to potentially steal the "visible" entries. | |
3780 | |
342 | 3781 while (refs_to_scan() > 0 || overflowed_refs_to_scan() > 0) { |
526 | 3782 while (overflowed_refs_to_scan() > 0) { |
3783 oop *ref_to_scan = NULL; | |
342 | 3784 pop_from_overflow_queue(ref_to_scan); |
526 | 3785 assert(ref_to_scan != NULL, "invariant"); |
3786 // We shouldn't have pushed it on the queue if it was not | |
3787 // pointing into the CSet. | |
3788 assert(ref_to_scan != NULL, "sanity"); | |
3789 assert(has_partial_array_mask(ref_to_scan) || | |
3790 _g1h->obj_in_cs(*ref_to_scan), "sanity"); | |
3791 | |
3792 deal_with_reference(ref_to_scan); | |
342 | 3793 } |
526 | 3794 |
3795 while (refs_to_scan() > 0) { | |
3796 oop *ref_to_scan = NULL; | |
3797 pop_from_queue(ref_to_scan); | |
3798 | |
3799 if (ref_to_scan != NULL) { | |
3800 // We shouldn't have pushed it on the queue if it was not | |
3801 // pointing into the CSet. | |
3802 assert(has_partial_array_mask(ref_to_scan) || | |
3803 _g1h->obj_in_cs(*ref_to_scan), "sanity"); | |
3804 | |
3805 deal_with_reference(ref_to_scan); | |
342 | 3806 } |
3807 } | |
3808 } | |
3809 } | |
3810 }; | |
3811 | |
3812 | |
3813 G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state) : | |
3814 _g1(g1), _g1_rem(_g1->g1_rem_set()), _cm(_g1->concurrent_mark()), | |
3815 _par_scan_state(par_scan_state) { } | |
3816 | |
3817 // This closure is applied to the fields of the objects that have just been copied. | |
3818 // Should probably be made inline and moved in g1OopClosures.inline.hpp. | |
3819 void G1ParScanClosure::do_oop_nv(oop* p) { | |
3820 oop obj = *p; | |
526 | 3821 |
342 | 3822 if (obj != NULL) { |
526 | 3823 if (_g1->in_cset_fast_test(obj)) { |
3824 // We're not going to even bother checking whether the object is | |
3825 // already forwarded or not, as this usually causes an immediate | |
3826 // stall. We'll try to prefetch the object (for write, given that | |
3827 // we might need to install the forwarding reference) and we'll | |
3828 // get back to it when pop it from the queue | |
3829 Prefetch::write(obj->mark_addr(), 0); | |
3830 Prefetch::read(obj->mark_addr(), (HeapWordSize*2)); | |
3831 | |
3832 // slightly paranoid test; I'm trying to catch potential | |
3833 // problems before we go into push_on_queue to know where the | |
3834 // problem is coming from | |
3835 assert(obj == *p, "the value of *p should not have changed"); | |
3836 _par_scan_state->push_on_queue(p); | |
3837 } else { | |
3838 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); | |
342 | 3839 } |
3840 } | |
3841 } | |
3842 | |
3843 void G1ParCopyHelper::mark_forwardee(oop* p) { | |
3844 // This is called _after_ do_oop_work has been called, hence after | |
3845 // the object has been relocated to its new location and *p points | |
3846 // to its new location. | |
3847 | |
3848 oop thisOop = *p; | |
3849 if (thisOop != NULL) { | |
3850 assert((_g1->evacuation_failed()) || (!_g1->obj_in_cs(thisOop)), | |
3851 "shouldn't still be in the CSet if evacuation didn't fail."); | |
3852 HeapWord* addr = (HeapWord*)thisOop; | |
3853 if (_g1->is_in_g1_reserved(addr)) | |
3854 _cm->grayRoot(oop(addr)); | |
3855 } | |
3856 } | |
3857 | |
3858 oop G1ParCopyHelper::copy_to_survivor_space(oop old) { | |
3859 size_t word_sz = old->size(); | |
3860 HeapRegion* from_region = _g1->heap_region_containing_raw(old); | |
3861 // +1 to make the -1 indexes valid... | |
3862 int young_index = from_region->young_index_in_cset()+1; | |
3863 assert( (from_region->is_young() && young_index > 0) || | |
3864 (!from_region->is_young() && young_index == 0), "invariant" ); | |
3865 G1CollectorPolicy* g1p = _g1->g1_policy(); | |
3866 markOop m = old->mark(); | |
545 | 3867 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age() |
3868 : m->age(); | |
3869 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age, | |
342 | 3870 word_sz); |
3871 HeapWord* obj_ptr = _par_scan_state->allocate(alloc_purpose, word_sz); | |
3872 oop obj = oop(obj_ptr); | |
3873 | |
3874 if (obj_ptr == NULL) { | |
3875 // This will either forward-to-self, or detect that someone else has | |
3876 // installed a forwarding pointer. | |
3877 OopsInHeapRegionClosure* cl = _par_scan_state->evac_failure_closure(); | |
3878 return _g1->handle_evacuation_failure_par(cl, old); | |
3879 } | |
3880 | |
526 | 3881 // We're going to allocate linearly, so might as well prefetch ahead. |
3882 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); | |
3883 | |
342 | 3884 oop forward_ptr = old->forward_to_atomic(obj); |
3885 if (forward_ptr == NULL) { | |
3886 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz); | |
526 | 3887 if (g1p->track_object_age(alloc_purpose)) { |
3888 // We could simply do obj->incr_age(). However, this causes a | |
3889 // performance issue. obj->incr_age() will first check whether | |
3890 // the object has a displaced mark by checking its mark word; | |
3891 // getting the mark word from the new location of the object | |
3892 // stalls. So, given that we already have the mark word and we | |
3893 // are about to install it anyway, it's better to increase the | |
3894 // age on the mark word, when the object does not have a | |
3895 // displaced mark word. We're not expecting many objects to have | |
3896 // a displaced marked word, so that case is not optimized | |
3897 // further (it could be...) and we simply call obj->incr_age(). | |
3898 | |
3899 if (m->has_displaced_mark_helper()) { | |
3900 // in this case, we have to install the mark word first, | |
3901 // otherwise obj looks to be forwarded (the old mark word, | |
3902 // which contains the forward pointer, was copied) | |
3903 obj->set_mark(m); | |
3904 obj->incr_age(); | |
3905 } else { | |
3906 m = m->incr_age(); | |
545 | 3907 obj->set_mark(m); |
526 | 3908 } |
545 | 3909 _par_scan_state->age_table()->add(obj, word_sz); |
3910 } else { | |
3911 obj->set_mark(m); | |
526 | 3912 } |
3913 | |
342 | 3914 // preserve "next" mark bit |
3915 if (_g1->mark_in_progress() && !_g1->is_obj_ill(old)) { | |
3916 if (!use_local_bitmaps || | |
3917 !_par_scan_state->alloc_buffer(alloc_purpose)->mark(obj_ptr)) { | |
3918 // if we couldn't mark it on the local bitmap (this happens when | |
3919 // the object was not allocated in the GCLab), we have to bite | |
3920 // the bullet and do the standard parallel mark | |
3921 _cm->markAndGrayObjectIfNecessary(obj); | |
3922 } | |
3923 #if 1 | |
3924 if (_g1->isMarkedNext(old)) { | |
3925 _cm->nextMarkBitMap()->parClear((HeapWord*)old); | |
3926 } | |
3927 #endif | |
3928 } | |
3929 | |
3930 size_t* surv_young_words = _par_scan_state->surviving_young_words(); | |
3931 surv_young_words[young_index] += word_sz; | |
3932 | |
3933 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) { | |
3934 arrayOop(old)->set_length(0); | |
526 | 3935 _par_scan_state->push_on_queue(set_partial_array_mask(old)); |
342 | 3936 } else { |
526 | 3937 // No point in using the slower heap_region_containing() method, |
3938 // given that we know obj is in the heap. | |
3939 _scanner->set_region(_g1->heap_region_containing_raw(obj)); | |
342 | 3940 obj->oop_iterate_backwards(_scanner); |
3941 } | |
3942 } else { | |
3943 _par_scan_state->undo_allocation(alloc_purpose, obj_ptr, word_sz); | |
3944 obj = forward_ptr; | |
3945 } | |
3946 return obj; | |
3947 } | |
3948 | |
526 | 3949 template<bool do_gen_barrier, G1Barrier barrier, |
3950 bool do_mark_forwardee, bool skip_cset_test> | |
3951 void G1ParCopyClosure<do_gen_barrier, barrier, | |
3952 do_mark_forwardee, skip_cset_test>::do_oop_work(oop* p) { | |
342 | 3953 oop obj = *p; |
3954 assert(barrier != G1BarrierRS || obj != NULL, | |
3955 "Precondition: G1BarrierRS implies obj is nonNull"); | |
3956 | |
526 | 3957 // The only time we skip the cset test is when we're scanning |
3958 // references popped from the queue. And we only push on the queue | |
3959 // references that we know point into the cset, so no point in | |
3960 // checking again. But we'll leave an assert here for peace of mind. | |
3961 assert(!skip_cset_test || _g1->obj_in_cs(obj), "invariant"); | |
3962 | |
3963 // here the null check is implicit in the cset_fast_test() test | |
3964 if (skip_cset_test || _g1->in_cset_fast_test(obj)) { | |
342 | 3965 #if G1_REM_SET_LOGGING |
526 | 3966 gclog_or_tty->print_cr("Loc "PTR_FORMAT" contains pointer "PTR_FORMAT" " |
3967 "into CS.", p, (void*) obj); | |
342 | 3968 #endif |
526 | 3969 if (obj->is_forwarded()) { |
3970 *p = obj->forwardee(); | |
3971 } else { | |
3972 *p = copy_to_survivor_space(obj); | |
342 | 3973 } |
526 | 3974 // When scanning the RS, we only care about objs in CS. |
3975 if (barrier == G1BarrierRS) { | |
342 | 3976 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); |
3977 } | |
526 | 3978 } |
3979 | |
3980 // When scanning moved objs, must look at all oops. | |
3981 if (barrier == G1BarrierEvac && obj != NULL) { | |
3982 _g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num()); | |
3983 } | |
3984 | |
3985 if (do_gen_barrier && obj != NULL) { | |
3986 par_do_barrier(p); | |
3987 } | |
3988 } | |
3989 | |
3990 template void G1ParCopyClosure<false, G1BarrierEvac, false, true>::do_oop_work(oop* p); | |
3991 | |
3992 template<class T> void G1ParScanPartialArrayClosure::process_array_chunk( | |
342 | 3993 oop obj, int start, int end) { |
3994 // process our set of indices (include header in first chunk) | |
3995 assert(start < end, "invariant"); | |
3996 T* const base = (T*)objArrayOop(obj)->base(); | |
526 | 3997 T* const start_addr = (start == 0) ? (T*) obj : base + start; |
342 | 3998 T* const end_addr = base + end; |
3999 MemRegion mr((HeapWord*)start_addr, (HeapWord*)end_addr); | |
4000 _scanner.set_region(_g1->heap_region_containing(obj)); | |
4001 obj->oop_iterate(&_scanner, mr); | |
4002 } | |
4003 | |
4004 void G1ParScanPartialArrayClosure::do_oop_nv(oop* p) { | |
4005 assert(!UseCompressedOops, "Needs to be fixed to work with compressed oops"); | |
526 | 4006 assert(has_partial_array_mask(p), "invariant"); |
4007 oop old = clear_partial_array_mask(p); | |
342 | 4008 assert(old->is_objArray(), "must be obj array"); |
4009 assert(old->is_forwarded(), "must be forwarded"); | |
4010 assert(Universe::heap()->is_in_reserved(old), "must be in heap."); | |
4011 | |
4012 objArrayOop obj = objArrayOop(old->forwardee()); | |
4013 assert((void*)old != (void*)old->forwardee(), "self forwarding here?"); | |
4014 // Process ParGCArrayScanChunk elements now | |
4015 // and push the remainder back onto queue | |
4016 int start = arrayOop(old)->length(); | |
4017 int end = obj->length(); | |
4018 int remainder = end - start; | |
4019 assert(start <= end, "just checking"); | |
4020 if (remainder > 2 * ParGCArrayScanChunk) { | |
4021 // Test above combines last partial chunk with a full chunk | |
4022 end = start + ParGCArrayScanChunk; | |
4023 arrayOop(old)->set_length(end); | |
4024 // Push remainder. | |
526 | 4025 _par_scan_state->push_on_queue(set_partial_array_mask(old)); |
342 | 4026 } else { |
4027 // Restore length so that the heap remains parsable in | |
4028 // case of evacuation failure. | |
4029 arrayOop(old)->set_length(end); | |
4030 } | |
4031 | |
4032 // process our set of indices (include header in first chunk) | |
4033 process_array_chunk<oop>(obj, start, end); | |
4034 } | |
4035 | |
4036 int G1ScanAndBalanceClosure::_nq = 0; | |
4037 | |
4038 class G1ParEvacuateFollowersClosure : public VoidClosure { | |
4039 protected: | |
4040 G1CollectedHeap* _g1h; | |
4041 G1ParScanThreadState* _par_scan_state; | |
4042 RefToScanQueueSet* _queues; | |
4043 ParallelTaskTerminator* _terminator; | |
4044 | |
4045 G1ParScanThreadState* par_scan_state() { return _par_scan_state; } | |
4046 RefToScanQueueSet* queues() { return _queues; } | |
4047 ParallelTaskTerminator* terminator() { return _terminator; } | |
4048 | |
4049 public: | |
4050 G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h, | |
4051 G1ParScanThreadState* par_scan_state, | |
4052 RefToScanQueueSet* queues, | |
4053 ParallelTaskTerminator* terminator) | |
4054 : _g1h(g1h), _par_scan_state(par_scan_state), | |
4055 _queues(queues), _terminator(terminator) {} | |
4056 | |
4057 void do_void() { | |
4058 G1ParScanThreadState* pss = par_scan_state(); | |
4059 while (true) { | |
4060 oop* ref_to_scan; | |
4061 pss->trim_queue(); | |
4062 IF_G1_DETAILED_STATS(pss->note_steal_attempt()); | |
4063 if (queues()->steal(pss->queue_num(), | |
4064 pss->hash_seed(), | |
4065 ref_to_scan)) { | |
4066 IF_G1_DETAILED_STATS(pss->note_steal()); | |
526 | 4067 |
4068 // slightly paranoid tests; I'm trying to catch potential | |
4069 // problems before we go into push_on_queue to know where the | |
4070 // problem is coming from | |
4071 assert(ref_to_scan != NULL, "invariant"); | |
4072 assert(has_partial_array_mask(ref_to_scan) || | |
4073 _g1h->obj_in_cs(*ref_to_scan), "invariant"); | |
342 | 4074 pss->push_on_queue(ref_to_scan); |
4075 continue; | |
4076 } | |
4077 pss->start_term_time(); | |
4078 if (terminator()->offer_termination()) break; | |
4079 pss->end_term_time(); | |
4080 } | |
4081 pss->end_term_time(); | |
4082 pss->retire_alloc_buffers(); | |
4083 } | |
4084 }; | |
4085 | |
4086 class G1ParTask : public AbstractGangTask { | |
4087 protected: | |
4088 G1CollectedHeap* _g1h; | |
4089 RefToScanQueueSet *_queues; | |
4090 ParallelTaskTerminator _terminator; | |
4091 | |
4092 Mutex _stats_lock; | |
4093 Mutex* stats_lock() { return &_stats_lock; } | |
4094 | |
4095 size_t getNCards() { | |
4096 return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1) | |
4097 / G1BlockOffsetSharedArray::N_bytes; | |
4098 } | |
4099 | |
4100 public: | |
4101 G1ParTask(G1CollectedHeap* g1h, int workers, RefToScanQueueSet *task_queues) | |
4102 : AbstractGangTask("G1 collection"), | |
4103 _g1h(g1h), | |
4104 _queues(task_queues), | |
4105 _terminator(workers, _queues), | |
4106 _stats_lock(Mutex::leaf, "parallel G1 stats lock", true) | |
4107 {} | |
4108 | |
4109 RefToScanQueueSet* queues() { return _queues; } | |
4110 | |
4111 RefToScanQueue *work_queue(int i) { | |
4112 return queues()->queue(i); | |
4113 } | |
4114 | |
4115 void work(int i) { | |
4116 ResourceMark rm; | |
4117 HandleMark hm; | |
4118 | |
526 | 4119 G1ParScanThreadState pss(_g1h, i); |
4120 G1ParScanHeapEvacClosure scan_evac_cl(_g1h, &pss); | |
4121 G1ParScanHeapEvacFailureClosure evac_failure_cl(_g1h, &pss); | |
4122 G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss); | |
342 | 4123 |
4124 pss.set_evac_closure(&scan_evac_cl); | |
4125 pss.set_evac_failure_closure(&evac_failure_cl); | |
4126 pss.set_partial_scan_closure(&partial_scan_cl); | |
4127 | |
4128 G1ParScanExtRootClosure only_scan_root_cl(_g1h, &pss); | |
4129 G1ParScanPermClosure only_scan_perm_cl(_g1h, &pss); | |
4130 G1ParScanHeapRSClosure only_scan_heap_rs_cl(_g1h, &pss); | |
4131 G1ParScanAndMarkExtRootClosure scan_mark_root_cl(_g1h, &pss); | |
4132 G1ParScanAndMarkPermClosure scan_mark_perm_cl(_g1h, &pss); | |
4133 G1ParScanAndMarkHeapRSClosure scan_mark_heap_rs_cl(_g1h, &pss); | |
4134 | |
4135 OopsInHeapRegionClosure *scan_root_cl; | |
4136 OopsInHeapRegionClosure *scan_perm_cl; | |
4137 OopsInHeapRegionClosure *scan_so_cl; | |
4138 | |
4139 if (_g1h->g1_policy()->should_initiate_conc_mark()) { | |
4140 scan_root_cl = &scan_mark_root_cl; | |
4141 scan_perm_cl = &scan_mark_perm_cl; | |
4142 scan_so_cl = &scan_mark_heap_rs_cl; | |
4143 } else { | |
4144 scan_root_cl = &only_scan_root_cl; | |
4145 scan_perm_cl = &only_scan_perm_cl; | |
4146 scan_so_cl = &only_scan_heap_rs_cl; | |
4147 } | |
4148 | |
4149 pss.start_strong_roots(); | |
4150 _g1h->g1_process_strong_roots(/* not collecting perm */ false, | |
4151 SharedHeap::SO_AllClasses, | |
4152 scan_root_cl, | |
4153 &only_scan_heap_rs_cl, | |
4154 scan_so_cl, | |
4155 scan_perm_cl, | |
4156 i); | |
4157 pss.end_strong_roots(); | |
4158 { | |
4159 double start = os::elapsedTime(); | |
4160 G1ParEvacuateFollowersClosure evac(_g1h, &pss, _queues, &_terminator); | |
4161 evac.do_void(); | |
4162 double elapsed_ms = (os::elapsedTime()-start)*1000.0; | |
4163 double term_ms = pss.term_time()*1000.0; | |
4164 _g1h->g1_policy()->record_obj_copy_time(i, elapsed_ms-term_ms); | |
4165 _g1h->g1_policy()->record_termination_time(i, term_ms); | |
4166 } | |
545 | 4167 if (G1UseSurvivorSpace) { |
4168 _g1h->g1_policy()->record_thread_age_table(pss.age_table()); | |
4169 } | |
342 | 4170 _g1h->update_surviving_young_words(pss.surviving_young_words()+1); |
4171 | |
4172 // Clean up any par-expanded rem sets. | |
4173 HeapRegionRemSet::par_cleanup(); | |
4174 | |
4175 MutexLocker x(stats_lock()); | |
4176 if (ParallelGCVerbose) { | |
4177 gclog_or_tty->print("Thread %d complete:\n", i); | |
4178 #if G1_DETAILED_STATS | |
4179 gclog_or_tty->print(" Pushes: %7d Pops: %7d Overflows: %7d Steals %7d (in %d attempts)\n", | |
4180 pss.pushes(), | |
4181 pss.pops(), | |
4182 pss.overflow_pushes(), | |
4183 pss.steals(), | |
4184 pss.steal_attempts()); | |
4185 #endif | |
4186 double elapsed = pss.elapsed(); | |
4187 double strong_roots = pss.strong_roots_time(); | |
4188 double term = pss.term_time(); | |
4189 gclog_or_tty->print(" Elapsed: %7.2f ms.\n" | |
4190 " Strong roots: %7.2f ms (%6.2f%%)\n" | |
4191 " Termination: %7.2f ms (%6.2f%%) (in %d entries)\n", | |
4192 elapsed * 1000.0, | |
4193 strong_roots * 1000.0, (strong_roots*100.0/elapsed), | |
4194 term * 1000.0, (term*100.0/elapsed), | |
4195 pss.term_attempts()); | |
4196 size_t total_waste = pss.alloc_buffer_waste() + pss.undo_waste(); | |
4197 gclog_or_tty->print(" Waste: %8dK\n" | |
4198 " Alloc Buffer: %8dK\n" | |
4199 " Undo: %8dK\n", | |
4200 (total_waste * HeapWordSize) / K, | |
4201 (pss.alloc_buffer_waste() * HeapWordSize) / K, | |
4202 (pss.undo_waste() * HeapWordSize) / K); | |
4203 } | |
4204 | |
4205 assert(pss.refs_to_scan() == 0, "Task queue should be empty"); | |
4206 assert(pss.overflowed_refs_to_scan() == 0, "Overflow queue should be empty"); | |
4207 } | |
4208 }; | |
4209 | |
4210 // *** Common G1 Evacuation Stuff | |
4211 | |
4212 class G1CountClosure: public OopsInHeapRegionClosure { | |
4213 public: | |
4214 int n; | |
4215 G1CountClosure() : n(0) {} | |
4216 void do_oop(narrowOop* p) { | |
4217 guarantee(false, "NYI"); | |
4218 } | |
4219 void do_oop(oop* p) { | |
4220 oop obj = *p; | |
4221 assert(obj != NULL && G1CollectedHeap::heap()->obj_in_cs(obj), | |
4222 "Rem set closure called on non-rem-set pointer."); | |
4223 n++; | |
4224 } | |
4225 }; | |
4226 | |
4227 static G1CountClosure count_closure; | |
4228 | |
4229 void | |
4230 G1CollectedHeap:: | |
4231 g1_process_strong_roots(bool collecting_perm_gen, | |
4232 SharedHeap::ScanningOption so, | |
4233 OopClosure* scan_non_heap_roots, | |
4234 OopsInHeapRegionClosure* scan_rs, | |
4235 OopsInHeapRegionClosure* scan_so, | |
4236 OopsInGenClosure* scan_perm, | |
4237 int worker_i) { | |
4238 // First scan the strong roots, including the perm gen. | |
4239 double ext_roots_start = os::elapsedTime(); | |
4240 double closure_app_time_sec = 0.0; | |
4241 | |
4242 BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots); | |
4243 BufferingOopsInGenClosure buf_scan_perm(scan_perm); | |
4244 buf_scan_perm.set_generation(perm_gen()); | |
4245 | |
4246 process_strong_roots(collecting_perm_gen, so, | |
4247 &buf_scan_non_heap_roots, | |
4248 &buf_scan_perm); | |
4249 // Finish up any enqueued closure apps. | |
4250 buf_scan_non_heap_roots.done(); | |
4251 buf_scan_perm.done(); | |
4252 double ext_roots_end = os::elapsedTime(); | |
4253 g1_policy()->reset_obj_copy_time(worker_i); | |
4254 double obj_copy_time_sec = | |
4255 buf_scan_non_heap_roots.closure_app_seconds() + | |
4256 buf_scan_perm.closure_app_seconds(); | |
4257 g1_policy()->record_obj_copy_time(worker_i, obj_copy_time_sec * 1000.0); | |
4258 double ext_root_time_ms = | |
4259 ((ext_roots_end - ext_roots_start) - obj_copy_time_sec) * 1000.0; | |
4260 g1_policy()->record_ext_root_scan_time(worker_i, ext_root_time_ms); | |
4261 | |
4262 // Scan strong roots in mark stack. | |
4263 if (!_process_strong_tasks->is_task_claimed(G1H_PS_mark_stack_oops_do)) { | |
4264 concurrent_mark()->oops_do(scan_non_heap_roots); | |
4265 } | |
4266 double mark_stack_scan_ms = (os::elapsedTime() - ext_roots_end) * 1000.0; | |
4267 g1_policy()->record_mark_stack_scan_time(worker_i, mark_stack_scan_ms); | |
4268 | |
4269 // XXX What should this be doing in the parallel case? | |
4270 g1_policy()->record_collection_pause_end_CH_strong_roots(); | |
4271 if (G1VerifyRemSet) { | |
4272 // :::: FIXME :::: | |
4273 // The stupid remembered set doesn't know how to filter out dead | |
4274 // objects, which the smart one does, and so when it is created | |
4275 // and then compared the number of entries in each differs and | |
4276 // the verification code fails. | |
4277 guarantee(false, "verification code is broken, see note"); | |
4278 | |
4279 // Let's make sure that the current rem set agrees with the stupidest | |
4280 // one possible! | |
4281 bool refs_enabled = ref_processor()->discovery_enabled(); | |
4282 if (refs_enabled) ref_processor()->disable_discovery(); | |
4283 StupidG1RemSet stupid(this); | |
4284 count_closure.n = 0; | |
4285 stupid.oops_into_collection_set_do(&count_closure, worker_i); | |
4286 int stupid_n = count_closure.n; | |
4287 count_closure.n = 0; | |
4288 g1_rem_set()->oops_into_collection_set_do(&count_closure, worker_i); | |
4289 guarantee(count_closure.n == stupid_n, "Old and new rem sets differ."); | |
4290 gclog_or_tty->print_cr("\nFound %d pointers in heap RS.", count_closure.n); | |
4291 if (refs_enabled) ref_processor()->enable_discovery(); | |
4292 } | |
4293 if (scan_so != NULL) { | |
4294 scan_scan_only_set(scan_so, worker_i); | |
4295 } | |
4296 // Now scan the complement of the collection set. | |
4297 if (scan_rs != NULL) { | |
4298 g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i); | |
4299 } | |
4300 // Finish with the ref_processor roots. | |
4301 if (!_process_strong_tasks->is_task_claimed(G1H_PS_refProcessor_oops_do)) { | |
4302 ref_processor()->oops_do(scan_non_heap_roots); | |
4303 } | |
4304 g1_policy()->record_collection_pause_end_G1_strong_roots(); | |
4305 _process_strong_tasks->all_tasks_completed(); | |
4306 } | |
4307 | |
4308 void | |
4309 G1CollectedHeap::scan_scan_only_region(HeapRegion* r, | |
4310 OopsInHeapRegionClosure* oc, | |
4311 int worker_i) { | |
4312 HeapWord* startAddr = r->bottom(); | |
4313 HeapWord* endAddr = r->used_region().end(); | |
4314 | |
4315 oc->set_region(r); | |
4316 | |
4317 HeapWord* p = r->bottom(); | |
4318 HeapWord* t = r->top(); | |
4319 guarantee( p == r->next_top_at_mark_start(), "invariant" ); | |
4320 while (p < t) { | |
4321 oop obj = oop(p); | |
4322 p += obj->oop_iterate(oc); | |
4323 } | |
4324 } | |
4325 | |
4326 void | |
4327 G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc, | |
4328 int worker_i) { | |
4329 double start = os::elapsedTime(); | |
4330 | |
4331 BufferingOopsInHeapRegionClosure boc(oc); | |
4332 | |
4333 FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc); | |
4334 FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark()); | |
4335 | |
4336 OopsInHeapRegionClosure *foc; | |
4337 if (g1_policy()->should_initiate_conc_mark()) | |
4338 foc = &scan_and_mark; | |
4339 else | |
4340 foc = &scan_only; | |
4341 | |
4342 HeapRegion* hr; | |
4343 int n = 0; | |
4344 while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) { | |
4345 scan_scan_only_region(hr, foc, worker_i); | |
4346 ++n; | |
4347 } | |
4348 boc.done(); | |
4349 | |
4350 double closure_app_s = boc.closure_app_seconds(); | |
4351 g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0); | |
4352 double ms = (os::elapsedTime() - start - closure_app_s)*1000.0; | |
4353 g1_policy()->record_scan_only_time(worker_i, ms, n); | |
4354 } | |
4355 | |
4356 void | |
4357 G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure, | |
4358 OopClosure* non_root_closure) { | |
4359 SharedHeap::process_weak_roots(root_closure, non_root_closure); | |
4360 } | |
4361 | |
4362 | |
4363 class SaveMarksClosure: public HeapRegionClosure { | |
4364 public: | |
4365 bool doHeapRegion(HeapRegion* r) { | |
4366 r->save_marks(); | |
4367 return false; | |
4368 } | |
4369 }; | |
4370 | |
4371 void G1CollectedHeap::save_marks() { | |
4372 if (ParallelGCThreads == 0) { | |
4373 SaveMarksClosure sm; | |
4374 heap_region_iterate(&sm); | |
4375 } | |
4376 // We do this even in the parallel case | |
4377 perm_gen()->save_marks(); | |
4378 } | |
4379 | |
4380 void G1CollectedHeap::evacuate_collection_set() { | |
4381 set_evacuation_failed(false); | |
4382 | |
4383 g1_rem_set()->prepare_for_oops_into_collection_set_do(); | |
4384 concurrent_g1_refine()->set_use_cache(false); | |
4385 int n_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1); | |
4386 | |
4387 set_par_threads(n_workers); | |
4388 G1ParTask g1_par_task(this, n_workers, _task_queues); | |
4389 | |
4390 init_for_evac_failure(NULL); | |
4391 | |
4392 change_strong_roots_parity(); // In preparation for parallel strong roots. | |
4393 rem_set()->prepare_for_younger_refs_iterate(true); | |
4394 double start_par = os::elapsedTime(); | |
4395 | |
4396 if (ParallelGCThreads > 0) { | |
4397 // The individual threads will set their evac-failure closures. | |
4398 workers()->run_task(&g1_par_task); | |
4399 } else { | |
4400 g1_par_task.work(0); | |
4401 } | |
4402 | |
4403 double par_time = (os::elapsedTime() - start_par) * 1000.0; | |
4404 g1_policy()->record_par_time(par_time); | |
4405 set_par_threads(0); | |
4406 // Is this the right thing to do here? We don't save marks | |
4407 // on individual heap regions when we allocate from | |
4408 // them in parallel, so this seems like the correct place for this. | |
545 | 4409 retire_all_alloc_regions(); |
342 | 4410 { |
4411 G1IsAliveClosure is_alive(this); | |
4412 G1KeepAliveClosure keep_alive(this); | |
4413 JNIHandles::weak_oops_do(&is_alive, &keep_alive); | |
4414 } | |
4415 | |
4416 g1_rem_set()->cleanup_after_oops_into_collection_set_do(); | |
4417 concurrent_g1_refine()->set_use_cache(true); | |
4418 | |
4419 finalize_for_evac_failure(); | |
4420 | |
4421 // Must do this before removing self-forwarding pointers, which clears | |
4422 // the per-region evac-failure flags. | |
4423 concurrent_mark()->complete_marking_in_collection_set(); | |
4424 | |
4425 if (evacuation_failed()) { | |
4426 remove_self_forwarding_pointers(); | |
4427 | |
4428 if (PrintGCDetails) { | |
4429 gclog_or_tty->print(" (evacuation failed)"); | |
4430 } else if (PrintGC) { | |
4431 gclog_or_tty->print("--"); | |
4432 } | |
4433 } | |
4434 | |
4435 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
4436 } | |
4437 | |
4438 void G1CollectedHeap::free_region(HeapRegion* hr) { | |
4439 size_t pre_used = 0; | |
4440 size_t cleared_h_regions = 0; | |
4441 size_t freed_regions = 0; | |
4442 UncleanRegionList local_list; | |
4443 | |
4444 HeapWord* start = hr->bottom(); | |
4445 HeapWord* end = hr->prev_top_at_mark_start(); | |
4446 size_t used_bytes = hr->used(); | |
4447 size_t live_bytes = hr->max_live_bytes(); | |
4448 if (used_bytes > 0) { | |
4449 guarantee( live_bytes <= used_bytes, "invariant" ); | |
4450 } else { | |
4451 guarantee( live_bytes == 0, "invariant" ); | |
4452 } | |
4453 | |
4454 size_t garbage_bytes = used_bytes - live_bytes; | |
4455 if (garbage_bytes > 0) | |
4456 g1_policy()->decrease_known_garbage_bytes(garbage_bytes); | |
4457 | |
4458 free_region_work(hr, pre_used, cleared_h_regions, freed_regions, | |
4459 &local_list); | |
4460 finish_free_region_work(pre_used, cleared_h_regions, freed_regions, | |
4461 &local_list); | |
4462 } | |
4463 | |
4464 void | |
4465 G1CollectedHeap::free_region_work(HeapRegion* hr, | |
4466 size_t& pre_used, | |
4467 size_t& cleared_h_regions, | |
4468 size_t& freed_regions, | |
4469 UncleanRegionList* list, | |
4470 bool par) { | |
4471 assert(!hr->popular(), "should not free popular regions"); | |
4472 pre_used += hr->used(); | |
4473 if (hr->isHumongous()) { | |
4474 assert(hr->startsHumongous(), | |
4475 "Only the start of a humongous region should be freed."); | |
4476 int ind = _hrs->find(hr); | |
4477 assert(ind != -1, "Should have an index."); | |
4478 // Clear the start region. | |
4479 hr->hr_clear(par, true /*clear_space*/); | |
4480 list->insert_before_head(hr); | |
4481 cleared_h_regions++; | |
4482 freed_regions++; | |
4483 // Clear any continued regions. | |
4484 ind++; | |
4485 while ((size_t)ind < n_regions()) { | |
4486 HeapRegion* hrc = _hrs->at(ind); | |
4487 if (!hrc->continuesHumongous()) break; | |
4488 // Otherwise, does continue the H region. | |
4489 assert(hrc->humongous_start_region() == hr, "Huh?"); | |
4490 hrc->hr_clear(par, true /*clear_space*/); | |
4491 cleared_h_regions++; | |
4492 freed_regions++; | |
4493 list->insert_before_head(hrc); | |
4494 ind++; | |
4495 } | |
4496 } else { | |
4497 hr->hr_clear(par, true /*clear_space*/); | |
4498 list->insert_before_head(hr); | |
4499 freed_regions++; | |
4500 // If we're using clear2, this should not be enabled. | |
4501 // assert(!hr->in_cohort(), "Can't be both free and in a cohort."); | |
4502 } | |
4503 } | |
4504 | |
4505 void G1CollectedHeap::finish_free_region_work(size_t pre_used, | |
4506 size_t cleared_h_regions, | |
4507 size_t freed_regions, | |
4508 UncleanRegionList* list) { | |
4509 if (list != NULL && list->sz() > 0) { | |
4510 prepend_region_list_on_unclean_list(list); | |
4511 } | |
4512 // Acquire a lock, if we're parallel, to update possibly-shared | |
4513 // variables. | |
4514 Mutex* lock = (n_par_threads() > 0) ? ParGCRareEvent_lock : NULL; | |
4515 { | |
4516 MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); | |
4517 _summary_bytes_used -= pre_used; | |
4518 _num_humongous_regions -= (int) cleared_h_regions; | |
4519 _free_regions += freed_regions; | |
4520 } | |
4521 } | |
4522 | |
4523 | |
4524 void G1CollectedHeap::dirtyCardsForYoungRegions(CardTableModRefBS* ct_bs, HeapRegion* list) { | |
4525 while (list != NULL) { | |
4526 guarantee( list->is_young(), "invariant" ); | |
4527 | |
4528 HeapWord* bottom = list->bottom(); | |
4529 HeapWord* end = list->end(); | |
4530 MemRegion mr(bottom, end); | |
4531 ct_bs->dirty(mr); | |
4532 | |
4533 list = list->get_next_young_region(); | |
4534 } | |
4535 } | |
4536 | |
4537 void G1CollectedHeap::cleanUpCardTable() { | |
4538 CardTableModRefBS* ct_bs = (CardTableModRefBS*) (barrier_set()); | |
4539 double start = os::elapsedTime(); | |
4540 | |
4541 ct_bs->clear(_g1_committed); | |
4542 | |
4543 // now, redirty the cards of the scan-only and survivor regions | |
4544 // (it seemed faster to do it this way, instead of iterating over | |
4545 // all regions and then clearing / dirtying as approprite) | |
4546 dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region()); | |
4547 dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region()); | |
4548 | |
4549 double elapsed = os::elapsedTime() - start; | |
4550 g1_policy()->record_clear_ct_time( elapsed * 1000.0); | |
4551 } | |
4552 | |
4553 | |
4554 void G1CollectedHeap::do_collection_pause_if_appropriate(size_t word_size) { | |
4555 // First do any popular regions. | |
4556 HeapRegion* hr; | |
4557 while ((hr = popular_region_to_evac()) != NULL) { | |
4558 evac_popular_region(hr); | |
4559 } | |
4560 // Now do heuristic pauses. | |
4561 if (g1_policy()->should_do_collection_pause(word_size)) { | |
4562 do_collection_pause(); | |
4563 } | |
4564 } | |
4565 | |
4566 void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) { | |
4567 double young_time_ms = 0.0; | |
4568 double non_young_time_ms = 0.0; | |
4569 | |
4570 G1CollectorPolicy* policy = g1_policy(); | |
4571 | |
4572 double start_sec = os::elapsedTime(); | |
4573 bool non_young = true; | |
4574 | |
4575 HeapRegion* cur = cs_head; | |
4576 int age_bound = -1; | |
4577 size_t rs_lengths = 0; | |
4578 | |
4579 while (cur != NULL) { | |
4580 if (non_young) { | |
4581 if (cur->is_young()) { | |
4582 double end_sec = os::elapsedTime(); | |
4583 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4584 non_young_time_ms += elapsed_ms; | |
4585 | |
4586 start_sec = os::elapsedTime(); | |
4587 non_young = false; | |
4588 } | |
4589 } else { | |
4590 if (!cur->is_on_free_list()) { | |
4591 double end_sec = os::elapsedTime(); | |
4592 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4593 young_time_ms += elapsed_ms; | |
4594 | |
4595 start_sec = os::elapsedTime(); | |
4596 non_young = true; | |
4597 } | |
4598 } | |
4599 | |
4600 rs_lengths += cur->rem_set()->occupied(); | |
4601 | |
4602 HeapRegion* next = cur->next_in_collection_set(); | |
4603 assert(cur->in_collection_set(), "bad CS"); | |
4604 cur->set_next_in_collection_set(NULL); | |
4605 cur->set_in_collection_set(false); | |
4606 | |
4607 if (cur->is_young()) { | |
4608 int index = cur->young_index_in_cset(); | |
4609 guarantee( index != -1, "invariant" ); | |
4610 guarantee( (size_t)index < policy->young_cset_length(), "invariant" ); | |
4611 size_t words_survived = _surviving_young_words[index]; | |
4612 cur->record_surv_words_in_group(words_survived); | |
4613 } else { | |
4614 int index = cur->young_index_in_cset(); | |
4615 guarantee( index == -1, "invariant" ); | |
4616 } | |
4617 | |
4618 assert( (cur->is_young() && cur->young_index_in_cset() > -1) || | |
4619 (!cur->is_young() && cur->young_index_in_cset() == -1), | |
4620 "invariant" ); | |
4621 | |
4622 if (!cur->evacuation_failed()) { | |
4623 // And the region is empty. | |
4624 assert(!cur->is_empty(), | |
4625 "Should not have empty regions in a CS."); | |
4626 free_region(cur); | |
4627 } else { | |
4628 guarantee( !cur->is_scan_only(), "should not be scan only" ); | |
4629 cur->uninstall_surv_rate_group(); | |
4630 if (cur->is_young()) | |
4631 cur->set_young_index_in_cset(-1); | |
4632 cur->set_not_young(); | |
4633 cur->set_evacuation_failed(false); | |
4634 } | |
4635 cur = next; | |
4636 } | |
4637 | |
4638 policy->record_max_rs_lengths(rs_lengths); | |
4639 policy->cset_regions_freed(); | |
4640 | |
4641 double end_sec = os::elapsedTime(); | |
4642 double elapsed_ms = (end_sec - start_sec) * 1000.0; | |
4643 if (non_young) | |
4644 non_young_time_ms += elapsed_ms; | |
4645 else | |
4646 young_time_ms += elapsed_ms; | |
4647 | |
4648 policy->record_young_free_cset_time_ms(young_time_ms); | |
4649 policy->record_non_young_free_cset_time_ms(non_young_time_ms); | |
4650 } | |
4651 | |
4652 HeapRegion* | |
4653 G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) { | |
4654 assert(ZF_mon->owned_by_self(), "Precondition"); | |
4655 HeapRegion* res = pop_unclean_region_list_locked(); | |
4656 if (res != NULL) { | |
4657 assert(!res->continuesHumongous() && | |
4658 res->zero_fill_state() != HeapRegion::Allocated, | |
4659 "Only free regions on unclean list."); | |
4660 if (zero_filled) { | |
4661 res->ensure_zero_filled_locked(); | |
4662 res->set_zero_fill_allocated(); | |
4663 } | |
4664 } | |
4665 return res; | |
4666 } | |
4667 | |
4668 HeapRegion* G1CollectedHeap::alloc_region_from_unclean_list(bool zero_filled) { | |
4669 MutexLockerEx zx(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4670 return alloc_region_from_unclean_list_locked(zero_filled); | |
4671 } | |
4672 | |
4673 void G1CollectedHeap::put_region_on_unclean_list(HeapRegion* r) { | |
4674 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4675 put_region_on_unclean_list_locked(r); | |
4676 if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread. | |
4677 } | |
4678 | |
4679 void G1CollectedHeap::set_unclean_regions_coming(bool b) { | |
4680 MutexLockerEx x(Cleanup_mon); | |
4681 set_unclean_regions_coming_locked(b); | |
4682 } | |
4683 | |
4684 void G1CollectedHeap::set_unclean_regions_coming_locked(bool b) { | |
4685 assert(Cleanup_mon->owned_by_self(), "Precondition"); | |
4686 _unclean_regions_coming = b; | |
4687 // Wake up mutator threads that might be waiting for completeCleanup to | |
4688 // finish. | |
4689 if (!b) Cleanup_mon->notify_all(); | |
4690 } | |
4691 | |
4692 void G1CollectedHeap::wait_for_cleanup_complete() { | |
4693 MutexLockerEx x(Cleanup_mon); | |
4694 wait_for_cleanup_complete_locked(); | |
4695 } | |
4696 | |
4697 void G1CollectedHeap::wait_for_cleanup_complete_locked() { | |
4698 assert(Cleanup_mon->owned_by_self(), "precondition"); | |
4699 while (_unclean_regions_coming) { | |
4700 Cleanup_mon->wait(); | |
4701 } | |
4702 } | |
4703 | |
4704 void | |
4705 G1CollectedHeap::put_region_on_unclean_list_locked(HeapRegion* r) { | |
4706 assert(ZF_mon->owned_by_self(), "precondition."); | |
4707 _unclean_region_list.insert_before_head(r); | |
4708 } | |
4709 | |
4710 void | |
4711 G1CollectedHeap::prepend_region_list_on_unclean_list(UncleanRegionList* list) { | |
4712 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4713 prepend_region_list_on_unclean_list_locked(list); | |
4714 if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread. | |
4715 } | |
4716 | |
4717 void | |
4718 G1CollectedHeap:: | |
4719 prepend_region_list_on_unclean_list_locked(UncleanRegionList* list) { | |
4720 assert(ZF_mon->owned_by_self(), "precondition."); | |
4721 _unclean_region_list.prepend_list(list); | |
4722 } | |
4723 | |
4724 HeapRegion* G1CollectedHeap::pop_unclean_region_list_locked() { | |
4725 assert(ZF_mon->owned_by_self(), "precondition."); | |
4726 HeapRegion* res = _unclean_region_list.pop(); | |
4727 if (res != NULL) { | |
4728 // Inform ZF thread that there's a new unclean head. | |
4729 if (_unclean_region_list.hd() != NULL && should_zf()) | |
4730 ZF_mon->notify_all(); | |
4731 } | |
4732 return res; | |
4733 } | |
4734 | |
4735 HeapRegion* G1CollectedHeap::peek_unclean_region_list_locked() { | |
4736 assert(ZF_mon->owned_by_self(), "precondition."); | |
4737 return _unclean_region_list.hd(); | |
4738 } | |
4739 | |
4740 | |
4741 bool G1CollectedHeap::move_cleaned_region_to_free_list_locked() { | |
4742 assert(ZF_mon->owned_by_self(), "Precondition"); | |
4743 HeapRegion* r = peek_unclean_region_list_locked(); | |
4744 if (r != NULL && r->zero_fill_state() == HeapRegion::ZeroFilled) { | |
4745 // Result of below must be equal to "r", since we hold the lock. | |
4746 (void)pop_unclean_region_list_locked(); | |
4747 put_free_region_on_list_locked(r); | |
4748 return true; | |
4749 } else { | |
4750 return false; | |
4751 } | |
4752 } | |
4753 | |
4754 bool G1CollectedHeap::move_cleaned_region_to_free_list() { | |
4755 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4756 return move_cleaned_region_to_free_list_locked(); | |
4757 } | |
4758 | |
4759 | |
4760 void G1CollectedHeap::put_free_region_on_list_locked(HeapRegion* r) { | |
4761 assert(ZF_mon->owned_by_self(), "precondition."); | |
4762 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4763 assert(r->zero_fill_state() == HeapRegion::ZeroFilled, | |
4764 "Regions on free list must be zero filled"); | |
4765 assert(!r->isHumongous(), "Must not be humongous."); | |
4766 assert(r->is_empty(), "Better be empty"); | |
4767 assert(!r->is_on_free_list(), | |
4768 "Better not already be on free list"); | |
4769 assert(!r->is_on_unclean_list(), | |
4770 "Better not already be on unclean list"); | |
4771 r->set_on_free_list(true); | |
4772 r->set_next_on_free_list(_free_region_list); | |
4773 _free_region_list = r; | |
4774 _free_region_list_size++; | |
4775 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4776 } | |
4777 | |
4778 void G1CollectedHeap::put_free_region_on_list(HeapRegion* r) { | |
4779 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4780 put_free_region_on_list_locked(r); | |
4781 } | |
4782 | |
4783 HeapRegion* G1CollectedHeap::pop_free_region_list_locked() { | |
4784 assert(ZF_mon->owned_by_self(), "precondition."); | |
4785 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4786 HeapRegion* res = _free_region_list; | |
4787 if (res != NULL) { | |
4788 _free_region_list = res->next_from_free_list(); | |
4789 _free_region_list_size--; | |
4790 res->set_on_free_list(false); | |
4791 res->set_next_on_free_list(NULL); | |
4792 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4793 } | |
4794 return res; | |
4795 } | |
4796 | |
4797 | |
4798 HeapRegion* G1CollectedHeap::alloc_free_region_from_lists(bool zero_filled) { | |
4799 // By self, or on behalf of self. | |
4800 assert(Heap_lock->is_locked(), "Precondition"); | |
4801 HeapRegion* res = NULL; | |
4802 bool first = true; | |
4803 while (res == NULL) { | |
4804 if (zero_filled || !first) { | |
4805 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4806 res = pop_free_region_list_locked(); | |
4807 if (res != NULL) { | |
4808 assert(!res->zero_fill_is_allocated(), | |
4809 "No allocated regions on free list."); | |
4810 res->set_zero_fill_allocated(); | |
4811 } else if (!first) { | |
4812 break; // We tried both, time to return NULL. | |
4813 } | |
4814 } | |
4815 | |
4816 if (res == NULL) { | |
4817 res = alloc_region_from_unclean_list(zero_filled); | |
4818 } | |
4819 assert(res == NULL || | |
4820 !zero_filled || | |
4821 res->zero_fill_is_allocated(), | |
4822 "We must have allocated the region we're returning"); | |
4823 first = false; | |
4824 } | |
4825 return res; | |
4826 } | |
4827 | |
4828 void G1CollectedHeap::remove_allocated_regions_from_lists() { | |
4829 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4830 { | |
4831 HeapRegion* prev = NULL; | |
4832 HeapRegion* cur = _unclean_region_list.hd(); | |
4833 while (cur != NULL) { | |
4834 HeapRegion* next = cur->next_from_unclean_list(); | |
4835 if (cur->zero_fill_is_allocated()) { | |
4836 // Remove from the list. | |
4837 if (prev == NULL) { | |
4838 (void)_unclean_region_list.pop(); | |
4839 } else { | |
4840 _unclean_region_list.delete_after(prev); | |
4841 } | |
4842 cur->set_on_unclean_list(false); | |
4843 cur->set_next_on_unclean_list(NULL); | |
4844 } else { | |
4845 prev = cur; | |
4846 } | |
4847 cur = next; | |
4848 } | |
4849 assert(_unclean_region_list.sz() == unclean_region_list_length(), | |
4850 "Inv"); | |
4851 } | |
4852 | |
4853 { | |
4854 HeapRegion* prev = NULL; | |
4855 HeapRegion* cur = _free_region_list; | |
4856 while (cur != NULL) { | |
4857 HeapRegion* next = cur->next_from_free_list(); | |
4858 if (cur->zero_fill_is_allocated()) { | |
4859 // Remove from the list. | |
4860 if (prev == NULL) { | |
4861 _free_region_list = cur->next_from_free_list(); | |
4862 } else { | |
4863 prev->set_next_on_free_list(cur->next_from_free_list()); | |
4864 } | |
4865 cur->set_on_free_list(false); | |
4866 cur->set_next_on_free_list(NULL); | |
4867 _free_region_list_size--; | |
4868 } else { | |
4869 prev = cur; | |
4870 } | |
4871 cur = next; | |
4872 } | |
4873 assert(_free_region_list_size == free_region_list_length(), "Inv"); | |
4874 } | |
4875 } | |
4876 | |
4877 bool G1CollectedHeap::verify_region_lists() { | |
4878 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
4879 return verify_region_lists_locked(); | |
4880 } | |
4881 | |
4882 bool G1CollectedHeap::verify_region_lists_locked() { | |
4883 HeapRegion* unclean = _unclean_region_list.hd(); | |
4884 while (unclean != NULL) { | |
4885 guarantee(unclean->is_on_unclean_list(), "Well, it is!"); | |
4886 guarantee(!unclean->is_on_free_list(), "Well, it shouldn't be!"); | |
4887 guarantee(unclean->zero_fill_state() != HeapRegion::Allocated, | |
4888 "Everything else is possible."); | |
4889 unclean = unclean->next_from_unclean_list(); | |
4890 } | |
4891 guarantee(_unclean_region_list.sz() == unclean_region_list_length(), "Inv"); | |
4892 | |
4893 HeapRegion* free_r = _free_region_list; | |
4894 while (free_r != NULL) { | |
4895 assert(free_r->is_on_free_list(), "Well, it is!"); | |
4896 assert(!free_r->is_on_unclean_list(), "Well, it shouldn't be!"); | |
4897 switch (free_r->zero_fill_state()) { | |
4898 case HeapRegion::NotZeroFilled: | |
4899 case HeapRegion::ZeroFilling: | |
4900 guarantee(false, "Should not be on free list."); | |
4901 break; | |
4902 default: | |
4903 // Everything else is possible. | |
4904 break; | |
4905 } | |
4906 free_r = free_r->next_from_free_list(); | |
4907 } | |
4908 guarantee(_free_region_list_size == free_region_list_length(), "Inv"); | |
4909 // If we didn't do an assertion... | |
4910 return true; | |
4911 } | |
4912 | |
4913 size_t G1CollectedHeap::free_region_list_length() { | |
4914 assert(ZF_mon->owned_by_self(), "precondition."); | |
4915 size_t len = 0; | |
4916 HeapRegion* cur = _free_region_list; | |
4917 while (cur != NULL) { | |
4918 len++; | |
4919 cur = cur->next_from_free_list(); | |
4920 } | |
4921 return len; | |
4922 } | |
4923 | |
4924 size_t G1CollectedHeap::unclean_region_list_length() { | |
4925 assert(ZF_mon->owned_by_self(), "precondition."); | |
4926 return _unclean_region_list.length(); | |
4927 } | |
4928 | |
4929 size_t G1CollectedHeap::n_regions() { | |
4930 return _hrs->length(); | |
4931 } | |
4932 | |
4933 size_t G1CollectedHeap::max_regions() { | |
4934 return | |
4935 (size_t)align_size_up(g1_reserved_obj_bytes(), HeapRegion::GrainBytes) / | |
4936 HeapRegion::GrainBytes; | |
4937 } | |
4938 | |
4939 size_t G1CollectedHeap::free_regions() { | |
4940 /* Possibly-expensive assert. | |
4941 assert(_free_regions == count_free_regions(), | |
4942 "_free_regions is off."); | |
4943 */ | |
4944 return _free_regions; | |
4945 } | |
4946 | |
4947 bool G1CollectedHeap::should_zf() { | |
4948 return _free_region_list_size < (size_t) G1ConcZFMaxRegions; | |
4949 } | |
4950 | |
4951 class RegionCounter: public HeapRegionClosure { | |
4952 size_t _n; | |
4953 public: | |
4954 RegionCounter() : _n(0) {} | |
4955 bool doHeapRegion(HeapRegion* r) { | |
4956 if (r->is_empty() && !r->popular()) { | |
4957 assert(!r->isHumongous(), "H regions should not be empty."); | |
4958 _n++; | |
4959 } | |
4960 return false; | |
4961 } | |
4962 int res() { return (int) _n; } | |
4963 }; | |
4964 | |
4965 size_t G1CollectedHeap::count_free_regions() { | |
4966 RegionCounter rc; | |
4967 heap_region_iterate(&rc); | |
4968 size_t n = rc.res(); | |
4969 if (_cur_alloc_region != NULL && _cur_alloc_region->is_empty()) | |
4970 n--; | |
4971 return n; | |
4972 } | |
4973 | |
4974 size_t G1CollectedHeap::count_free_regions_list() { | |
4975 size_t n = 0; | |
4976 size_t o = 0; | |
4977 ZF_mon->lock_without_safepoint_check(); | |
4978 HeapRegion* cur = _free_region_list; | |
4979 while (cur != NULL) { | |
4980 cur = cur->next_from_free_list(); | |
4981 n++; | |
4982 } | |
4983 size_t m = unclean_region_list_length(); | |
4984 ZF_mon->unlock(); | |
4985 return n + m; | |
4986 } | |
4987 | |
4988 bool G1CollectedHeap::should_set_young_locked() { | |
4989 assert(heap_lock_held_for_gc(), | |
4990 "the heap lock should already be held by or for this thread"); | |
4991 return (g1_policy()->in_young_gc_mode() && | |
4992 g1_policy()->should_add_next_region_to_young_list()); | |
4993 } | |
4994 | |
4995 void G1CollectedHeap::set_region_short_lived_locked(HeapRegion* hr) { | |
4996 assert(heap_lock_held_for_gc(), | |
4997 "the heap lock should already be held by or for this thread"); | |
4998 _young_list->push_region(hr); | |
4999 g1_policy()->set_region_short_lived(hr); | |
5000 } | |
5001 | |
5002 class NoYoungRegionsClosure: public HeapRegionClosure { | |
5003 private: | |
5004 bool _success; | |
5005 public: | |
5006 NoYoungRegionsClosure() : _success(true) { } | |
5007 bool doHeapRegion(HeapRegion* r) { | |
5008 if (r->is_young()) { | |
5009 gclog_or_tty->print_cr("Region ["PTR_FORMAT", "PTR_FORMAT") tagged as young", | |
5010 r->bottom(), r->end()); | |
5011 _success = false; | |
5012 } | |
5013 return false; | |
5014 } | |
5015 bool success() { return _success; } | |
5016 }; | |
5017 | |
5018 bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list, | |
5019 bool check_sample) { | |
5020 bool ret = true; | |
5021 | |
5022 ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample); | |
5023 if (!ignore_scan_only_list) { | |
5024 NoYoungRegionsClosure closure; | |
5025 heap_region_iterate(&closure); | |
5026 ret = ret && closure.success(); | |
5027 } | |
5028 | |
5029 return ret; | |
5030 } | |
5031 | |
5032 void G1CollectedHeap::empty_young_list() { | |
5033 assert(heap_lock_held_for_gc(), | |
5034 "the heap lock should already be held by or for this thread"); | |
5035 assert(g1_policy()->in_young_gc_mode(), "should be in young GC mode"); | |
5036 | |
5037 _young_list->empty_list(); | |
5038 } | |
5039 | |
5040 bool G1CollectedHeap::all_alloc_regions_no_allocs_since_save_marks() { | |
5041 bool no_allocs = true; | |
5042 for (int ap = 0; ap < GCAllocPurposeCount && no_allocs; ++ap) { | |
5043 HeapRegion* r = _gc_alloc_regions[ap]; | |
5044 no_allocs = r == NULL || r->saved_mark_at_top(); | |
5045 } | |
5046 return no_allocs; | |
5047 } | |
5048 | |
545 | 5049 void G1CollectedHeap::retire_all_alloc_regions() { |
342 | 5050 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { |
5051 HeapRegion* r = _gc_alloc_regions[ap]; | |
5052 if (r != NULL) { | |
5053 // Check for aliases. | |
5054 bool has_processed_alias = false; | |
5055 for (int i = 0; i < ap; ++i) { | |
5056 if (_gc_alloc_regions[i] == r) { | |
5057 has_processed_alias = true; | |
5058 break; | |
5059 } | |
5060 } | |
5061 if (!has_processed_alias) { | |
545 | 5062 retire_alloc_region(r, false /* par */); |
342 | 5063 } |
5064 } | |
5065 } | |
5066 } | |
5067 | |
5068 | |
5069 // Done at the start of full GC. | |
5070 void G1CollectedHeap::tear_down_region_lists() { | |
5071 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
5072 while (pop_unclean_region_list_locked() != NULL) ; | |
5073 assert(_unclean_region_list.hd() == NULL && _unclean_region_list.sz() == 0, | |
5074 "Postconditions of loop.") | |
5075 while (pop_free_region_list_locked() != NULL) ; | |
5076 assert(_free_region_list == NULL, "Postcondition of loop."); | |
5077 if (_free_region_list_size != 0) { | |
5078 gclog_or_tty->print_cr("Size is %d.", _free_region_list_size); | |
5079 print(); | |
5080 } | |
5081 assert(_free_region_list_size == 0, "Postconditions of loop."); | |
5082 } | |
5083 | |
5084 | |
5085 class RegionResetter: public HeapRegionClosure { | |
5086 G1CollectedHeap* _g1; | |
5087 int _n; | |
5088 public: | |
5089 RegionResetter() : _g1(G1CollectedHeap::heap()), _n(0) {} | |
5090 bool doHeapRegion(HeapRegion* r) { | |
5091 if (r->continuesHumongous()) return false; | |
5092 if (r->top() > r->bottom()) { | |
5093 if (r->top() < r->end()) { | |
5094 Copy::fill_to_words(r->top(), | |
5095 pointer_delta(r->end(), r->top())); | |
5096 } | |
5097 r->set_zero_fill_allocated(); | |
5098 } else { | |
5099 assert(r->is_empty(), "tautology"); | |
5100 if (r->popular()) { | |
5101 if (r->zero_fill_state() != HeapRegion::Allocated) { | |
5102 r->ensure_zero_filled_locked(); | |
5103 r->set_zero_fill_allocated(); | |
5104 } | |
5105 } else { | |
5106 _n++; | |
5107 switch (r->zero_fill_state()) { | |
5108 case HeapRegion::NotZeroFilled: | |
5109 case HeapRegion::ZeroFilling: | |
5110 _g1->put_region_on_unclean_list_locked(r); | |
5111 break; | |
5112 case HeapRegion::Allocated: | |
5113 r->set_zero_fill_complete(); | |
5114 // no break; go on to put on free list. | |
5115 case HeapRegion::ZeroFilled: | |
5116 _g1->put_free_region_on_list_locked(r); | |
5117 break; | |
5118 } | |
5119 } | |
5120 } | |
5121 return false; | |
5122 } | |
5123 | |
5124 int getFreeRegionCount() {return _n;} | |
5125 }; | |
5126 | |
5127 // Done at the end of full GC. | |
5128 void G1CollectedHeap::rebuild_region_lists() { | |
5129 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
5130 // This needs to go at the end of the full GC. | |
5131 RegionResetter rs; | |
5132 heap_region_iterate(&rs); | |
5133 _free_regions = rs.getFreeRegionCount(); | |
5134 // Tell the ZF thread it may have work to do. | |
5135 if (should_zf()) ZF_mon->notify_all(); | |
5136 } | |
5137 | |
5138 class UsedRegionsNeedZeroFillSetter: public HeapRegionClosure { | |
5139 G1CollectedHeap* _g1; | |
5140 int _n; | |
5141 public: | |
5142 UsedRegionsNeedZeroFillSetter() : _g1(G1CollectedHeap::heap()), _n(0) {} | |
5143 bool doHeapRegion(HeapRegion* r) { | |
5144 if (r->continuesHumongous()) return false; | |
5145 if (r->top() > r->bottom()) { | |
5146 // There are assertions in "set_zero_fill_needed()" below that | |
5147 // require top() == bottom(), so this is technically illegal. | |
5148 // We'll skirt the law here, by making that true temporarily. | |
5149 DEBUG_ONLY(HeapWord* save_top = r->top(); | |
5150 r->set_top(r->bottom())); | |
5151 r->set_zero_fill_needed(); | |
5152 DEBUG_ONLY(r->set_top(save_top)); | |
5153 } | |
5154 return false; | |
5155 } | |
5156 }; | |
5157 | |
5158 // Done at the start of full GC. | |
5159 void G1CollectedHeap::set_used_regions_to_need_zero_fill() { | |
5160 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
5161 // This needs to go at the end of the full GC. | |
5162 UsedRegionsNeedZeroFillSetter rs; | |
5163 heap_region_iterate(&rs); | |
5164 } | |
5165 | |
5166 class CountObjClosure: public ObjectClosure { | |
5167 size_t _n; | |
5168 public: | |
5169 CountObjClosure() : _n(0) {} | |
5170 void do_object(oop obj) { _n++; } | |
5171 size_t n() { return _n; } | |
5172 }; | |
5173 | |
5174 size_t G1CollectedHeap::pop_object_used_objs() { | |
5175 size_t sum_objs = 0; | |
5176 for (int i = 0; i < G1NumPopularRegions; i++) { | |
5177 CountObjClosure cl; | |
5178 _hrs->at(i)->object_iterate(&cl); | |
5179 sum_objs += cl.n(); | |
5180 } | |
5181 return sum_objs; | |
5182 } | |
5183 | |
5184 size_t G1CollectedHeap::pop_object_used_bytes() { | |
5185 size_t sum_bytes = 0; | |
5186 for (int i = 0; i < G1NumPopularRegions; i++) { | |
5187 sum_bytes += _hrs->at(i)->used(); | |
5188 } | |
5189 return sum_bytes; | |
5190 } | |
5191 | |
5192 | |
5193 static int nq = 0; | |
5194 | |
5195 HeapWord* G1CollectedHeap::allocate_popular_object(size_t word_size) { | |
5196 while (_cur_pop_hr_index < G1NumPopularRegions) { | |
5197 HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index); | |
5198 HeapWord* res = cur_pop_region->allocate(word_size); | |
5199 if (res != NULL) { | |
5200 // We account for popular objs directly in the used summary: | |
5201 _summary_bytes_used += (word_size * HeapWordSize); | |
5202 return res; | |
5203 } | |
5204 // Otherwise, try the next region (first making sure that we remember | |
5205 // the last "top" value as the "next_top_at_mark_start", so that | |
5206 // objects made popular during markings aren't automatically considered | |
5207 // live). | |
5208 cur_pop_region->note_end_of_copying(); | |
5209 // Otherwise, try the next region. | |
5210 _cur_pop_hr_index++; | |
5211 } | |
5212 // XXX: For now !!! | |
5213 vm_exit_out_of_memory(word_size, | |
5214 "Not enough pop obj space (To Be Fixed)"); | |
5215 return NULL; | |
5216 } | |
5217 | |
5218 class HeapRegionList: public CHeapObj { | |
5219 public: | |
5220 HeapRegion* hr; | |
5221 HeapRegionList* next; | |
5222 }; | |
5223 | |
5224 void G1CollectedHeap::schedule_popular_region_evac(HeapRegion* r) { | |
5225 // This might happen during parallel GC, so protect by this lock. | |
5226 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
5227 // We don't schedule regions whose evacuations are already pending, or | |
5228 // are already being evacuated. | |
5229 if (!r->popular_pending() && !r->in_collection_set()) { | |
5230 r->set_popular_pending(true); | |
5231 if (G1TracePopularity) { | |
5232 gclog_or_tty->print_cr("Scheduling region "PTR_FORMAT" " | |
5233 "["PTR_FORMAT", "PTR_FORMAT") for pop-object evacuation.", | |
5234 r, r->bottom(), r->end()); | |
5235 } | |
5236 HeapRegionList* hrl = new HeapRegionList; | |
5237 hrl->hr = r; | |
5238 hrl->next = _popular_regions_to_be_evacuated; | |
5239 _popular_regions_to_be_evacuated = hrl; | |
5240 } | |
5241 } | |
5242 | |
5243 HeapRegion* G1CollectedHeap::popular_region_to_evac() { | |
5244 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
5245 HeapRegion* res = NULL; | |
5246 while (_popular_regions_to_be_evacuated != NULL && res == NULL) { | |
5247 HeapRegionList* hrl = _popular_regions_to_be_evacuated; | |
5248 _popular_regions_to_be_evacuated = hrl->next; | |
5249 res = hrl->hr; | |
5250 // The G1RSPopLimit may have increased, so recheck here... | |
5251 if (res->rem_set()->occupied() < (size_t) G1RSPopLimit) { | |
5252 // Hah: don't need to schedule. | |
5253 if (G1TracePopularity) { | |
5254 gclog_or_tty->print_cr("Unscheduling region "PTR_FORMAT" " | |
5255 "["PTR_FORMAT", "PTR_FORMAT") " | |
5256 "for pop-object evacuation (size %d < limit %d)", | |
5257 res, res->bottom(), res->end(), | |
5258 res->rem_set()->occupied(), G1RSPopLimit); | |
5259 } | |
5260 res->set_popular_pending(false); | |
5261 res = NULL; | |
5262 } | |
5263 // We do not reset res->popular() here; if we did so, it would allow | |
5264 // the region to be "rescheduled" for popularity evacuation. Instead, | |
5265 // this is done in the collection pause, with the world stopped. | |
5266 // So the invariant is that the regions in the list have the popularity | |
5267 // boolean set, but having the boolean set does not imply membership | |
5268 // on the list (though there can at most one such pop-pending region | |
5269 // not on the list at any time). | |
5270 delete hrl; | |
5271 } | |
5272 return res; | |
5273 } | |
5274 | |
5275 void G1CollectedHeap::evac_popular_region(HeapRegion* hr) { | |
5276 while (true) { | |
5277 // Don't want to do a GC pause while cleanup is being completed! | |
5278 wait_for_cleanup_complete(); | |
5279 | |
5280 // Read the GC count while holding the Heap_lock | |
5281 int gc_count_before = SharedHeap::heap()->total_collections(); | |
5282 g1_policy()->record_stop_world_start(); | |
5283 | |
5284 { | |
5285 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back | |
5286 VM_G1PopRegionCollectionPause op(gc_count_before, hr); | |
5287 VMThread::execute(&op); | |
5288 | |
5289 // If the prolog succeeded, we didn't do a GC for this. | |
5290 if (op.prologue_succeeded()) break; | |
5291 } | |
5292 // Otherwise we didn't. We should recheck the size, though, since | |
5293 // the limit may have increased... | |
5294 if (hr->rem_set()->occupied() < (size_t) G1RSPopLimit) { | |
5295 hr->set_popular_pending(false); | |
5296 break; | |
5297 } | |
5298 } | |
5299 } | |
5300 | |
5301 void G1CollectedHeap::atomic_inc_obj_rc(oop obj) { | |
5302 Atomic::inc(obj_rc_addr(obj)); | |
5303 } | |
5304 | |
5305 class CountRCClosure: public OopsInHeapRegionClosure { | |
5306 G1CollectedHeap* _g1h; | |
5307 bool _parallel; | |
5308 public: | |
5309 CountRCClosure(G1CollectedHeap* g1h) : | |
5310 _g1h(g1h), _parallel(ParallelGCThreads > 0) | |
5311 {} | |
5312 void do_oop(narrowOop* p) { | |
5313 guarantee(false, "NYI"); | |
5314 } | |
5315 void do_oop(oop* p) { | |
5316 oop obj = *p; | |
5317 assert(obj != NULL, "Precondition."); | |
5318 if (_parallel) { | |
5319 // We go sticky at the limit to avoid excess contention. | |
5320 // If we want to track the actual RC's further, we'll need to keep a | |
5321 // per-thread hash table or something for the popular objects. | |
5322 if (_g1h->obj_rc(obj) < G1ObjPopLimit) { | |
5323 _g1h->atomic_inc_obj_rc(obj); | |
5324 } | |
5325 } else { | |
5326 _g1h->inc_obj_rc(obj); | |
5327 } | |
5328 } | |
5329 }; | |
5330 | |
5331 class EvacPopObjClosure: public ObjectClosure { | |
5332 G1CollectedHeap* _g1h; | |
5333 size_t _pop_objs; | |
5334 size_t _max_rc; | |
5335 public: | |
5336 EvacPopObjClosure(G1CollectedHeap* g1h) : | |
5337 _g1h(g1h), _pop_objs(0), _max_rc(0) {} | |
5338 | |
5339 void do_object(oop obj) { | |
5340 size_t rc = _g1h->obj_rc(obj); | |
5341 _max_rc = MAX2(rc, _max_rc); | |
5342 if (rc >= (size_t) G1ObjPopLimit) { | |
5343 _g1h->_pop_obj_rc_at_copy.add((double)rc); | |
5344 size_t word_sz = obj->size(); | |
5345 HeapWord* new_pop_loc = _g1h->allocate_popular_object(word_sz); | |
5346 oop new_pop_obj = (oop)new_pop_loc; | |
5347 Copy::aligned_disjoint_words((HeapWord*)obj, new_pop_loc, word_sz); | |
5348 obj->forward_to(new_pop_obj); | |
5349 G1ScanAndBalanceClosure scan_and_balance(_g1h); | |
5350 new_pop_obj->oop_iterate_backwards(&scan_and_balance); | |
5351 // preserve "next" mark bit if marking is in progress. | |
5352 if (_g1h->mark_in_progress() && !_g1h->is_obj_ill(obj)) { | |
5353 _g1h->concurrent_mark()->markAndGrayObjectIfNecessary(new_pop_obj); | |
5354 } | |
5355 | |
5356 if (G1TracePopularity) { | |
5357 gclog_or_tty->print_cr("Found obj " PTR_FORMAT " of word size " SIZE_FORMAT | |
5358 " pop (%d), move to " PTR_FORMAT, | |
5359 (void*) obj, word_sz, | |
5360 _g1h->obj_rc(obj), (void*) new_pop_obj); | |
5361 } | |
5362 _pop_objs++; | |
5363 } | |
5364 } | |
5365 size_t pop_objs() { return _pop_objs; } | |
5366 size_t max_rc() { return _max_rc; } | |
5367 }; | |
5368 | |
5369 class G1ParCountRCTask : public AbstractGangTask { | |
5370 G1CollectedHeap* _g1h; | |
5371 BitMap _bm; | |
5372 | |
5373 size_t getNCards() { | |
5374 return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1) | |
5375 / G1BlockOffsetSharedArray::N_bytes; | |
5376 } | |
5377 CountRCClosure _count_rc_closure; | |
5378 public: | |
5379 G1ParCountRCTask(G1CollectedHeap* g1h) : | |
5380 AbstractGangTask("G1 Par RC Count task"), | |
5381 _g1h(g1h), _bm(getNCards()), _count_rc_closure(g1h) | |
5382 {} | |
5383 | |
5384 void work(int i) { | |
5385 ResourceMark rm; | |
5386 HandleMark hm; | |
5387 _g1h->g1_rem_set()->oops_into_collection_set_do(&_count_rc_closure, i); | |
5388 } | |
5389 }; | |
5390 | |
5391 void G1CollectedHeap::popularity_pause_preamble(HeapRegion* popular_region) { | |
5392 // We're evacuating a single region (for popularity). | |
5393 if (G1TracePopularity) { | |
5394 gclog_or_tty->print_cr("Doing pop region pause for ["PTR_FORMAT", "PTR_FORMAT")", | |
5395 popular_region->bottom(), popular_region->end()); | |
5396 } | |
5397 g1_policy()->set_single_region_collection_set(popular_region); | |
5398 size_t max_rc; | |
5399 if (!compute_reference_counts_and_evac_popular(popular_region, | |
5400 &max_rc)) { | |
5401 // We didn't evacuate any popular objects. | |
5402 // We increase the RS popularity limit, to prevent this from | |
5403 // happening in the future. | |
5404 if (G1RSPopLimit < (1 << 30)) { | |
5405 G1RSPopLimit *= 2; | |
5406 } | |
5407 // For now, interesting enough for a message: | |
5408 #if 1 | |
5409 gclog_or_tty->print_cr("In pop region pause for ["PTR_FORMAT", "PTR_FORMAT"), " | |
5410 "failed to find a pop object (max = %d).", | |
5411 popular_region->bottom(), popular_region->end(), | |
5412 max_rc); | |
5413 gclog_or_tty->print_cr("Increased G1RSPopLimit to %d.", G1RSPopLimit); | |
5414 #endif // 0 | |
5415 // Also, we reset the collection set to NULL, to make the rest of | |
5416 // the collection do nothing. | |
5417 assert(popular_region->next_in_collection_set() == NULL, | |
5418 "should be single-region."); | |
5419 popular_region->set_in_collection_set(false); | |
5420 popular_region->set_popular_pending(false); | |
5421 g1_policy()->clear_collection_set(); | |
5422 } | |
5423 } | |
5424 | |
5425 bool G1CollectedHeap:: | |
5426 compute_reference_counts_and_evac_popular(HeapRegion* popular_region, | |
5427 size_t* max_rc) { | |
5428 HeapWord* rc_region_bot; | |
5429 HeapWord* rc_region_end; | |
5430 | |
5431 // Set up the reference count region. | |
5432 HeapRegion* rc_region = newAllocRegion(HeapRegion::GrainWords); | |
5433 if (rc_region != NULL) { | |
5434 rc_region_bot = rc_region->bottom(); | |
5435 rc_region_end = rc_region->end(); | |
5436 } else { | |
5437 rc_region_bot = NEW_C_HEAP_ARRAY(HeapWord, HeapRegion::GrainWords); | |
5438 if (rc_region_bot == NULL) { | |
5439 vm_exit_out_of_memory(HeapRegion::GrainWords, | |
5440 "No space for RC region."); | |
5441 } | |
5442 rc_region_end = rc_region_bot + HeapRegion::GrainWords; | |
5443 } | |
5444 | |
5445 if (G1TracePopularity) | |
5446 gclog_or_tty->print_cr("RC region is ["PTR_FORMAT", "PTR_FORMAT")", | |
5447 rc_region_bot, rc_region_end); | |
5448 if (rc_region_bot > popular_region->bottom()) { | |
5449 _rc_region_above = true; | |
5450 _rc_region_diff = | |
5451 pointer_delta(rc_region_bot, popular_region->bottom(), 1); | |
5452 } else { | |
5453 assert(rc_region_bot < popular_region->bottom(), "Can't be equal."); | |
5454 _rc_region_above = false; | |
5455 _rc_region_diff = | |
5456 pointer_delta(popular_region->bottom(), rc_region_bot, 1); | |
5457 } | |
5458 g1_policy()->record_pop_compute_rc_start(); | |
5459 // Count external references. | |
5460 g1_rem_set()->prepare_for_oops_into_collection_set_do(); | |
5461 if (ParallelGCThreads > 0) { | |
5462 | |
5463 set_par_threads(workers()->total_workers()); | |
5464 G1ParCountRCTask par_count_rc_task(this); | |
5465 workers()->run_task(&par_count_rc_task); | |
5466 set_par_threads(0); | |
5467 | |
5468 } else { | |
5469 CountRCClosure count_rc_closure(this); | |
5470 g1_rem_set()->oops_into_collection_set_do(&count_rc_closure, 0); | |
5471 } | |
5472 g1_rem_set()->cleanup_after_oops_into_collection_set_do(); | |
5473 g1_policy()->record_pop_compute_rc_end(); | |
5474 | |
5475 // Now evacuate popular objects. | |
5476 g1_policy()->record_pop_evac_start(); | |
5477 EvacPopObjClosure evac_pop_obj_cl(this); | |
5478 popular_region->object_iterate(&evac_pop_obj_cl); | |
5479 *max_rc = evac_pop_obj_cl.max_rc(); | |
5480 | |
5481 // Make sure the last "top" value of the current popular region is copied | |
5482 // as the "next_top_at_mark_start", so that objects made popular during | |
5483 // markings aren't automatically considered live. | |
5484 HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index); | |
5485 cur_pop_region->note_end_of_copying(); | |
5486 | |
5487 if (rc_region != NULL) { | |
5488 free_region(rc_region); | |
5489 } else { | |
5490 FREE_C_HEAP_ARRAY(HeapWord, rc_region_bot); | |
5491 } | |
5492 g1_policy()->record_pop_evac_end(); | |
5493 | |
5494 return evac_pop_obj_cl.pop_objs() > 0; | |
5495 } | |
5496 | |
5497 class CountPopObjInfoClosure: public HeapRegionClosure { | |
5498 size_t _objs; | |
5499 size_t _bytes; | |
5500 | |
5501 class CountObjClosure: public ObjectClosure { | |
5502 int _n; | |
5503 public: | |
5504 CountObjClosure() : _n(0) {} | |
5505 void do_object(oop obj) { _n++; } | |
5506 size_t n() { return _n; } | |
5507 }; | |
5508 | |
5509 public: | |
5510 CountPopObjInfoClosure() : _objs(0), _bytes(0) {} | |
5511 bool doHeapRegion(HeapRegion* r) { | |
5512 _bytes += r->used(); | |
5513 CountObjClosure blk; | |
5514 r->object_iterate(&blk); | |
5515 _objs += blk.n(); | |
5516 return false; | |
5517 } | |
5518 size_t objs() { return _objs; } | |
5519 size_t bytes() { return _bytes; } | |
5520 }; | |
5521 | |
5522 | |
5523 void G1CollectedHeap::print_popularity_summary_info() const { | |
5524 CountPopObjInfoClosure blk; | |
5525 for (int i = 0; i <= _cur_pop_hr_index; i++) { | |
5526 blk.doHeapRegion(_hrs->at(i)); | |
5527 } | |
5528 gclog_or_tty->print_cr("\nPopular objects: %d objs, %d bytes.", | |
5529 blk.objs(), blk.bytes()); | |
5530 gclog_or_tty->print_cr(" RC at copy = [avg = %5.2f, max = %5.2f, sd = %5.2f].", | |
5531 _pop_obj_rc_at_copy.avg(), | |
5532 _pop_obj_rc_at_copy.maximum(), | |
5533 _pop_obj_rc_at_copy.sd()); | |
5534 } | |
5535 | |
5536 void G1CollectedHeap::set_refine_cte_cl_concurrency(bool concurrent) { | |
5537 _refine_cte_cl->set_concurrent(concurrent); | |
5538 } | |
5539 | |
5540 #ifndef PRODUCT | |
5541 | |
5542 class PrintHeapRegionClosure: public HeapRegionClosure { | |
5543 public: | |
5544 bool doHeapRegion(HeapRegion *r) { | |
5545 gclog_or_tty->print("Region: "PTR_FORMAT":", r); | |
5546 if (r != NULL) { | |
5547 if (r->is_on_free_list()) | |
5548 gclog_or_tty->print("Free "); | |
5549 if (r->is_young()) | |
5550 gclog_or_tty->print("Young "); | |
5551 if (r->isHumongous()) | |
5552 gclog_or_tty->print("Is Humongous "); | |
5553 r->print(); | |
5554 } | |
5555 return false; | |
5556 } | |
5557 }; | |
5558 | |
5559 class SortHeapRegionClosure : public HeapRegionClosure { | |
5560 size_t young_regions,free_regions, unclean_regions; | |
5561 size_t hum_regions, count; | |
5562 size_t unaccounted, cur_unclean, cur_alloc; | |
5563 size_t total_free; | |
5564 HeapRegion* cur; | |
5565 public: | |
5566 SortHeapRegionClosure(HeapRegion *_cur) : cur(_cur), young_regions(0), | |
5567 free_regions(0), unclean_regions(0), | |
5568 hum_regions(0), | |
5569 count(0), unaccounted(0), | |
5570 cur_alloc(0), total_free(0) | |
5571 {} | |
5572 bool doHeapRegion(HeapRegion *r) { | |
5573 count++; | |
5574 if (r->is_on_free_list()) free_regions++; | |
5575 else if (r->is_on_unclean_list()) unclean_regions++; | |
5576 else if (r->isHumongous()) hum_regions++; | |
5577 else if (r->is_young()) young_regions++; | |
5578 else if (r == cur) cur_alloc++; | |
5579 else unaccounted++; | |
5580 return false; | |
5581 } | |
5582 void print() { | |
5583 total_free = free_regions + unclean_regions; | |
5584 gclog_or_tty->print("%d regions\n", count); | |
5585 gclog_or_tty->print("%d free: free_list = %d unclean = %d\n", | |
5586 total_free, free_regions, unclean_regions); | |
5587 gclog_or_tty->print("%d humongous %d young\n", | |
5588 hum_regions, young_regions); | |
5589 gclog_or_tty->print("%d cur_alloc\n", cur_alloc); | |
5590 gclog_or_tty->print("UHOH unaccounted = %d\n", unaccounted); | |
5591 } | |
5592 }; | |
5593 | |
5594 void G1CollectedHeap::print_region_counts() { | |
5595 SortHeapRegionClosure sc(_cur_alloc_region); | |
5596 PrintHeapRegionClosure cl; | |
5597 heap_region_iterate(&cl); | |
5598 heap_region_iterate(&sc); | |
5599 sc.print(); | |
5600 print_region_accounting_info(); | |
5601 }; | |
5602 | |
5603 bool G1CollectedHeap::regions_accounted_for() { | |
5604 // TODO: regions accounting for young/survivor/tenured | |
5605 return true; | |
5606 } | |
5607 | |
5608 bool G1CollectedHeap::print_region_accounting_info() { | |
5609 gclog_or_tty->print_cr("P regions: %d.", G1NumPopularRegions); | |
5610 gclog_or_tty->print_cr("Free regions: %d (count: %d count list %d) (clean: %d unclean: %d).", | |
5611 free_regions(), | |
5612 count_free_regions(), count_free_regions_list(), | |
5613 _free_region_list_size, _unclean_region_list.sz()); | |
5614 gclog_or_tty->print_cr("cur_alloc: %d.", | |
5615 (_cur_alloc_region == NULL ? 0 : 1)); | |
5616 gclog_or_tty->print_cr("H regions: %d.", _num_humongous_regions); | |
5617 | |
5618 // TODO: check regions accounting for young/survivor/tenured | |
5619 return true; | |
5620 } | |
5621 | |
5622 bool G1CollectedHeap::is_in_closed_subset(const void* p) const { | |
5623 HeapRegion* hr = heap_region_containing(p); | |
5624 if (hr == NULL) { | |
5625 return is_in_permanent(p); | |
5626 } else { | |
5627 return hr->is_in(p); | |
5628 } | |
5629 } | |
5630 #endif // PRODUCT | |
5631 | |
5632 void G1CollectedHeap::g1_unimplemented() { | |
5633 // Unimplemented(); | |
5634 } | |
5635 | |
5636 | |
5637 // Local Variables: *** | |
5638 // c-indentation-style: gnu *** | |
5639 // End: *** |