1 /*
2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/concurrentG1Refine.hpp"
27 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
29 #include "gc_implementation/g1/heapRegionRemSet.hpp"
30 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
31 #include "memory/allocation.hpp"
32 #include "memory/padded.inline.hpp"
33 #include "memory/space.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "runtime/atomic.inline.hpp"
36 #include "utilities/bitMap.inline.hpp"
37 #include "utilities/globalDefinitions.hpp"
38 #include "utilities/growableArray.hpp"
39
40 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
41
42 class PerRegionTable: public CHeapObj<mtGC> {
43 friend class OtherRegionsTable;
44 friend class HeapRegionRemSetIterator;
45
46 HeapRegion* _hr;
47 BitMap _bm;
48 jint _occupied;
49
50 // next pointer for free/allocated 'all' list
51 PerRegionTable* _next;
52
53 // prev pointer for the allocated 'all' list
54 PerRegionTable* _prev;
55
56 // next pointer in collision list
57 PerRegionTable * _collision_list_next;
58
59 // Global free list of PRTs
60 static PerRegionTable* _free_list;
61
62 protected:
63 // We need access in order to union things into the base table.
64 BitMap* bm() { return &_bm; }
65
66 void recount_occupied() {
67 _occupied = (jint) bm()->count_one_bits();
68 }
69
70 PerRegionTable(HeapRegion* hr) :
71 _hr(hr),
72 _occupied(0),
73 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
74 _collision_list_next(NULL), _next(NULL), _prev(NULL)
75 {}
76
77 void add_card_work(CardIdx_t from_card, bool par) {
78 if (!_bm.at(from_card)) {
79 if (par) {
80 if (_bm.par_at_put(from_card, 1)) {
81 Atomic::inc(&_occupied);
82 }
83 } else {
84 _bm.at_put(from_card, 1);
85 _occupied++;
86 }
87 }
88 }
89
90 void add_reference_work(OopOrNarrowOopStar from, bool par) {
91 // Must make this robust in case "from" is not in "_hr", because of
92 // concurrency.
93
94 if (G1TraceHeapRegionRememberedSet) {
95 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
96 from,
97 UseCompressedOops
98 ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
99 : (void *)oopDesc::load_decode_heap_oop((oop*)from));
100 }
101
102 HeapRegion* loc_hr = hr();
103 // If the test below fails, then this table was reused concurrently
104 // with this operation. This is OK, since the old table was coarsened,
105 // and adding a bit to the new table is never incorrect.
106 // If the table used to belong to a continues humongous region and is
107 // now reused for the corresponding start humongous region, we need to
108 // make sure that we detect this. Thus, we call is_in_reserved_raw()
109 // instead of just is_in_reserved() here.
110 if (loc_hr->is_in_reserved_raw(from)) {
111 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
112 CardIdx_t from_card = (CardIdx_t)
113 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
114
115 assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
116 "Must be in range.");
117 add_card_work(from_card, par);
118 }
119 }
120
121 public:
122
123 HeapRegion* hr() const { return _hr; }
124
125 jint occupied() const {
126 // Overkill, but if we ever need it...
127 // guarantee(_occupied == _bm.count_one_bits(), "Check");
128 return _occupied;
129 }
130
131 void init(HeapRegion* hr, bool clear_links_to_all_list) {
132 if (clear_links_to_all_list) {
133 set_next(NULL);
134 set_prev(NULL);
135 }
136 _hr = hr;
137 _collision_list_next = NULL;
138 _occupied = 0;
139 _bm.clear();
140 }
141
142 void add_reference(OopOrNarrowOopStar from) {
143 add_reference_work(from, /*parallel*/ true);
144 }
145
146 void seq_add_reference(OopOrNarrowOopStar from) {
147 add_reference_work(from, /*parallel*/ false);
148 }
149
150 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
151 HeapWord* hr_bot = hr()->bottom();
152 size_t hr_first_card_index = ctbs->index_for(hr_bot);
153 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
154 recount_occupied();
155 }
156
157 void add_card(CardIdx_t from_card_index) {
158 add_card_work(from_card_index, /*parallel*/ true);
159 }
160
161 void seq_add_card(CardIdx_t from_card_index) {
162 add_card_work(from_card_index, /*parallel*/ false);
163 }
164
165 // (Destructively) union the bitmap of the current table into the given
166 // bitmap (which is assumed to be of the same size.)
167 void union_bitmap_into(BitMap* bm) {
168 bm->set_union(_bm);
169 }
170
171 // Mem size in bytes.
172 size_t mem_size() const {
173 return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
174 }
175
176 // Requires "from" to be in "hr()".
177 bool contains_reference(OopOrNarrowOopStar from) const {
178 assert(hr()->is_in_reserved(from), "Precondition.");
179 size_t card_ind = pointer_delta(from, hr()->bottom(),
180 CardTableModRefBS::card_size);
181 return _bm.at(card_ind);
182 }
183
184 // Bulk-free the PRTs from prt to last, assumes that they are
185 // linked together using their _next field.
186 static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
187 while (true) {
188 PerRegionTable* fl = _free_list;
189 last->set_next(fl);
190 PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
191 if (res == fl) {
192 return;
193 }
194 }
195 ShouldNotReachHere();
196 }
197
198 static void free(PerRegionTable* prt) {
199 bulk_free(prt, prt);
200 }
201
202 // Returns an initialized PerRegionTable instance.
203 static PerRegionTable* alloc(HeapRegion* hr) {
204 PerRegionTable* fl = _free_list;
205 while (fl != NULL) {
206 PerRegionTable* nxt = fl->next();
207 PerRegionTable* res =
208 (PerRegionTable*)
209 Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
210 if (res == fl) {
211 fl->init(hr, true);
212 return fl;
213 } else {
214 fl = _free_list;
215 }
216 }
217 assert(fl == NULL, "Loop condition.");
218 return new PerRegionTable(hr);
219 }
220
221 PerRegionTable* next() const { return _next; }
222 void set_next(PerRegionTable* next) { _next = next; }
223 PerRegionTable* prev() const { return _prev; }
224 void set_prev(PerRegionTable* prev) { _prev = prev; }
225
226 // Accessor and Modification routines for the pointer for the
227 // singly linked collision list that links the PRTs within the
228 // OtherRegionsTable::_fine_grain_regions hash table.
229 //
230 // It might be useful to also make the collision list doubly linked
231 // to avoid iteration over the collisions list during scrubbing/deletion.
232 // OTOH there might not be many collisions.
233
234 PerRegionTable* collision_list_next() const {
235 return _collision_list_next;
236 }
237
238 void set_collision_list_next(PerRegionTable* next) {
239 _collision_list_next = next;
240 }
241
242 PerRegionTable** collision_list_next_addr() {
243 return &_collision_list_next;
244 }
245
246 static size_t fl_mem_size() {
247 PerRegionTable* cur = _free_list;
248 size_t res = 0;
249 while (cur != NULL) {
250 res += cur->mem_size();
251 cur = cur->next();
252 }
253 return res;
254 }
255
256 static void test_fl_mem_size();
257 };
258
259 PerRegionTable* PerRegionTable::_free_list = NULL;
260
261 size_t OtherRegionsTable::_max_fine_entries = 0;
262 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
263 size_t OtherRegionsTable::_fine_eviction_stride = 0;
264 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
265
266 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
267 _g1h(G1CollectedHeap::heap()),
268 _hr(hr), _m(m),
269 _coarse_map(G1CollectedHeap::heap()->max_regions(),
270 false /* in-resource-area */),
271 _fine_grain_regions(NULL),
272 _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
273 _n_fine_entries(0), _n_coarse_entries(0),
274 _fine_eviction_start(0),
275 _sparse_table(hr)
276 {
277 typedef PerRegionTable* PerRegionTablePtr;
278
279 if (_max_fine_entries == 0) {
280 assert(_mod_max_fine_entries_mask == 0, "Both or none.");
281 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
282 _max_fine_entries = (size_t)1 << max_entries_log;
283 _mod_max_fine_entries_mask = _max_fine_entries - 1;
284
285 assert(_fine_eviction_sample_size == 0
286 && _fine_eviction_stride == 0, "All init at same time.");
287 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
288 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
289 }
290
291 _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
292 mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
293
294 if (_fine_grain_regions == NULL) {
295 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
296 "Failed to allocate _fine_grain_entries.");
297 }
298
299 for (size_t i = 0; i < _max_fine_entries; i++) {
300 _fine_grain_regions[i] = NULL;
301 }
302 }
303
304 void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
305 // We always append to the beginning of the list for convenience;
306 // the order of entries in this list does not matter.
307 if (_first_all_fine_prts != NULL) {
308 assert(_first_all_fine_prts->prev() == NULL, "invariant");
309 _first_all_fine_prts->set_prev(prt);
310 prt->set_next(_first_all_fine_prts);
311 } else {
312 // this is the first element we insert. Adjust the "last" pointer
313 _last_all_fine_prts = prt;
314 assert(prt->next() == NULL, "just checking");
315 }
316 // the new element is always the first element without a predecessor
317 prt->set_prev(NULL);
318 _first_all_fine_prts = prt;
319
320 assert(prt->prev() == NULL, "just checking");
321 assert(_first_all_fine_prts == prt, "just checking");
322 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
323 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
324 "just checking");
325 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
326 "just checking");
327 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
328 "just checking");
329 }
330
331 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
332 if (prt->prev() != NULL) {
333 assert(_first_all_fine_prts != prt, "just checking");
334 prt->prev()->set_next(prt->next());
335 // removing the last element in the list?
336 if (_last_all_fine_prts == prt) {
337 _last_all_fine_prts = prt->prev();
338 }
339 } else {
340 assert(_first_all_fine_prts == prt, "just checking");
341 _first_all_fine_prts = prt->next();
342 // list is empty now?
343 if (_first_all_fine_prts == NULL) {
344 _last_all_fine_prts = NULL;
345 }
346 }
347
348 if (prt->next() != NULL) {
349 prt->next()->set_prev(prt->prev());
350 }
351
352 prt->set_next(NULL);
353 prt->set_prev(NULL);
354
355 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
356 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
357 "just checking");
358 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
359 "just checking");
360 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
361 "just checking");
362 }
363
364 int** FromCardCache::_cache = NULL;
365 uint FromCardCache::_max_regions = 0;
366 size_t FromCardCache::_static_mem_size = 0;
367
368 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
369 guarantee(_cache == NULL, "Should not call this multiple times");
370
371 _max_regions = max_num_regions;
372 _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
373 _max_regions,
374 &_static_mem_size);
375
376 invalidate(0, _max_regions);
377 }
378
379 void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) {
380 guarantee((size_t)start_idx + new_num_regions <= max_uintx,
381 err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT,
382 start_idx, new_num_regions));
383 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
384 uint end_idx = (start_idx + (uint)new_num_regions);
385 assert(end_idx <= _max_regions, "Must be within max.");
386 for (uint j = start_idx; j < end_idx; j++) {
387 set(i, j, InvalidCard);
388 }
389 }
390 }
391
392 #ifndef PRODUCT
393 void FromCardCache::print(outputStream* out) {
394 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
395 for (uint j = 0; j < _max_regions; j++) {
396 out->print_cr("_from_card_cache[%u][%u] = %d.",
397 i, j, at(i, j));
398 }
399 }
400 }
401 #endif
402
403 void FromCardCache::clear(uint region_idx) {
404 uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
405 for (uint i = 0; i < num_par_remsets; i++) {
406 set(i, region_idx, InvalidCard);
407 }
408 }
409
410 void OtherRegionsTable::initialize(uint max_regions) {
411 FromCardCache::initialize(HeapRegionRemSet::num_par_rem_sets(), max_regions);
412 }
413
414 void OtherRegionsTable::invalidate(uint start_idx, size_t num_regions) {
415 FromCardCache::invalidate(start_idx, num_regions);
416 }
417
418 void OtherRegionsTable::print_from_card_cache() {
419 FromCardCache::print();
420 }
421
422 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) {
423 uint cur_hrm_ind = hr()->hrm_index();
424
425 if (G1TraceHeapRegionRememberedSet) {
426 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
427 from,
428 UseCompressedOops
429 ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
430 : (void *)oopDesc::load_decode_heap_oop((oop*)from));
431 }
432
433 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
434
435 if (G1TraceHeapRegionRememberedSet) {
436 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
437 hr()->bottom(), from_card,
438 FromCardCache::at(tid, cur_hrm_ind));
439 }
440
441 if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) {
442 if (G1TraceHeapRegionRememberedSet) {
443 gclog_or_tty->print_cr(" from-card cache hit.");
444 }
445 assert(contains_reference(from), "We just added it!");
446 return;
447 }
448
449 // Note that this may be a continued H region.
450 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
451 RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index();
452
453 // If the region is already coarsened, return.
454 if (_coarse_map.at(from_hrm_ind)) {
455 if (G1TraceHeapRegionRememberedSet) {
456 gclog_or_tty->print_cr(" coarse map hit.");
457 }
458 assert(contains_reference(from), "We just added it!");
459 return;
460 }
461
462 // Otherwise find a per-region table to add it to.
463 size_t ind = from_hrm_ind & _mod_max_fine_entries_mask;
464 PerRegionTable* prt = find_region_table(ind, from_hr);
465 if (prt == NULL) {
466 MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
467 // Confirm that it's really not there...
468 prt = find_region_table(ind, from_hr);
469 if (prt == NULL) {
470
471 uintptr_t from_hr_bot_card_index =
472 uintptr_t(from_hr->bottom())
473 >> CardTableModRefBS::card_shift;
474 CardIdx_t card_index = from_card - from_hr_bot_card_index;
475 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
476 "Must be in range.");
477 if (G1HRRSUseSparseTable &&
478 _sparse_table.add_card(from_hrm_ind, card_index)) {
479 if (G1RecordHRRSOops) {
480 HeapRegionRemSet::record(hr(), from);
481 if (G1TraceHeapRegionRememberedSet) {
482 gclog_or_tty->print(" Added card " PTR_FORMAT " to region "
483 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
484 align_size_down(uintptr_t(from),
485 CardTableModRefBS::card_size),
486 hr()->bottom(), from);
487 }
488 }
489 if (G1TraceHeapRegionRememberedSet) {
490 gclog_or_tty->print_cr(" added card to sparse table.");
491 }
492 assert(contains_reference_locked(from), "We just added it!");
493 return;
494 } else {
495 if (G1TraceHeapRegionRememberedSet) {
496 gclog_or_tty->print_cr(" [tid %u] sparse table entry "
497 "overflow(f: %d, t: %u)",
498 tid, from_hrm_ind, cur_hrm_ind);
499 }
500 }
501
502 if (_n_fine_entries == _max_fine_entries) {
503 prt = delete_region_table();
504 // There is no need to clear the links to the 'all' list here:
505 // prt will be reused immediately, i.e. remain in the 'all' list.
506 prt->init(from_hr, false /* clear_links_to_all_list */);
507 } else {
508 prt = PerRegionTable::alloc(from_hr);
509 link_to_all(prt);
510 }
511
512 PerRegionTable* first_prt = _fine_grain_regions[ind];
513 prt->set_collision_list_next(first_prt);
514 _fine_grain_regions[ind] = prt;
515 _n_fine_entries++;
516
517 if (G1HRRSUseSparseTable) {
518 // Transfer from sparse to fine-grain.
519 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind);
520 assert(sprt_entry != NULL, "There should have been an entry");
521 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
522 CardIdx_t c = sprt_entry->card(i);
523 if (c != SparsePRTEntry::NullEntry) {
524 prt->add_card(c);
525 }
526 }
527 // Now we can delete the sparse entry.
528 bool res = _sparse_table.delete_entry(from_hrm_ind);
529 assert(res, "It should have been there.");
530 }
531 }
532 assert(prt != NULL && prt->hr() == from_hr, "consequence");
533 }
534 // Note that we can't assert "prt->hr() == from_hr", because of the
535 // possibility of concurrent reuse. But see head comment of
536 // OtherRegionsTable for why this is OK.
537 assert(prt != NULL, "Inv");
538
539 prt->add_reference(from);
540
541 if (G1RecordHRRSOops) {
542 HeapRegionRemSet::record(hr(), from);
543 if (G1TraceHeapRegionRememberedSet) {
544 gclog_or_tty->print("Added card " PTR_FORMAT " to region "
545 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
546 align_size_down(uintptr_t(from),
547 CardTableModRefBS::card_size),
548 hr()->bottom(), from);
549 }
550 }
551 assert(contains_reference(from), "We just added it!");
552 }
553
554 PerRegionTable*
555 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
556 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
557 PerRegionTable* prt = _fine_grain_regions[ind];
558 while (prt != NULL && prt->hr() != hr) {
559 prt = prt->collision_list_next();
560 }
561 // Loop postcondition is the method postcondition.
562 return prt;
563 }
564
565 jint OtherRegionsTable::_n_coarsenings = 0;
566
567 PerRegionTable* OtherRegionsTable::delete_region_table() {
568 assert(_m->owned_by_self(), "Precondition");
569 assert(_n_fine_entries == _max_fine_entries, "Precondition");
570 PerRegionTable* max = NULL;
571 jint max_occ = 0;
572 PerRegionTable** max_prev;
573 size_t max_ind;
574
575 size_t i = _fine_eviction_start;
576 for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
577 size_t ii = i;
578 // Make sure we get a non-NULL sample.
579 while (_fine_grain_regions[ii] == NULL) {
580 ii++;
581 if (ii == _max_fine_entries) ii = 0;
582 guarantee(ii != i, "We must find one.");
583 }
584 PerRegionTable** prev = &_fine_grain_regions[ii];
585 PerRegionTable* cur = *prev;
586 while (cur != NULL) {
587 jint cur_occ = cur->occupied();
588 if (max == NULL || cur_occ > max_occ) {
589 max = cur;
590 max_prev = prev;
591 max_ind = i;
592 max_occ = cur_occ;
593 }
594 prev = cur->collision_list_next_addr();
595 cur = cur->collision_list_next();
596 }
597 i = i + _fine_eviction_stride;
598 if (i >= _n_fine_entries) i = i - _n_fine_entries;
599 }
600
601 _fine_eviction_start++;
602
603 if (_fine_eviction_start >= _n_fine_entries) {
604 _fine_eviction_start -= _n_fine_entries;
605 }
606
607 guarantee(max != NULL, "Since _n_fine_entries > 0");
608
609 // Set the corresponding coarse bit.
610 size_t max_hrm_index = (size_t) max->hr()->hrm_index();
611 if (!_coarse_map.at(max_hrm_index)) {
612 _coarse_map.at_put(max_hrm_index, true);
613 _n_coarse_entries++;
614 if (G1TraceHeapRegionRememberedSet) {
615 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
616 "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n",
617 hr()->bottom(),
618 max->hr()->bottom(),
619 _n_coarse_entries);
620 }
621 }
622
623 // Unsplice.
624 *max_prev = max->collision_list_next();
625 Atomic::inc(&_n_coarsenings);
626 _n_fine_entries--;
627 return max;
628 }
629
630
631 // At present, this must be called stop-world single-threaded.
632 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
633 BitMap* region_bm, BitMap* card_bm) {
634 // First eliminated garbage regions from the coarse map.
635 if (G1RSScrubVerbose) {
636 gclog_or_tty->print_cr("Scrubbing region %u:", hr()->hrm_index());
637 }
638
639 assert(_coarse_map.size() == region_bm->size(), "Precondition");
640 if (G1RSScrubVerbose) {
641 gclog_or_tty->print(" Coarse map: before = "SIZE_FORMAT"...",
642 _n_coarse_entries);
643 }
644 _coarse_map.set_intersection(*region_bm);
645 _n_coarse_entries = _coarse_map.count_one_bits();
646 if (G1RSScrubVerbose) {
647 gclog_or_tty->print_cr(" after = "SIZE_FORMAT".", _n_coarse_entries);
648 }
649
650 // Now do the fine-grained maps.
651 for (size_t i = 0; i < _max_fine_entries; i++) {
652 PerRegionTable* cur = _fine_grain_regions[i];
653 PerRegionTable** prev = &_fine_grain_regions[i];
654 while (cur != NULL) {
655 PerRegionTable* nxt = cur->collision_list_next();
656 // If the entire region is dead, eliminate.
657 if (G1RSScrubVerbose) {
658 gclog_or_tty->print_cr(" For other region %u:",
659 cur->hr()->hrm_index());
660 }
661 if (!region_bm->at((size_t) cur->hr()->hrm_index())) {
662 *prev = nxt;
663 cur->set_collision_list_next(NULL);
664 _n_fine_entries--;
665 if (G1RSScrubVerbose) {
666 gclog_or_tty->print_cr(" deleted via region map.");
667 }
668 unlink_from_all(cur);
669 PerRegionTable::free(cur);
670 } else {
671 // Do fine-grain elimination.
672 if (G1RSScrubVerbose) {
673 gclog_or_tty->print(" occ: before = %4d.", cur->occupied());
674 }
675 cur->scrub(ctbs, card_bm);
676 if (G1RSScrubVerbose) {
677 gclog_or_tty->print_cr(" after = %4d.", cur->occupied());
678 }
679 // Did that empty the table completely?
680 if (cur->occupied() == 0) {
681 *prev = nxt;
682 cur->set_collision_list_next(NULL);
683 _n_fine_entries--;
684 unlink_from_all(cur);
685 PerRegionTable::free(cur);
686 } else {
687 prev = cur->collision_list_next_addr();
688 }
689 }
690 cur = nxt;
691 }
692 }
693 // Since we may have deleted a from_card_cache entry from the RS, clear
694 // the FCC.
695 clear_fcc();
696 }
697
698 bool OtherRegionsTable::is_empty() const {
699 return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL;
700 }
701
702 size_t OtherRegionsTable::occupied() const {
703 size_t sum = occ_fine();
704 sum += occ_sparse();
705 sum += occ_coarse();
706 return sum;
707 }
708
709 size_t OtherRegionsTable::occ_fine() const {
710 size_t sum = 0;
711
712 size_t num = 0;
713 PerRegionTable * cur = _first_all_fine_prts;
714 while (cur != NULL) {
715 sum += cur->occupied();
716 cur = cur->next();
717 num++;
718 }
719 guarantee(num == _n_fine_entries, "just checking");
720 return sum;
721 }
722
723 size_t OtherRegionsTable::occ_coarse() const {
724 return (_n_coarse_entries * HeapRegion::CardsPerRegion);
725 }
726
727 size_t OtherRegionsTable::occ_sparse() const {
728 return _sparse_table.occupied();
729 }
730
731 size_t OtherRegionsTable::mem_size() const {
732 size_t sum = 0;
733 // all PRTs are of the same size so it is sufficient to query only one of them.
734 if (_first_all_fine_prts != NULL) {
735 assert(_last_all_fine_prts != NULL &&
736 _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
737 sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
738 }
739 sum += (sizeof(PerRegionTable*) * _max_fine_entries);
740 sum += (_coarse_map.size_in_words() * HeapWordSize);
741 sum += (_sparse_table.mem_size());
742 sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
743 return sum;
744 }
745
746 size_t OtherRegionsTable::static_mem_size() {
747 return FromCardCache::static_mem_size();
748 }
749
750 size_t OtherRegionsTable::fl_mem_size() {
751 return PerRegionTable::fl_mem_size();
752 }
753
754 void OtherRegionsTable::clear_fcc() {
755 FromCardCache::clear(hr()->hrm_index());
756 }
757
758 void OtherRegionsTable::clear() {
759 // if there are no entries, skip this step
760 if (_first_all_fine_prts != NULL) {
761 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
762 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
763 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
764 } else {
765 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
766 }
767
768 _first_all_fine_prts = _last_all_fine_prts = NULL;
769 _sparse_table.clear();
770 _coarse_map.clear();
771 _n_fine_entries = 0;
772 _n_coarse_entries = 0;
773
774 clear_fcc();
775 }
776
777 bool OtherRegionsTable::del_single_region_table(size_t ind,
778 HeapRegion* hr) {
779 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
780 PerRegionTable** prev_addr = &_fine_grain_regions[ind];
781 PerRegionTable* prt = *prev_addr;
782 while (prt != NULL && prt->hr() != hr) {
783 prev_addr = prt->collision_list_next_addr();
784 prt = prt->collision_list_next();
785 }
786 if (prt != NULL) {
787 assert(prt->hr() == hr, "Loop postcondition.");
788 *prev_addr = prt->collision_list_next();
789 unlink_from_all(prt);
790 PerRegionTable::free(prt);
791 _n_fine_entries--;
792 return true;
793 } else {
794 return false;
795 }
796 }
797
798 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
799 // Cast away const in this case.
800 MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
801 return contains_reference_locked(from);
802 }
803
804 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
805 HeapRegion* hr = _g1h->heap_region_containing_raw(from);
806 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
807 // Is this region in the coarse map?
808 if (_coarse_map.at(hr_ind)) return true;
809
810 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
811 hr);
812 if (prt != NULL) {
813 return prt->contains_reference(from);
814
815 } else {
816 uintptr_t from_card =
817 (uintptr_t(from) >> CardTableModRefBS::card_shift);
818 uintptr_t hr_bot_card_index =
819 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
820 assert(from_card >= hr_bot_card_index, "Inv");
821 CardIdx_t card_index = from_card - hr_bot_card_index;
822 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
823 "Must be in range.");
824 return _sparse_table.contains_card(hr_ind, card_index);
825 }
826 }
827
828 void
829 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
830 _sparse_table.do_cleanup_work(hrrs_cleanup_task);
831 }
832
833 // Determines how many threads can add records to an rset in parallel.
834 // This can be done by either mutator threads together with the
835 // concurrent refinement threads or GC threads.
836 uint HeapRegionRemSet::num_par_rem_sets() {
837 return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
838 }
839
840 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
841 HeapRegion* hr)
842 : _bosa(bosa),
843 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true),
844 _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
845 reset_for_par_iteration();
846 }
847
848 void HeapRegionRemSet::setup_remset_size() {
849 // Setup sparse and fine-grain tables sizes.
850 // table_size = base * (log(region_size / 1M) + 1)
851 const int LOG_M = 20;
852 int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
853 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
854 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
855 }
856 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
857 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
858 }
859 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
860 }
861
862 bool HeapRegionRemSet::claim_iter() {
863 if (_iter_state != Unclaimed) return false;
864 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
865 return (res == Unclaimed);
866 }
867
868 void HeapRegionRemSet::set_iter_complete() {
869 _iter_state = Complete;
870 }
871
872 bool HeapRegionRemSet::iter_is_complete() {
873 return _iter_state == Complete;
874 }
875
876 #ifndef PRODUCT
877 void HeapRegionRemSet::print() {
878 HeapRegionRemSetIterator iter(this);
879 size_t card_index;
880 while (iter.has_next(card_index)) {
881 HeapWord* card_start =
882 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
883 gclog_or_tty->print_cr(" Card " PTR_FORMAT, card_start);
884 }
885 if (iter.n_yielded() != occupied()) {
886 gclog_or_tty->print_cr("Yielded disagrees with occupied:");
887 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6)
888 " coarse, " SIZE_FORMAT_W(6) " fine).",
889 iter.n_yielded(),
890 iter.n_yielded_coarse(), iter.n_yielded_fine());
891 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " occ (" SIZE_FORMAT_W(6)
892 " coarse, " SIZE_FORMAT_W(6) " fine).",
893 occupied(), occ_coarse(), occ_fine());
894 }
895 guarantee(iter.n_yielded() == occupied(),
896 "We should have yielded all the represented cards.");
897 }
898 #endif
899
900 void HeapRegionRemSet::cleanup() {
901 SparsePRT::cleanup_all();
902 }
903
904 void HeapRegionRemSet::clear() {
905 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
906 clear_locked();
907 }
908
909 void HeapRegionRemSet::clear_locked() {
910 _code_roots.clear();
911 _other_regions.clear();
912 assert(occupied_locked() == 0, "Should be clear.");
913 reset_for_par_iteration();
914 }
915
916 void HeapRegionRemSet::reset_for_par_iteration() {
917 _iter_state = Unclaimed;
918 _iter_claimed = 0;
919 // It's good to check this to make sure that the two methods are in sync.
920 assert(verify_ready_for_par_iteration(), "post-condition");
921 }
922
923 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
924 BitMap* region_bm, BitMap* card_bm) {
925 _other_regions.scrub(ctbs, region_bm, card_bm);
926 }
927
928 // Code roots support
929 //
930 // The code root set is protected by two separate locking schemes
931 // When at safepoint the per-hrrs lock must be held during modifications
932 // except when doing a full gc.
933 // When not at safepoint the CodeCache_lock must be held during modifications.
934 // When concurrent readers access the contains() function
935 // (during the evacuation phase) no removals are allowed.
936
937 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
938 assert(nm != NULL, "sanity");
939 // Optimistic unlocked contains-check
940 if (!_code_roots.contains(nm)) {
941 MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
942 add_strong_code_root_locked(nm);
943 }
944 }
945
946 void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
947 assert(nm != NULL, "sanity");
948 _code_roots.add(nm);
949 }
950
951 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
952 assert(nm != NULL, "sanity");
953 assert_locked_or_safepoint(CodeCache_lock);
954
955 MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
956 _code_roots.remove(nm);
957
958 // Check that there were no duplicates
959 guarantee(!_code_roots.contains(nm), "duplicate entry found");
960 }
961
962 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
963 _code_roots.nmethods_do(blk);
964 }
965
966 void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
967 _code_roots.clean(hr);
968 }
969
970 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
971 return _code_roots.mem_size();
972 }
973
974 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
975 _hrrs(hrrs),
976 _g1h(G1CollectedHeap::heap()),
977 _coarse_map(&hrrs->_other_regions._coarse_map),
978 _bosa(hrrs->bosa()),
979 _is(Sparse),
980 // Set these values so that we increment to the first region.
981 _coarse_cur_region_index(-1),
982 _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
983 _cur_card_in_prt(HeapRegion::CardsPerRegion),
984 _fine_cur_prt(NULL),
985 _n_yielded_coarse(0),
986 _n_yielded_fine(0),
987 _n_yielded_sparse(0),
988 _sparse_iter(&hrrs->_other_regions._sparse_table) {}
989
990 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
991 if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
992 // Go to the next card.
993 _coarse_cur_region_cur_card++;
994 // Was the last the last card in the current region?
995 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
996 // Yes: find the next region. This may leave _coarse_cur_region_index
997 // Set to the last index, in which case there are no more coarse
998 // regions.
999 _coarse_cur_region_index =
1000 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
1001 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
1002 _coarse_cur_region_cur_card = 0;
1003 HeapWord* r_bot =
1004 _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
1005 _cur_region_card_offset = _bosa->index_for(r_bot);
1006 } else {
1007 return false;
1008 }
1009 }
1010 // If we didn't return false above, then we can yield a card.
1011 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
1012 return true;
1013 }
1014
1015 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
1016 if (fine_has_next()) {
1017 _cur_card_in_prt =
1018 _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1019 }
1020 if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
1021 // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
1022 // the remembered set.
1023 if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
1024 return false;
1025 }
1026 PerRegionTable* next_prt = _fine_cur_prt->next();
1027 switch_to_prt(next_prt);
1028 _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1029 }
1030
1031 card_index = _cur_region_card_offset + _cur_card_in_prt;
1032 guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
1033 err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
1034 return true;
1035 }
1036
1037 bool HeapRegionRemSetIterator::fine_has_next() {
1038 return _cur_card_in_prt != HeapRegion::CardsPerRegion;
1039 }
1040
1041 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
1042 assert(prt != NULL, "Cannot switch to NULL prt");
1043 _fine_cur_prt = prt;
1044
1045 HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
1046 _cur_region_card_offset = _bosa->index_for(r_bot);
1047
1048 // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
1049 // To avoid special-casing this start case, and not miss the first bitmap
1050 // entry, initialize _cur_region_cur_card with -1 instead of 0.
1051 _cur_card_in_prt = (size_t)-1;
1052 }
1053
1054 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1055 switch (_is) {
1056 case Sparse: {
1057 if (_sparse_iter.has_next(card_index)) {
1058 _n_yielded_sparse++;
1059 return true;
1060 }
1061 // Otherwise, deliberate fall-through
1062 _is = Fine;
1063 PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
1064 if (initial_fine_prt != NULL) {
1065 switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
1066 }
1067 }
1068 case Fine:
1069 if (fine_has_next(card_index)) {
1070 _n_yielded_fine++;
1071 return true;
1072 }
1073 // Otherwise, deliberate fall-through
1074 _is = Coarse;
1075 case Coarse:
1076 if (coarse_has_next(card_index)) {
1077 _n_yielded_coarse++;
1078 return true;
1079 }
1080 // Otherwise...
1081 break;
1082 }
1083 assert(ParallelGCThreads > 1 ||
1084 n_yielded() == _hrrs->occupied(),
1085 "Should have yielded all the cards in the rem set "
1086 "(in the non-par case).");
1087 return false;
1088 }
1089
1090
1091
1092 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1093 HeapWord** HeapRegionRemSet::_recorded_cards = NULL;
1094 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL;
1095 int HeapRegionRemSet::_n_recorded = 0;
1096
1097 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1098 int* HeapRegionRemSet::_recorded_event_index = NULL;
1099 int HeapRegionRemSet::_n_recorded_events = 0;
1100
1101 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1102 if (_recorded_oops == NULL) {
1103 assert(_n_recorded == 0
1104 && _recorded_cards == NULL
1105 && _recorded_regions == NULL,
1106 "Inv");
1107 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
1108 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded, mtGC);
1109 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded, mtGC);
1110 }
1111 if (_n_recorded == MaxRecorded) {
1112 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1113 } else {
1114 _recorded_cards[_n_recorded] =
1115 (HeapWord*)align_size_down(uintptr_t(f),
1116 CardTableModRefBS::card_size);
1117 _recorded_oops[_n_recorded] = f;
1118 _recorded_regions[_n_recorded] = hr;
1119 _n_recorded++;
1120 }
1121 }
1122
1123 void HeapRegionRemSet::record_event(Event evnt) {
1124 if (!G1RecordHRRSEvents) return;
1125
1126 if (_recorded_events == NULL) {
1127 assert(_n_recorded_events == 0
1128 && _recorded_event_index == NULL,
1129 "Inv");
1130 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
1131 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
1132 }
1133 if (_n_recorded_events == MaxRecordedEvents) {
1134 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1135 } else {
1136 _recorded_events[_n_recorded_events] = evnt;
1137 _recorded_event_index[_n_recorded_events] = _n_recorded;
1138 _n_recorded_events++;
1139 }
1140 }
1141
1142 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1143 switch (evnt) {
1144 case Event_EvacStart:
1145 str->print("Evac Start");
1146 break;
1147 case Event_EvacEnd:
1148 str->print("Evac End");
1149 break;
1150 case Event_RSUpdateEnd:
1151 str->print("RS Update End");
1152 break;
1153 }
1154 }
1155
1156 void HeapRegionRemSet::print_recorded() {
1157 int cur_evnt = 0;
1158 Event cur_evnt_kind;
1159 int cur_evnt_ind = 0;
1160 if (_n_recorded_events > 0) {
1161 cur_evnt_kind = _recorded_events[cur_evnt];
1162 cur_evnt_ind = _recorded_event_index[cur_evnt];
1163 }
1164
1165 for (int i = 0; i < _n_recorded; i++) {
1166 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1167 gclog_or_tty->print("Event: ");
1168 print_event(gclog_or_tty, cur_evnt_kind);
1169 gclog_or_tty->cr();
1170 cur_evnt++;
1171 if (cur_evnt < MaxRecordedEvents) {
1172 cur_evnt_kind = _recorded_events[cur_evnt];
1173 cur_evnt_ind = _recorded_event_index[cur_evnt];
1174 }
1175 }
1176 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1177 " for ref " PTR_FORMAT ".\n",
1178 _recorded_cards[i], _recorded_regions[i]->bottom(),
1179 _recorded_oops[i]);
1180 }
1181 }
1182
1183 void HeapRegionRemSet::reset_for_cleanup_tasks() {
1184 SparsePRT::reset_for_cleanup_tasks();
1185 }
1186
1187 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
1188 _other_regions.do_cleanup_work(hrrs_cleanup_task);
1189 }
1190
1191 void
1192 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
1193 SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
1194 }
1195
1196 #ifndef PRODUCT
1197 void PerRegionTable::test_fl_mem_size() {
1198 PerRegionTable* dummy = alloc(NULL);
1199
1200 size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
1201 assert(dummy->mem_size() > min_prt_size,
1202 err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
1203 "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
1204 free(dummy);
1205 guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
1206 // try to reset the state
1207 _free_list = NULL;
1208 delete dummy;
1209 }
1210
1211 void HeapRegionRemSet::test_prt() {
1212 PerRegionTable::test_fl_mem_size();
1213 }
1214
1215 void HeapRegionRemSet::test() {
1216 os::sleep(Thread::current(), (jlong)5000, false);
1217 G1CollectedHeap* g1h = G1CollectedHeap::heap();
1218
1219 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1220 // hash bucket.
1221 HeapRegion* hr0 = g1h->region_at(0);
1222 HeapRegion* hr1 = g1h->region_at(1);
1223 HeapRegion* hr2 = g1h->region_at(5);
1224 HeapRegion* hr3 = g1h->region_at(6);
1225 HeapRegion* hr4 = g1h->region_at(7);
1226 HeapRegion* hr5 = g1h->region_at(8);
1227
1228 HeapWord* hr1_start = hr1->bottom();
1229 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1230 HeapWord* hr1_last = hr1->end() - 1;
1231
1232 HeapWord* hr2_start = hr2->bottom();
1233 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1234 HeapWord* hr2_last = hr2->end() - 1;
1235
1236 HeapWord* hr3_start = hr3->bottom();
1237 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1238 HeapWord* hr3_last = hr3->end() - 1;
1239
1240 HeapRegionRemSet* hrrs = hr0->rem_set();
1241
1242 // Make three references from region 0x101...
1243 hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1244 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1245 hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1246
1247 hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1248 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1249 hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1250
1251 hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1252 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1253 hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1254
1255 // Now cause a coarsening.
1256 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1257 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1258
1259 // Now, does iteration yield these three?
1260 HeapRegionRemSetIterator iter(hrrs);
1261 size_t sum = 0;
1262 size_t card_index;
1263 while (iter.has_next(card_index)) {
1264 HeapWord* card_start =
1265 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1266 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start);
1267 sum++;
1268 }
1269 guarantee(sum == 11 - 3 + 2048, "Failure");
1270 guarantee(sum == hrrs->occupied(), "Failure");
1271 }
1272 #endif