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 "utilities/bitMap.inline.hpp"
36 #include "utilities/globalDefinitions.hpp"
37 #include "utilities/growableArray.hpp"
38
39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
40
41 class PerRegionTable: public CHeapObj<mtGC> {
42 friend class OtherRegionsTable;
43 friend class HeapRegionRemSetIterator;
44
45 HeapRegion* _hr;
46 BitMap _bm;
47 jint _occupied;
48
49 // next pointer for free/allocated 'all' list
50 PerRegionTable* _next;
51
52 // prev pointer for the allocated 'all' list
53 PerRegionTable* _prev;
54
55 // next pointer in collision list
56 PerRegionTable * _collision_list_next;
57
58 // Global free list of PRTs
59 static PerRegionTable* _free_list;
60
61 protected:
62 // We need access in order to union things into the base table.
63 BitMap* bm() { return &_bm; }
64
65 void recount_occupied() {
66 _occupied = (jint) bm()->count_one_bits();
67 }
68
69 PerRegionTable(HeapRegion* hr) :
70 _hr(hr),
71 _occupied(0),
72 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
73 _collision_list_next(NULL), _next(NULL), _prev(NULL)
74 {}
75
76 void add_card_work(CardIdx_t from_card, bool par) {
77 if (!_bm.at(from_card)) {
78 if (par) {
79 if (_bm.par_at_put(from_card, 1)) {
80 Atomic::inc(&_occupied);
81 }
82 } else {
83 _bm.at_put(from_card, 1);
84 _occupied++;
85 }
86 }
87 }
88
89 void add_reference_work(OopOrNarrowOopStar from, bool par) {
90 // Must make this robust in case "from" is not in "_hr", because of
91 // concurrency.
92
93 if (G1TraceHeapRegionRememberedSet) {
94 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
95 from,
96 UseCompressedOops
97 ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
98 : (void *)oopDesc::load_decode_heap_oop((oop*)from));
99 }
100
101 HeapRegion* loc_hr = hr();
102 // If the test below fails, then this table was reused concurrently
103 // with this operation. This is OK, since the old table was coarsened,
104 // and adding a bit to the new table is never incorrect.
105 // If the table used to belong to a continues humongous region and is
106 // now reused for the corresponding start humongous region, we need to
107 // make sure that we detect this. Thus, we call is_in_reserved_raw()
108 // instead of just is_in_reserved() here.
109 if (loc_hr->is_in_reserved_raw(from)) {
110 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
111 CardIdx_t from_card = (CardIdx_t)
112 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
113
114 assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
115 "Must be in range.");
116 add_card_work(from_card, par);
117 }
118 }
119
120 public:
121
122 HeapRegion* hr() const { return _hr; }
123
124 jint occupied() const {
125 // Overkill, but if we ever need it...
126 // guarantee(_occupied == _bm.count_one_bits(), "Check");
127 return _occupied;
128 }
129
130 void init(HeapRegion* hr, bool clear_links_to_all_list) {
131 if (clear_links_to_all_list) {
132 set_next(NULL);
133 set_prev(NULL);
134 }
135 _hr = hr;
136 _collision_list_next = NULL;
137 _occupied = 0;
138 _bm.clear();
139 }
140
141 void add_reference(OopOrNarrowOopStar from) {
142 add_reference_work(from, /*parallel*/ true);
143 }
144
145 void seq_add_reference(OopOrNarrowOopStar from) {
146 add_reference_work(from, /*parallel*/ false);
147 }
148
149 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
150 HeapWord* hr_bot = hr()->bottom();
151 size_t hr_first_card_index = ctbs->index_for(hr_bot);
152 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
153 recount_occupied();
154 }
155
156 void add_card(CardIdx_t from_card_index) {
157 add_card_work(from_card_index, /*parallel*/ true);
158 }
159
160 void seq_add_card(CardIdx_t from_card_index) {
161 add_card_work(from_card_index, /*parallel*/ false);
162 }
163
164 // (Destructively) union the bitmap of the current table into the given
165 // bitmap (which is assumed to be of the same size.)
166 void union_bitmap_into(BitMap* bm) {
167 bm->set_union(_bm);
168 }
169
170 // Mem size in bytes.
171 size_t mem_size() const {
172 return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
173 }
174
175 // Requires "from" to be in "hr()".
176 bool contains_reference(OopOrNarrowOopStar from) const {
177 assert(hr()->is_in_reserved(from), "Precondition.");
178 size_t card_ind = pointer_delta(from, hr()->bottom(),
179 CardTableModRefBS::card_size);
180 return _bm.at(card_ind);
181 }
182
183 // Bulk-free the PRTs from prt to last, assumes that they are
184 // linked together using their _next field.
185 static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
186 while (true) {
187 PerRegionTable* fl = _free_list;
188 last->set_next(fl);
189 PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
190 if (res == fl) {
191 return;
192 }
193 }
194 ShouldNotReachHere();
195 }
196
197 static void free(PerRegionTable* prt) {
198 bulk_free(prt, prt);
199 }
200
201 // Returns an initialized PerRegionTable instance.
202 static PerRegionTable* alloc(HeapRegion* hr) {
203 PerRegionTable* fl = _free_list;
204 while (fl != NULL) {
205 PerRegionTable* nxt = fl->next();
206 PerRegionTable* res =
207 (PerRegionTable*)
208 Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
209 if (res == fl) {
210 fl->init(hr, true);
211 return fl;
212 } else {
213 fl = _free_list;
214 }
215 }
216 assert(fl == NULL, "Loop condition.");
217 return new PerRegionTable(hr);
218 }
219
220 PerRegionTable* next() const { return _next; }
221 void set_next(PerRegionTable* next) { _next = next; }
222 PerRegionTable* prev() const { return _prev; }
223 void set_prev(PerRegionTable* prev) { _prev = prev; }
224
225 // Accessor and Modification routines for the pointer for the
226 // singly linked collision list that links the PRTs within the
227 // OtherRegionsTable::_fine_grain_regions hash table.
228 //
229 // It might be useful to also make the collision list doubly linked
230 // to avoid iteration over the collisions list during scrubbing/deletion.
231 // OTOH there might not be many collisions.
232
233 PerRegionTable* collision_list_next() const {
234 return _collision_list_next;
235 }
236
237 void set_collision_list_next(PerRegionTable* next) {
238 _collision_list_next = next;
239 }
240
241 PerRegionTable** collision_list_next_addr() {
242 return &_collision_list_next;
243 }
244
245 static size_t fl_mem_size() {
246 PerRegionTable* cur = _free_list;
247 size_t res = 0;
248 while (cur != NULL) {
249 res += cur->mem_size();
250 cur = cur->next();
251 }
252 return res;
253 }
254
255 static void test_fl_mem_size();
256 };
257
258 PerRegionTable* PerRegionTable::_free_list = NULL;
259
260 size_t OtherRegionsTable::_max_fine_entries = 0;
261 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
262 size_t OtherRegionsTable::_fine_eviction_stride = 0;
263 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
264
265 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
266 _g1h(G1CollectedHeap::heap()),
267 _hr(hr), _m(m),
268 _coarse_map(G1CollectedHeap::heap()->max_regions(),
269 false /* in-resource-area */),
270 _fine_grain_regions(NULL),
271 _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
272 _n_fine_entries(0), _n_coarse_entries(0),
273 _fine_eviction_start(0),
274 _sparse_table(hr)
275 {
276 typedef PerRegionTable* PerRegionTablePtr;
277
278 if (_max_fine_entries == 0) {
279 assert(_mod_max_fine_entries_mask == 0, "Both or none.");
280 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
281 _max_fine_entries = (size_t)1 << max_entries_log;
282 _mod_max_fine_entries_mask = _max_fine_entries - 1;
283
284 assert(_fine_eviction_sample_size == 0
285 && _fine_eviction_stride == 0, "All init at same time.");
286 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
287 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
288 }
289
290 _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
291 mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
292
293 if (_fine_grain_regions == NULL) {
294 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
295 "Failed to allocate _fine_grain_entries.");
296 }
297
298 for (size_t i = 0; i < _max_fine_entries; i++) {
299 _fine_grain_regions[i] = NULL;
300 }
301 }
302
303 void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
304 // We always append to the beginning of the list for convenience;
305 // the order of entries in this list does not matter.
306 if (_first_all_fine_prts != NULL) {
307 assert(_first_all_fine_prts->prev() == NULL, "invariant");
308 _first_all_fine_prts->set_prev(prt);
309 prt->set_next(_first_all_fine_prts);
310 } else {
311 // this is the first element we insert. Adjust the "last" pointer
312 _last_all_fine_prts = prt;
313 assert(prt->next() == NULL, "just checking");
314 }
315 // the new element is always the first element without a predecessor
316 prt->set_prev(NULL);
317 _first_all_fine_prts = prt;
318
319 assert(prt->prev() == NULL, "just checking");
320 assert(_first_all_fine_prts == prt, "just checking");
321 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
322 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
323 "just checking");
324 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
325 "just checking");
326 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
327 "just checking");
328 }
329
330 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
331 if (prt->prev() != NULL) {
332 assert(_first_all_fine_prts != prt, "just checking");
333 prt->prev()->set_next(prt->next());
334 // removing the last element in the list?
335 if (_last_all_fine_prts == prt) {
336 _last_all_fine_prts = prt->prev();
337 }
338 } else {
339 assert(_first_all_fine_prts == prt, "just checking");
340 _first_all_fine_prts = prt->next();
341 // list is empty now?
342 if (_first_all_fine_prts == NULL) {
343 _last_all_fine_prts = NULL;
344 }
345 }
346
347 if (prt->next() != NULL) {
348 prt->next()->set_prev(prt->prev());
349 }
350
351 prt->set_next(NULL);
352 prt->set_prev(NULL);
353
354 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
355 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
356 "just checking");
357 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
358 "just checking");
359 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
360 "just checking");
361 }
362
363 int** FromCardCache::_cache = NULL;
364 uint FromCardCache::_max_regions = 0;
365 size_t FromCardCache::_static_mem_size = 0;
366
367 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
368 guarantee(_cache == NULL, "Should not call this multiple times");
369
370 _max_regions = max_num_regions;
371 _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
372 _max_regions,
373 &_static_mem_size);
374
375 invalidate(0, _max_regions);
376 }
377
378 void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) {
379 guarantee((size_t)start_idx + new_num_regions <= max_uintx,
380 err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT,
381 start_idx, new_num_regions));
382 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
383 uint end_idx = (start_idx + (uint)new_num_regions);
384 assert(end_idx <= _max_regions, "Must be within max.");
385 for (uint j = start_idx; j < end_idx; j++) {
386 set(i, j, InvalidCard);
387 }
388 }
389 }
390
391 #ifndef PRODUCT
392 void FromCardCache::print(outputStream* out) {
393 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
394 for (uint j = 0; j < _max_regions; j++) {
395 out->print_cr("_from_card_cache["UINT32_FORMAT"]["UINT32_FORMAT"] = "INT32_FORMAT".",
396 i, j, at(i, j));
397 }
398 }
399 }
400 #endif
401
402 void FromCardCache::clear(uint region_idx) {
403 uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
404 for (uint i = 0; i < num_par_remsets; i++) {
405 set(i, region_idx, InvalidCard);
406 }
407 }
408
409 void OtherRegionsTable::initialize(uint max_regions) {
410 FromCardCache::initialize(HeapRegionRemSet::num_par_rem_sets(), max_regions);
411 }
412
413 void OtherRegionsTable::invalidate(uint start_idx, size_t num_regions) {
414 FromCardCache::invalidate(start_idx, num_regions);
415 }
416
417 void OtherRegionsTable::print_from_card_cache() {
418 FromCardCache::print();
419 }
420
421 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
422 uint cur_hrm_ind = hr()->hrm_index();
423
424 if (G1TraceHeapRegionRememberedSet) {
425 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
426 from,
427 UseCompressedOops
428 ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
429 : (void *)oopDesc::load_decode_heap_oop((oop*)from));
430 }
431
432 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
433
434 if (G1TraceHeapRegionRememberedSet) {
435 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = "INT32_FORMAT")",
436 hr()->bottom(), from_card,
437 FromCardCache::at((uint)tid, cur_hrm_ind));
438 }
439
440 if (FromCardCache::contains_or_replace((uint)tid, cur_hrm_ind, from_card)) {
441 if (G1TraceHeapRegionRememberedSet) {
442 gclog_or_tty->print_cr(" from-card cache hit.");
443 }
444 assert(contains_reference(from), "We just added it!");
445 return;
446 }
447
448 // Note that this may be a continued H region.
449 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
450 RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index();
451
452 // If the region is already coarsened, return.
453 if (_coarse_map.at(from_hrm_ind)) {
454 if (G1TraceHeapRegionRememberedSet) {
455 gclog_or_tty->print_cr(" coarse map hit.");
456 }
457 assert(contains_reference(from), "We just added it!");
458 return;
459 }
460
461 // Otherwise find a per-region table to add it to.
462 size_t ind = from_hrm_ind & _mod_max_fine_entries_mask;
463 PerRegionTable* prt = find_region_table(ind, from_hr);
464 if (prt == NULL) {
465 MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
466 // Confirm that it's really not there...
467 prt = find_region_table(ind, from_hr);
468 if (prt == NULL) {
469
470 uintptr_t from_hr_bot_card_index =
471 uintptr_t(from_hr->bottom())
472 >> CardTableModRefBS::card_shift;
473 CardIdx_t card_index = from_card - from_hr_bot_card_index;
474 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
475 "Must be in range.");
476 if (G1HRRSUseSparseTable &&
477 _sparse_table.add_card(from_hrm_ind, card_index)) {
478 if (G1RecordHRRSOops) {
479 HeapRegionRemSet::record(hr(), from);
480 if (G1TraceHeapRegionRememberedSet) {
481 gclog_or_tty->print(" Added card " PTR_FORMAT " to region "
482 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
483 align_size_down(uintptr_t(from),
484 CardTableModRefBS::card_size),
485 hr()->bottom(), from);
486 }
487 }
488 if (G1TraceHeapRegionRememberedSet) {
489 gclog_or_tty->print_cr(" added card to sparse table.");
490 }
491 assert(contains_reference_locked(from), "We just added it!");
492 return;
493 } else {
494 if (G1TraceHeapRegionRememberedSet) {
495 gclog_or_tty->print_cr(" [tid %d] sparse table entry "
496 "overflow(f: %d, t: %u)",
497 tid, from_hrm_ind, cur_hrm_ind);
498 }
499 }
500
501 if (_n_fine_entries == _max_fine_entries) {
502 prt = delete_region_table();
503 // There is no need to clear the links to the 'all' list here:
504 // prt will be reused immediately, i.e. remain in the 'all' list.
505 prt->init(from_hr, false /* clear_links_to_all_list */);
506 } else {
507 prt = PerRegionTable::alloc(from_hr);
508 link_to_all(prt);
509 }
510
511 PerRegionTable* first_prt = _fine_grain_regions[ind];
512 prt->set_collision_list_next(first_prt);
513 _fine_grain_regions[ind] = prt;
514 _n_fine_entries++;
515
516 if (G1HRRSUseSparseTable) {
517 // Transfer from sparse to fine-grain.
518 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind);
519 assert(sprt_entry != NULL, "There should have been an entry");
520 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
521 CardIdx_t c = sprt_entry->card(i);
522 if (c != SparsePRTEntry::NullEntry) {
523 prt->add_card(c);
524 }
525 }
526 // Now we can delete the sparse entry.
527 bool res = _sparse_table.delete_entry(from_hrm_ind);
528 assert(res, "It should have been there.");
529 }
530 }
531 assert(prt != NULL && prt->hr() == from_hr, "consequence");
532 }
533 // Note that we can't assert "prt->hr() == from_hr", because of the
534 // possibility of concurrent reuse. But see head comment of
535 // OtherRegionsTable for why this is OK.
536 assert(prt != NULL, "Inv");
537
538 prt->add_reference(from);
539
540 if (G1RecordHRRSOops) {
541 HeapRegionRemSet::record(hr(), from);
542 if (G1TraceHeapRegionRememberedSet) {
543 gclog_or_tty->print("Added card " PTR_FORMAT " to region "
544 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
545 align_size_down(uintptr_t(from),
546 CardTableModRefBS::card_size),
547 hr()->bottom(), from);
548 }
549 }
550 assert(contains_reference(from), "We just added it!");
551 }
552
553 PerRegionTable*
554 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
555 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
556 PerRegionTable* prt = _fine_grain_regions[ind];
557 while (prt != NULL && prt->hr() != hr) {
558 prt = prt->collision_list_next();
559 }
560 // Loop postcondition is the method postcondition.
561 return prt;
562 }
563
564 jint OtherRegionsTable::_n_coarsenings = 0;
565
566 PerRegionTable* OtherRegionsTable::delete_region_table() {
567 assert(_m->owned_by_self(), "Precondition");
568 assert(_n_fine_entries == _max_fine_entries, "Precondition");
569 PerRegionTable* max = NULL;
570 jint max_occ = 0;
571 PerRegionTable** max_prev;
572 size_t max_ind;
573
574 size_t i = _fine_eviction_start;
575 for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
576 size_t ii = i;
577 // Make sure we get a non-NULL sample.
578 while (_fine_grain_regions[ii] == NULL) {
579 ii++;
580 if (ii == _max_fine_entries) ii = 0;
581 guarantee(ii != i, "We must find one.");
582 }
583 PerRegionTable** prev = &_fine_grain_regions[ii];
584 PerRegionTable* cur = *prev;
585 while (cur != NULL) {
586 jint cur_occ = cur->occupied();
587 if (max == NULL || cur_occ > max_occ) {
588 max = cur;
589 max_prev = prev;
590 max_ind = i;
591 max_occ = cur_occ;
592 }
593 prev = cur->collision_list_next_addr();
594 cur = cur->collision_list_next();
595 }
596 i = i + _fine_eviction_stride;
597 if (i >= _n_fine_entries) i = i - _n_fine_entries;
598 }
599
600 _fine_eviction_start++;
601
602 if (_fine_eviction_start >= _n_fine_entries) {
603 _fine_eviction_start -= _n_fine_entries;
604 }
605
606 guarantee(max != NULL, "Since _n_fine_entries > 0");
607
608 // Set the corresponding coarse bit.
609 size_t max_hrm_index = (size_t) max->hr()->hrm_index();
610 if (!_coarse_map.at(max_hrm_index)) {
611 _coarse_map.at_put(max_hrm_index, true);
612 _n_coarse_entries++;
613 if (G1TraceHeapRegionRememberedSet) {
614 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
615 "for region [" PTR_FORMAT "...] (%d coarse entries).\n",
616 hr()->bottom(),
617 max->hr()->bottom(),
618 _n_coarse_entries);
619 }
620 }
621
622 // Unsplice.
623 *max_prev = max->collision_list_next();
624 Atomic::inc(&_n_coarsenings);
625 _n_fine_entries--;
626 return max;
627 }
628
629
630 // At present, this must be called stop-world single-threaded.
631 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
632 BitMap* region_bm, BitMap* card_bm) {
633 // First eliminated garbage regions from the coarse map.
634 if (G1RSScrubVerbose) {
635 gclog_or_tty->print_cr("Scrubbing region %u:", hr()->hrm_index());
636 }
637
638 assert(_coarse_map.size() == region_bm->size(), "Precondition");
639 if (G1RSScrubVerbose) {
640 gclog_or_tty->print(" Coarse map: before = "SIZE_FORMAT"...",
641 _n_coarse_entries);
642 }
643 _coarse_map.set_intersection(*region_bm);
644 _n_coarse_entries = _coarse_map.count_one_bits();
645 if (G1RSScrubVerbose) {
646 gclog_or_tty->print_cr(" after = "SIZE_FORMAT".", _n_coarse_entries);
647 }
648
649 // Now do the fine-grained maps.
650 for (size_t i = 0; i < _max_fine_entries; i++) {
651 PerRegionTable* cur = _fine_grain_regions[i];
652 PerRegionTable** prev = &_fine_grain_regions[i];
653 while (cur != NULL) {
654 PerRegionTable* nxt = cur->collision_list_next();
655 // If the entire region is dead, eliminate.
656 if (G1RSScrubVerbose) {
657 gclog_or_tty->print_cr(" For other region %u:",
658 cur->hr()->hrm_index());
659 }
660 if (!region_bm->at((size_t) cur->hr()->hrm_index())) {
661 *prev = nxt;
662 cur->set_collision_list_next(NULL);
663 _n_fine_entries--;
664 if (G1RSScrubVerbose) {
665 gclog_or_tty->print_cr(" deleted via region map.");
666 }
667 unlink_from_all(cur);
668 PerRegionTable::free(cur);
669 } else {
670 // Do fine-grain elimination.
671 if (G1RSScrubVerbose) {
672 gclog_or_tty->print(" occ: before = %4d.", cur->occupied());
673 }
674 cur->scrub(ctbs, card_bm);
675 if (G1RSScrubVerbose) {
676 gclog_or_tty->print_cr(" after = %4d.", cur->occupied());
677 }
678 // Did that empty the table completely?
679 if (cur->occupied() == 0) {
680 *prev = nxt;
681 cur->set_collision_list_next(NULL);
682 _n_fine_entries--;
683 unlink_from_all(cur);
684 PerRegionTable::free(cur);
685 } else {
686 prev = cur->collision_list_next_addr();
687 }
688 }
689 cur = nxt;
690 }
691 }
692 // Since we may have deleted a from_card_cache entry from the RS, clear
693 // the FCC.
694 clear_fcc();
695 }
696
697 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
698 if (limit <= (size_t)G1RSetSparseRegionEntries) {
699 return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit;
700 } else {
701 // Current uses of this method may only use values less than G1RSetSparseRegionEntries
702 // for the limit. The solution, comparing against occupied() would be too slow
703 // at this time.
704 Unimplemented();
705 return false;
706 }
707 }
708
709 bool OtherRegionsTable::is_empty() const {
710 return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL;
711 }
712
713 size_t OtherRegionsTable::occupied() const {
714 size_t sum = occ_fine();
715 sum += occ_sparse();
716 sum += occ_coarse();
717 return sum;
718 }
719
720 size_t OtherRegionsTable::occ_fine() const {
721 size_t sum = 0;
722
723 size_t num = 0;
724 PerRegionTable * cur = _first_all_fine_prts;
725 while (cur != NULL) {
726 sum += cur->occupied();
727 cur = cur->next();
728 num++;
729 }
730 guarantee(num == _n_fine_entries, "just checking");
731 return sum;
732 }
733
734 size_t OtherRegionsTable::occ_coarse() const {
735 return (_n_coarse_entries * HeapRegion::CardsPerRegion);
736 }
737
738 size_t OtherRegionsTable::occ_sparse() const {
739 return _sparse_table.occupied();
740 }
741
742 size_t OtherRegionsTable::mem_size() const {
743 size_t sum = 0;
744 // all PRTs are of the same size so it is sufficient to query only one of them.
745 if (_first_all_fine_prts != NULL) {
746 assert(_last_all_fine_prts != NULL &&
747 _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
748 sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
749 }
750 sum += (sizeof(PerRegionTable*) * _max_fine_entries);
751 sum += (_coarse_map.size_in_words() * HeapWordSize);
752 sum += (_sparse_table.mem_size());
753 sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
754 return sum;
755 }
756
757 size_t OtherRegionsTable::static_mem_size() {
758 return FromCardCache::static_mem_size();
759 }
760
761 size_t OtherRegionsTable::fl_mem_size() {
762 return PerRegionTable::fl_mem_size();
763 }
764
765 void OtherRegionsTable::clear_fcc() {
766 FromCardCache::clear(hr()->hrm_index());
767 }
768
769 void OtherRegionsTable::clear() {
770 // if there are no entries, skip this step
771 if (_first_all_fine_prts != NULL) {
772 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
773 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
774 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
775 } else {
776 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
777 }
778
779 _first_all_fine_prts = _last_all_fine_prts = NULL;
780 _sparse_table.clear();
781 _coarse_map.clear();
782 _n_fine_entries = 0;
783 _n_coarse_entries = 0;
784
785 clear_fcc();
786 }
787
788 bool OtherRegionsTable::del_single_region_table(size_t ind,
789 HeapRegion* hr) {
790 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
791 PerRegionTable** prev_addr = &_fine_grain_regions[ind];
792 PerRegionTable* prt = *prev_addr;
793 while (prt != NULL && prt->hr() != hr) {
794 prev_addr = prt->collision_list_next_addr();
795 prt = prt->collision_list_next();
796 }
797 if (prt != NULL) {
798 assert(prt->hr() == hr, "Loop postcondition.");
799 *prev_addr = prt->collision_list_next();
800 unlink_from_all(prt);
801 PerRegionTable::free(prt);
802 _n_fine_entries--;
803 return true;
804 } else {
805 return false;
806 }
807 }
808
809 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
810 // Cast away const in this case.
811 MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
812 return contains_reference_locked(from);
813 }
814
815 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
816 HeapRegion* hr = _g1h->heap_region_containing_raw(from);
817 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
818 // Is this region in the coarse map?
819 if (_coarse_map.at(hr_ind)) return true;
820
821 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
822 hr);
823 if (prt != NULL) {
824 return prt->contains_reference(from);
825
826 } else {
827 uintptr_t from_card =
828 (uintptr_t(from) >> CardTableModRefBS::card_shift);
829 uintptr_t hr_bot_card_index =
830 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
831 assert(from_card >= hr_bot_card_index, "Inv");
832 CardIdx_t card_index = from_card - hr_bot_card_index;
833 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
834 "Must be in range.");
835 return _sparse_table.contains_card(hr_ind, card_index);
836 }
837 }
838
839 void
840 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
841 _sparse_table.do_cleanup_work(hrrs_cleanup_task);
842 }
843
844 // Determines how many threads can add records to an rset in parallel.
845 // This can be done by either mutator threads together with the
846 // concurrent refinement threads or GC threads.
847 uint HeapRegionRemSet::num_par_rem_sets() {
848 return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
849 }
850
851 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
852 HeapRegion* hr)
853 : _bosa(bosa),
854 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true),
855 _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
856 reset_for_par_iteration();
857 }
858
859 void HeapRegionRemSet::setup_remset_size() {
860 // Setup sparse and fine-grain tables sizes.
861 // table_size = base * (log(region_size / 1M) + 1)
862 const int LOG_M = 20;
863 int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
864 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
865 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
866 }
867 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
868 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
869 }
870 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
871 }
872
873 bool HeapRegionRemSet::claim_iter() {
874 if (_iter_state != Unclaimed) return false;
875 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
876 return (res == Unclaimed);
877 }
878
879 void HeapRegionRemSet::set_iter_complete() {
880 _iter_state = Complete;
881 }
882
883 bool HeapRegionRemSet::iter_is_complete() {
884 return _iter_state == Complete;
885 }
886
887 #ifndef PRODUCT
888 void HeapRegionRemSet::print() {
889 HeapRegionRemSetIterator iter(this);
890 size_t card_index;
891 while (iter.has_next(card_index)) {
892 HeapWord* card_start =
893 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
894 gclog_or_tty->print_cr(" Card " PTR_FORMAT, card_start);
895 }
896 if (iter.n_yielded() != occupied()) {
897 gclog_or_tty->print_cr("Yielded disagrees with occupied:");
898 gclog_or_tty->print_cr(" %6d yielded (%6d coarse, %6d fine).",
899 iter.n_yielded(),
900 iter.n_yielded_coarse(), iter.n_yielded_fine());
901 gclog_or_tty->print_cr(" %6d occ (%6d coarse, %6d fine).",
902 occupied(), occ_coarse(), occ_fine());
903 }
904 guarantee(iter.n_yielded() == occupied(),
905 "We should have yielded all the represented cards.");
906 }
907 #endif
908
909 void HeapRegionRemSet::cleanup() {
910 SparsePRT::cleanup_all();
911 }
912
913 void HeapRegionRemSet::clear() {
914 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
915 clear_locked();
916 }
917
918 void HeapRegionRemSet::clear_locked() {
919 _code_roots.clear();
920 _other_regions.clear();
921 assert(occupied_locked() == 0, "Should be clear.");
922 reset_for_par_iteration();
923 }
924
925 void HeapRegionRemSet::reset_for_par_iteration() {
926 _iter_state = Unclaimed;
927 _iter_claimed = 0;
928 // It's good to check this to make sure that the two methods are in sync.
929 assert(verify_ready_for_par_iteration(), "post-condition");
930 }
931
932 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
933 BitMap* region_bm, BitMap* card_bm) {
934 _other_regions.scrub(ctbs, region_bm, card_bm);
935 }
936
937 // Code roots support
938 //
939 // The code root set is protected by two separate locking schemes
940 // When at safepoint the per-hrrs lock must be held during modifications
941 // except when doing a full gc.
942 // When not at safepoint the CodeCache_lock must be held during modifications.
943 // When concurrent readers access the contains() function
944 // (during the evacuation phase) no removals are allowed.
945
946 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
947 assert(nm != NULL, "sanity");
948 // Optimistic unlocked contains-check
949 if (!_code_roots.contains(nm)) {
950 MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
951 add_strong_code_root_locked(nm);
952 }
953 }
954
955 void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
956 assert(nm != NULL, "sanity");
957 _code_roots.add(nm);
958 }
959
960 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
961 assert(nm != NULL, "sanity");
962 assert_locked_or_safepoint(CodeCache_lock);
963
964 MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
965 _code_roots.remove(nm);
966
967 // Check that there were no duplicates
968 guarantee(!_code_roots.contains(nm), "duplicate entry found");
969 }
970
971 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
972 _code_roots.nmethods_do(blk);
973 }
974
975 void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
976 _code_roots.clean(hr);
977 }
978
979 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
980 return _code_roots.mem_size();
981 }
982
983 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
984 _hrrs(hrrs),
985 _g1h(G1CollectedHeap::heap()),
986 _coarse_map(&hrrs->_other_regions._coarse_map),
987 _bosa(hrrs->bosa()),
988 _is(Sparse),
989 // Set these values so that we increment to the first region.
990 _coarse_cur_region_index(-1),
991 _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
992 _cur_card_in_prt(HeapRegion::CardsPerRegion),
993 _fine_cur_prt(NULL),
994 _n_yielded_coarse(0),
995 _n_yielded_fine(0),
996 _n_yielded_sparse(0),
997 _sparse_iter(&hrrs->_other_regions._sparse_table) {}
998
999 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
1000 if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
1001 // Go to the next card.
1002 _coarse_cur_region_cur_card++;
1003 // Was the last the last card in the current region?
1004 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
1005 // Yes: find the next region. This may leave _coarse_cur_region_index
1006 // Set to the last index, in which case there are no more coarse
1007 // regions.
1008 _coarse_cur_region_index =
1009 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
1010 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
1011 _coarse_cur_region_cur_card = 0;
1012 HeapWord* r_bot =
1013 _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
1014 _cur_region_card_offset = _bosa->index_for(r_bot);
1015 } else {
1016 return false;
1017 }
1018 }
1019 // If we didn't return false above, then we can yield a card.
1020 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
1021 return true;
1022 }
1023
1024 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
1025 if (fine_has_next()) {
1026 _cur_card_in_prt =
1027 _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1028 }
1029 if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
1030 // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
1031 // the remembered set.
1032 if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
1033 return false;
1034 }
1035 PerRegionTable* next_prt = _fine_cur_prt->next();
1036 switch_to_prt(next_prt);
1037 _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1038 }
1039
1040 card_index = _cur_region_card_offset + _cur_card_in_prt;
1041 guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
1042 err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
1043 return true;
1044 }
1045
1046 bool HeapRegionRemSetIterator::fine_has_next() {
1047 return _cur_card_in_prt != HeapRegion::CardsPerRegion;
1048 }
1049
1050 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
1051 assert(prt != NULL, "Cannot switch to NULL prt");
1052 _fine_cur_prt = prt;
1053
1054 HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
1055 _cur_region_card_offset = _bosa->index_for(r_bot);
1056
1057 // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
1058 // To avoid special-casing this start case, and not miss the first bitmap
1059 // entry, initialize _cur_region_cur_card with -1 instead of 0.
1060 _cur_card_in_prt = (size_t)-1;
1061 }
1062
1063 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1064 switch (_is) {
1065 case Sparse: {
1066 if (_sparse_iter.has_next(card_index)) {
1067 _n_yielded_sparse++;
1068 return true;
1069 }
1070 // Otherwise, deliberate fall-through
1071 _is = Fine;
1072 PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
1073 if (initial_fine_prt != NULL) {
1074 switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
1075 }
1076 }
1077 case Fine:
1078 if (fine_has_next(card_index)) {
1079 _n_yielded_fine++;
1080 return true;
1081 }
1082 // Otherwise, deliberate fall-through
1083 _is = Coarse;
1084 case Coarse:
1085 if (coarse_has_next(card_index)) {
1086 _n_yielded_coarse++;
1087 return true;
1088 }
1089 // Otherwise...
1090 break;
1091 }
1092 assert(ParallelGCThreads > 1 ||
1093 n_yielded() == _hrrs->occupied(),
1094 "Should have yielded all the cards in the rem set "
1095 "(in the non-par case).");
1096 return false;
1097 }
1098
1099
1100
1101 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1102 HeapWord** HeapRegionRemSet::_recorded_cards = NULL;
1103 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL;
1104 int HeapRegionRemSet::_n_recorded = 0;
1105
1106 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1107 int* HeapRegionRemSet::_recorded_event_index = NULL;
1108 int HeapRegionRemSet::_n_recorded_events = 0;
1109
1110 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1111 if (_recorded_oops == NULL) {
1112 assert(_n_recorded == 0
1113 && _recorded_cards == NULL
1114 && _recorded_regions == NULL,
1115 "Inv");
1116 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
1117 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded, mtGC);
1118 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded, mtGC);
1119 }
1120 if (_n_recorded == MaxRecorded) {
1121 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1122 } else {
1123 _recorded_cards[_n_recorded] =
1124 (HeapWord*)align_size_down(uintptr_t(f),
1125 CardTableModRefBS::card_size);
1126 _recorded_oops[_n_recorded] = f;
1127 _recorded_regions[_n_recorded] = hr;
1128 _n_recorded++;
1129 }
1130 }
1131
1132 void HeapRegionRemSet::record_event(Event evnt) {
1133 if (!G1RecordHRRSEvents) return;
1134
1135 if (_recorded_events == NULL) {
1136 assert(_n_recorded_events == 0
1137 && _recorded_event_index == NULL,
1138 "Inv");
1139 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
1140 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
1141 }
1142 if (_n_recorded_events == MaxRecordedEvents) {
1143 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1144 } else {
1145 _recorded_events[_n_recorded_events] = evnt;
1146 _recorded_event_index[_n_recorded_events] = _n_recorded;
1147 _n_recorded_events++;
1148 }
1149 }
1150
1151 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1152 switch (evnt) {
1153 case Event_EvacStart:
1154 str->print("Evac Start");
1155 break;
1156 case Event_EvacEnd:
1157 str->print("Evac End");
1158 break;
1159 case Event_RSUpdateEnd:
1160 str->print("RS Update End");
1161 break;
1162 }
1163 }
1164
1165 void HeapRegionRemSet::print_recorded() {
1166 int cur_evnt = 0;
1167 Event cur_evnt_kind;
1168 int cur_evnt_ind = 0;
1169 if (_n_recorded_events > 0) {
1170 cur_evnt_kind = _recorded_events[cur_evnt];
1171 cur_evnt_ind = _recorded_event_index[cur_evnt];
1172 }
1173
1174 for (int i = 0; i < _n_recorded; i++) {
1175 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1176 gclog_or_tty->print("Event: ");
1177 print_event(gclog_or_tty, cur_evnt_kind);
1178 gclog_or_tty->cr();
1179 cur_evnt++;
1180 if (cur_evnt < MaxRecordedEvents) {
1181 cur_evnt_kind = _recorded_events[cur_evnt];
1182 cur_evnt_ind = _recorded_event_index[cur_evnt];
1183 }
1184 }
1185 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1186 " for ref " PTR_FORMAT ".\n",
1187 _recorded_cards[i], _recorded_regions[i]->bottom(),
1188 _recorded_oops[i]);
1189 }
1190 }
1191
1192 void HeapRegionRemSet::reset_for_cleanup_tasks() {
1193 SparsePRT::reset_for_cleanup_tasks();
1194 }
1195
1196 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
1197 _other_regions.do_cleanup_work(hrrs_cleanup_task);
1198 }
1199
1200 void
1201 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
1202 SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
1203 }
1204
1205 #ifndef PRODUCT
1206 void PerRegionTable::test_fl_mem_size() {
1207 PerRegionTable* dummy = alloc(NULL);
1208
1209 size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
1210 assert(dummy->mem_size() > min_prt_size,
1211 err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
1212 "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
1213 free(dummy);
1214 guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
1215 // try to reset the state
1216 _free_list = NULL;
1217 delete dummy;
1218 }
1219
1220 void HeapRegionRemSet::test_prt() {
1221 PerRegionTable::test_fl_mem_size();
1222 }
1223
1224 void HeapRegionRemSet::test() {
1225 os::sleep(Thread::current(), (jlong)5000, false);
1226 G1CollectedHeap* g1h = G1CollectedHeap::heap();
1227
1228 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1229 // hash bucket.
1230 HeapRegion* hr0 = g1h->region_at(0);
1231 HeapRegion* hr1 = g1h->region_at(1);
1232 HeapRegion* hr2 = g1h->region_at(5);
1233 HeapRegion* hr3 = g1h->region_at(6);
1234 HeapRegion* hr4 = g1h->region_at(7);
1235 HeapRegion* hr5 = g1h->region_at(8);
1236
1237 HeapWord* hr1_start = hr1->bottom();
1238 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1239 HeapWord* hr1_last = hr1->end() - 1;
1240
1241 HeapWord* hr2_start = hr2->bottom();
1242 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1243 HeapWord* hr2_last = hr2->end() - 1;
1244
1245 HeapWord* hr3_start = hr3->bottom();
1246 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1247 HeapWord* hr3_last = hr3->end() - 1;
1248
1249 HeapRegionRemSet* hrrs = hr0->rem_set();
1250
1251 // Make three references from region 0x101...
1252 hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1253 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1254 hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1255
1256 hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1257 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1258 hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1259
1260 hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1261 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1262 hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1263
1264 // Now cause a coarsening.
1265 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1266 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1267
1268 // Now, does iteration yield these three?
1269 HeapRegionRemSetIterator iter(hrrs);
1270 size_t sum = 0;
1271 size_t card_index;
1272 while (iter.has_next(card_index)) {
1273 HeapWord* card_start =
1274 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1275 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start);
1276 sum++;
1277 }
1278 guarantee(sum == 11 - 3 + 2048, "Failure");
1279 guarantee(sum == hrrs->occupied(), "Failure");
1280 }
1281 #endif