1 /*
2 * Copyright (c) 2001, 2009, 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 "incls/_precompiled.incl"
26 #include "incls/_heapRegionRemSet.cpp.incl"
27
28 #define HRRS_VERBOSE 0
29
30 #define PRT_COUNT_OCCUPIED 1
31
32 // OtherRegionsTable
33
34 class PerRegionTable: public CHeapObj {
35 friend class OtherRegionsTable;
36 friend class HeapRegionRemSetIterator;
37
38 HeapRegion* _hr;
39 BitMap _bm;
40 #if PRT_COUNT_OCCUPIED
41 jint _occupied;
42 #endif
43 PerRegionTable* _next_free;
44
45 PerRegionTable* next_free() { return _next_free; }
46 void set_next_free(PerRegionTable* prt) { _next_free = prt; }
47
48
49 static PerRegionTable* _free_list;
50
51 #ifdef _MSC_VER
52 // For some reason even though the classes are marked as friend they are unable
53 // to access CardsPerRegion when private/protected. Only the windows c++ compiler
54 // says this Sun CC and linux gcc don't have a problem with access when private
55
56 public:
57
58 #endif // _MSC_VER
59
60 protected:
61 // We need access in order to union things into the base table.
62 BitMap* bm() { return &_bm; }
63
64 #if PRT_COUNT_OCCUPIED
65 void recount_occupied() {
66 _occupied = (jint) bm()->count_one_bits();
67 }
68 #endif
69
70 PerRegionTable(HeapRegion* hr) :
71 _hr(hr),
72 #if PRT_COUNT_OCCUPIED
73 _occupied(0),
74 #endif
75 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */)
76 {}
77
78 static void free(PerRegionTable* prt) {
79 while (true) {
80 PerRegionTable* fl = _free_list;
81 prt->set_next_free(fl);
82 PerRegionTable* res =
83 (PerRegionTable*)
84 Atomic::cmpxchg_ptr(prt, &_free_list, fl);
85 if (res == fl) return;
86 }
87 ShouldNotReachHere();
88 }
89
90 static PerRegionTable* alloc(HeapRegion* hr) {
91 PerRegionTable* fl = _free_list;
92 while (fl != NULL) {
93 PerRegionTable* nxt = fl->next_free();
94 PerRegionTable* res =
95 (PerRegionTable*)
96 Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
97 if (res == fl) {
98 fl->init(hr);
99 return fl;
100 } else {
101 fl = _free_list;
102 }
103 }
104 assert(fl == NULL, "Loop condition.");
105 return new PerRegionTable(hr);
106 }
107
108 void add_card_work(CardIdx_t from_card, bool par) {
109 if (!_bm.at(from_card)) {
110 if (par) {
111 if (_bm.par_at_put(from_card, 1)) {
112 #if PRT_COUNT_OCCUPIED
113 Atomic::inc(&_occupied);
114 #endif
115 }
116 } else {
117 _bm.at_put(from_card, 1);
118 #if PRT_COUNT_OCCUPIED
119 _occupied++;
120 #endif
121 }
122 }
123 }
124
125 void add_reference_work(OopOrNarrowOopStar from, bool par) {
126 // Must make this robust in case "from" is not in "_hr", because of
127 // concurrency.
128
129 #if HRRS_VERBOSE
130 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
131 from, *from);
132 #endif
133
134 HeapRegion* loc_hr = hr();
135 // If the test below fails, then this table was reused concurrently
136 // with this operation. This is OK, since the old table was coarsened,
137 // and adding a bit to the new table is never incorrect.
138 if (loc_hr->is_in_reserved(from)) {
139 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
140 CardIdx_t from_card = (CardIdx_t)
141 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
142
143 assert(0 <= from_card && from_card < HeapRegion::CardsPerRegion,
144 "Must be in range.");
145 add_card_work(from_card, par);
146 }
147 }
148
149 public:
150
151 HeapRegion* hr() const { return _hr; }
152
153 #if PRT_COUNT_OCCUPIED
154 jint occupied() const {
155 // Overkill, but if we ever need it...
156 // guarantee(_occupied == _bm.count_one_bits(), "Check");
157 return _occupied;
158 }
159 #else
160 jint occupied() const {
161 return _bm.count_one_bits();
162 }
163 #endif
164
165 void init(HeapRegion* hr) {
166 _hr = hr;
167 #if PRT_COUNT_OCCUPIED
168 _occupied = 0;
169 #endif
170 _bm.clear();
171 }
172
173 void add_reference(OopOrNarrowOopStar from) {
174 add_reference_work(from, /*parallel*/ true);
175 }
176
177 void seq_add_reference(OopOrNarrowOopStar from) {
178 add_reference_work(from, /*parallel*/ false);
179 }
180
181 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
182 HeapWord* hr_bot = hr()->bottom();
183 size_t hr_first_card_index = ctbs->index_for(hr_bot);
184 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
185 #if PRT_COUNT_OCCUPIED
186 recount_occupied();
187 #endif
188 }
189
190 void add_card(CardIdx_t from_card_index) {
191 add_card_work(from_card_index, /*parallel*/ true);
192 }
193
194 void seq_add_card(CardIdx_t from_card_index) {
195 add_card_work(from_card_index, /*parallel*/ false);
196 }
197
198 // (Destructively) union the bitmap of the current table into the given
199 // bitmap (which is assumed to be of the same size.)
200 void union_bitmap_into(BitMap* bm) {
201 bm->set_union(_bm);
202 }
203
204 // Mem size in bytes.
205 size_t mem_size() const {
206 return sizeof(this) + _bm.size_in_words() * HeapWordSize;
207 }
208
209 static size_t fl_mem_size() {
210 PerRegionTable* cur = _free_list;
211 size_t res = 0;
212 while (cur != NULL) {
213 res += sizeof(PerRegionTable);
214 cur = cur->next_free();
215 }
216 return res;
217 }
218
219 // Requires "from" to be in "hr()".
220 bool contains_reference(OopOrNarrowOopStar from) const {
221 assert(hr()->is_in_reserved(from), "Precondition.");
222 size_t card_ind = pointer_delta(from, hr()->bottom(),
223 CardTableModRefBS::card_size);
224 return _bm.at(card_ind);
225 }
226 };
227
228 PerRegionTable* PerRegionTable::_free_list = NULL;
229
230
231 #define COUNT_PAR_EXPANDS 0
232
233 #if COUNT_PAR_EXPANDS
234 static jint n_par_expands = 0;
235 static jint n_par_contracts = 0;
236 static jint par_expand_list_len = 0;
237 static jint max_par_expand_list_len = 0;
238
239 static void print_par_expand() {
240 Atomic::inc(&n_par_expands);
241 Atomic::inc(&par_expand_list_len);
242 if (par_expand_list_len > max_par_expand_list_len) {
243 max_par_expand_list_len = par_expand_list_len;
244 }
245 if ((n_par_expands % 10) == 0) {
246 gclog_or_tty->print_cr("\n\n%d par expands: %d contracts, "
247 "len = %d, max_len = %d\n.",
248 n_par_expands, n_par_contracts, par_expand_list_len,
249 max_par_expand_list_len);
250 }
251 }
252 #endif
253
254 class PosParPRT: public PerRegionTable {
255 PerRegionTable** _par_tables;
256
257 enum SomePrivateConstants {
258 ReserveParTableExpansion = 1
259 };
260
261 void par_contract() {
262 assert(_par_tables != NULL, "Precondition.");
263 int n = HeapRegionRemSet::num_par_rem_sets()-1;
264 for (int i = 0; i < n; i++) {
265 _par_tables[i]->union_bitmap_into(bm());
266 PerRegionTable::free(_par_tables[i]);
267 _par_tables[i] = NULL;
268 }
269 #if PRT_COUNT_OCCUPIED
270 // We must recount the "occupied."
271 recount_occupied();
272 #endif
273 FREE_C_HEAP_ARRAY(PerRegionTable*, _par_tables);
274 _par_tables = NULL;
275 #if COUNT_PAR_EXPANDS
276 Atomic::inc(&n_par_contracts);
277 Atomic::dec(&par_expand_list_len);
278 #endif
279 }
280
281 static PerRegionTable** _par_table_fl;
282
283 PosParPRT* _next;
284
285 static PosParPRT* _free_list;
286
287 PerRegionTable** par_tables() const {
288 assert(uintptr_t(NULL) == 0, "Assumption.");
289 if (uintptr_t(_par_tables) <= ReserveParTableExpansion)
290 return NULL;
291 else
292 return _par_tables;
293 }
294
295 PosParPRT* _next_par_expanded;
296 PosParPRT* next_par_expanded() { return _next_par_expanded; }
297 void set_next_par_expanded(PosParPRT* ppprt) { _next_par_expanded = ppprt; }
298 static PosParPRT* _par_expanded_list;
299
300 public:
301
302 PosParPRT(HeapRegion* hr) : PerRegionTable(hr), _par_tables(NULL) {}
303
304 jint occupied() const {
305 jint res = PerRegionTable::occupied();
306 if (par_tables() != NULL) {
307 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) {
308 res += par_tables()[i]->occupied();
309 }
310 }
311 return res;
312 }
313
314 void init(HeapRegion* hr) {
315 PerRegionTable::init(hr);
316 _next = NULL;
317 if (par_tables() != NULL) {
318 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) {
319 par_tables()[i]->init(hr);
320 }
321 }
322 }
323
324 static void free(PosParPRT* prt) {
325 while (true) {
326 PosParPRT* fl = _free_list;
327 prt->set_next(fl);
328 PosParPRT* res =
329 (PosParPRT*)
330 Atomic::cmpxchg_ptr(prt, &_free_list, fl);
331 if (res == fl) return;
332 }
333 ShouldNotReachHere();
334 }
335
336 static PosParPRT* alloc(HeapRegion* hr) {
337 PosParPRT* fl = _free_list;
338 while (fl != NULL) {
339 PosParPRT* nxt = fl->next();
340 PosParPRT* res =
341 (PosParPRT*)
342 Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
343 if (res == fl) {
344 fl->init(hr);
345 return fl;
346 } else {
347 fl = _free_list;
348 }
349 }
350 assert(fl == NULL, "Loop condition.");
351 return new PosParPRT(hr);
352 }
353
354 PosParPRT* next() const { return _next; }
355 void set_next(PosParPRT* nxt) { _next = nxt; }
356 PosParPRT** next_addr() { return &_next; }
357
358 bool should_expand(int tid) {
359 return par_tables() == NULL && tid > 0 && hr()->is_gc_alloc_region();
360 }
361
362 void par_expand() {
363 int n = HeapRegionRemSet::num_par_rem_sets()-1;
364 if (n <= 0) return;
365 if (_par_tables == NULL) {
366 PerRegionTable* res =
367 (PerRegionTable*)
368 Atomic::cmpxchg_ptr((PerRegionTable*)ReserveParTableExpansion,
369 &_par_tables, NULL);
370 if (res != NULL) return;
371 // Otherwise, we reserved the right to do the expansion.
372
373 PerRegionTable** ptables = NEW_C_HEAP_ARRAY(PerRegionTable*, n);
374 for (int i = 0; i < n; i++) {
375 PerRegionTable* ptable = PerRegionTable::alloc(hr());
376 ptables[i] = ptable;
377 }
378 // Here we do not need an atomic.
379 _par_tables = ptables;
380 #if COUNT_PAR_EXPANDS
381 print_par_expand();
382 #endif
383 // We must put this table on the expanded list.
384 PosParPRT* exp_head = _par_expanded_list;
385 while (true) {
386 set_next_par_expanded(exp_head);
387 PosParPRT* res =
388 (PosParPRT*)
389 Atomic::cmpxchg_ptr(this, &_par_expanded_list, exp_head);
390 if (res == exp_head) return;
391 // Otherwise.
392 exp_head = res;
393 }
394 ShouldNotReachHere();
395 }
396 }
397
398 void add_reference(OopOrNarrowOopStar from, int tid) {
399 // Expand if necessary.
400 PerRegionTable** pt = par_tables();
401 if (pt != NULL) {
402 // We always have to assume that mods to table 0 are in parallel,
403 // because of the claiming scheme in parallel expansion. A thread
404 // with tid != 0 that finds the table to be NULL, but doesn't succeed
405 // in claiming the right of expanding it, will end up in the else
406 // clause of the above if test. That thread could be delayed, and a
407 // thread 0 add reference could see the table expanded, and come
408 // here. Both threads would be adding in parallel. But we get to
409 // not use atomics for tids > 0.
410 if (tid == 0) {
411 PerRegionTable::add_reference(from);
412 } else {
413 pt[tid-1]->seq_add_reference(from);
414 }
415 } else {
416 // Not expanded -- add to the base table.
417 PerRegionTable::add_reference(from);
418 }
419 }
420
421 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
422 assert(_par_tables == NULL, "Precondition");
423 PerRegionTable::scrub(ctbs, card_bm);
424 }
425
426 size_t mem_size() const {
427 size_t res =
428 PerRegionTable::mem_size() + sizeof(this) - sizeof(PerRegionTable);
429 if (_par_tables != NULL) {
430 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) {
431 res += _par_tables[i]->mem_size();
432 }
433 }
434 return res;
435 }
436
437 static size_t fl_mem_size() {
438 PosParPRT* cur = _free_list;
439 size_t res = 0;
440 while (cur != NULL) {
441 res += sizeof(PosParPRT);
442 cur = cur->next();
443 }
444 return res;
445 }
446
447 bool contains_reference(OopOrNarrowOopStar from) const {
448 if (PerRegionTable::contains_reference(from)) return true;
449 if (_par_tables != NULL) {
450 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets()-1; i++) {
451 if (_par_tables[i]->contains_reference(from)) return true;
452 }
453 }
454 return false;
455 }
456
457 static void par_contract_all();
458
459 };
460
461 void PosParPRT::par_contract_all() {
462 PosParPRT* hd = _par_expanded_list;
463 while (hd != NULL) {
464 PosParPRT* nxt = hd->next_par_expanded();
465 PosParPRT* res =
466 (PosParPRT*)
467 Atomic::cmpxchg_ptr(nxt, &_par_expanded_list, hd);
468 if (res == hd) {
469 // We claimed the right to contract this table.
470 hd->set_next_par_expanded(NULL);
471 hd->par_contract();
472 hd = _par_expanded_list;
473 } else {
474 hd = res;
475 }
476 }
477 }
478
479 PosParPRT* PosParPRT::_free_list = NULL;
480 PosParPRT* PosParPRT::_par_expanded_list = NULL;
481
482 jint OtherRegionsTable::_cache_probes = 0;
483 jint OtherRegionsTable::_cache_hits = 0;
484
485 size_t OtherRegionsTable::_max_fine_entries = 0;
486 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
487 #if SAMPLE_FOR_EVICTION
488 size_t OtherRegionsTable::_fine_eviction_stride = 0;
489 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
490 #endif
491
492 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) :
493 _g1h(G1CollectedHeap::heap()),
494 _m(Mutex::leaf, "An OtherRegionsTable lock", true),
495 _hr(hr),
496 _coarse_map(G1CollectedHeap::heap()->max_regions(),
497 false /* in-resource-area */),
498 _fine_grain_regions(NULL),
499 _n_fine_entries(0), _n_coarse_entries(0),
500 #if SAMPLE_FOR_EVICTION
501 _fine_eviction_start(0),
502 #endif
503 _sparse_table(hr)
504 {
505 typedef PosParPRT* PosParPRTPtr;
506 if (_max_fine_entries == 0) {
507 assert(_mod_max_fine_entries_mask == 0, "Both or none.");
508 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
509 _max_fine_entries = (size_t)(1 << max_entries_log);
510 _mod_max_fine_entries_mask = _max_fine_entries - 1;
511 #if SAMPLE_FOR_EVICTION
512 assert(_fine_eviction_sample_size == 0
513 && _fine_eviction_stride == 0, "All init at same time.");
514 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
515 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
516 #endif
517 }
518 _fine_grain_regions = new PosParPRTPtr[_max_fine_entries];
519 if (_fine_grain_regions == NULL)
520 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries,
521 "Failed to allocate _fine_grain_entries.");
522 for (size_t i = 0; i < _max_fine_entries; i++) {
523 _fine_grain_regions[i] = NULL;
524 }
525 }
526
527 int** OtherRegionsTable::_from_card_cache = NULL;
528 size_t OtherRegionsTable::_from_card_cache_max_regions = 0;
529 size_t OtherRegionsTable::_from_card_cache_mem_size = 0;
530
531 void OtherRegionsTable::init_from_card_cache(size_t max_regions) {
532 _from_card_cache_max_regions = max_regions;
533
534 int n_par_rs = HeapRegionRemSet::num_par_rem_sets();
535 _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs);
536 for (int i = 0; i < n_par_rs; i++) {
537 _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions);
538 for (size_t j = 0; j < max_regions; j++) {
539 _from_card_cache[i][j] = -1; // An invalid value.
540 }
541 }
542 _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int);
543 }
544
545 void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) {
546 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
547 assert(new_n_regs <= _from_card_cache_max_regions, "Must be within max.");
548 for (size_t j = new_n_regs; j < _from_card_cache_max_regions; j++) {
549 _from_card_cache[i][j] = -1; // An invalid value.
550 }
551 }
552 }
553
554 #ifndef PRODUCT
555 void OtherRegionsTable::print_from_card_cache() {
556 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
557 for (size_t j = 0; j < _from_card_cache_max_regions; j++) {
558 gclog_or_tty->print_cr("_from_card_cache[%d][%d] = %d.",
559 i, j, _from_card_cache[i][j]);
560 }
561 }
562 }
563 #endif
564
565 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
566 size_t cur_hrs_ind = hr()->hrs_index();
567
568 #if HRRS_VERBOSE
569 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
570 from,
571 UseCompressedOops
572 ? oopDesc::load_decode_heap_oop((narrowOop*)from)
573 : oopDesc::load_decode_heap_oop((oop*)from));
574 #endif
575
576 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
577
578 #if HRRS_VERBOSE
579 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
580 hr()->bottom(), from_card,
581 _from_card_cache[tid][cur_hrs_ind]);
582 #endif
583
584 #define COUNT_CACHE 0
585 #if COUNT_CACHE
586 jint p = Atomic::add(1, &_cache_probes);
587 if ((p % 10000) == 0) {
588 jint hits = _cache_hits;
589 gclog_or_tty->print_cr("%d/%d = %5.2f%% RS cache hits.",
590 _cache_hits, p, 100.0* (float)hits/(float)p);
591 }
592 #endif
593 if (from_card == _from_card_cache[tid][cur_hrs_ind]) {
594 #if HRRS_VERBOSE
595 gclog_or_tty->print_cr(" from-card cache hit.");
596 #endif
597 #if COUNT_CACHE
598 Atomic::inc(&_cache_hits);
599 #endif
600 assert(contains_reference(from), "We just added it!");
601 return;
602 } else {
603 _from_card_cache[tid][cur_hrs_ind] = from_card;
604 }
605
606 // Note that this may be a continued H region.
607 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
608 RegionIdx_t from_hrs_ind = (RegionIdx_t) from_hr->hrs_index();
609
610 // If the region is already coarsened, return.
611 if (_coarse_map.at(from_hrs_ind)) {
612 #if HRRS_VERBOSE
613 gclog_or_tty->print_cr(" coarse map hit.");
614 #endif
615 assert(contains_reference(from), "We just added it!");
616 return;
617 }
618
619 // Otherwise find a per-region table to add it to.
620 size_t ind = from_hrs_ind & _mod_max_fine_entries_mask;
621 PosParPRT* prt = find_region_table(ind, from_hr);
622 if (prt == NULL) {
623 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
624 // Confirm that it's really not there...
625 prt = find_region_table(ind, from_hr);
626 if (prt == NULL) {
627
628 uintptr_t from_hr_bot_card_index =
629 uintptr_t(from_hr->bottom())
630 >> CardTableModRefBS::card_shift;
631 CardIdx_t card_index = from_card - from_hr_bot_card_index;
632 assert(0 <= card_index && card_index < HeapRegion::CardsPerRegion,
633 "Must be in range.");
634 if (G1HRRSUseSparseTable &&
635 _sparse_table.add_card(from_hrs_ind, card_index)) {
636 if (G1RecordHRRSOops) {
637 HeapRegionRemSet::record(hr(), from);
638 #if HRRS_VERBOSE
639 gclog_or_tty->print(" Added card " PTR_FORMAT " to region "
640 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
641 align_size_down(uintptr_t(from),
642 CardTableModRefBS::card_size),
643 hr()->bottom(), from);
644 #endif
645 }
646 #if HRRS_VERBOSE
647 gclog_or_tty->print_cr(" added card to sparse table.");
648 #endif
649 assert(contains_reference_locked(from), "We just added it!");
650 return;
651 } else {
652 #if HRRS_VERBOSE
653 gclog_or_tty->print_cr(" [tid %d] sparse table entry "
654 "overflow(f: %d, t: %d)",
655 tid, from_hrs_ind, cur_hrs_ind);
656 #endif
657 }
658
659 if (_n_fine_entries == _max_fine_entries) {
660 prt = delete_region_table();
661 } else {
662 prt = PosParPRT::alloc(from_hr);
663 }
664 prt->init(from_hr);
665
666 PosParPRT* first_prt = _fine_grain_regions[ind];
667 prt->set_next(first_prt); // XXX Maybe move to init?
668 _fine_grain_regions[ind] = prt;
669 _n_fine_entries++;
670
671 if (G1HRRSUseSparseTable) {
672 // Transfer from sparse to fine-grain.
673 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrs_ind);
674 assert(sprt_entry != NULL, "There should have been an entry");
675 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
676 CardIdx_t c = sprt_entry->card(i);
677 if (c != SparsePRTEntry::NullEntry) {
678 prt->add_card(c);
679 }
680 }
681 // Now we can delete the sparse entry.
682 bool res = _sparse_table.delete_entry(from_hrs_ind);
683 assert(res, "It should have been there.");
684 }
685 }
686 assert(prt != NULL && prt->hr() == from_hr, "consequence");
687 }
688 // Note that we can't assert "prt->hr() == from_hr", because of the
689 // possibility of concurrent reuse. But see head comment of
690 // OtherRegionsTable for why this is OK.
691 assert(prt != NULL, "Inv");
692
693 if (prt->should_expand(tid)) {
694 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
695 HeapRegion* prt_hr = prt->hr();
696 if (prt_hr == from_hr) {
697 // Make sure the table still corresponds to the same region
698 prt->par_expand();
699 prt->add_reference(from, tid);
700 }
701 // else: The table has been concurrently coarsened, evicted, and
702 // the table data structure re-used for another table. So, we
703 // don't need to add the reference any more given that the table
704 // has been coarsened and the whole region will be scanned anyway.
705 } else {
706 prt->add_reference(from, tid);
707 }
708 if (G1RecordHRRSOops) {
709 HeapRegionRemSet::record(hr(), from);
710 #if HRRS_VERBOSE
711 gclog_or_tty->print("Added card " PTR_FORMAT " to region "
712 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
713 align_size_down(uintptr_t(from),
714 CardTableModRefBS::card_size),
715 hr()->bottom(), from);
716 #endif
717 }
718 assert(contains_reference(from), "We just added it!");
719 }
720
721 PosParPRT*
722 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
723 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
724 PosParPRT* prt = _fine_grain_regions[ind];
725 while (prt != NULL && prt->hr() != hr) {
726 prt = prt->next();
727 }
728 // Loop postcondition is the method postcondition.
729 return prt;
730 }
731
732
733 #define DRT_CENSUS 0
734
735 #if DRT_CENSUS
736 static const int HistoSize = 6;
737 static int global_histo[HistoSize] = { 0, 0, 0, 0, 0, 0 };
738 static int coarsenings = 0;
739 static int occ_sum = 0;
740 #endif
741
742 jint OtherRegionsTable::_n_coarsenings = 0;
743
744 PosParPRT* OtherRegionsTable::delete_region_table() {
745 #if DRT_CENSUS
746 int histo[HistoSize] = { 0, 0, 0, 0, 0, 0 };
747 const int histo_limits[] = { 1, 4, 16, 64, 256, 2048 };
748 #endif
749
750 assert(_m.owned_by_self(), "Precondition");
751 assert(_n_fine_entries == _max_fine_entries, "Precondition");
752 PosParPRT* max = NULL;
753 jint max_occ = 0;
754 PosParPRT** max_prev;
755 size_t max_ind;
756
757 #if SAMPLE_FOR_EVICTION
758 size_t i = _fine_eviction_start;
759 for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
760 size_t ii = i;
761 // Make sure we get a non-NULL sample.
762 while (_fine_grain_regions[ii] == NULL) {
763 ii++;
764 if (ii == _max_fine_entries) ii = 0;
765 guarantee(ii != i, "We must find one.");
766 }
767 PosParPRT** prev = &_fine_grain_regions[ii];
768 PosParPRT* cur = *prev;
769 while (cur != NULL) {
770 jint cur_occ = cur->occupied();
771 if (max == NULL || cur_occ > max_occ) {
772 max = cur;
773 max_prev = prev;
774 max_ind = i;
775 max_occ = cur_occ;
776 }
777 prev = cur->next_addr();
778 cur = cur->next();
779 }
780 i = i + _fine_eviction_stride;
781 if (i >= _n_fine_entries) i = i - _n_fine_entries;
782 }
783 _fine_eviction_start++;
784 if (_fine_eviction_start >= _n_fine_entries)
785 _fine_eviction_start -= _n_fine_entries;
786 #else
787 for (int i = 0; i < _max_fine_entries; i++) {
788 PosParPRT** prev = &_fine_grain_regions[i];
789 PosParPRT* cur = *prev;
790 while (cur != NULL) {
791 jint cur_occ = cur->occupied();
792 #if DRT_CENSUS
793 for (int k = 0; k < HistoSize; k++) {
794 if (cur_occ <= histo_limits[k]) {
795 histo[k]++; global_histo[k]++; break;
796 }
797 }
798 #endif
799 if (max == NULL || cur_occ > max_occ) {
800 max = cur;
801 max_prev = prev;
802 max_ind = i;
803 max_occ = cur_occ;
804 }
805 prev = cur->next_addr();
806 cur = cur->next();
807 }
808 }
809 #endif
810 // XXX
811 guarantee(max != NULL, "Since _n_fine_entries > 0");
812 #if DRT_CENSUS
813 gclog_or_tty->print_cr("In a coarsening: histo of occs:");
814 for (int k = 0; k < HistoSize; k++) {
815 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], histo[k]);
816 }
817 coarsenings++;
818 occ_sum += max_occ;
819 if ((coarsenings % 100) == 0) {
820 gclog_or_tty->print_cr("\ncoarsenings = %d; global summary:", coarsenings);
821 for (int k = 0; k < HistoSize; k++) {
822 gclog_or_tty->print_cr(" <= %4d: %5d.", histo_limits[k], global_histo[k]);
823 }
824 gclog_or_tty->print_cr("Avg occ of deleted region = %6.2f.",
825 (float)occ_sum/(float)coarsenings);
826 }
827 #endif
828
829 // Set the corresponding coarse bit.
830 int max_hrs_index = max->hr()->hrs_index();
831 if (!_coarse_map.at(max_hrs_index)) {
832 _coarse_map.at_put(max_hrs_index, true);
833 _n_coarse_entries++;
834 #if 0
835 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
836 "for region [" PTR_FORMAT "...] (%d coarse entries).\n",
837 hr()->bottom(),
838 max->hr()->bottom(),
839 _n_coarse_entries);
840 #endif
841 }
842
843 // Unsplice.
844 *max_prev = max->next();
845 Atomic::inc(&_n_coarsenings);
846 _n_fine_entries--;
847 return max;
848 }
849
850
851 // At present, this must be called stop-world single-threaded.
852 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
853 BitMap* region_bm, BitMap* card_bm) {
854 // First eliminated garbage regions from the coarse map.
855 if (G1RSScrubVerbose)
856 gclog_or_tty->print_cr("Scrubbing region %d:", hr()->hrs_index());
857
858 assert(_coarse_map.size() == region_bm->size(), "Precondition");
859 if (G1RSScrubVerbose)
860 gclog_or_tty->print(" Coarse map: before = %d...", _n_coarse_entries);
861 _coarse_map.set_intersection(*region_bm);
862 _n_coarse_entries = _coarse_map.count_one_bits();
863 if (G1RSScrubVerbose)
864 gclog_or_tty->print_cr(" after = %d.", _n_coarse_entries);
865
866 // Now do the fine-grained maps.
867 for (size_t i = 0; i < _max_fine_entries; i++) {
868 PosParPRT* cur = _fine_grain_regions[i];
869 PosParPRT** prev = &_fine_grain_regions[i];
870 while (cur != NULL) {
871 PosParPRT* nxt = cur->next();
872 // If the entire region is dead, eliminate.
873 if (G1RSScrubVerbose)
874 gclog_or_tty->print_cr(" For other region %d:", cur->hr()->hrs_index());
875 if (!region_bm->at(cur->hr()->hrs_index())) {
876 *prev = nxt;
877 cur->set_next(NULL);
878 _n_fine_entries--;
879 if (G1RSScrubVerbose)
880 gclog_or_tty->print_cr(" deleted via region map.");
881 PosParPRT::free(cur);
882 } else {
883 // Do fine-grain elimination.
884 if (G1RSScrubVerbose)
885 gclog_or_tty->print(" occ: before = %4d.", cur->occupied());
886 cur->scrub(ctbs, card_bm);
887 if (G1RSScrubVerbose)
888 gclog_or_tty->print_cr(" after = %4d.", cur->occupied());
889 // Did that empty the table completely?
890 if (cur->occupied() == 0) {
891 *prev = nxt;
892 cur->set_next(NULL);
893 _n_fine_entries--;
894 PosParPRT::free(cur);
895 } else {
896 prev = cur->next_addr();
897 }
898 }
899 cur = nxt;
900 }
901 }
902 // Since we may have deleted a from_card_cache entry from the RS, clear
903 // the FCC.
904 clear_fcc();
905 }
906
907
908 size_t OtherRegionsTable::occupied() const {
909 // Cast away const in this case.
910 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
911 size_t sum = occ_fine();
912 sum += occ_sparse();
913 sum += occ_coarse();
914 return sum;
915 }
916
917 size_t OtherRegionsTable::occ_fine() const {
918 size_t sum = 0;
919 for (size_t i = 0; i < _max_fine_entries; i++) {
920 PosParPRT* cur = _fine_grain_regions[i];
921 while (cur != NULL) {
922 sum += cur->occupied();
923 cur = cur->next();
924 }
925 }
926 return sum;
927 }
928
929 size_t OtherRegionsTable::occ_coarse() const {
930 return (_n_coarse_entries * HeapRegion::CardsPerRegion);
931 }
932
933 size_t OtherRegionsTable::occ_sparse() const {
934 return _sparse_table.occupied();
935 }
936
937 size_t OtherRegionsTable::mem_size() const {
938 // Cast away const in this case.
939 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
940 size_t sum = 0;
941 for (size_t i = 0; i < _max_fine_entries; i++) {
942 PosParPRT* cur = _fine_grain_regions[i];
943 while (cur != NULL) {
944 sum += cur->mem_size();
945 cur = cur->next();
946 }
947 }
948 sum += (sizeof(PosParPRT*) * _max_fine_entries);
949 sum += (_coarse_map.size_in_words() * HeapWordSize);
950 sum += (_sparse_table.mem_size());
951 sum += sizeof(*this) - sizeof(_sparse_table); // Avoid double counting above.
952 return sum;
953 }
954
955 size_t OtherRegionsTable::static_mem_size() {
956 return _from_card_cache_mem_size;
957 }
958
959 size_t OtherRegionsTable::fl_mem_size() {
960 return PerRegionTable::fl_mem_size() + PosParPRT::fl_mem_size();
961 }
962
963 void OtherRegionsTable::clear_fcc() {
964 for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
965 _from_card_cache[i][hr()->hrs_index()] = -1;
966 }
967 }
968
969 void OtherRegionsTable::clear() {
970 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
971 for (size_t i = 0; i < _max_fine_entries; i++) {
972 PosParPRT* cur = _fine_grain_regions[i];
973 while (cur != NULL) {
974 PosParPRT* nxt = cur->next();
975 PosParPRT::free(cur);
976 cur = nxt;
977 }
978 _fine_grain_regions[i] = NULL;
979 }
980 _sparse_table.clear();
981 _coarse_map.clear();
982 _n_fine_entries = 0;
983 _n_coarse_entries = 0;
984
985 clear_fcc();
986 }
987
988 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) {
989 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
990 size_t hrs_ind = (size_t)from_hr->hrs_index();
991 size_t ind = hrs_ind & _mod_max_fine_entries_mask;
992 if (del_single_region_table(ind, from_hr)) {
993 assert(!_coarse_map.at(hrs_ind), "Inv");
994 } else {
995 _coarse_map.par_at_put(hrs_ind, 0);
996 }
997 // Check to see if any of the fcc entries come from here.
998 int hr_ind = hr()->hrs_index();
999 for (int tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) {
1000 int fcc_ent = _from_card_cache[tid][hr_ind];
1001 if (fcc_ent != -1) {
1002 HeapWord* card_addr = (HeapWord*)
1003 (uintptr_t(fcc_ent) << CardTableModRefBS::card_shift);
1004 if (hr()->is_in_reserved(card_addr)) {
1005 // Clear the from card cache.
1006 _from_card_cache[tid][hr_ind] = -1;
1007 }
1008 }
1009 }
1010 }
1011
1012 bool OtherRegionsTable::del_single_region_table(size_t ind,
1013 HeapRegion* hr) {
1014 assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
1015 PosParPRT** prev_addr = &_fine_grain_regions[ind];
1016 PosParPRT* prt = *prev_addr;
1017 while (prt != NULL && prt->hr() != hr) {
1018 prev_addr = prt->next_addr();
1019 prt = prt->next();
1020 }
1021 if (prt != NULL) {
1022 assert(prt->hr() == hr, "Loop postcondition.");
1023 *prev_addr = prt->next();
1024 PosParPRT::free(prt);
1025 _n_fine_entries--;
1026 return true;
1027 } else {
1028 return false;
1029 }
1030 }
1031
1032 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
1033 // Cast away const in this case.
1034 MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
1035 return contains_reference_locked(from);
1036 }
1037
1038 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
1039 HeapRegion* hr = _g1h->heap_region_containing_raw(from);
1040 if (hr == NULL) return false;
1041 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrs_index();
1042 // Is this region in the coarse map?
1043 if (_coarse_map.at(hr_ind)) return true;
1044
1045 PosParPRT* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
1046 hr);
1047 if (prt != NULL) {
1048 return prt->contains_reference(from);
1049
1050 } else {
1051 uintptr_t from_card =
1052 (uintptr_t(from) >> CardTableModRefBS::card_shift);
1053 uintptr_t hr_bot_card_index =
1054 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
1055 assert(from_card >= hr_bot_card_index, "Inv");
1056 CardIdx_t card_index = from_card - hr_bot_card_index;
1057 assert(0 <= card_index && card_index < HeapRegion::CardsPerRegion,
1058 "Must be in range.");
1059 return _sparse_table.contains_card(hr_ind, card_index);
1060 }
1061
1062
1063 }
1064
1065 // Determines how many threads can add records to an rset in parallel.
1066 // This can be done by either mutator threads together with the
1067 // concurrent refinement threads or GC threads.
1068 int HeapRegionRemSet::num_par_rem_sets() {
1069 return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
1070 }
1071
1072 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
1073 HeapRegion* hr)
1074 : _bosa(bosa), _other_regions(hr), _iter_state(Unclaimed) { }
1075
1076
1077 void HeapRegionRemSet::setup_remset_size() {
1078 // Setup sparse and fine-grain tables sizes.
1079 // table_size = base * (log(region_size / 1M) + 1)
1080 int region_size_log_mb = MAX2((int)HeapRegion::LogOfHRGrainBytes - (int)LOG_M, 0);
1081 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
1082 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
1083 }
1084 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
1085 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
1086 }
1087 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
1088 }
1089
1090 void HeapRegionRemSet::init_for_par_iteration() {
1091 _iter_state = Unclaimed;
1092 }
1093
1094 bool HeapRegionRemSet::claim_iter() {
1095 if (_iter_state != Unclaimed) return false;
1096 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
1097 return (res == Unclaimed);
1098 }
1099
1100 void HeapRegionRemSet::set_iter_complete() {
1101 _iter_state = Complete;
1102 }
1103
1104 bool HeapRegionRemSet::iter_is_complete() {
1105 return _iter_state == Complete;
1106 }
1107
1108
1109 void HeapRegionRemSet::init_iterator(HeapRegionRemSetIterator* iter) const {
1110 iter->initialize(this);
1111 }
1112
1113 #ifndef PRODUCT
1114 void HeapRegionRemSet::print() const {
1115 HeapRegionRemSetIterator iter;
1116 init_iterator(&iter);
1117 size_t card_index;
1118 while (iter.has_next(card_index)) {
1119 HeapWord* card_start =
1120 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1121 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start);
1122 }
1123 // XXX
1124 if (iter.n_yielded() != occupied()) {
1125 gclog_or_tty->print_cr("Yielded disagrees with occupied:");
1126 gclog_or_tty->print_cr(" %6d yielded (%6d coarse, %6d fine).",
1127 iter.n_yielded(),
1128 iter.n_yielded_coarse(), iter.n_yielded_fine());
1129 gclog_or_tty->print_cr(" %6d occ (%6d coarse, %6d fine).",
1130 occupied(), occ_coarse(), occ_fine());
1131 }
1132 guarantee(iter.n_yielded() == occupied(),
1133 "We should have yielded all the represented cards.");
1134 }
1135 #endif
1136
1137 void HeapRegionRemSet::cleanup() {
1138 SparsePRT::cleanup_all();
1139 }
1140
1141 void HeapRegionRemSet::par_cleanup() {
1142 PosParPRT::par_contract_all();
1143 }
1144
1145 void HeapRegionRemSet::clear() {
1146 _other_regions.clear();
1147 assert(occupied() == 0, "Should be clear.");
1148 }
1149
1150 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
1151 BitMap* region_bm, BitMap* card_bm) {
1152 _other_regions.scrub(ctbs, region_bm, card_bm);
1153 }
1154
1155 //-------------------- Iteration --------------------
1156
1157 HeapRegionRemSetIterator::
1158 HeapRegionRemSetIterator() :
1159 _hrrs(NULL),
1160 _g1h(G1CollectedHeap::heap()),
1161 _bosa(NULL),
1162 _sparse_iter(size_t(G1CollectedHeap::heap()->reserved_region().start())
1163 >> CardTableModRefBS::card_shift)
1164 {}
1165
1166 void HeapRegionRemSetIterator::initialize(const HeapRegionRemSet* hrrs) {
1167 _hrrs = hrrs;
1168 _coarse_map = &_hrrs->_other_regions._coarse_map;
1169 _fine_grain_regions = _hrrs->_other_regions._fine_grain_regions;
1170 _bosa = _hrrs->bosa();
1171
1172 _is = Sparse;
1173 // Set these values so that we increment to the first region.
1174 _coarse_cur_region_index = -1;
1175 _coarse_cur_region_cur_card = (HeapRegion::CardsPerRegion-1);;
1176
1177 _cur_region_cur_card = 0;
1178
1179 _fine_array_index = -1;
1180 _fine_cur_prt = NULL;
1181
1182 _n_yielded_coarse = 0;
1183 _n_yielded_fine = 0;
1184 _n_yielded_sparse = 0;
1185
1186 _sparse_iter.init(&hrrs->_other_regions._sparse_table);
1187 }
1188
1189 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
1190 if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
1191 // Go to the next card.
1192 _coarse_cur_region_cur_card++;
1193 // Was the last the last card in the current region?
1194 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
1195 // Yes: find the next region. This may leave _coarse_cur_region_index
1196 // Set to the last index, in which case there are no more coarse
1197 // regions.
1198 _coarse_cur_region_index =
1199 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
1200 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
1201 _coarse_cur_region_cur_card = 0;
1202 HeapWord* r_bot =
1203 _g1h->region_at(_coarse_cur_region_index)->bottom();
1204 _cur_region_card_offset = _bosa->index_for(r_bot);
1205 } else {
1206 return false;
1207 }
1208 }
1209 // If we didn't return false above, then we can yield a card.
1210 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
1211 return true;
1212 }
1213
1214 void HeapRegionRemSetIterator::fine_find_next_non_null_prt() {
1215 // Otherwise, find the next bucket list in the array.
1216 _fine_array_index++;
1217 while (_fine_array_index < (int) OtherRegionsTable::_max_fine_entries) {
1218 _fine_cur_prt = _fine_grain_regions[_fine_array_index];
1219 if (_fine_cur_prt != NULL) return;
1220 else _fine_array_index++;
1221 }
1222 assert(_fine_cur_prt == NULL, "Loop post");
1223 }
1224
1225 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
1226 if (fine_has_next()) {
1227 _cur_region_cur_card =
1228 _fine_cur_prt->_bm.get_next_one_offset(_cur_region_cur_card + 1);
1229 }
1230 while (!fine_has_next()) {
1231 if (_cur_region_cur_card == (size_t) HeapRegion::CardsPerRegion) {
1232 _cur_region_cur_card = 0;
1233 _fine_cur_prt = _fine_cur_prt->next();
1234 }
1235 if (_fine_cur_prt == NULL) {
1236 fine_find_next_non_null_prt();
1237 if (_fine_cur_prt == NULL) return false;
1238 }
1239 assert(_fine_cur_prt != NULL && _cur_region_cur_card == 0,
1240 "inv.");
1241 HeapWord* r_bot =
1242 _fine_cur_prt->hr()->bottom();
1243 _cur_region_card_offset = _bosa->index_for(r_bot);
1244 _cur_region_cur_card = _fine_cur_prt->_bm.get_next_one_offset(0);
1245 }
1246 assert(fine_has_next(), "Or else we exited the loop via the return.");
1247 card_index = _cur_region_card_offset + _cur_region_cur_card;
1248 return true;
1249 }
1250
1251 bool HeapRegionRemSetIterator::fine_has_next() {
1252 return
1253 _fine_cur_prt != NULL &&
1254 _cur_region_cur_card < (size_t) HeapRegion::CardsPerRegion;
1255 }
1256
1257 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1258 switch (_is) {
1259 case Sparse:
1260 if (_sparse_iter.has_next(card_index)) {
1261 _n_yielded_sparse++;
1262 return true;
1263 }
1264 // Otherwise, deliberate fall-through
1265 _is = Fine;
1266 case Fine:
1267 if (fine_has_next(card_index)) {
1268 _n_yielded_fine++;
1269 return true;
1270 }
1271 // Otherwise, deliberate fall-through
1272 _is = Coarse;
1273 case Coarse:
1274 if (coarse_has_next(card_index)) {
1275 _n_yielded_coarse++;
1276 return true;
1277 }
1278 // Otherwise...
1279 break;
1280 }
1281 assert(ParallelGCThreads > 1 ||
1282 n_yielded() == _hrrs->occupied(),
1283 "Should have yielded all the cards in the rem set "
1284 "(in the non-par case).");
1285 return false;
1286 }
1287
1288
1289
1290 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1291 HeapWord** HeapRegionRemSet::_recorded_cards = NULL;
1292 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL;
1293 int HeapRegionRemSet::_n_recorded = 0;
1294
1295 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1296 int* HeapRegionRemSet::_recorded_event_index = NULL;
1297 int HeapRegionRemSet::_n_recorded_events = 0;
1298
1299 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1300 if (_recorded_oops == NULL) {
1301 assert(_n_recorded == 0
1302 && _recorded_cards == NULL
1303 && _recorded_regions == NULL,
1304 "Inv");
1305 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded);
1306 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded);
1307 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded);
1308 }
1309 if (_n_recorded == MaxRecorded) {
1310 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1311 } else {
1312 _recorded_cards[_n_recorded] =
1313 (HeapWord*)align_size_down(uintptr_t(f),
1314 CardTableModRefBS::card_size);
1315 _recorded_oops[_n_recorded] = f;
1316 _recorded_regions[_n_recorded] = hr;
1317 _n_recorded++;
1318 }
1319 }
1320
1321 void HeapRegionRemSet::record_event(Event evnt) {
1322 if (!G1RecordHRRSEvents) return;
1323
1324 if (_recorded_events == NULL) {
1325 assert(_n_recorded_events == 0
1326 && _recorded_event_index == NULL,
1327 "Inv");
1328 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents);
1329 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents);
1330 }
1331 if (_n_recorded_events == MaxRecordedEvents) {
1332 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1333 } else {
1334 _recorded_events[_n_recorded_events] = evnt;
1335 _recorded_event_index[_n_recorded_events] = _n_recorded;
1336 _n_recorded_events++;
1337 }
1338 }
1339
1340 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1341 switch (evnt) {
1342 case Event_EvacStart:
1343 str->print("Evac Start");
1344 break;
1345 case Event_EvacEnd:
1346 str->print("Evac End");
1347 break;
1348 case Event_RSUpdateEnd:
1349 str->print("RS Update End");
1350 break;
1351 }
1352 }
1353
1354 void HeapRegionRemSet::print_recorded() {
1355 int cur_evnt = 0;
1356 Event cur_evnt_kind;
1357 int cur_evnt_ind = 0;
1358 if (_n_recorded_events > 0) {
1359 cur_evnt_kind = _recorded_events[cur_evnt];
1360 cur_evnt_ind = _recorded_event_index[cur_evnt];
1361 }
1362
1363 for (int i = 0; i < _n_recorded; i++) {
1364 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1365 gclog_or_tty->print("Event: ");
1366 print_event(gclog_or_tty, cur_evnt_kind);
1367 gclog_or_tty->print_cr("");
1368 cur_evnt++;
1369 if (cur_evnt < MaxRecordedEvents) {
1370 cur_evnt_kind = _recorded_events[cur_evnt];
1371 cur_evnt_ind = _recorded_event_index[cur_evnt];
1372 }
1373 }
1374 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1375 " for ref " PTR_FORMAT ".\n",
1376 _recorded_cards[i], _recorded_regions[i]->bottom(),
1377 _recorded_oops[i]);
1378 }
1379 }
1380
1381 #ifndef PRODUCT
1382 void HeapRegionRemSet::test() {
1383 os::sleep(Thread::current(), (jlong)5000, false);
1384 G1CollectedHeap* g1h = G1CollectedHeap::heap();
1385
1386 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1387 // hash bucket.
1388 HeapRegion* hr0 = g1h->region_at(0);
1389 HeapRegion* hr1 = g1h->region_at(1);
1390 HeapRegion* hr2 = g1h->region_at(5);
1391 HeapRegion* hr3 = g1h->region_at(6);
1392 HeapRegion* hr4 = g1h->region_at(7);
1393 HeapRegion* hr5 = g1h->region_at(8);
1394
1395 HeapWord* hr1_start = hr1->bottom();
1396 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1397 HeapWord* hr1_last = hr1->end() - 1;
1398
1399 HeapWord* hr2_start = hr2->bottom();
1400 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1401 HeapWord* hr2_last = hr2->end() - 1;
1402
1403 HeapWord* hr3_start = hr3->bottom();
1404 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1405 HeapWord* hr3_last = hr3->end() - 1;
1406
1407 HeapRegionRemSet* hrrs = hr0->rem_set();
1408
1409 // Make three references from region 0x101...
1410 hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1411 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1412 hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1413
1414 hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1415 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1416 hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1417
1418 hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1419 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1420 hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1421
1422 // Now cause a coarsening.
1423 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1424 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1425
1426 // Now, does iteration yield these three?
1427 HeapRegionRemSetIterator iter;
1428 hrrs->init_iterator(&iter);
1429 size_t sum = 0;
1430 size_t card_index;
1431 while (iter.has_next(card_index)) {
1432 HeapWord* card_start =
1433 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1434 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", card_start);
1435 sum++;
1436 }
1437 guarantee(sum == 11 - 3 + 2048, "Failure");
1438 guarantee(sum == hrrs->occupied(), "Failure");
1439 }
1440 #endif