Mercurial > hg > graal-jvmci-8
comparison src/share/vm/memory/cardTableModRefBS.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 73e96e5c30df b611e572fc5b |
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1 /* | |
2 * Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and | |
26 // enumerate ref fields that have been modified (since the last | |
27 // enumeration.) | |
28 | |
29 # include "incls/_precompiled.incl" | |
30 # include "incls/_cardTableModRefBS.cpp.incl" | |
31 | |
32 size_t CardTableModRefBS::cards_required(size_t covered_words) | |
33 { | |
34 // Add one for a guard card, used to detect errors. | |
35 const size_t words = align_size_up(covered_words, card_size_in_words); | |
36 return words / card_size_in_words + 1; | |
37 } | |
38 | |
39 size_t CardTableModRefBS::compute_byte_map_size() | |
40 { | |
41 assert(_guard_index == cards_required(_whole_heap.word_size()) - 1, | |
42 "unitialized, check declaration order"); | |
43 assert(_page_size != 0, "unitialized, check declaration order"); | |
44 const size_t granularity = os::vm_allocation_granularity(); | |
45 return align_size_up(_guard_index + 1, MAX2(_page_size, granularity)); | |
46 } | |
47 | |
48 CardTableModRefBS::CardTableModRefBS(MemRegion whole_heap, | |
49 int max_covered_regions): | |
50 ModRefBarrierSet(max_covered_regions), | |
51 _whole_heap(whole_heap), | |
52 _guard_index(cards_required(whole_heap.word_size()) - 1), | |
53 _last_valid_index(_guard_index - 1), | |
54 _page_size(os::page_size_for_region(_guard_index + 1, _guard_index + 1, 1)), | |
55 _byte_map_size(compute_byte_map_size()) | |
56 { | |
57 _kind = BarrierSet::CardTableModRef; | |
58 | |
59 HeapWord* low_bound = _whole_heap.start(); | |
60 HeapWord* high_bound = _whole_heap.end(); | |
61 assert((uintptr_t(low_bound) & (card_size - 1)) == 0, "heap must start at card boundary"); | |
62 assert((uintptr_t(high_bound) & (card_size - 1)) == 0, "heap must end at card boundary"); | |
63 | |
64 assert(card_size <= 512, "card_size must be less than 512"); // why? | |
65 | |
66 _covered = new MemRegion[max_covered_regions]; | |
67 _committed = new MemRegion[max_covered_regions]; | |
68 if (_covered == NULL || _committed == NULL) | |
69 vm_exit_during_initialization("couldn't alloc card table covered region set."); | |
70 int i; | |
71 for (i = 0; i < max_covered_regions; i++) { | |
72 _covered[i].set_word_size(0); | |
73 _committed[i].set_word_size(0); | |
74 } | |
75 _cur_covered_regions = 0; | |
76 | |
77 const size_t rs_align = _page_size == (size_t) os::vm_page_size() ? 0 : | |
78 MAX2(_page_size, (size_t) os::vm_allocation_granularity()); | |
79 ReservedSpace heap_rs(_byte_map_size, rs_align, false); | |
80 os::trace_page_sizes("card table", _guard_index + 1, _guard_index + 1, | |
81 _page_size, heap_rs.base(), heap_rs.size()); | |
82 if (!heap_rs.is_reserved()) { | |
83 vm_exit_during_initialization("Could not reserve enough space for the " | |
84 "card marking array"); | |
85 } | |
86 | |
87 // The assember store_check code will do an unsigned shift of the oop, | |
88 // then add it to byte_map_base, i.e. | |
89 // | |
90 // _byte_map = byte_map_base + (uintptr_t(low_bound) >> card_shift) | |
91 _byte_map = (jbyte*) heap_rs.base(); | |
92 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift); | |
93 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map"); | |
94 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map"); | |
95 | |
96 jbyte* guard_card = &_byte_map[_guard_index]; | |
97 uintptr_t guard_page = align_size_down((uintptr_t)guard_card, _page_size); | |
98 _guard_region = MemRegion((HeapWord*)guard_page, _page_size); | |
99 if (!os::commit_memory((char*)guard_page, _page_size, _page_size)) { | |
100 // Do better than this for Merlin | |
101 vm_exit_out_of_memory(_page_size, "card table last card"); | |
102 } | |
103 *guard_card = last_card; | |
104 | |
105 _lowest_non_clean = | |
106 NEW_C_HEAP_ARRAY(CardArr, max_covered_regions); | |
107 _lowest_non_clean_chunk_size = | |
108 NEW_C_HEAP_ARRAY(size_t, max_covered_regions); | |
109 _lowest_non_clean_base_chunk_index = | |
110 NEW_C_HEAP_ARRAY(uintptr_t, max_covered_regions); | |
111 _last_LNC_resizing_collection = | |
112 NEW_C_HEAP_ARRAY(int, max_covered_regions); | |
113 if (_lowest_non_clean == NULL | |
114 || _lowest_non_clean_chunk_size == NULL | |
115 || _lowest_non_clean_base_chunk_index == NULL | |
116 || _last_LNC_resizing_collection == NULL) | |
117 vm_exit_during_initialization("couldn't allocate an LNC array."); | |
118 for (i = 0; i < max_covered_regions; i++) { | |
119 _lowest_non_clean[i] = NULL; | |
120 _lowest_non_clean_chunk_size[i] = 0; | |
121 _last_LNC_resizing_collection[i] = -1; | |
122 } | |
123 | |
124 if (TraceCardTableModRefBS) { | |
125 gclog_or_tty->print_cr("CardTableModRefBS::CardTableModRefBS: "); | |
126 gclog_or_tty->print_cr(" " | |
127 " &_byte_map[0]: " INTPTR_FORMAT | |
128 " &_byte_map[_last_valid_index]: " INTPTR_FORMAT, | |
129 &_byte_map[0], | |
130 &_byte_map[_last_valid_index]); | |
131 gclog_or_tty->print_cr(" " | |
132 " byte_map_base: " INTPTR_FORMAT, | |
133 byte_map_base); | |
134 } | |
135 } | |
136 | |
137 int CardTableModRefBS::find_covering_region_by_base(HeapWord* base) { | |
138 int i; | |
139 for (i = 0; i < _cur_covered_regions; i++) { | |
140 if (_covered[i].start() == base) return i; | |
141 if (_covered[i].start() > base) break; | |
142 } | |
143 // If we didn't find it, create a new one. | |
144 assert(_cur_covered_regions < _max_covered_regions, | |
145 "too many covered regions"); | |
146 // Move the ones above up, to maintain sorted order. | |
147 for (int j = _cur_covered_regions; j > i; j--) { | |
148 _covered[j] = _covered[j-1]; | |
149 _committed[j] = _committed[j-1]; | |
150 } | |
151 int res = i; | |
152 _cur_covered_regions++; | |
153 _covered[res].set_start(base); | |
154 _covered[res].set_word_size(0); | |
155 jbyte* ct_start = byte_for(base); | |
156 uintptr_t ct_start_aligned = align_size_down((uintptr_t)ct_start, _page_size); | |
157 _committed[res].set_start((HeapWord*)ct_start_aligned); | |
158 _committed[res].set_word_size(0); | |
159 return res; | |
160 } | |
161 | |
162 int CardTableModRefBS::find_covering_region_containing(HeapWord* addr) { | |
163 for (int i = 0; i < _cur_covered_regions; i++) { | |
164 if (_covered[i].contains(addr)) { | |
165 return i; | |
166 } | |
167 } | |
168 assert(0, "address outside of heap?"); | |
169 return -1; | |
170 } | |
171 | |
172 HeapWord* CardTableModRefBS::largest_prev_committed_end(int ind) const { | |
173 HeapWord* max_end = NULL; | |
174 for (int j = 0; j < ind; j++) { | |
175 HeapWord* this_end = _committed[j].end(); | |
176 if (this_end > max_end) max_end = this_end; | |
177 } | |
178 return max_end; | |
179 } | |
180 | |
181 MemRegion CardTableModRefBS::committed_unique_to_self(int self, | |
182 MemRegion mr) const { | |
183 MemRegion result = mr; | |
184 for (int r = 0; r < _cur_covered_regions; r += 1) { | |
185 if (r != self) { | |
186 result = result.minus(_committed[r]); | |
187 } | |
188 } | |
189 // Never include the guard page. | |
190 result = result.minus(_guard_region); | |
191 return result; | |
192 } | |
193 | |
194 void CardTableModRefBS::resize_covered_region(MemRegion new_region) { | |
195 // We don't change the start of a region, only the end. | |
196 assert(_whole_heap.contains(new_region), | |
197 "attempt to cover area not in reserved area"); | |
198 debug_only(verify_guard();) | |
199 int ind = find_covering_region_by_base(new_region.start()); | |
200 MemRegion old_region = _covered[ind]; | |
201 assert(old_region.start() == new_region.start(), "just checking"); | |
202 if (new_region.word_size() != old_region.word_size()) { | |
203 // Commit new or uncommit old pages, if necessary. | |
204 MemRegion cur_committed = _committed[ind]; | |
205 // Extend the end of this _commited region | |
206 // to cover the end of any lower _committed regions. | |
207 // This forms overlapping regions, but never interior regions. | |
208 HeapWord* max_prev_end = largest_prev_committed_end(ind); | |
209 if (max_prev_end > cur_committed.end()) { | |
210 cur_committed.set_end(max_prev_end); | |
211 } | |
212 // Align the end up to a page size (starts are already aligned). | |
213 jbyte* new_end = byte_after(new_region.last()); | |
214 HeapWord* new_end_aligned = | |
215 (HeapWord*)align_size_up((uintptr_t)new_end, _page_size); | |
216 assert(new_end_aligned >= (HeapWord*) new_end, | |
217 "align up, but less"); | |
218 // The guard page is always committed and should not be committed over. | |
219 HeapWord* new_end_for_commit = MIN2(new_end_aligned, _guard_region.start()); | |
220 if (new_end_for_commit > cur_committed.end()) { | |
221 // Must commit new pages. | |
222 MemRegion new_committed = | |
223 MemRegion(cur_committed.end(), new_end_for_commit); | |
224 | |
225 assert(!new_committed.is_empty(), "Region should not be empty here"); | |
226 if (!os::commit_memory((char*)new_committed.start(), | |
227 new_committed.byte_size(), _page_size)) { | |
228 // Do better than this for Merlin | |
229 vm_exit_out_of_memory(new_committed.byte_size(), | |
230 "card table expansion"); | |
231 } | |
232 // Use new_end_aligned (as opposed to new_end_for_commit) because | |
233 // the cur_committed region may include the guard region. | |
234 } else if (new_end_aligned < cur_committed.end()) { | |
235 // Must uncommit pages. | |
236 MemRegion uncommit_region = | |
237 committed_unique_to_self(ind, MemRegion(new_end_aligned, | |
238 cur_committed.end())); | |
239 if (!uncommit_region.is_empty()) { | |
240 if (!os::uncommit_memory((char*)uncommit_region.start(), | |
241 uncommit_region.byte_size())) { | |
242 // Do better than this for Merlin | |
243 vm_exit_out_of_memory(uncommit_region.byte_size(), | |
244 "card table contraction"); | |
245 } | |
246 } | |
247 } | |
248 // In any case, we can reset the end of the current committed entry. | |
249 _committed[ind].set_end(new_end_aligned); | |
250 | |
251 // The default of 0 is not necessarily clean cards. | |
252 jbyte* entry; | |
253 if (old_region.last() < _whole_heap.start()) { | |
254 entry = byte_for(_whole_heap.start()); | |
255 } else { | |
256 entry = byte_after(old_region.last()); | |
257 } | |
258 assert(index_for(new_region.last()) < (int) _guard_index, | |
259 "The guard card will be overwritten"); | |
260 jbyte* end = byte_after(new_region.last()); | |
261 // do nothing if we resized downward. | |
262 if (entry < end) { | |
263 memset(entry, clean_card, pointer_delta(end, entry, sizeof(jbyte))); | |
264 } | |
265 } | |
266 // In any case, the covered size changes. | |
267 _covered[ind].set_word_size(new_region.word_size()); | |
268 if (TraceCardTableModRefBS) { | |
269 gclog_or_tty->print_cr("CardTableModRefBS::resize_covered_region: "); | |
270 gclog_or_tty->print_cr(" " | |
271 " _covered[%d].start(): " INTPTR_FORMAT | |
272 " _covered[%d].last(): " INTPTR_FORMAT, | |
273 ind, _covered[ind].start(), | |
274 ind, _covered[ind].last()); | |
275 gclog_or_tty->print_cr(" " | |
276 " _committed[%d].start(): " INTPTR_FORMAT | |
277 " _committed[%d].last(): " INTPTR_FORMAT, | |
278 ind, _committed[ind].start(), | |
279 ind, _committed[ind].last()); | |
280 gclog_or_tty->print_cr(" " | |
281 " byte_for(start): " INTPTR_FORMAT | |
282 " byte_for(last): " INTPTR_FORMAT, | |
283 byte_for(_covered[ind].start()), | |
284 byte_for(_covered[ind].last())); | |
285 gclog_or_tty->print_cr(" " | |
286 " addr_for(start): " INTPTR_FORMAT | |
287 " addr_for(last): " INTPTR_FORMAT, | |
288 addr_for((jbyte*) _committed[ind].start()), | |
289 addr_for((jbyte*) _committed[ind].last())); | |
290 } | |
291 debug_only(verify_guard();) | |
292 } | |
293 | |
294 // Note that these versions are precise! The scanning code has to handle the | |
295 // fact that the write barrier may be either precise or imprecise. | |
296 | |
297 void CardTableModRefBS::write_ref_field_work(oop* field, oop newVal) { | |
298 inline_write_ref_field(field, newVal); | |
299 } | |
300 | |
301 | |
302 void CardTableModRefBS::non_clean_card_iterate(Space* sp, | |
303 MemRegion mr, | |
304 DirtyCardToOopClosure* dcto_cl, | |
305 MemRegionClosure* cl, | |
306 bool clear) { | |
307 if (!mr.is_empty()) { | |
308 int n_threads = SharedHeap::heap()->n_par_threads(); | |
309 if (n_threads > 0) { | |
310 #ifndef SERIALGC | |
311 par_non_clean_card_iterate_work(sp, mr, dcto_cl, cl, clear, n_threads); | |
312 #else // SERIALGC | |
313 fatal("Parallel gc not supported here."); | |
314 #endif // SERIALGC | |
315 } else { | |
316 non_clean_card_iterate_work(mr, cl, clear); | |
317 } | |
318 } | |
319 } | |
320 | |
321 // NOTE: For this to work correctly, it is important that | |
322 // we look for non-clean cards below (so as to catch those | |
323 // marked precleaned), rather than look explicitly for dirty | |
324 // cards (and miss those marked precleaned). In that sense, | |
325 // the name precleaned is currently somewhat of a misnomer. | |
326 void CardTableModRefBS::non_clean_card_iterate_work(MemRegion mr, | |
327 MemRegionClosure* cl, | |
328 bool clear) { | |
329 // Figure out whether we have to worry about parallelism. | |
330 bool is_par = (SharedHeap::heap()->n_par_threads() > 1); | |
331 for (int i = 0; i < _cur_covered_regions; i++) { | |
332 MemRegion mri = mr.intersection(_covered[i]); | |
333 if (mri.word_size() > 0) { | |
334 jbyte* cur_entry = byte_for(mri.last()); | |
335 jbyte* limit = byte_for(mri.start()); | |
336 while (cur_entry >= limit) { | |
337 jbyte* next_entry = cur_entry - 1; | |
338 if (*cur_entry != clean_card) { | |
339 size_t non_clean_cards = 1; | |
340 // Should the next card be included in this range of dirty cards. | |
341 while (next_entry >= limit && *next_entry != clean_card) { | |
342 non_clean_cards++; | |
343 cur_entry = next_entry; | |
344 next_entry--; | |
345 } | |
346 // The memory region may not be on a card boundary. So that | |
347 // objects beyond the end of the region are not processed, make | |
348 // cur_cards precise with regard to the end of the memory region. | |
349 MemRegion cur_cards(addr_for(cur_entry), | |
350 non_clean_cards * card_size_in_words); | |
351 MemRegion dirty_region = cur_cards.intersection(mri); | |
352 if (clear) { | |
353 for (size_t i = 0; i < non_clean_cards; i++) { | |
354 // Clean the dirty cards (but leave the other non-clean | |
355 // alone.) If parallel, do the cleaning atomically. | |
356 jbyte cur_entry_val = cur_entry[i]; | |
357 if (card_is_dirty_wrt_gen_iter(cur_entry_val)) { | |
358 if (is_par) { | |
359 jbyte res = Atomic::cmpxchg(clean_card, &cur_entry[i], cur_entry_val); | |
360 assert(res != clean_card, | |
361 "Dirty card mysteriously cleaned"); | |
362 } else { | |
363 cur_entry[i] = clean_card; | |
364 } | |
365 } | |
366 } | |
367 } | |
368 cl->do_MemRegion(dirty_region); | |
369 } | |
370 cur_entry = next_entry; | |
371 } | |
372 } | |
373 } | |
374 } | |
375 | |
376 void CardTableModRefBS::mod_oop_in_space_iterate(Space* sp, | |
377 OopClosure* cl, | |
378 bool clear, | |
379 bool before_save_marks) { | |
380 // Note that dcto_cl is resource-allocated, so there is no | |
381 // corresponding "delete". | |
382 DirtyCardToOopClosure* dcto_cl = sp->new_dcto_cl(cl, precision()); | |
383 MemRegion used_mr; | |
384 if (before_save_marks) { | |
385 used_mr = sp->used_region_at_save_marks(); | |
386 } else { | |
387 used_mr = sp->used_region(); | |
388 } | |
389 non_clean_card_iterate(sp, used_mr, dcto_cl, dcto_cl, clear); | |
390 } | |
391 | |
392 void CardTableModRefBS::dirty_MemRegion(MemRegion mr) { | |
393 jbyte* cur = byte_for(mr.start()); | |
394 jbyte* last = byte_after(mr.last()); | |
395 while (cur < last) { | |
396 *cur = dirty_card; | |
397 cur++; | |
398 } | |
399 } | |
400 | |
401 void CardTableModRefBS::invalidate(MemRegion mr) { | |
402 for (int i = 0; i < _cur_covered_regions; i++) { | |
403 MemRegion mri = mr.intersection(_covered[i]); | |
404 if (!mri.is_empty()) dirty_MemRegion(mri); | |
405 } | |
406 } | |
407 | |
408 void CardTableModRefBS::clear_MemRegion(MemRegion mr) { | |
409 // Be conservative: only clean cards entirely contained within the | |
410 // region. | |
411 jbyte* cur; | |
412 if (mr.start() == _whole_heap.start()) { | |
413 cur = byte_for(mr.start()); | |
414 } else { | |
415 assert(mr.start() > _whole_heap.start(), "mr is not covered."); | |
416 cur = byte_after(mr.start() - 1); | |
417 } | |
418 jbyte* last = byte_after(mr.last()); | |
419 memset(cur, clean_card, pointer_delta(last, cur, sizeof(jbyte))); | |
420 } | |
421 | |
422 void CardTableModRefBS::clear(MemRegion mr) { | |
423 for (int i = 0; i < _cur_covered_regions; i++) { | |
424 MemRegion mri = mr.intersection(_covered[i]); | |
425 if (!mri.is_empty()) clear_MemRegion(mri); | |
426 } | |
427 } | |
428 | |
429 // NOTES: | |
430 // (1) Unlike mod_oop_in_space_iterate() above, dirty_card_iterate() | |
431 // iterates over dirty cards ranges in increasing address order. | |
432 // (2) Unlike, e.g., dirty_card_range_after_preclean() below, | |
433 // this method does not make the dirty cards prelceaned. | |
434 void CardTableModRefBS::dirty_card_iterate(MemRegion mr, | |
435 MemRegionClosure* cl) { | |
436 for (int i = 0; i < _cur_covered_regions; i++) { | |
437 MemRegion mri = mr.intersection(_covered[i]); | |
438 if (!mri.is_empty()) { | |
439 jbyte *cur_entry, *next_entry, *limit; | |
440 for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last()); | |
441 cur_entry <= limit; | |
442 cur_entry = next_entry) { | |
443 next_entry = cur_entry + 1; | |
444 if (*cur_entry == dirty_card) { | |
445 size_t dirty_cards; | |
446 // Accumulate maximal dirty card range, starting at cur_entry | |
447 for (dirty_cards = 1; | |
448 next_entry <= limit && *next_entry == dirty_card; | |
449 dirty_cards++, next_entry++); | |
450 MemRegion cur_cards(addr_for(cur_entry), | |
451 dirty_cards*card_size_in_words); | |
452 cl->do_MemRegion(cur_cards); | |
453 } | |
454 } | |
455 } | |
456 } | |
457 } | |
458 | |
459 MemRegion CardTableModRefBS::dirty_card_range_after_preclean(MemRegion mr) { | |
460 for (int i = 0; i < _cur_covered_regions; i++) { | |
461 MemRegion mri = mr.intersection(_covered[i]); | |
462 if (!mri.is_empty()) { | |
463 jbyte* cur_entry, *next_entry, *limit; | |
464 for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last()); | |
465 cur_entry <= limit; | |
466 cur_entry = next_entry) { | |
467 next_entry = cur_entry + 1; | |
468 if (*cur_entry == dirty_card) { | |
469 size_t dirty_cards; | |
470 // Accumulate maximal dirty card range, starting at cur_entry | |
471 for (dirty_cards = 1; | |
472 next_entry <= limit && *next_entry == dirty_card; | |
473 dirty_cards++, next_entry++); | |
474 MemRegion cur_cards(addr_for(cur_entry), | |
475 dirty_cards*card_size_in_words); | |
476 for (size_t i = 0; i < dirty_cards; i++) { | |
477 cur_entry[i] = precleaned_card; | |
478 } | |
479 return cur_cards; | |
480 } | |
481 } | |
482 } | |
483 } | |
484 return MemRegion(mr.end(), mr.end()); | |
485 } | |
486 | |
487 // Set all the dirty cards in the given region to "precleaned" state. | |
488 void CardTableModRefBS::preclean_dirty_cards(MemRegion mr) { | |
489 for (int i = 0; i < _cur_covered_regions; i++) { | |
490 MemRegion mri = mr.intersection(_covered[i]); | |
491 if (!mri.is_empty()) { | |
492 jbyte *cur_entry, *limit; | |
493 for (cur_entry = byte_for(mri.start()), limit = byte_for(mri.last()); | |
494 cur_entry <= limit; | |
495 cur_entry++) { | |
496 if (*cur_entry == dirty_card) { | |
497 *cur_entry = precleaned_card; | |
498 } | |
499 } | |
500 } | |
501 } | |
502 } | |
503 | |
504 uintx CardTableModRefBS::ct_max_alignment_constraint() { | |
505 return card_size * os::vm_page_size(); | |
506 } | |
507 | |
508 void CardTableModRefBS::verify_guard() { | |
509 // For product build verification | |
510 guarantee(_byte_map[_guard_index] == last_card, | |
511 "card table guard has been modified"); | |
512 } | |
513 | |
514 void CardTableModRefBS::verify() { | |
515 verify_guard(); | |
516 } | |
517 | |
518 #ifndef PRODUCT | |
519 class GuaranteeNotModClosure: public MemRegionClosure { | |
520 CardTableModRefBS* _ct; | |
521 public: | |
522 GuaranteeNotModClosure(CardTableModRefBS* ct) : _ct(ct) {} | |
523 void do_MemRegion(MemRegion mr) { | |
524 jbyte* entry = _ct->byte_for(mr.start()); | |
525 guarantee(*entry != CardTableModRefBS::clean_card, | |
526 "Dirty card in region that should be clean"); | |
527 } | |
528 }; | |
529 | |
530 void CardTableModRefBS::verify_clean_region(MemRegion mr) { | |
531 GuaranteeNotModClosure blk(this); | |
532 non_clean_card_iterate_work(mr, &blk, false); | |
533 } | |
534 #endif | |
535 | |
536 bool CardTableModRefBSForCTRS::card_will_be_scanned(jbyte cv) { | |
537 return | |
538 CardTableModRefBS::card_will_be_scanned(cv) || | |
539 _rs->is_prev_nonclean_card_val(cv); | |
540 }; | |
541 | |
542 bool CardTableModRefBSForCTRS::card_may_have_been_dirty(jbyte cv) { | |
543 return | |
544 cv != clean_card && | |
545 (CardTableModRefBS::card_may_have_been_dirty(cv) || | |
546 CardTableRS::youngergen_may_have_been_dirty(cv)); | |
547 }; |