Mercurial > hg > truffle
annotate src/share/vm/memory/cardTableModRefBS.cpp @ 46:8b6e49187640
Merge
| author | rasbold |
|---|---|
| date | Thu, 13 Mar 2008 05:40:44 -0700 |
| parents | 762905818571 b611e572fc5b |
| children | ba764ed4b6f2 |
| rev | line source |
|---|---|
| 0 | 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), | |
| 21 | 54 _page_size(os::vm_page_size()), |
| 0 | 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();) | |
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199 int const ind = find_covering_region_by_base(new_region.start()); |
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200 MemRegion const old_region = _covered[ind]; |
| 0 | 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. | |
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208 HeapWord* const max_prev_end = largest_prev_committed_end(ind); |
| 0 | 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). | |
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213 jbyte* const new_end = byte_after(new_region.last()); |
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214 HeapWord* const new_end_aligned = |
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215 (HeapWord*) align_size_up((uintptr_t)new_end, _page_size); |
| 0 | 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. | |
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219 HeapWord* const new_end_for_commit = MIN2(new_end_aligned, _guard_region.start()); |
| 0 | 220 if (new_end_for_commit > cur_committed.end()) { |
| 221 // Must commit new pages. | |
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222 MemRegion const new_committed = |
| 0 | 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. | |
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236 MemRegion const uncommit_region = |
| 0 | 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"); | |
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260 jbyte* const end = byte_after(new_region.last()); |
| 0 | 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 }; |