Thu, 11 Dec 2008 12:05:08 -0800
6578152: fill_region_with_object has usability and safety issues
Reviewed-by: apetrusenko, ysr
duke@435 | 1 | /* |
xdono@631 | 2 | * Copyright 2000-2008 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | // This kind of "BarrierSet" allows a "CollectedHeap" to detect and |
duke@435 | 26 | // enumerate ref fields that have been modified (since the last |
duke@435 | 27 | // enumeration.) |
duke@435 | 28 | |
duke@435 | 29 | // As it currently stands, this barrier is *imprecise*: when a ref field in |
duke@435 | 30 | // an object "o" is modified, the card table entry for the card containing |
duke@435 | 31 | // the head of "o" is dirtied, not necessarily the card containing the |
duke@435 | 32 | // modified field itself. For object arrays, however, the barrier *is* |
duke@435 | 33 | // precise; only the card containing the modified element is dirtied. |
duke@435 | 34 | // Any MemRegionClosures used to scan dirty cards should take these |
duke@435 | 35 | // considerations into account. |
duke@435 | 36 | |
duke@435 | 37 | class Generation; |
duke@435 | 38 | class OopsInGenClosure; |
duke@435 | 39 | class DirtyCardToOopClosure; |
duke@435 | 40 | |
duke@435 | 41 | class CardTableModRefBS: public ModRefBarrierSet { |
duke@435 | 42 | // Some classes get to look at some private stuff. |
duke@435 | 43 | friend class BytecodeInterpreter; |
duke@435 | 44 | friend class VMStructs; |
duke@435 | 45 | friend class CardTableRS; |
duke@435 | 46 | friend class CheckForUnmarkedOops; // Needs access to raw card bytes. |
duke@435 | 47 | #ifndef PRODUCT |
duke@435 | 48 | // For debugging. |
duke@435 | 49 | friend class GuaranteeNotModClosure; |
duke@435 | 50 | #endif |
duke@435 | 51 | protected: |
duke@435 | 52 | |
duke@435 | 53 | enum CardValues { |
duke@435 | 54 | clean_card = -1, |
duke@435 | 55 | dirty_card = 0, |
duke@435 | 56 | precleaned_card = 1, |
ysr@777 | 57 | claimed_card = 3, |
duke@435 | 58 | last_card = 4, |
duke@435 | 59 | CT_MR_BS_last_reserved = 10 |
duke@435 | 60 | }; |
duke@435 | 61 | |
duke@435 | 62 | // dirty and precleaned are equivalent wrt younger_refs_iter. |
duke@435 | 63 | static bool card_is_dirty_wrt_gen_iter(jbyte cv) { |
duke@435 | 64 | return cv == dirty_card || cv == precleaned_card; |
duke@435 | 65 | } |
duke@435 | 66 | |
duke@435 | 67 | // Returns "true" iff the value "cv" will cause the card containing it |
duke@435 | 68 | // to be scanned in the current traversal. May be overridden by |
duke@435 | 69 | // subtypes. |
duke@435 | 70 | virtual bool card_will_be_scanned(jbyte cv) { |
duke@435 | 71 | return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv); |
duke@435 | 72 | } |
duke@435 | 73 | |
duke@435 | 74 | // Returns "true" iff the value "cv" may have represented a dirty card at |
duke@435 | 75 | // some point. |
duke@435 | 76 | virtual bool card_may_have_been_dirty(jbyte cv) { |
duke@435 | 77 | return card_is_dirty_wrt_gen_iter(cv); |
duke@435 | 78 | } |
duke@435 | 79 | |
duke@435 | 80 | // The declaration order of these const fields is important; see the |
duke@435 | 81 | // constructor before changing. |
duke@435 | 82 | const MemRegion _whole_heap; // the region covered by the card table |
duke@435 | 83 | const size_t _guard_index; // index of very last element in the card |
duke@435 | 84 | // table; it is set to a guard value |
duke@435 | 85 | // (last_card) and should never be modified |
duke@435 | 86 | const size_t _last_valid_index; // index of the last valid element |
duke@435 | 87 | const size_t _page_size; // page size used when mapping _byte_map |
duke@435 | 88 | const size_t _byte_map_size; // in bytes |
duke@435 | 89 | jbyte* _byte_map; // the card marking array |
duke@435 | 90 | |
duke@435 | 91 | int _cur_covered_regions; |
duke@435 | 92 | // The covered regions should be in address order. |
duke@435 | 93 | MemRegion* _covered; |
duke@435 | 94 | // The committed regions correspond one-to-one to the covered regions. |
duke@435 | 95 | // They represent the card-table memory that has been committed to service |
duke@435 | 96 | // the corresponding covered region. It may be that committed region for |
duke@435 | 97 | // one covered region corresponds to a larger region because of page-size |
duke@435 | 98 | // roundings. Thus, a committed region for one covered region may |
duke@435 | 99 | // actually extend onto the card-table space for the next covered region. |
duke@435 | 100 | MemRegion* _committed; |
duke@435 | 101 | |
duke@435 | 102 | // The last card is a guard card, and we commit the page for it so |
duke@435 | 103 | // we can use the card for verification purposes. We make sure we never |
duke@435 | 104 | // uncommit the MemRegion for that page. |
duke@435 | 105 | MemRegion _guard_region; |
duke@435 | 106 | |
duke@435 | 107 | protected: |
duke@435 | 108 | // Initialization utilities; covered_words is the size of the covered region |
duke@435 | 109 | // in, um, words. |
duke@435 | 110 | inline size_t cards_required(size_t covered_words); |
duke@435 | 111 | inline size_t compute_byte_map_size(); |
duke@435 | 112 | |
duke@435 | 113 | // Finds and return the index of the region, if any, to which the given |
duke@435 | 114 | // region would be contiguous. If none exists, assign a new region and |
duke@435 | 115 | // returns its index. Requires that no more than the maximum number of |
duke@435 | 116 | // covered regions defined in the constructor are ever in use. |
duke@435 | 117 | int find_covering_region_by_base(HeapWord* base); |
duke@435 | 118 | |
duke@435 | 119 | // Same as above, but finds the region containing the given address |
duke@435 | 120 | // instead of starting at a given base address. |
duke@435 | 121 | int find_covering_region_containing(HeapWord* addr); |
duke@435 | 122 | |
duke@435 | 123 | // Resize one of the regions covered by the remembered set. |
duke@435 | 124 | void resize_covered_region(MemRegion new_region); |
duke@435 | 125 | |
duke@435 | 126 | // Returns the leftmost end of a committed region corresponding to a |
duke@435 | 127 | // covered region before covered region "ind", or else "NULL" if "ind" is |
duke@435 | 128 | // the first covered region. |
duke@435 | 129 | HeapWord* largest_prev_committed_end(int ind) const; |
duke@435 | 130 | |
duke@435 | 131 | // Returns the part of the region mr that doesn't intersect with |
duke@435 | 132 | // any committed region other than self. Used to prevent uncommitting |
duke@435 | 133 | // regions that are also committed by other regions. Also protects |
duke@435 | 134 | // against uncommitting the guard region. |
duke@435 | 135 | MemRegion committed_unique_to_self(int self, MemRegion mr) const; |
duke@435 | 136 | |
duke@435 | 137 | // Mapping from address to card marking array entry |
duke@435 | 138 | jbyte* byte_for(const void* p) const { |
duke@435 | 139 | assert(_whole_heap.contains(p), |
duke@435 | 140 | "out of bounds access to card marking array"); |
duke@435 | 141 | jbyte* result = &byte_map_base[uintptr_t(p) >> card_shift]; |
duke@435 | 142 | assert(result >= _byte_map && result < _byte_map + _byte_map_size, |
duke@435 | 143 | "out of bounds accessor for card marking array"); |
duke@435 | 144 | return result; |
duke@435 | 145 | } |
duke@435 | 146 | |
duke@435 | 147 | // The card table byte one after the card marking array |
duke@435 | 148 | // entry for argument address. Typically used for higher bounds |
duke@435 | 149 | // for loops iterating through the card table. |
duke@435 | 150 | jbyte* byte_after(const void* p) const { |
duke@435 | 151 | return byte_for(p) + 1; |
duke@435 | 152 | } |
duke@435 | 153 | |
duke@435 | 154 | // Iterate over the portion of the card-table which covers the given |
duke@435 | 155 | // region mr in the given space and apply cl to any dirty sub-regions |
duke@435 | 156 | // of mr. cl and dcto_cl must either be the same closure or cl must |
duke@435 | 157 | // wrap dcto_cl. Both are required - neither may be NULL. Also, dcto_cl |
duke@435 | 158 | // may be modified. Note that this function will operate in a parallel |
duke@435 | 159 | // mode if worker threads are available. |
duke@435 | 160 | void non_clean_card_iterate(Space* sp, MemRegion mr, |
duke@435 | 161 | DirtyCardToOopClosure* dcto_cl, |
duke@435 | 162 | MemRegionClosure* cl, |
duke@435 | 163 | bool clear); |
duke@435 | 164 | |
duke@435 | 165 | // Utility function used to implement the other versions below. |
duke@435 | 166 | void non_clean_card_iterate_work(MemRegion mr, MemRegionClosure* cl, |
duke@435 | 167 | bool clear); |
duke@435 | 168 | |
duke@435 | 169 | void par_non_clean_card_iterate_work(Space* sp, MemRegion mr, |
duke@435 | 170 | DirtyCardToOopClosure* dcto_cl, |
duke@435 | 171 | MemRegionClosure* cl, |
duke@435 | 172 | bool clear, |
duke@435 | 173 | int n_threads); |
duke@435 | 174 | |
duke@435 | 175 | // Dirty the bytes corresponding to "mr" (not all of which must be |
duke@435 | 176 | // covered.) |
duke@435 | 177 | void dirty_MemRegion(MemRegion mr); |
duke@435 | 178 | |
duke@435 | 179 | // Clear (to clean_card) the bytes entirely contained within "mr" (not |
duke@435 | 180 | // all of which must be covered.) |
duke@435 | 181 | void clear_MemRegion(MemRegion mr); |
duke@435 | 182 | |
duke@435 | 183 | // *** Support for parallel card scanning. |
duke@435 | 184 | |
duke@435 | 185 | enum SomeConstantsForParallelism { |
duke@435 | 186 | StridesPerThread = 2, |
duke@435 | 187 | CardsPerStrideChunk = 256 |
duke@435 | 188 | }; |
duke@435 | 189 | |
duke@435 | 190 | // This is an array, one element per covered region of the card table. |
duke@435 | 191 | // Each entry is itself an array, with one element per chunk in the |
duke@435 | 192 | // covered region. Each entry of these arrays is the lowest non-clean |
duke@435 | 193 | // card of the corresponding chunk containing part of an object from the |
duke@435 | 194 | // previous chunk, or else NULL. |
duke@435 | 195 | typedef jbyte* CardPtr; |
duke@435 | 196 | typedef CardPtr* CardArr; |
duke@435 | 197 | CardArr* _lowest_non_clean; |
duke@435 | 198 | size_t* _lowest_non_clean_chunk_size; |
duke@435 | 199 | uintptr_t* _lowest_non_clean_base_chunk_index; |
duke@435 | 200 | int* _last_LNC_resizing_collection; |
duke@435 | 201 | |
duke@435 | 202 | // Initializes "lowest_non_clean" to point to the array for the region |
duke@435 | 203 | // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk |
duke@435 | 204 | // index of the corresponding to the first element of that array. |
duke@435 | 205 | // Ensures that these arrays are of sufficient size, allocating if necessary. |
duke@435 | 206 | // May be called by several threads concurrently. |
duke@435 | 207 | void get_LNC_array_for_space(Space* sp, |
duke@435 | 208 | jbyte**& lowest_non_clean, |
duke@435 | 209 | uintptr_t& lowest_non_clean_base_chunk_index, |
duke@435 | 210 | size_t& lowest_non_clean_chunk_size); |
duke@435 | 211 | |
duke@435 | 212 | // Returns the number of chunks necessary to cover "mr". |
duke@435 | 213 | size_t chunks_to_cover(MemRegion mr) { |
duke@435 | 214 | return (size_t)(addr_to_chunk_index(mr.last()) - |
duke@435 | 215 | addr_to_chunk_index(mr.start()) + 1); |
duke@435 | 216 | } |
duke@435 | 217 | |
duke@435 | 218 | // Returns the index of the chunk in a stride which |
duke@435 | 219 | // covers the given address. |
duke@435 | 220 | uintptr_t addr_to_chunk_index(const void* addr) { |
duke@435 | 221 | uintptr_t card = (uintptr_t) byte_for(addr); |
duke@435 | 222 | return card / CardsPerStrideChunk; |
duke@435 | 223 | } |
duke@435 | 224 | |
duke@435 | 225 | // Apply cl, which must either itself apply dcto_cl or be dcto_cl, |
duke@435 | 226 | // to the cards in the stride (of n_strides) within the given space. |
duke@435 | 227 | void process_stride(Space* sp, |
duke@435 | 228 | MemRegion used, |
duke@435 | 229 | jint stride, int n_strides, |
duke@435 | 230 | DirtyCardToOopClosure* dcto_cl, |
duke@435 | 231 | MemRegionClosure* cl, |
duke@435 | 232 | bool clear, |
duke@435 | 233 | jbyte** lowest_non_clean, |
duke@435 | 234 | uintptr_t lowest_non_clean_base_chunk_index, |
duke@435 | 235 | size_t lowest_non_clean_chunk_size); |
duke@435 | 236 | |
duke@435 | 237 | // Makes sure that chunk boundaries are handled appropriately, by |
duke@435 | 238 | // adjusting the min_done of dcto_cl, and by using a special card-table |
duke@435 | 239 | // value to indicate how min_done should be set. |
duke@435 | 240 | void process_chunk_boundaries(Space* sp, |
duke@435 | 241 | DirtyCardToOopClosure* dcto_cl, |
duke@435 | 242 | MemRegion chunk_mr, |
duke@435 | 243 | MemRegion used, |
duke@435 | 244 | jbyte** lowest_non_clean, |
duke@435 | 245 | uintptr_t lowest_non_clean_base_chunk_index, |
duke@435 | 246 | size_t lowest_non_clean_chunk_size); |
duke@435 | 247 | |
duke@435 | 248 | public: |
duke@435 | 249 | // Constants |
duke@435 | 250 | enum SomePublicConstants { |
duke@435 | 251 | card_shift = 9, |
duke@435 | 252 | card_size = 1 << card_shift, |
duke@435 | 253 | card_size_in_words = card_size / sizeof(HeapWord) |
duke@435 | 254 | }; |
duke@435 | 255 | |
ysr@777 | 256 | static int clean_card_val() { return clean_card; } |
ysr@777 | 257 | static int dirty_card_val() { return dirty_card; } |
ysr@777 | 258 | static int claimed_card_val() { return claimed_card; } |
ysr@777 | 259 | static int precleaned_card_val() { return precleaned_card; } |
ysr@777 | 260 | |
duke@435 | 261 | // For RTTI simulation. |
duke@435 | 262 | bool is_a(BarrierSet::Name bsn) { |
ysr@777 | 263 | return bsn == BarrierSet::CardTableModRef || ModRefBarrierSet::is_a(bsn); |
duke@435 | 264 | } |
duke@435 | 265 | |
duke@435 | 266 | CardTableModRefBS(MemRegion whole_heap, int max_covered_regions); |
duke@435 | 267 | |
duke@435 | 268 | // *** Barrier set functions. |
duke@435 | 269 | |
ysr@777 | 270 | bool has_write_ref_pre_barrier() { return false; } |
ysr@777 | 271 | |
coleenp@548 | 272 | inline bool write_ref_needs_barrier(void* field, oop new_val) { |
duke@435 | 273 | // Note that this assumes the perm gen is the highest generation |
duke@435 | 274 | // in the address space |
duke@435 | 275 | return new_val != NULL && !new_val->is_perm(); |
duke@435 | 276 | } |
duke@435 | 277 | |
duke@435 | 278 | // Record a reference update. Note that these versions are precise! |
duke@435 | 279 | // The scanning code has to handle the fact that the write barrier may be |
duke@435 | 280 | // either precise or imprecise. We make non-virtual inline variants of |
duke@435 | 281 | // these functions here for performance. |
duke@435 | 282 | protected: |
duke@435 | 283 | void write_ref_field_work(oop obj, size_t offset, oop newVal); |
coleenp@548 | 284 | void write_ref_field_work(void* field, oop newVal); |
duke@435 | 285 | public: |
duke@435 | 286 | |
duke@435 | 287 | bool has_write_ref_array_opt() { return true; } |
duke@435 | 288 | bool has_write_region_opt() { return true; } |
duke@435 | 289 | |
duke@435 | 290 | inline void inline_write_region(MemRegion mr) { |
duke@435 | 291 | dirty_MemRegion(mr); |
duke@435 | 292 | } |
duke@435 | 293 | protected: |
duke@435 | 294 | void write_region_work(MemRegion mr) { |
duke@435 | 295 | inline_write_region(mr); |
duke@435 | 296 | } |
duke@435 | 297 | public: |
duke@435 | 298 | |
duke@435 | 299 | inline void inline_write_ref_array(MemRegion mr) { |
duke@435 | 300 | dirty_MemRegion(mr); |
duke@435 | 301 | } |
duke@435 | 302 | protected: |
duke@435 | 303 | void write_ref_array_work(MemRegion mr) { |
duke@435 | 304 | inline_write_ref_array(mr); |
duke@435 | 305 | } |
duke@435 | 306 | public: |
duke@435 | 307 | |
duke@435 | 308 | bool is_aligned(HeapWord* addr) { |
duke@435 | 309 | return is_card_aligned(addr); |
duke@435 | 310 | } |
duke@435 | 311 | |
duke@435 | 312 | // *** Card-table-barrier-specific things. |
duke@435 | 313 | |
ysr@777 | 314 | inline void inline_write_ref_field_pre(void* field, oop newVal) {} |
ysr@777 | 315 | |
coleenp@548 | 316 | inline void inline_write_ref_field(void* field, oop newVal) { |
duke@435 | 317 | jbyte* byte = byte_for(field); |
duke@435 | 318 | *byte = dirty_card; |
duke@435 | 319 | } |
duke@435 | 320 | |
ysr@777 | 321 | // These are used by G1, when it uses the card table as a temporary data |
ysr@777 | 322 | // structure for card claiming. |
ysr@777 | 323 | bool is_card_dirty(size_t card_index) { |
ysr@777 | 324 | return _byte_map[card_index] == dirty_card_val(); |
ysr@777 | 325 | } |
ysr@777 | 326 | |
ysr@777 | 327 | void mark_card_dirty(size_t card_index) { |
ysr@777 | 328 | _byte_map[card_index] = dirty_card_val(); |
ysr@777 | 329 | } |
ysr@777 | 330 | |
ysr@777 | 331 | bool is_card_claimed(size_t card_index) { |
ysr@777 | 332 | return _byte_map[card_index] == claimed_card_val(); |
ysr@777 | 333 | } |
ysr@777 | 334 | |
ysr@777 | 335 | bool claim_card(size_t card_index); |
ysr@777 | 336 | |
ysr@777 | 337 | bool is_card_clean(size_t card_index) { |
ysr@777 | 338 | return _byte_map[card_index] == clean_card_val(); |
ysr@777 | 339 | } |
ysr@777 | 340 | |
duke@435 | 341 | // Card marking array base (adjusted for heap low boundary) |
duke@435 | 342 | // This would be the 0th element of _byte_map, if the heap started at 0x0. |
duke@435 | 343 | // But since the heap starts at some higher address, this points to somewhere |
duke@435 | 344 | // before the beginning of the actual _byte_map. |
duke@435 | 345 | jbyte* byte_map_base; |
duke@435 | 346 | |
duke@435 | 347 | // Return true if "p" is at the start of a card. |
duke@435 | 348 | bool is_card_aligned(HeapWord* p) { |
duke@435 | 349 | jbyte* pcard = byte_for(p); |
duke@435 | 350 | return (addr_for(pcard) == p); |
duke@435 | 351 | } |
duke@435 | 352 | |
duke@435 | 353 | // The kinds of precision a CardTableModRefBS may offer. |
duke@435 | 354 | enum PrecisionStyle { |
duke@435 | 355 | Precise, |
duke@435 | 356 | ObjHeadPreciseArray |
duke@435 | 357 | }; |
duke@435 | 358 | |
duke@435 | 359 | // Tells what style of precision this card table offers. |
duke@435 | 360 | PrecisionStyle precision() { |
duke@435 | 361 | return ObjHeadPreciseArray; // Only one supported for now. |
duke@435 | 362 | } |
duke@435 | 363 | |
duke@435 | 364 | // ModRefBS functions. |
ysr@777 | 365 | virtual void invalidate(MemRegion mr, bool whole_heap = false); |
duke@435 | 366 | void clear(MemRegion mr); |
ysr@777 | 367 | void dirty(MemRegion mr); |
duke@435 | 368 | void mod_oop_in_space_iterate(Space* sp, OopClosure* cl, |
duke@435 | 369 | bool clear = false, |
duke@435 | 370 | bool before_save_marks = false); |
duke@435 | 371 | |
duke@435 | 372 | // *** Card-table-RemSet-specific things. |
duke@435 | 373 | |
duke@435 | 374 | // Invoke "cl.do_MemRegion" on a set of MemRegions that collectively |
duke@435 | 375 | // includes all the modified cards (expressing each card as a |
duke@435 | 376 | // MemRegion). Thus, several modified cards may be lumped into one |
duke@435 | 377 | // region. The regions are non-overlapping, and are visited in |
duke@435 | 378 | // *decreasing* address order. (This order aids with imprecise card |
duke@435 | 379 | // marking, where a dirty card may cause scanning, and summarization |
duke@435 | 380 | // marking, of objects that extend onto subsequent cards.) |
duke@435 | 381 | // If "clear" is true, the card is (conceptually) marked unmodified before |
duke@435 | 382 | // applying the closure. |
duke@435 | 383 | void mod_card_iterate(MemRegionClosure* cl, bool clear = false) { |
duke@435 | 384 | non_clean_card_iterate_work(_whole_heap, cl, clear); |
duke@435 | 385 | } |
duke@435 | 386 | |
duke@435 | 387 | // Like the "mod_cards_iterate" above, except only invokes the closure |
duke@435 | 388 | // for cards within the MemRegion "mr" (which is required to be |
duke@435 | 389 | // card-aligned and sized.) |
duke@435 | 390 | void mod_card_iterate(MemRegion mr, MemRegionClosure* cl, |
duke@435 | 391 | bool clear = false) { |
duke@435 | 392 | non_clean_card_iterate_work(mr, cl, clear); |
duke@435 | 393 | } |
duke@435 | 394 | |
duke@435 | 395 | static uintx ct_max_alignment_constraint(); |
duke@435 | 396 | |
ysr@777 | 397 | // Apply closure "cl" to the dirty cards containing some part of |
ysr@777 | 398 | // MemRegion "mr". |
ysr@777 | 399 | void dirty_card_iterate(MemRegion mr, MemRegionClosure* cl); |
duke@435 | 400 | |
duke@435 | 401 | // Return the MemRegion corresponding to the first maximal run |
ysr@777 | 402 | // of dirty cards lying completely within MemRegion mr. |
ysr@777 | 403 | // If reset is "true", then sets those card table entries to the given |
ysr@777 | 404 | // value. |
ysr@777 | 405 | MemRegion dirty_card_range_after_reset(MemRegion mr, bool reset, |
ysr@777 | 406 | int reset_val); |
duke@435 | 407 | |
duke@435 | 408 | // Set all the dirty cards in the given region to precleaned state. |
duke@435 | 409 | void preclean_dirty_cards(MemRegion mr); |
duke@435 | 410 | |
ysr@777 | 411 | // Provide read-only access to the card table array. |
ysr@777 | 412 | const jbyte* byte_for_const(const void* p) const { |
ysr@777 | 413 | return byte_for(p); |
ysr@777 | 414 | } |
ysr@777 | 415 | const jbyte* byte_after_const(const void* p) const { |
ysr@777 | 416 | return byte_after(p); |
ysr@777 | 417 | } |
ysr@777 | 418 | |
ysr@777 | 419 | // Mapping from card marking array entry to address of first word |
ysr@777 | 420 | HeapWord* addr_for(const jbyte* p) const { |
ysr@777 | 421 | assert(p >= _byte_map && p < _byte_map + _byte_map_size, |
ysr@777 | 422 | "out of bounds access to card marking array"); |
ysr@777 | 423 | size_t delta = pointer_delta(p, byte_map_base, sizeof(jbyte)); |
ysr@777 | 424 | HeapWord* result = (HeapWord*) (delta << card_shift); |
ysr@777 | 425 | assert(_whole_heap.contains(result), |
ysr@777 | 426 | "out of bounds accessor from card marking array"); |
ysr@777 | 427 | return result; |
ysr@777 | 428 | } |
ysr@777 | 429 | |
duke@435 | 430 | // Mapping from address to card marking array index. |
duke@435 | 431 | int index_for(void* p) { |
duke@435 | 432 | assert(_whole_heap.contains(p), |
duke@435 | 433 | "out of bounds access to card marking array"); |
duke@435 | 434 | return byte_for(p) - _byte_map; |
duke@435 | 435 | } |
duke@435 | 436 | |
duke@435 | 437 | void verify(); |
duke@435 | 438 | void verify_guard(); |
duke@435 | 439 | |
duke@435 | 440 | void verify_clean_region(MemRegion mr) PRODUCT_RETURN; |
duke@435 | 441 | |
duke@435 | 442 | static size_t par_chunk_heapword_alignment() { |
duke@435 | 443 | return CardsPerStrideChunk * card_size_in_words; |
duke@435 | 444 | } |
ysr@777 | 445 | |
duke@435 | 446 | }; |
duke@435 | 447 | |
duke@435 | 448 | class CardTableRS; |
duke@435 | 449 | |
duke@435 | 450 | // A specialization for the CardTableRS gen rem set. |
duke@435 | 451 | class CardTableModRefBSForCTRS: public CardTableModRefBS { |
duke@435 | 452 | CardTableRS* _rs; |
duke@435 | 453 | protected: |
duke@435 | 454 | bool card_will_be_scanned(jbyte cv); |
duke@435 | 455 | bool card_may_have_been_dirty(jbyte cv); |
duke@435 | 456 | public: |
duke@435 | 457 | CardTableModRefBSForCTRS(MemRegion whole_heap, |
duke@435 | 458 | int max_covered_regions) : |
duke@435 | 459 | CardTableModRefBS(whole_heap, max_covered_regions) {} |
duke@435 | 460 | |
duke@435 | 461 | void set_CTRS(CardTableRS* rs) { _rs = rs; } |
duke@435 | 462 | }; |