Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
ysr@777 | 1 | /* |
drchase@6680 | 2 | * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP |
stefank@2314 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP |
stefank@2314 | 27 | |
tschatzl@7051 | 28 | #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp" |
stefank@2314 | 29 | #include "memory/memRegion.hpp" |
stefank@2314 | 30 | #include "runtime/virtualspace.hpp" |
stefank@2314 | 31 | #include "utilities/globalDefinitions.hpp" |
stefank@2314 | 32 | |
ysr@777 | 33 | // The CollectedHeap type requires subtypes to implement a method |
ysr@777 | 34 | // "block_start". For some subtypes, notably generational |
ysr@777 | 35 | // systems using card-table-based write barriers, the efficiency of this |
ysr@777 | 36 | // operation may be important. Implementations of the "BlockOffsetArray" |
ysr@777 | 37 | // class may be useful in providing such efficient implementations. |
ysr@777 | 38 | // |
ysr@777 | 39 | // While generally mirroring the structure of the BOT for GenCollectedHeap, |
ysr@777 | 40 | // the following types are tailored more towards G1's uses; these should, |
ysr@777 | 41 | // however, be merged back into a common BOT to avoid code duplication |
ysr@777 | 42 | // and reduce maintenance overhead. |
ysr@777 | 43 | // |
ysr@777 | 44 | // G1BlockOffsetTable (abstract) |
ysr@777 | 45 | // -- G1BlockOffsetArray (uses G1BlockOffsetSharedArray) |
ysr@777 | 46 | // -- G1BlockOffsetArrayContigSpace |
ysr@777 | 47 | // |
ysr@777 | 48 | // A main impediment to the consolidation of this code might be the |
ysr@777 | 49 | // effect of making some of the block_start*() calls non-const as |
ysr@777 | 50 | // below. Whether that might adversely affect performance optimizations |
ysr@777 | 51 | // that compilers might normally perform in the case of non-G1 |
ysr@777 | 52 | // collectors needs to be carefully investigated prior to any such |
ysr@777 | 53 | // consolidation. |
ysr@777 | 54 | |
ysr@777 | 55 | // Forward declarations |
ysr@777 | 56 | class G1BlockOffsetSharedArray; |
mgerdin@6987 | 57 | class G1OffsetTableContigSpace; |
ysr@777 | 58 | |
ysr@777 | 59 | class G1BlockOffsetTable VALUE_OBJ_CLASS_SPEC { |
ysr@777 | 60 | friend class VMStructs; |
ysr@777 | 61 | protected: |
ysr@777 | 62 | // These members describe the region covered by the table. |
ysr@777 | 63 | |
ysr@777 | 64 | // The space this table is covering. |
ysr@777 | 65 | HeapWord* _bottom; // == reserved.start |
ysr@777 | 66 | HeapWord* _end; // End of currently allocated region. |
ysr@777 | 67 | |
ysr@777 | 68 | public: |
ysr@777 | 69 | // Initialize the table to cover the given space. |
ysr@777 | 70 | // The contents of the initial table are undefined. |
ysr@777 | 71 | G1BlockOffsetTable(HeapWord* bottom, HeapWord* end) : |
ysr@777 | 72 | _bottom(bottom), _end(end) |
ysr@777 | 73 | { |
ysr@777 | 74 | assert(_bottom <= _end, "arguments out of order"); |
ysr@777 | 75 | } |
ysr@777 | 76 | |
ysr@777 | 77 | // Note that the committed size of the covered space may have changed, |
ysr@777 | 78 | // so the table size might also wish to change. |
ysr@777 | 79 | virtual void resize(size_t new_word_size) = 0; |
ysr@777 | 80 | |
ysr@777 | 81 | virtual void set_bottom(HeapWord* new_bottom) { |
johnc@4300 | 82 | assert(new_bottom <= _end, |
johnc@4300 | 83 | err_msg("new_bottom (" PTR_FORMAT ") > _end (" PTR_FORMAT ")", |
drchase@6680 | 84 | p2i(new_bottom), p2i(_end))); |
ysr@777 | 85 | _bottom = new_bottom; |
ysr@777 | 86 | resize(pointer_delta(_end, _bottom)); |
ysr@777 | 87 | } |
ysr@777 | 88 | |
ysr@777 | 89 | // Requires "addr" to be contained by a block, and returns the address of |
ysr@777 | 90 | // the start of that block. (May have side effects, namely updating of |
ysr@777 | 91 | // shared array entries that "point" too far backwards. This can occur, |
ysr@777 | 92 | // for example, when LAB allocation is used in a space covered by the |
ysr@777 | 93 | // table.) |
ysr@777 | 94 | virtual HeapWord* block_start_unsafe(const void* addr) = 0; |
ysr@777 | 95 | // Same as above, but does not have any of the possible side effects |
ysr@777 | 96 | // discussed above. |
ysr@777 | 97 | virtual HeapWord* block_start_unsafe_const(const void* addr) const = 0; |
ysr@777 | 98 | |
ysr@777 | 99 | // Returns the address of the start of the block containing "addr", or |
ysr@777 | 100 | // else "null" if it is covered by no block. (May have side effects, |
ysr@777 | 101 | // namely updating of shared array entries that "point" too far |
ysr@777 | 102 | // backwards. This can occur, for example, when lab allocation is used |
ysr@777 | 103 | // in a space covered by the table.) |
ysr@777 | 104 | inline HeapWord* block_start(const void* addr); |
ysr@777 | 105 | // Same as above, but does not have any of the possible side effects |
ysr@777 | 106 | // discussed above. |
ysr@777 | 107 | inline HeapWord* block_start_const(const void* addr) const; |
ysr@777 | 108 | }; |
ysr@777 | 109 | |
tschatzl@7051 | 110 | class G1BlockOffsetSharedArrayMappingChangedListener : public G1MappingChangedListener { |
tschatzl@7051 | 111 | public: |
tschatzl@7051 | 112 | virtual void on_commit(uint start_idx, size_t num_regions); |
tschatzl@7051 | 113 | }; |
tschatzl@7051 | 114 | |
ysr@777 | 115 | // This implementation of "G1BlockOffsetTable" divides the covered region |
ysr@777 | 116 | // into "N"-word subregions (where "N" = 2^"LogN". An array with an entry |
ysr@777 | 117 | // for each such subregion indicates how far back one must go to find the |
ysr@777 | 118 | // start of the chunk that includes the first word of the subregion. |
ysr@777 | 119 | // |
ysr@777 | 120 | // Each BlockOffsetArray is owned by a Space. However, the actual array |
ysr@777 | 121 | // may be shared by several BlockOffsetArrays; this is useful |
ysr@777 | 122 | // when a single resizable area (such as a generation) is divided up into |
ysr@777 | 123 | // several spaces in which contiguous allocation takes place, |
ysr@777 | 124 | // such as, for example, in G1 or in the train generation.) |
ysr@777 | 125 | |
ysr@777 | 126 | // Here is the shared array type. |
ysr@777 | 127 | |
zgu@3900 | 128 | class G1BlockOffsetSharedArray: public CHeapObj<mtGC> { |
ysr@777 | 129 | friend class G1BlockOffsetArray; |
ysr@777 | 130 | friend class G1BlockOffsetArrayContigSpace; |
ysr@777 | 131 | friend class VMStructs; |
ysr@777 | 132 | |
ysr@777 | 133 | private: |
tschatzl@7051 | 134 | G1BlockOffsetSharedArrayMappingChangedListener _listener; |
ysr@777 | 135 | // The reserved region covered by the shared array. |
ysr@777 | 136 | MemRegion _reserved; |
ysr@777 | 137 | |
ysr@777 | 138 | // End of the current committed region. |
ysr@777 | 139 | HeapWord* _end; |
ysr@777 | 140 | |
ysr@777 | 141 | // Array for keeping offsets for retrieving object start fast given an |
ysr@777 | 142 | // address. |
ysr@777 | 143 | u_char* _offset_array; // byte array keeping backwards offsets |
ysr@777 | 144 | |
johnc@4300 | 145 | void check_offset(size_t offset, const char* msg) const { |
johnc@4300 | 146 | assert(offset <= N_words, |
johnc@4300 | 147 | err_msg("%s - " |
drchase@6680 | 148 | "offset: " SIZE_FORMAT ", N_words: " UINT32_FORMAT, |
johnc@4300 | 149 | msg, offset, N_words)); |
johnc@4300 | 150 | } |
johnc@4300 | 151 | |
ysr@777 | 152 | // Bounds checking accessors: |
ysr@777 | 153 | // For performance these have to devolve to array accesses in product builds. |
tschatzl@7051 | 154 | inline u_char offset_array(size_t index) const; |
ysr@777 | 155 | |
mgerdin@6987 | 156 | void set_offset_array(HeapWord* left, HeapWord* right, u_char offset); |
mgerdin@6987 | 157 | |
tschatzl@7051 | 158 | void set_offset_array_raw(size_t index, u_char offset) { |
ysr@777 | 159 | _offset_array[index] = offset; |
ysr@777 | 160 | } |
ysr@777 | 161 | |
tschatzl@7051 | 162 | inline void set_offset_array(size_t index, u_char offset); |
ysr@777 | 163 | |
tschatzl@7051 | 164 | inline void set_offset_array(size_t index, HeapWord* high, HeapWord* low); |
ysr@777 | 165 | |
tschatzl@7051 | 166 | inline void set_offset_array(size_t left, size_t right, u_char offset); |
tschatzl@7051 | 167 | |
tschatzl@7051 | 168 | inline void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const; |
ysr@777 | 169 | |
ysr@777 | 170 | bool is_card_boundary(HeapWord* p) const; |
ysr@777 | 171 | |
tschatzl@7051 | 172 | public: |
tschatzl@7051 | 173 | |
ysr@777 | 174 | // Return the number of slots needed for an offset array |
ysr@777 | 175 | // that covers mem_region_words words. |
tschatzl@7051 | 176 | static size_t compute_size(size_t mem_region_words) { |
tschatzl@7051 | 177 | size_t number_of_slots = (mem_region_words / N_words); |
tschatzl@7051 | 178 | return ReservedSpace::allocation_align_size_up(number_of_slots); |
ysr@777 | 179 | } |
ysr@777 | 180 | |
ysr@777 | 181 | enum SomePublicConstants { |
ysr@777 | 182 | LogN = 9, |
ysr@777 | 183 | LogN_words = LogN - LogHeapWordSize, |
ysr@777 | 184 | N_bytes = 1 << LogN, |
ysr@777 | 185 | N_words = 1 << LogN_words |
ysr@777 | 186 | }; |
ysr@777 | 187 | |
ysr@777 | 188 | // Initialize the table to cover from "base" to (at least) |
ysr@777 | 189 | // "base + init_word_size". In the future, the table may be expanded |
ysr@777 | 190 | // (see "resize" below) up to the size of "_reserved" (which must be at |
ysr@777 | 191 | // least "init_word_size".) The contents of the initial table are |
ysr@777 | 192 | // undefined; it is the responsibility of the constituent |
ysr@777 | 193 | // G1BlockOffsetTable(s) to initialize cards. |
tschatzl@7051 | 194 | G1BlockOffsetSharedArray(MemRegion heap, G1RegionToSpaceMapper* storage); |
ysr@777 | 195 | |
ysr@777 | 196 | void set_bottom(HeapWord* new_bottom); |
ysr@777 | 197 | |
ysr@777 | 198 | // Return the appropriate index into "_offset_array" for "p". |
ysr@777 | 199 | inline size_t index_for(const void* p) const; |
tschatzl@7051 | 200 | inline size_t index_for_raw(const void* p) const; |
ysr@777 | 201 | |
ysr@777 | 202 | // Return the address indicating the start of the region corresponding to |
ysr@777 | 203 | // "index" in "_offset_array". |
ysr@777 | 204 | inline HeapWord* address_for_index(size_t index) const; |
tschatzl@7051 | 205 | // Variant of address_for_index that does not check the index for validity. |
tschatzl@7051 | 206 | inline HeapWord* address_for_index_raw(size_t index) const { |
tschatzl@7051 | 207 | return _reserved.start() + (index << LogN_words); |
tschatzl@7051 | 208 | } |
ysr@777 | 209 | }; |
ysr@777 | 210 | |
ysr@777 | 211 | // And here is the G1BlockOffsetTable subtype that uses the array. |
ysr@777 | 212 | |
ysr@777 | 213 | class G1BlockOffsetArray: public G1BlockOffsetTable { |
ysr@777 | 214 | friend class G1BlockOffsetSharedArray; |
ysr@777 | 215 | friend class G1BlockOffsetArrayContigSpace; |
ysr@777 | 216 | friend class VMStructs; |
ysr@777 | 217 | private: |
ysr@777 | 218 | enum SomePrivateConstants { |
ysr@777 | 219 | N_words = G1BlockOffsetSharedArray::N_words, |
ysr@777 | 220 | LogN = G1BlockOffsetSharedArray::LogN |
ysr@777 | 221 | }; |
ysr@777 | 222 | |
ysr@777 | 223 | // The following enums are used by do_block_helper |
ysr@777 | 224 | enum Action { |
ysr@777 | 225 | Action_single, // BOT records a single block (see single_block()) |
ysr@777 | 226 | Action_mark, // BOT marks the start of a block (see mark_block()) |
ysr@777 | 227 | Action_check // Check that BOT records block correctly |
ysr@777 | 228 | // (see verify_single_block()). |
ysr@777 | 229 | }; |
ysr@777 | 230 | |
ysr@777 | 231 | // This is the array, which can be shared by several BlockOffsetArray's |
ysr@777 | 232 | // servicing different |
ysr@777 | 233 | G1BlockOffsetSharedArray* _array; |
ysr@777 | 234 | |
ysr@777 | 235 | // The space that owns this subregion. |
mgerdin@6987 | 236 | G1OffsetTableContigSpace* _gsp; |
ysr@777 | 237 | |
ysr@777 | 238 | // If true, array entries are initialized to 0; otherwise, they are |
ysr@777 | 239 | // initialized to point backwards to the beginning of the covered region. |
ysr@777 | 240 | bool _init_to_zero; |
ysr@777 | 241 | |
ysr@777 | 242 | // The portion [_unallocated_block, _sp.end()) of the space that |
ysr@777 | 243 | // is a single block known not to contain any objects. |
ysr@777 | 244 | // NOTE: See BlockOffsetArrayUseUnallocatedBlock flag. |
ysr@777 | 245 | HeapWord* _unallocated_block; |
ysr@777 | 246 | |
ysr@777 | 247 | // Sets the entries |
ysr@777 | 248 | // corresponding to the cards starting at "start" and ending at "end" |
ysr@777 | 249 | // to point back to the card before "start": the interval [start, end) |
ysr@777 | 250 | // is right-open. |
ysr@777 | 251 | void set_remainder_to_point_to_start(HeapWord* start, HeapWord* end); |
ysr@777 | 252 | // Same as above, except that the args here are a card _index_ interval |
ysr@777 | 253 | // that is closed: [start_index, end_index] |
ysr@777 | 254 | void set_remainder_to_point_to_start_incl(size_t start, size_t end); |
ysr@777 | 255 | |
ysr@777 | 256 | // A helper function for BOT adjustment/verification work |
ysr@777 | 257 | void do_block_internal(HeapWord* blk_start, HeapWord* blk_end, Action action); |
ysr@777 | 258 | |
ysr@777 | 259 | protected: |
ysr@777 | 260 | |
mgerdin@6987 | 261 | G1OffsetTableContigSpace* gsp() const { return _gsp; } |
mgerdin@6987 | 262 | |
mgerdin@6987 | 263 | inline size_t block_size(const HeapWord* p) const; |
ysr@777 | 264 | |
ysr@777 | 265 | // Returns the address of a block whose start is at most "addr". |
ysr@777 | 266 | // If "has_max_index" is true, "assumes "max_index" is the last valid one |
ysr@777 | 267 | // in the array. |
ysr@777 | 268 | inline HeapWord* block_at_or_preceding(const void* addr, |
ysr@777 | 269 | bool has_max_index, |
ysr@777 | 270 | size_t max_index) const; |
ysr@777 | 271 | |
ysr@777 | 272 | // "q" is a block boundary that is <= "addr"; "n" is the address of the |
ysr@777 | 273 | // next block (or the end of the space.) Return the address of the |
ysr@777 | 274 | // beginning of the block that contains "addr". Does so without side |
ysr@777 | 275 | // effects (see, e.g., spec of block_start.) |
ysr@777 | 276 | inline HeapWord* |
ysr@777 | 277 | forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n, |
ysr@777 | 278 | const void* addr) const; |
ysr@777 | 279 | |
ysr@777 | 280 | // "q" is a block boundary that is <= "addr"; return the address of the |
ysr@777 | 281 | // beginning of the block that contains "addr". May have side effects |
ysr@777 | 282 | // on "this", by updating imprecise entries. |
ysr@777 | 283 | inline HeapWord* forward_to_block_containing_addr(HeapWord* q, |
ysr@777 | 284 | const void* addr); |
ysr@777 | 285 | |
ysr@777 | 286 | // "q" is a block boundary that is <= "addr"; "n" is the address of the |
ysr@777 | 287 | // next block (or the end of the space.) Return the address of the |
ysr@777 | 288 | // beginning of the block that contains "addr". May have side effects |
ysr@777 | 289 | // on "this", by updating imprecise entries. |
ysr@777 | 290 | HeapWord* forward_to_block_containing_addr_slow(HeapWord* q, |
ysr@777 | 291 | HeapWord* n, |
ysr@777 | 292 | const void* addr); |
ysr@777 | 293 | |
ysr@777 | 294 | // Requires that "*threshold_" be the first array entry boundary at or |
ysr@777 | 295 | // above "blk_start", and that "*index_" be the corresponding array |
ysr@777 | 296 | // index. If the block starts at or crosses "*threshold_", records |
ysr@777 | 297 | // "blk_start" as the appropriate block start for the array index |
ysr@777 | 298 | // starting at "*threshold_", and for any other indices crossed by the |
ysr@777 | 299 | // block. Updates "*threshold_" and "*index_" to correspond to the first |
ysr@777 | 300 | // index after the block end. |
ysr@777 | 301 | void alloc_block_work2(HeapWord** threshold_, size_t* index_, |
ysr@777 | 302 | HeapWord* blk_start, HeapWord* blk_end); |
ysr@777 | 303 | |
ysr@777 | 304 | public: |
ysr@777 | 305 | // The space may not have it's bottom and top set yet, which is why the |
ysr@777 | 306 | // region is passed as a parameter. If "init_to_zero" is true, the |
ysr@777 | 307 | // elements of the array are initialized to zero. Otherwise, they are |
ysr@777 | 308 | // initialized to point backwards to the beginning. |
ysr@777 | 309 | G1BlockOffsetArray(G1BlockOffsetSharedArray* array, MemRegion mr, |
ysr@777 | 310 | bool init_to_zero); |
ysr@777 | 311 | |
ysr@777 | 312 | // Note: this ought to be part of the constructor, but that would require |
ysr@777 | 313 | // "this" to be passed as a parameter to a member constructor for |
ysr@777 | 314 | // the containing concrete subtype of Space. |
ysr@777 | 315 | // This would be legal C++, but MS VC++ doesn't allow it. |
mgerdin@6987 | 316 | void set_space(G1OffsetTableContigSpace* sp); |
ysr@777 | 317 | |
ysr@777 | 318 | // Resets the covered region to the given "mr". |
ysr@777 | 319 | void set_region(MemRegion mr); |
ysr@777 | 320 | |
ysr@777 | 321 | // Resets the covered region to one with the same _bottom as before but |
ysr@777 | 322 | // the "new_word_size". |
ysr@777 | 323 | void resize(size_t new_word_size); |
ysr@777 | 324 | |
ysr@777 | 325 | // These must be guaranteed to work properly (i.e., do nothing) |
ysr@777 | 326 | // when "blk_start" ("blk" for second version) is "NULL". |
ysr@777 | 327 | virtual void alloc_block(HeapWord* blk_start, HeapWord* blk_end); |
ysr@777 | 328 | virtual void alloc_block(HeapWord* blk, size_t size) { |
ysr@777 | 329 | alloc_block(blk, blk + size); |
ysr@777 | 330 | } |
ysr@777 | 331 | |
ysr@777 | 332 | // The following methods are useful and optimized for a |
ysr@777 | 333 | // general, non-contiguous space. |
ysr@777 | 334 | |
ysr@777 | 335 | // Given a block [blk_start, blk_start + full_blk_size), and |
ysr@777 | 336 | // a left_blk_size < full_blk_size, adjust the BOT to show two |
ysr@777 | 337 | // blocks [blk_start, blk_start + left_blk_size) and |
ysr@777 | 338 | // [blk_start + left_blk_size, blk_start + full_blk_size). |
ysr@777 | 339 | // It is assumed (and verified in the non-product VM) that the |
ysr@777 | 340 | // BOT was correct for the original block. |
ysr@777 | 341 | void split_block(HeapWord* blk_start, size_t full_blk_size, |
ysr@777 | 342 | size_t left_blk_size); |
ysr@777 | 343 | |
ysr@777 | 344 | // Adjust the BOT to show that it has a single block in the |
ysr@777 | 345 | // range [blk_start, blk_start + size). All necessary BOT |
ysr@777 | 346 | // cards are adjusted, but _unallocated_block isn't. |
ysr@777 | 347 | void single_block(HeapWord* blk_start, HeapWord* blk_end); |
ysr@777 | 348 | void single_block(HeapWord* blk, size_t size) { |
ysr@777 | 349 | single_block(blk, blk + size); |
ysr@777 | 350 | } |
ysr@777 | 351 | |
ysr@777 | 352 | // Adjust BOT to show that it has a block in the range |
ysr@777 | 353 | // [blk_start, blk_start + size). Only the first card |
ysr@777 | 354 | // of BOT is touched. It is assumed (and verified in the |
ysr@777 | 355 | // non-product VM) that the remaining cards of the block |
ysr@777 | 356 | // are correct. |
ysr@777 | 357 | void mark_block(HeapWord* blk_start, HeapWord* blk_end); |
ysr@777 | 358 | void mark_block(HeapWord* blk, size_t size) { |
ysr@777 | 359 | mark_block(blk, blk + size); |
ysr@777 | 360 | } |
ysr@777 | 361 | |
ysr@777 | 362 | // Adjust _unallocated_block to indicate that a particular |
ysr@777 | 363 | // block has been newly allocated or freed. It is assumed (and |
ysr@777 | 364 | // verified in the non-product VM) that the BOT is correct for |
ysr@777 | 365 | // the given block. |
ysr@777 | 366 | inline void allocated(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 367 | // Verify that the BOT shows [blk, blk + blk_size) to be one block. |
ysr@777 | 368 | verify_single_block(blk_start, blk_end); |
ysr@777 | 369 | if (BlockOffsetArrayUseUnallocatedBlock) { |
ysr@777 | 370 | _unallocated_block = MAX2(_unallocated_block, blk_end); |
ysr@777 | 371 | } |
ysr@777 | 372 | } |
ysr@777 | 373 | |
ysr@777 | 374 | inline void allocated(HeapWord* blk, size_t size) { |
ysr@777 | 375 | allocated(blk, blk + size); |
ysr@777 | 376 | } |
ysr@777 | 377 | |
ysr@777 | 378 | inline void freed(HeapWord* blk_start, HeapWord* blk_end); |
ysr@777 | 379 | |
ysr@777 | 380 | inline void freed(HeapWord* blk, size_t size); |
ysr@777 | 381 | |
ysr@777 | 382 | virtual HeapWord* block_start_unsafe(const void* addr); |
ysr@777 | 383 | virtual HeapWord* block_start_unsafe_const(const void* addr) const; |
ysr@777 | 384 | |
ysr@777 | 385 | // Requires "addr" to be the start of a card and returns the |
ysr@777 | 386 | // start of the block that contains the given address. |
ysr@777 | 387 | HeapWord* block_start_careful(const void* addr) const; |
ysr@777 | 388 | |
ysr@777 | 389 | // If true, initialize array slots with no allocated blocks to zero. |
ysr@777 | 390 | // Otherwise, make them point back to the front. |
ysr@777 | 391 | bool init_to_zero() { return _init_to_zero; } |
ysr@777 | 392 | |
ysr@777 | 393 | // Verification & debugging - ensure that the offset table reflects the fact |
ysr@777 | 394 | // that the block [blk_start, blk_end) or [blk, blk + size) is a |
ysr@777 | 395 | // single block of storage. NOTE: can;t const this because of |
ysr@777 | 396 | // call to non-const do_block_internal() below. |
ysr@777 | 397 | inline void verify_single_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 398 | if (VerifyBlockOffsetArray) { |
ysr@777 | 399 | do_block_internal(blk_start, blk_end, Action_check); |
ysr@777 | 400 | } |
ysr@777 | 401 | } |
ysr@777 | 402 | |
ysr@777 | 403 | inline void verify_single_block(HeapWord* blk, size_t size) { |
ysr@777 | 404 | verify_single_block(blk, blk + size); |
ysr@777 | 405 | } |
ysr@777 | 406 | |
tonyp@2453 | 407 | // Used by region verification. Checks that the contents of the |
tonyp@2453 | 408 | // BOT reflect that there's a single object that spans the address |
tonyp@2453 | 409 | // range [obj_start, obj_start + word_size); returns true if this is |
tonyp@2453 | 410 | // the case, returns false if it's not. |
tonyp@2453 | 411 | bool verify_for_object(HeapWord* obj_start, size_t word_size) const; |
tonyp@2453 | 412 | |
ysr@777 | 413 | // Verify that the given block is before _unallocated_block |
ysr@777 | 414 | inline void verify_not_unallocated(HeapWord* blk_start, |
ysr@777 | 415 | HeapWord* blk_end) const { |
ysr@777 | 416 | if (BlockOffsetArrayUseUnallocatedBlock) { |
ysr@777 | 417 | assert(blk_start < blk_end, "Block inconsistency?"); |
ysr@777 | 418 | assert(blk_end <= _unallocated_block, "_unallocated_block problem"); |
ysr@777 | 419 | } |
ysr@777 | 420 | } |
ysr@777 | 421 | |
ysr@777 | 422 | inline void verify_not_unallocated(HeapWord* blk, size_t size) const { |
ysr@777 | 423 | verify_not_unallocated(blk, blk + size); |
ysr@777 | 424 | } |
ysr@777 | 425 | |
ysr@777 | 426 | void check_all_cards(size_t left_card, size_t right_card) const; |
tonyp@2241 | 427 | |
tonyp@2453 | 428 | virtual void print_on(outputStream* out) PRODUCT_RETURN; |
ysr@777 | 429 | }; |
ysr@777 | 430 | |
ysr@777 | 431 | // A subtype of BlockOffsetArray that takes advantage of the fact |
ysr@777 | 432 | // that its underlying space is a ContiguousSpace, so that its "active" |
ysr@777 | 433 | // region can be more efficiently tracked (than for a non-contiguous space). |
ysr@777 | 434 | class G1BlockOffsetArrayContigSpace: public G1BlockOffsetArray { |
ysr@777 | 435 | friend class VMStructs; |
ysr@777 | 436 | |
ysr@777 | 437 | // allocation boundary at which offset array must be updated |
ysr@777 | 438 | HeapWord* _next_offset_threshold; |
ysr@777 | 439 | size_t _next_offset_index; // index corresponding to that boundary |
ysr@777 | 440 | |
ysr@777 | 441 | // Work function to be called when allocation start crosses the next |
ysr@777 | 442 | // threshold in the contig space. |
ysr@777 | 443 | void alloc_block_work1(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 444 | alloc_block_work2(&_next_offset_threshold, &_next_offset_index, |
ysr@777 | 445 | blk_start, blk_end); |
ysr@777 | 446 | } |
ysr@777 | 447 | |
tschatzl@7051 | 448 | // Variant of zero_bottom_entry that does not check for availability of the |
tschatzl@7051 | 449 | // memory first. |
tschatzl@7051 | 450 | void zero_bottom_entry_raw(); |
tschatzl@7051 | 451 | // Variant of initialize_threshold that does not check for availability of the |
tschatzl@7051 | 452 | // memory first. |
tschatzl@7051 | 453 | HeapWord* initialize_threshold_raw(); |
tschatzl@7050 | 454 | // Zero out the entry for _bottom (offset will be zero). |
tschatzl@7050 | 455 | void zero_bottom_entry(); |
ysr@777 | 456 | public: |
ysr@777 | 457 | G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, MemRegion mr); |
ysr@777 | 458 | |
ysr@777 | 459 | // Initialize the threshold to reflect the first boundary after the |
ysr@777 | 460 | // bottom of the covered region. |
ysr@777 | 461 | HeapWord* initialize_threshold(); |
ysr@777 | 462 | |
tschatzl@7050 | 463 | void reset_bot() { |
tschatzl@7051 | 464 | zero_bottom_entry_raw(); |
tschatzl@7051 | 465 | initialize_threshold_raw(); |
tschatzl@7050 | 466 | } |
ysr@777 | 467 | |
ysr@777 | 468 | // Return the next threshold, the point at which the table should be |
ysr@777 | 469 | // updated. |
ysr@777 | 470 | HeapWord* threshold() const { return _next_offset_threshold; } |
ysr@777 | 471 | |
ysr@777 | 472 | // These must be guaranteed to work properly (i.e., do nothing) |
ysr@777 | 473 | // when "blk_start" ("blk" for second version) is "NULL". In this |
ysr@777 | 474 | // implementation, that's true because NULL is represented as 0, and thus |
ysr@777 | 475 | // never exceeds the "_next_offset_threshold". |
ysr@777 | 476 | void alloc_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 477 | if (blk_end > _next_offset_threshold) |
ysr@777 | 478 | alloc_block_work1(blk_start, blk_end); |
ysr@777 | 479 | } |
ysr@777 | 480 | void alloc_block(HeapWord* blk, size_t size) { |
ysr@777 | 481 | alloc_block(blk, blk+size); |
ysr@777 | 482 | } |
ysr@777 | 483 | |
ysr@777 | 484 | HeapWord* block_start_unsafe(const void* addr); |
ysr@777 | 485 | HeapWord* block_start_unsafe_const(const void* addr) const; |
tonyp@2241 | 486 | |
tonyp@2453 | 487 | void set_for_starts_humongous(HeapWord* new_top); |
tonyp@2453 | 488 | |
tonyp@2453 | 489 | virtual void print_on(outputStream* out) PRODUCT_RETURN; |
ysr@777 | 490 | }; |
stefank@2314 | 491 | |
stefank@2314 | 492 | #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP |