1 /* 2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" 27 #include "memory/space.hpp" 28 #include "oops/oop.inline.hpp" 29 #include "runtime/java.hpp" 30 #include "services/memTracker.hpp" 31 32 ////////////////////////////////////////////////////////////////////// 33 // G1BlockOffsetSharedArray 34 ////////////////////////////////////////////////////////////////////// 35 36 G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion reserved, 37 size_t init_word_size) : 38 _reserved(reserved), _end(NULL) 39 { 40 size_t size = compute_size(reserved.word_size()); 41 ReservedSpace rs(ReservedSpace::allocation_align_size_up(size)); 42 if (!rs.is_reserved()) { 43 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); 44 } 45 if (!_vs.initialize(rs, 0)) { 46 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); 47 } 48 49 MemTracker::record_virtual_memory_type((address)rs.base(), mtGC); 50 51 _offset_array = (u_char*)_vs.low_boundary(); 52 resize(init_word_size); 53 if (TraceBlockOffsetTable) { 54 gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: "); 55 gclog_or_tty->print_cr(" " 56 " rs.base(): " INTPTR_FORMAT 57 " rs.size(): " INTPTR_FORMAT 58 " rs end(): " INTPTR_FORMAT, 59 rs.base(), rs.size(), rs.base() + rs.size()); 60 gclog_or_tty->print_cr(" " 61 " _vs.low_boundary(): " INTPTR_FORMAT 62 " _vs.high_boundary(): " INTPTR_FORMAT, 63 _vs.low_boundary(), 64 _vs.high_boundary()); 65 } 66 } 67 68 void G1BlockOffsetSharedArray::resize(size_t new_word_size) { 69 assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved"); 70 size_t new_size = compute_size(new_word_size); 71 size_t old_size = _vs.committed_size(); 72 size_t delta; 73 char* high = _vs.high(); 74 _end = _reserved.start() + new_word_size; 75 if (new_size > old_size) { 76 delta = ReservedSpace::page_align_size_up(new_size - old_size); 77 assert(delta > 0, "just checking"); 78 if (!_vs.expand_by(delta)) { 79 // Do better than this for Merlin 80 vm_exit_out_of_memory(delta, "offset table expansion"); 81 } 82 assert(_vs.high() == high + delta, "invalid expansion"); 83 // Initialization of the contents is left to the 84 // G1BlockOffsetArray that uses it. 85 } else { 86 delta = ReservedSpace::page_align_size_down(old_size - new_size); 87 if (delta == 0) return; 88 _vs.shrink_by(delta); 89 assert(_vs.high() == high - delta, "invalid expansion"); 90 } 91 } 92 93 bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const { 94 assert(p >= _reserved.start(), "just checking"); 95 size_t delta = pointer_delta(p, _reserved.start()); 96 return (delta & right_n_bits(LogN_words)) == (size_t)NoBits; 97 } 98 99 100 ////////////////////////////////////////////////////////////////////// 101 // G1BlockOffsetArray 102 ////////////////////////////////////////////////////////////////////// 103 104 G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array, 105 MemRegion mr, bool init_to_zero) : 106 G1BlockOffsetTable(mr.start(), mr.end()), 107 _unallocated_block(_bottom), 108 _array(array), _csp(NULL), 109 _init_to_zero(init_to_zero) { 110 assert(_bottom <= _end, "arguments out of order"); 111 if (!_init_to_zero) { 112 // initialize cards to point back to mr.start() 113 set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); 114 _array->set_offset_array(0, 0); // set first card to 0 115 } 116 } 117 118 void G1BlockOffsetArray::set_space(Space* sp) { 119 _sp = sp; 120 _csp = sp->toContiguousSpace(); 121 } 122 123 // The arguments follow the normal convention of denoting 124 // a right-open interval: [start, end) 125 void 126 G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) { 127 128 if (start >= end) { 129 // The start address is equal to the end address (or to 130 // the right of the end address) so there are not cards 131 // that need to be updated.. 132 return; 133 } 134 135 // Write the backskip value for each region. 136 // 137 // offset 138 // card 2nd 3rd 139 // | +- 1st | | 140 // v v v v 141 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- 142 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ... 143 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- 144 // 11 19 75 145 // 12 146 // 147 // offset card is the card that points to the start of an object 148 // x - offset value of offset card 149 // 1st - start of first logarithmic region 150 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 151 // 2nd - start of second logarithmic region 152 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 153 // 3rd - start of third logarithmic region 154 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 155 // 156 // integer below the block offset entry is an example of 157 // the index of the entry 158 // 159 // Given an address, 160 // Find the index for the address 161 // Find the block offset table entry 162 // Convert the entry to a back slide 163 // (e.g., with today's, offset = 0x81 => 164 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 165 // Move back N (e.g., 8) entries and repeat with the 166 // value of the new entry 167 // 168 size_t start_card = _array->index_for(start); 169 size_t end_card = _array->index_for(end-1); 170 assert(start ==_array->address_for_index(start_card), "Precondition"); 171 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); 172 set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval 173 } 174 175 // Unlike the normal convention in this code, the argument here denotes 176 // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start() 177 // above. 178 void 179 G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) { 180 if (start_card > end_card) { 181 return; 182 } 183 assert(start_card > _array->index_for(_bottom), "Cannot be first card"); 184 assert(_array->offset_array(start_card-1) <= N_words, 185 "Offset card has an unexpected value"); 186 size_t start_card_for_region = start_card; 187 u_char offset = max_jubyte; 188 for (int i = 0; i < BlockOffsetArray::N_powers; i++) { 189 // -1 so that the the card with the actual offset is counted. Another -1 190 // so that the reach ends in this region and not at the start 191 // of the next. 192 size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1); 193 offset = N_words + i; 194 if (reach >= end_card) { 195 _array->set_offset_array(start_card_for_region, end_card, offset); 196 start_card_for_region = reach + 1; 197 break; 198 } 199 _array->set_offset_array(start_card_for_region, reach, offset); 200 start_card_for_region = reach + 1; 201 } 202 assert(start_card_for_region > end_card, "Sanity check"); 203 DEBUG_ONLY(check_all_cards(start_card, end_card);) 204 } 205 206 // The block [blk_start, blk_end) has been allocated; 207 // adjust the block offset table to represent this information; 208 // right-open interval: [blk_start, blk_end) 209 void 210 G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { 211 mark_block(blk_start, blk_end); 212 allocated(blk_start, blk_end); 213 } 214 215 // Adjust BOT to show that a previously whole block has been split 216 // into two. 217 void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size, 218 size_t left_blk_size) { 219 // Verify that the BOT shows [blk, blk + blk_size) to be one block. 220 verify_single_block(blk, blk_size); 221 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) 222 // is one single block. 223 mark_block(blk + left_blk_size, blk + blk_size); 224 } 225 226 227 // Action_mark - update the BOT for the block [blk_start, blk_end). 228 // Current typical use is for splitting a block. 229 // Action_single - update the BOT for an allocation. 230 // Action_verify - BOT verification. 231 void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start, 232 HeapWord* blk_end, 233 Action action) { 234 assert(Universe::heap()->is_in_reserved(blk_start), 235 "reference must be into the heap"); 236 assert(Universe::heap()->is_in_reserved(blk_end-1), 237 "limit must be within the heap"); 238 // This is optimized to make the test fast, assuming we only rarely 239 // cross boundaries. 240 uintptr_t end_ui = (uintptr_t)(blk_end - 1); 241 uintptr_t start_ui = (uintptr_t)blk_start; 242 // Calculate the last card boundary preceding end of blk 243 intptr_t boundary_before_end = (intptr_t)end_ui; 244 clear_bits(boundary_before_end, right_n_bits(LogN)); 245 if (start_ui <= (uintptr_t)boundary_before_end) { 246 // blk starts at or crosses a boundary 247 // Calculate index of card on which blk begins 248 size_t start_index = _array->index_for(blk_start); 249 // Index of card on which blk ends 250 size_t end_index = _array->index_for(blk_end - 1); 251 // Start address of card on which blk begins 252 HeapWord* boundary = _array->address_for_index(start_index); 253 assert(boundary <= blk_start, "blk should start at or after boundary"); 254 if (blk_start != boundary) { 255 // blk starts strictly after boundary 256 // adjust card boundary and start_index forward to next card 257 boundary += N_words; 258 start_index++; 259 } 260 assert(start_index <= end_index, "monotonicity of index_for()"); 261 assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); 262 switch (action) { 263 case Action_mark: { 264 if (init_to_zero()) { 265 _array->set_offset_array(start_index, boundary, blk_start); 266 break; 267 } // Else fall through to the next case 268 } 269 case Action_single: { 270 _array->set_offset_array(start_index, boundary, blk_start); 271 // We have finished marking the "offset card". We need to now 272 // mark the subsequent cards that this blk spans. 273 if (start_index < end_index) { 274 HeapWord* rem_st = _array->address_for_index(start_index) + N_words; 275 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; 276 set_remainder_to_point_to_start(rem_st, rem_end); 277 } 278 break; 279 } 280 case Action_check: { 281 _array->check_offset_array(start_index, boundary, blk_start); 282 // We have finished checking the "offset card". We need to now 283 // check the subsequent cards that this blk spans. 284 check_all_cards(start_index + 1, end_index); 285 break; 286 } 287 default: 288 ShouldNotReachHere(); 289 } 290 } 291 } 292 293 // The card-interval [start_card, end_card] is a closed interval; this 294 // is an expensive check -- use with care and only under protection of 295 // suitable flag. 296 void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { 297 298 if (end_card < start_card) { 299 return; 300 } 301 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); 302 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { 303 u_char entry = _array->offset_array(c); 304 if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) { 305 guarantee(entry > N_words, "Should be in logarithmic region"); 306 } 307 size_t backskip = BlockOffsetArray::entry_to_cards_back(entry); 308 size_t landing_card = c - backskip; 309 guarantee(landing_card >= (start_card - 1), "Inv"); 310 if (landing_card >= start_card) { 311 guarantee(_array->offset_array(landing_card) <= entry, "monotonicity"); 312 } else { 313 guarantee(landing_card == start_card - 1, "Tautology"); 314 guarantee(_array->offset_array(landing_card) <= N_words, "Offset value"); 315 } 316 } 317 } 318 319 // The range [blk_start, blk_end) represents a single contiguous block 320 // of storage; modify the block offset table to represent this 321 // information; Right-open interval: [blk_start, blk_end) 322 // NOTE: this method does _not_ adjust _unallocated_block. 323 void 324 G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) { 325 do_block_internal(blk_start, blk_end, Action_single); 326 } 327 328 // Mark the BOT such that if [blk_start, blk_end) straddles a card 329 // boundary, the card following the first such boundary is marked 330 // with the appropriate offset. 331 // NOTE: this method does _not_ adjust _unallocated_block or 332 // any cards subsequent to the first one. 333 void 334 G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) { 335 do_block_internal(blk_start, blk_end, Action_mark); 336 } 337 338 HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) { 339 assert(_bottom <= addr && addr < _end, 340 "addr must be covered by this Array"); 341 // Must read this exactly once because it can be modified by parallel 342 // allocation. 343 HeapWord* ub = _unallocated_block; 344 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { 345 assert(ub < _end, "tautology (see above)"); 346 return ub; 347 } 348 // Otherwise, find the block start using the table. 349 HeapWord* q = block_at_or_preceding(addr, false, 0); 350 return forward_to_block_containing_addr(q, addr); 351 } 352 353 // This duplicates a little code from the above: unavoidable. 354 HeapWord* 355 G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const { 356 assert(_bottom <= addr && addr < _end, 357 "addr must be covered by this Array"); 358 // Must read this exactly once because it can be modified by parallel 359 // allocation. 360 HeapWord* ub = _unallocated_block; 361 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { 362 assert(ub < _end, "tautology (see above)"); 363 return ub; 364 } 365 // Otherwise, find the block start using the table. 366 HeapWord* q = block_at_or_preceding(addr, false, 0); 367 HeapWord* n = q + _sp->block_size(q); 368 return forward_to_block_containing_addr_const(q, n, addr); 369 } 370 371 372 HeapWord* 373 G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q, 374 HeapWord* n, 375 const void* addr) { 376 // We're not in the normal case. We need to handle an important subcase 377 // here: LAB allocation. An allocation previously recorded in the 378 // offset table was actually a lab allocation, and was divided into 379 // several objects subsequently. Fix this situation as we answer the 380 // query, by updating entries as we cross them. 381 382 // If the fist object's end q is at the card boundary. Start refining 383 // with the corresponding card (the value of the entry will be basically 384 // set to 0). If the object crosses the boundary -- start from the next card. 385 size_t n_index = _array->index_for(n); 386 size_t next_index = _array->index_for(n) + !_array->is_card_boundary(n); 387 // Calculate a consistent next boundary. If "n" is not at the boundary 388 // already, step to the boundary. 389 HeapWord* next_boundary = _array->address_for_index(n_index) + 390 (n_index == next_index ? 0 : N_words); 391 assert(next_boundary <= _array->_end, 392 err_msg("next_boundary is beyond the end of the covered region " 393 " next_boundary " PTR_FORMAT " _array->_end " PTR_FORMAT, 394 next_boundary, _array->_end)); 395 if (csp() != NULL) { 396 if (addr >= csp()->top()) return csp()->top(); 397 while (next_boundary < addr) { 398 while (n <= next_boundary) { 399 q = n; 400 oop obj = oop(q); 401 if (obj->klass_or_null() == NULL) return q; 402 n += obj->size(); 403 } 404 assert(q <= next_boundary && n > next_boundary, "Consequence of loop"); 405 // [q, n) is the block that crosses the boundary. 406 alloc_block_work2(&next_boundary, &next_index, q, n); 407 } 408 } else { 409 while (next_boundary < addr) { 410 while (n <= next_boundary) { 411 q = n; 412 oop obj = oop(q); 413 if (obj->klass_or_null() == NULL) return q; 414 n += _sp->block_size(q); 415 } 416 assert(q <= next_boundary && n > next_boundary, "Consequence of loop"); 417 // [q, n) is the block that crosses the boundary. 418 alloc_block_work2(&next_boundary, &next_index, q, n); 419 } 420 } 421 return forward_to_block_containing_addr_const(q, n, addr); 422 } 423 424 HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const { 425 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); 426 427 assert(_bottom <= addr && addr < _end, 428 "addr must be covered by this Array"); 429 // Must read this exactly once because it can be modified by parallel 430 // allocation. 431 HeapWord* ub = _unallocated_block; 432 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { 433 assert(ub < _end, "tautology (see above)"); 434 return ub; 435 } 436 437 // Otherwise, find the block start using the table, but taking 438 // care (cf block_start_unsafe() above) not to parse any objects/blocks 439 // on the cards themsleves. 440 size_t index = _array->index_for(addr); 441 assert(_array->address_for_index(index) == addr, 442 "arg should be start of card"); 443 444 HeapWord* q = (HeapWord*)addr; 445 uint offset; 446 do { 447 offset = _array->offset_array(index--); 448 q -= offset; 449 } while (offset == N_words); 450 assert(q <= addr, "block start should be to left of arg"); 451 return q; 452 } 453 454 // Note that the committed size of the covered space may have changed, 455 // so the table size might also wish to change. 456 void G1BlockOffsetArray::resize(size_t new_word_size) { 457 HeapWord* new_end = _bottom + new_word_size; 458 if (_end < new_end && !init_to_zero()) { 459 // verify that the old and new boundaries are also card boundaries 460 assert(_array->is_card_boundary(_end), 461 "_end not a card boundary"); 462 assert(_array->is_card_boundary(new_end), 463 "new _end would not be a card boundary"); 464 // set all the newly added cards 465 _array->set_offset_array(_end, new_end, N_words); 466 } 467 _end = new_end; // update _end 468 } 469 470 void G1BlockOffsetArray::set_region(MemRegion mr) { 471 _bottom = mr.start(); 472 _end = mr.end(); 473 } 474 475 // 476 // threshold_ 477 // | _index_ 478 // v v 479 // +-------+-------+-------+-------+-------+ 480 // | i-1 | i | i+1 | i+2 | i+3 | 481 // +-------+-------+-------+-------+-------+ 482 // ( ^ ] 483 // block-start 484 // 485 void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_, 486 HeapWord* blk_start, HeapWord* blk_end) { 487 // For efficiency, do copy-in/copy-out. 488 HeapWord* threshold = *threshold_; 489 size_t index = *index_; 490 491 assert(blk_start != NULL && blk_end > blk_start, 492 "phantom block"); 493 assert(blk_end > threshold, "should be past threshold"); 494 assert(blk_start <= threshold, "blk_start should be at or before threshold"); 495 assert(pointer_delta(threshold, blk_start) <= N_words, 496 "offset should be <= BlockOffsetSharedArray::N"); 497 assert(Universe::heap()->is_in_reserved(blk_start), 498 "reference must be into the heap"); 499 assert(Universe::heap()->is_in_reserved(blk_end-1), 500 "limit must be within the heap"); 501 assert(threshold == _array->_reserved.start() + index*N_words, 502 "index must agree with threshold"); 503 504 DEBUG_ONLY(size_t orig_index = index;) 505 506 // Mark the card that holds the offset into the block. Note 507 // that _next_offset_index and _next_offset_threshold are not 508 // updated until the end of this method. 509 _array->set_offset_array(index, threshold, blk_start); 510 511 // We need to now mark the subsequent cards that this blk spans. 512 513 // Index of card on which blk ends. 514 size_t end_index = _array->index_for(blk_end - 1); 515 516 // Are there more cards left to be updated? 517 if (index + 1 <= end_index) { 518 HeapWord* rem_st = _array->address_for_index(index + 1); 519 // Calculate rem_end this way because end_index 520 // may be the last valid index in the covered region. 521 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; 522 set_remainder_to_point_to_start(rem_st, rem_end); 523 } 524 525 index = end_index + 1; 526 // Calculate threshold_ this way because end_index 527 // may be the last valid index in the covered region. 528 threshold = _array->address_for_index(end_index) + N_words; 529 assert(threshold >= blk_end, "Incorrect offset threshold"); 530 531 // index_ and threshold_ updated here. 532 *threshold_ = threshold; 533 *index_ = index; 534 535 #ifdef ASSERT 536 // The offset can be 0 if the block starts on a boundary. That 537 // is checked by an assertion above. 538 size_t start_index = _array->index_for(blk_start); 539 HeapWord* boundary = _array->address_for_index(start_index); 540 assert((_array->offset_array(orig_index) == 0 && 541 blk_start == boundary) || 542 (_array->offset_array(orig_index) > 0 && 543 _array->offset_array(orig_index) <= N_words), 544 "offset array should have been set"); 545 for (size_t j = orig_index + 1; j <= end_index; j++) { 546 assert(_array->offset_array(j) > 0 && 547 _array->offset_array(j) <= 548 (u_char) (N_words+BlockOffsetArray::N_powers-1), 549 "offset array should have been set"); 550 } 551 #endif 552 } 553 554 bool 555 G1BlockOffsetArray::verify_for_object(HeapWord* obj_start, 556 size_t word_size) const { 557 size_t first_card = _array->index_for(obj_start); 558 size_t last_card = _array->index_for(obj_start + word_size - 1); 559 if (!_array->is_card_boundary(obj_start)) { 560 // If the object is not on a card boundary the BOT entry of the 561 // first card should point to another object so we should not 562 // check that one. 563 first_card += 1; 564 } 565 for (size_t card = first_card; card <= last_card; card += 1) { 566 HeapWord* card_addr = _array->address_for_index(card); 567 HeapWord* block_start = block_start_const(card_addr); 568 if (block_start != obj_start) { 569 gclog_or_tty->print_cr("block start: "PTR_FORMAT" is incorrect - " 570 "card index: "SIZE_FORMAT" " 571 "card addr: "PTR_FORMAT" BOT entry: %u " 572 "obj: "PTR_FORMAT" word size: "SIZE_FORMAT" " 573 "cards: ["SIZE_FORMAT","SIZE_FORMAT"]", 574 block_start, card, card_addr, 575 _array->offset_array(card), 576 obj_start, word_size, first_card, last_card); 577 return false; 578 } 579 } 580 return true; 581 } 582 583 #ifndef PRODUCT 584 void 585 G1BlockOffsetArray::print_on(outputStream* out) { 586 size_t from_index = _array->index_for(_bottom); 587 size_t to_index = _array->index_for(_end); 588 out->print_cr(">> BOT for area ["PTR_FORMAT","PTR_FORMAT") " 589 "cards ["SIZE_FORMAT","SIZE_FORMAT")", 590 _bottom, _end, from_index, to_index); 591 for (size_t i = from_index; i < to_index; ++i) { 592 out->print_cr(" entry "SIZE_FORMAT_W(8)" | "PTR_FORMAT" : %3u", 593 i, _array->address_for_index(i), 594 (uint) _array->offset_array(i)); 595 } 596 } 597 #endif // !PRODUCT 598 599 ////////////////////////////////////////////////////////////////////// 600 // G1BlockOffsetArrayContigSpace 601 ////////////////////////////////////////////////////////////////////// 602 603 HeapWord* 604 G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) { 605 assert(_bottom <= addr && addr < _end, 606 "addr must be covered by this Array"); 607 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); 608 return forward_to_block_containing_addr(q, addr); 609 } 610 611 HeapWord* 612 G1BlockOffsetArrayContigSpace:: 613 block_start_unsafe_const(const void* addr) const { 614 assert(_bottom <= addr && addr < _end, 615 "addr must be covered by this Array"); 616 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); 617 HeapWord* n = q + _sp->block_size(q); 618 return forward_to_block_containing_addr_const(q, n, addr); 619 } 620 621 G1BlockOffsetArrayContigSpace:: 622 G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, 623 MemRegion mr) : 624 G1BlockOffsetArray(array, mr, true) 625 { 626 _next_offset_threshold = NULL; 627 _next_offset_index = 0; 628 } 629 630 HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() { 631 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), 632 "just checking"); 633 _next_offset_index = _array->index_for(_bottom); 634 _next_offset_index++; 635 _next_offset_threshold = 636 _array->address_for_index(_next_offset_index); 637 return _next_offset_threshold; 638 } 639 640 void G1BlockOffsetArrayContigSpace::zero_bottom_entry() { 641 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), 642 "just checking"); 643 size_t bottom_index = _array->index_for(_bottom); 644 assert(_array->address_for_index(bottom_index) == _bottom, 645 "Precondition of call"); 646 _array->set_offset_array(bottom_index, 0); 647 } 648 649 void 650 G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) { 651 assert(new_top <= _end, "_end should have already been updated"); 652 653 // The first BOT entry should have offset 0. 654 zero_bottom_entry(); 655 initialize_threshold(); 656 alloc_block(_bottom, new_top); 657 } 658 659 #ifndef PRODUCT 660 void 661 G1BlockOffsetArrayContigSpace::print_on(outputStream* out) { 662 G1BlockOffsetArray::print_on(out); 663 out->print_cr(" next offset threshold: "PTR_FORMAT, _next_offset_threshold); 664 out->print_cr(" next offset index: "SIZE_FORMAT, _next_offset_index); 665 } 666 #endif // !PRODUCT