Tue, 05 May 2009 22:15:35 -0700
6833576: G1: assert illegal index, growableArray.hpp:186
Summary: The code that calculates the heap region index for an object address incorrectly used signed arithmetic.
Reviewed-by: jcoomes, ysr
ysr@777 | 1 | /* |
xdono@905 | 2 | * Copyright 2001-2008 Sun Microsystems, Inc. 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 | * |
ysr@777 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
ysr@777 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
ysr@777 | 21 | * have any questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
ysr@777 | 25 | #include "incls/_precompiled.incl" |
ysr@777 | 26 | #include "incls/_g1BlockOffsetTable.cpp.incl" |
ysr@777 | 27 | |
ysr@777 | 28 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 29 | // G1BlockOffsetSharedArray |
ysr@777 | 30 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 31 | |
ysr@777 | 32 | G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion reserved, |
ysr@777 | 33 | size_t init_word_size) : |
ysr@777 | 34 | _reserved(reserved), _end(NULL) |
ysr@777 | 35 | { |
ysr@777 | 36 | size_t size = compute_size(reserved.word_size()); |
ysr@777 | 37 | ReservedSpace rs(ReservedSpace::allocation_align_size_up(size)); |
ysr@777 | 38 | if (!rs.is_reserved()) { |
ysr@777 | 39 | vm_exit_during_initialization("Could not reserve enough space for heap offset array"); |
ysr@777 | 40 | } |
ysr@777 | 41 | if (!_vs.initialize(rs, 0)) { |
ysr@777 | 42 | vm_exit_during_initialization("Could not reserve enough space for heap offset array"); |
ysr@777 | 43 | } |
ysr@777 | 44 | _offset_array = (u_char*)_vs.low_boundary(); |
ysr@777 | 45 | resize(init_word_size); |
ysr@777 | 46 | if (TraceBlockOffsetTable) { |
ysr@777 | 47 | gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: "); |
ysr@777 | 48 | gclog_or_tty->print_cr(" " |
ysr@777 | 49 | " rs.base(): " INTPTR_FORMAT |
ysr@777 | 50 | " rs.size(): " INTPTR_FORMAT |
ysr@777 | 51 | " rs end(): " INTPTR_FORMAT, |
ysr@777 | 52 | rs.base(), rs.size(), rs.base() + rs.size()); |
ysr@777 | 53 | gclog_or_tty->print_cr(" " |
ysr@777 | 54 | " _vs.low_boundary(): " INTPTR_FORMAT |
ysr@777 | 55 | " _vs.high_boundary(): " INTPTR_FORMAT, |
ysr@777 | 56 | _vs.low_boundary(), |
ysr@777 | 57 | _vs.high_boundary()); |
ysr@777 | 58 | } |
ysr@777 | 59 | } |
ysr@777 | 60 | |
ysr@777 | 61 | void G1BlockOffsetSharedArray::resize(size_t new_word_size) { |
ysr@777 | 62 | assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved"); |
ysr@777 | 63 | size_t new_size = compute_size(new_word_size); |
ysr@777 | 64 | size_t old_size = _vs.committed_size(); |
ysr@777 | 65 | size_t delta; |
ysr@777 | 66 | char* high = _vs.high(); |
ysr@777 | 67 | _end = _reserved.start() + new_word_size; |
ysr@777 | 68 | if (new_size > old_size) { |
ysr@777 | 69 | delta = ReservedSpace::page_align_size_up(new_size - old_size); |
ysr@777 | 70 | assert(delta > 0, "just checking"); |
ysr@777 | 71 | if (!_vs.expand_by(delta)) { |
ysr@777 | 72 | // Do better than this for Merlin |
ysr@777 | 73 | vm_exit_out_of_memory(delta, "offset table expansion"); |
ysr@777 | 74 | } |
ysr@777 | 75 | assert(_vs.high() == high + delta, "invalid expansion"); |
ysr@777 | 76 | // Initialization of the contents is left to the |
ysr@777 | 77 | // G1BlockOffsetArray that uses it. |
ysr@777 | 78 | } else { |
ysr@777 | 79 | delta = ReservedSpace::page_align_size_down(old_size - new_size); |
ysr@777 | 80 | if (delta == 0) return; |
ysr@777 | 81 | _vs.shrink_by(delta); |
ysr@777 | 82 | assert(_vs.high() == high - delta, "invalid expansion"); |
ysr@777 | 83 | } |
ysr@777 | 84 | } |
ysr@777 | 85 | |
ysr@777 | 86 | bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const { |
ysr@777 | 87 | assert(p >= _reserved.start(), "just checking"); |
ysr@777 | 88 | size_t delta = pointer_delta(p, _reserved.start()); |
ysr@777 | 89 | return (delta & right_n_bits(LogN_words)) == (size_t)NoBits; |
ysr@777 | 90 | } |
ysr@777 | 91 | |
ysr@777 | 92 | |
ysr@777 | 93 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 94 | // G1BlockOffsetArray |
ysr@777 | 95 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 96 | |
ysr@777 | 97 | G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array, |
ysr@777 | 98 | MemRegion mr, bool init_to_zero) : |
ysr@777 | 99 | G1BlockOffsetTable(mr.start(), mr.end()), |
ysr@777 | 100 | _unallocated_block(_bottom), |
ysr@777 | 101 | _array(array), _csp(NULL), |
ysr@777 | 102 | _init_to_zero(init_to_zero) { |
ysr@777 | 103 | assert(_bottom <= _end, "arguments out of order"); |
ysr@777 | 104 | if (!_init_to_zero) { |
ysr@777 | 105 | // initialize cards to point back to mr.start() |
ysr@777 | 106 | set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); |
ysr@777 | 107 | _array->set_offset_array(0, 0); // set first card to 0 |
ysr@777 | 108 | } |
ysr@777 | 109 | } |
ysr@777 | 110 | |
ysr@777 | 111 | void G1BlockOffsetArray::set_space(Space* sp) { |
ysr@777 | 112 | _sp = sp; |
ysr@777 | 113 | _csp = sp->toContiguousSpace(); |
ysr@777 | 114 | } |
ysr@777 | 115 | |
ysr@777 | 116 | // The arguments follow the normal convention of denoting |
ysr@777 | 117 | // a right-open interval: [start, end) |
ysr@777 | 118 | void |
ysr@777 | 119 | G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) { |
ysr@777 | 120 | |
ysr@777 | 121 | if (start >= end) { |
ysr@777 | 122 | // The start address is equal to the end address (or to |
ysr@777 | 123 | // the right of the end address) so there are not cards |
ysr@777 | 124 | // that need to be updated.. |
ysr@777 | 125 | return; |
ysr@777 | 126 | } |
ysr@777 | 127 | |
ysr@777 | 128 | // Write the backskip value for each region. |
ysr@777 | 129 | // |
ysr@777 | 130 | // offset |
ysr@777 | 131 | // card 2nd 3rd |
ysr@777 | 132 | // | +- 1st | | |
ysr@777 | 133 | // v v v v |
ysr@777 | 134 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- |
ysr@777 | 135 | // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ... |
ysr@777 | 136 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- |
ysr@777 | 137 | // 11 19 75 |
ysr@777 | 138 | // 12 |
ysr@777 | 139 | // |
ysr@777 | 140 | // offset card is the card that points to the start of an object |
ysr@777 | 141 | // x - offset value of offset card |
ysr@777 | 142 | // 1st - start of first logarithmic region |
ysr@777 | 143 | // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 |
ysr@777 | 144 | // 2nd - start of second logarithmic region |
ysr@777 | 145 | // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 |
ysr@777 | 146 | // 3rd - start of third logarithmic region |
ysr@777 | 147 | // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 |
ysr@777 | 148 | // |
ysr@777 | 149 | // integer below the block offset entry is an example of |
ysr@777 | 150 | // the index of the entry |
ysr@777 | 151 | // |
ysr@777 | 152 | // Given an address, |
ysr@777 | 153 | // Find the index for the address |
ysr@777 | 154 | // Find the block offset table entry |
ysr@777 | 155 | // Convert the entry to a back slide |
ysr@777 | 156 | // (e.g., with today's, offset = 0x81 => |
ysr@777 | 157 | // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 |
ysr@777 | 158 | // Move back N (e.g., 8) entries and repeat with the |
ysr@777 | 159 | // value of the new entry |
ysr@777 | 160 | // |
ysr@777 | 161 | size_t start_card = _array->index_for(start); |
ysr@777 | 162 | size_t end_card = _array->index_for(end-1); |
ysr@777 | 163 | assert(start ==_array->address_for_index(start_card), "Precondition"); |
ysr@777 | 164 | assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); |
ysr@777 | 165 | set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval |
ysr@777 | 166 | } |
ysr@777 | 167 | |
ysr@777 | 168 | // Unlike the normal convention in this code, the argument here denotes |
ysr@777 | 169 | // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start() |
ysr@777 | 170 | // above. |
ysr@777 | 171 | void |
ysr@777 | 172 | G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) { |
ysr@777 | 173 | if (start_card > end_card) { |
ysr@777 | 174 | return; |
ysr@777 | 175 | } |
ysr@777 | 176 | assert(start_card > _array->index_for(_bottom), "Cannot be first card"); |
ysr@777 | 177 | assert(_array->offset_array(start_card-1) <= N_words, |
ysr@777 | 178 | "Offset card has an unexpected value"); |
ysr@777 | 179 | size_t start_card_for_region = start_card; |
ysr@777 | 180 | u_char offset = max_jubyte; |
ysr@777 | 181 | for (int i = 0; i < BlockOffsetArray::N_powers; i++) { |
ysr@777 | 182 | // -1 so that the the card with the actual offset is counted. Another -1 |
ysr@777 | 183 | // so that the reach ends in this region and not at the start |
ysr@777 | 184 | // of the next. |
ysr@777 | 185 | size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1); |
ysr@777 | 186 | offset = N_words + i; |
ysr@777 | 187 | if (reach >= end_card) { |
ysr@777 | 188 | _array->set_offset_array(start_card_for_region, end_card, offset); |
ysr@777 | 189 | start_card_for_region = reach + 1; |
ysr@777 | 190 | break; |
ysr@777 | 191 | } |
ysr@777 | 192 | _array->set_offset_array(start_card_for_region, reach, offset); |
ysr@777 | 193 | start_card_for_region = reach + 1; |
ysr@777 | 194 | } |
ysr@777 | 195 | assert(start_card_for_region > end_card, "Sanity check"); |
ysr@777 | 196 | DEBUG_ONLY(check_all_cards(start_card, end_card);) |
ysr@777 | 197 | } |
ysr@777 | 198 | |
ysr@777 | 199 | // The block [blk_start, blk_end) has been allocated; |
ysr@777 | 200 | // adjust the block offset table to represent this information; |
ysr@777 | 201 | // right-open interval: [blk_start, blk_end) |
ysr@777 | 202 | void |
ysr@777 | 203 | G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 204 | mark_block(blk_start, blk_end); |
ysr@777 | 205 | allocated(blk_start, blk_end); |
ysr@777 | 206 | } |
ysr@777 | 207 | |
ysr@777 | 208 | // Adjust BOT to show that a previously whole block has been split |
ysr@777 | 209 | // into two. |
ysr@777 | 210 | void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size, |
ysr@777 | 211 | size_t left_blk_size) { |
ysr@777 | 212 | // Verify that the BOT shows [blk, blk + blk_size) to be one block. |
ysr@777 | 213 | verify_single_block(blk, blk_size); |
ysr@777 | 214 | // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) |
ysr@777 | 215 | // is one single block. |
ysr@777 | 216 | mark_block(blk + left_blk_size, blk + blk_size); |
ysr@777 | 217 | } |
ysr@777 | 218 | |
ysr@777 | 219 | |
ysr@777 | 220 | // Action_mark - update the BOT for the block [blk_start, blk_end). |
ysr@777 | 221 | // Current typical use is for splitting a block. |
ysr@777 | 222 | // Action_single - udpate the BOT for an allocation. |
ysr@777 | 223 | // Action_verify - BOT verification. |
ysr@777 | 224 | void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start, |
ysr@777 | 225 | HeapWord* blk_end, |
ysr@777 | 226 | Action action) { |
ysr@777 | 227 | assert(Universe::heap()->is_in_reserved(blk_start), |
ysr@777 | 228 | "reference must be into the heap"); |
ysr@777 | 229 | assert(Universe::heap()->is_in_reserved(blk_end-1), |
ysr@777 | 230 | "limit must be within the heap"); |
ysr@777 | 231 | // This is optimized to make the test fast, assuming we only rarely |
ysr@777 | 232 | // cross boundaries. |
ysr@777 | 233 | uintptr_t end_ui = (uintptr_t)(blk_end - 1); |
ysr@777 | 234 | uintptr_t start_ui = (uintptr_t)blk_start; |
ysr@777 | 235 | // Calculate the last card boundary preceding end of blk |
ysr@777 | 236 | intptr_t boundary_before_end = (intptr_t)end_ui; |
ysr@777 | 237 | clear_bits(boundary_before_end, right_n_bits(LogN)); |
ysr@777 | 238 | if (start_ui <= (uintptr_t)boundary_before_end) { |
ysr@777 | 239 | // blk starts at or crosses a boundary |
ysr@777 | 240 | // Calculate index of card on which blk begins |
ysr@777 | 241 | size_t start_index = _array->index_for(blk_start); |
ysr@777 | 242 | // Index of card on which blk ends |
ysr@777 | 243 | size_t end_index = _array->index_for(blk_end - 1); |
ysr@777 | 244 | // Start address of card on which blk begins |
ysr@777 | 245 | HeapWord* boundary = _array->address_for_index(start_index); |
ysr@777 | 246 | assert(boundary <= blk_start, "blk should start at or after boundary"); |
ysr@777 | 247 | if (blk_start != boundary) { |
ysr@777 | 248 | // blk starts strictly after boundary |
ysr@777 | 249 | // adjust card boundary and start_index forward to next card |
ysr@777 | 250 | boundary += N_words; |
ysr@777 | 251 | start_index++; |
ysr@777 | 252 | } |
ysr@777 | 253 | assert(start_index <= end_index, "monotonicity of index_for()"); |
ysr@777 | 254 | assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); |
ysr@777 | 255 | switch (action) { |
ysr@777 | 256 | case Action_mark: { |
ysr@777 | 257 | if (init_to_zero()) { |
ysr@777 | 258 | _array->set_offset_array(start_index, boundary, blk_start); |
ysr@777 | 259 | break; |
ysr@777 | 260 | } // Else fall through to the next case |
ysr@777 | 261 | } |
ysr@777 | 262 | case Action_single: { |
ysr@777 | 263 | _array->set_offset_array(start_index, boundary, blk_start); |
ysr@777 | 264 | // We have finished marking the "offset card". We need to now |
ysr@777 | 265 | // mark the subsequent cards that this blk spans. |
ysr@777 | 266 | if (start_index < end_index) { |
ysr@777 | 267 | HeapWord* rem_st = _array->address_for_index(start_index) + N_words; |
ysr@777 | 268 | HeapWord* rem_end = _array->address_for_index(end_index) + N_words; |
ysr@777 | 269 | set_remainder_to_point_to_start(rem_st, rem_end); |
ysr@777 | 270 | } |
ysr@777 | 271 | break; |
ysr@777 | 272 | } |
ysr@777 | 273 | case Action_check: { |
ysr@777 | 274 | _array->check_offset_array(start_index, boundary, blk_start); |
ysr@777 | 275 | // We have finished checking the "offset card". We need to now |
ysr@777 | 276 | // check the subsequent cards that this blk spans. |
ysr@777 | 277 | check_all_cards(start_index + 1, end_index); |
ysr@777 | 278 | break; |
ysr@777 | 279 | } |
ysr@777 | 280 | default: |
ysr@777 | 281 | ShouldNotReachHere(); |
ysr@777 | 282 | } |
ysr@777 | 283 | } |
ysr@777 | 284 | } |
ysr@777 | 285 | |
ysr@777 | 286 | // The card-interval [start_card, end_card] is a closed interval; this |
ysr@777 | 287 | // is an expensive check -- use with care and only under protection of |
ysr@777 | 288 | // suitable flag. |
ysr@777 | 289 | void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { |
ysr@777 | 290 | |
ysr@777 | 291 | if (end_card < start_card) { |
ysr@777 | 292 | return; |
ysr@777 | 293 | } |
ysr@777 | 294 | guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); |
ysr@777 | 295 | for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { |
ysr@777 | 296 | u_char entry = _array->offset_array(c); |
ysr@777 | 297 | if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) { |
ysr@777 | 298 | guarantee(entry > N_words, "Should be in logarithmic region"); |
ysr@777 | 299 | } |
ysr@777 | 300 | size_t backskip = BlockOffsetArray::entry_to_cards_back(entry); |
ysr@777 | 301 | size_t landing_card = c - backskip; |
ysr@777 | 302 | guarantee(landing_card >= (start_card - 1), "Inv"); |
ysr@777 | 303 | if (landing_card >= start_card) { |
ysr@777 | 304 | guarantee(_array->offset_array(landing_card) <= entry, "monotonicity"); |
ysr@777 | 305 | } else { |
ysr@777 | 306 | guarantee(landing_card == start_card - 1, "Tautology"); |
ysr@777 | 307 | guarantee(_array->offset_array(landing_card) <= N_words, "Offset value"); |
ysr@777 | 308 | } |
ysr@777 | 309 | } |
ysr@777 | 310 | } |
ysr@777 | 311 | |
ysr@777 | 312 | // The range [blk_start, blk_end) represents a single contiguous block |
ysr@777 | 313 | // of storage; modify the block offset table to represent this |
ysr@777 | 314 | // information; Right-open interval: [blk_start, blk_end) |
ysr@777 | 315 | // NOTE: this method does _not_ adjust _unallocated_block. |
ysr@777 | 316 | void |
ysr@777 | 317 | G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 318 | do_block_internal(blk_start, blk_end, Action_single); |
ysr@777 | 319 | } |
ysr@777 | 320 | |
ysr@777 | 321 | // Mark the BOT such that if [blk_start, blk_end) straddles a card |
ysr@777 | 322 | // boundary, the card following the first such boundary is marked |
ysr@777 | 323 | // with the appropriate offset. |
ysr@777 | 324 | // NOTE: this method does _not_ adjust _unallocated_block or |
ysr@777 | 325 | // any cards subsequent to the first one. |
ysr@777 | 326 | void |
ysr@777 | 327 | G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 328 | do_block_internal(blk_start, blk_end, Action_mark); |
ysr@777 | 329 | } |
ysr@777 | 330 | |
ysr@777 | 331 | void G1BlockOffsetArray::join_blocks(HeapWord* blk1, HeapWord* blk2) { |
ysr@777 | 332 | HeapWord* blk1_start = Universe::heap()->block_start(blk1); |
ysr@777 | 333 | HeapWord* blk2_start = Universe::heap()->block_start(blk2); |
ysr@777 | 334 | assert(blk1 == blk1_start && blk2 == blk2_start, |
ysr@777 | 335 | "Must be block starts."); |
ysr@777 | 336 | assert(blk1 + _sp->block_size(blk1) == blk2, "Must be contiguous."); |
ysr@777 | 337 | size_t blk1_start_index = _array->index_for(blk1); |
ysr@777 | 338 | size_t blk2_start_index = _array->index_for(blk2); |
ysr@777 | 339 | assert(blk1_start_index <= blk2_start_index, "sanity"); |
ysr@777 | 340 | HeapWord* blk2_card_start = _array->address_for_index(blk2_start_index); |
ysr@777 | 341 | if (blk2 == blk2_card_start) { |
ysr@777 | 342 | // blk2 starts a card. Does blk1 start on the prevous card, or futher |
ysr@777 | 343 | // back? |
ysr@777 | 344 | assert(blk1_start_index < blk2_start_index, "must be lower card."); |
ysr@777 | 345 | if (blk1_start_index + 1 == blk2_start_index) { |
ysr@777 | 346 | // previous card; new value for blk2 card is size of blk1. |
ysr@777 | 347 | _array->set_offset_array(blk2_start_index, (u_char) _sp->block_size(blk1)); |
ysr@777 | 348 | } else { |
ysr@777 | 349 | // Earlier card; go back a card. |
ysr@777 | 350 | _array->set_offset_array(blk2_start_index, N_words); |
ysr@777 | 351 | } |
ysr@777 | 352 | } else { |
ysr@777 | 353 | // blk2 does not start a card. Does it cross a card? If not, nothing |
ysr@777 | 354 | // to do. |
ysr@777 | 355 | size_t blk2_end_index = |
ysr@777 | 356 | _array->index_for(blk2 + _sp->block_size(blk2) - 1); |
ysr@777 | 357 | assert(blk2_end_index >= blk2_start_index, "sanity"); |
ysr@777 | 358 | if (blk2_end_index > blk2_start_index) { |
ysr@777 | 359 | // Yes, it crosses a card. The value for the next card must change. |
ysr@777 | 360 | if (blk1_start_index + 1 == blk2_start_index) { |
ysr@777 | 361 | // previous card; new value for second blk2 card is size of blk1. |
ysr@777 | 362 | _array->set_offset_array(blk2_start_index + 1, |
ysr@777 | 363 | (u_char) _sp->block_size(blk1)); |
ysr@777 | 364 | } else { |
ysr@777 | 365 | // Earlier card; go back a card. |
ysr@777 | 366 | _array->set_offset_array(blk2_start_index + 1, N_words); |
ysr@777 | 367 | } |
ysr@777 | 368 | } |
ysr@777 | 369 | } |
ysr@777 | 370 | } |
ysr@777 | 371 | |
ysr@777 | 372 | HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) { |
ysr@777 | 373 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 374 | "addr must be covered by this Array"); |
ysr@777 | 375 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 376 | // allocation. |
ysr@777 | 377 | HeapWord* ub = _unallocated_block; |
ysr@777 | 378 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 379 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 380 | return ub; |
ysr@777 | 381 | } |
ysr@777 | 382 | // Otherwise, find the block start using the table. |
ysr@777 | 383 | HeapWord* q = block_at_or_preceding(addr, false, 0); |
ysr@777 | 384 | return forward_to_block_containing_addr(q, addr); |
ysr@777 | 385 | } |
ysr@777 | 386 | |
ysr@777 | 387 | // This duplicates a little code from the above: unavoidable. |
ysr@777 | 388 | HeapWord* |
ysr@777 | 389 | G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const { |
ysr@777 | 390 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 391 | "addr must be covered by this Array"); |
ysr@777 | 392 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 393 | // allocation. |
ysr@777 | 394 | HeapWord* ub = _unallocated_block; |
ysr@777 | 395 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 396 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 397 | return ub; |
ysr@777 | 398 | } |
ysr@777 | 399 | // Otherwise, find the block start using the table. |
ysr@777 | 400 | HeapWord* q = block_at_or_preceding(addr, false, 0); |
ysr@777 | 401 | HeapWord* n = q + _sp->block_size(q); |
ysr@777 | 402 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 403 | } |
ysr@777 | 404 | |
ysr@777 | 405 | |
ysr@777 | 406 | HeapWord* |
ysr@777 | 407 | G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q, |
ysr@777 | 408 | HeapWord* n, |
ysr@777 | 409 | const void* addr) { |
ysr@777 | 410 | // We're not in the normal case. We need to handle an important subcase |
ysr@777 | 411 | // here: LAB allocation. An allocation previously recorded in the |
ysr@777 | 412 | // offset table was actually a lab allocation, and was divided into |
ysr@777 | 413 | // several objects subsequently. Fix this situation as we answer the |
ysr@777 | 414 | // query, by updating entries as we cross them. |
iveresov@787 | 415 | |
iveresov@787 | 416 | // If the fist object's end q is at the card boundary. Start refining |
iveresov@787 | 417 | // with the corresponding card (the value of the entry will be basically |
iveresov@787 | 418 | // set to 0). If the object crosses the boundary -- start from the next card. |
iveresov@787 | 419 | size_t next_index = _array->index_for(n) + !_array->is_card_boundary(n); |
ysr@777 | 420 | HeapWord* next_boundary = _array->address_for_index(next_index); |
ysr@777 | 421 | if (csp() != NULL) { |
ysr@777 | 422 | if (addr >= csp()->top()) return csp()->top(); |
ysr@777 | 423 | while (next_boundary < addr) { |
ysr@777 | 424 | while (n <= next_boundary) { |
ysr@777 | 425 | q = n; |
ysr@777 | 426 | oop obj = oop(q); |
ysr@777 | 427 | if (obj->klass() == NULL) return q; |
ysr@777 | 428 | n += obj->size(); |
ysr@777 | 429 | } |
ysr@777 | 430 | assert(q <= next_boundary && n > next_boundary, "Consequence of loop"); |
ysr@777 | 431 | // [q, n) is the block that crosses the boundary. |
ysr@777 | 432 | alloc_block_work2(&next_boundary, &next_index, q, n); |
ysr@777 | 433 | } |
ysr@777 | 434 | } else { |
ysr@777 | 435 | while (next_boundary < addr) { |
ysr@777 | 436 | while (n <= next_boundary) { |
ysr@777 | 437 | q = n; |
ysr@777 | 438 | oop obj = oop(q); |
ysr@777 | 439 | if (obj->klass() == NULL) return q; |
ysr@777 | 440 | n += _sp->block_size(q); |
ysr@777 | 441 | } |
ysr@777 | 442 | assert(q <= next_boundary && n > next_boundary, "Consequence of loop"); |
ysr@777 | 443 | // [q, n) is the block that crosses the boundary. |
ysr@777 | 444 | alloc_block_work2(&next_boundary, &next_index, q, n); |
ysr@777 | 445 | } |
ysr@777 | 446 | } |
ysr@777 | 447 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 448 | } |
ysr@777 | 449 | |
ysr@777 | 450 | HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const { |
ysr@777 | 451 | assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); |
ysr@777 | 452 | |
ysr@777 | 453 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 454 | "addr must be covered by this Array"); |
ysr@777 | 455 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 456 | // allocation. |
ysr@777 | 457 | HeapWord* ub = _unallocated_block; |
ysr@777 | 458 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 459 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 460 | return ub; |
ysr@777 | 461 | } |
ysr@777 | 462 | |
ysr@777 | 463 | // Otherwise, find the block start using the table, but taking |
ysr@777 | 464 | // care (cf block_start_unsafe() above) not to parse any objects/blocks |
ysr@777 | 465 | // on the cards themsleves. |
ysr@777 | 466 | size_t index = _array->index_for(addr); |
ysr@777 | 467 | assert(_array->address_for_index(index) == addr, |
ysr@777 | 468 | "arg should be start of card"); |
ysr@777 | 469 | |
ysr@777 | 470 | HeapWord* q = (HeapWord*)addr; |
ysr@777 | 471 | uint offset; |
ysr@777 | 472 | do { |
ysr@777 | 473 | offset = _array->offset_array(index--); |
ysr@777 | 474 | q -= offset; |
ysr@777 | 475 | } while (offset == N_words); |
ysr@777 | 476 | assert(q <= addr, "block start should be to left of arg"); |
ysr@777 | 477 | return q; |
ysr@777 | 478 | } |
ysr@777 | 479 | |
ysr@777 | 480 | // Note that the committed size of the covered space may have changed, |
ysr@777 | 481 | // so the table size might also wish to change. |
ysr@777 | 482 | void G1BlockOffsetArray::resize(size_t new_word_size) { |
ysr@777 | 483 | HeapWord* new_end = _bottom + new_word_size; |
ysr@777 | 484 | if (_end < new_end && !init_to_zero()) { |
ysr@777 | 485 | // verify that the old and new boundaries are also card boundaries |
ysr@777 | 486 | assert(_array->is_card_boundary(_end), |
ysr@777 | 487 | "_end not a card boundary"); |
ysr@777 | 488 | assert(_array->is_card_boundary(new_end), |
ysr@777 | 489 | "new _end would not be a card boundary"); |
ysr@777 | 490 | // set all the newly added cards |
ysr@777 | 491 | _array->set_offset_array(_end, new_end, N_words); |
ysr@777 | 492 | } |
ysr@777 | 493 | _end = new_end; // update _end |
ysr@777 | 494 | } |
ysr@777 | 495 | |
ysr@777 | 496 | void G1BlockOffsetArray::set_region(MemRegion mr) { |
ysr@777 | 497 | _bottom = mr.start(); |
ysr@777 | 498 | _end = mr.end(); |
ysr@777 | 499 | } |
ysr@777 | 500 | |
ysr@777 | 501 | // |
ysr@777 | 502 | // threshold_ |
ysr@777 | 503 | // | _index_ |
ysr@777 | 504 | // v v |
ysr@777 | 505 | // +-------+-------+-------+-------+-------+ |
ysr@777 | 506 | // | i-1 | i | i+1 | i+2 | i+3 | |
ysr@777 | 507 | // +-------+-------+-------+-------+-------+ |
ysr@777 | 508 | // ( ^ ] |
ysr@777 | 509 | // block-start |
ysr@777 | 510 | // |
ysr@777 | 511 | void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_, |
ysr@777 | 512 | HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 513 | // For efficiency, do copy-in/copy-out. |
ysr@777 | 514 | HeapWord* threshold = *threshold_; |
ysr@777 | 515 | size_t index = *index_; |
ysr@777 | 516 | |
ysr@777 | 517 | assert(blk_start != NULL && blk_end > blk_start, |
ysr@777 | 518 | "phantom block"); |
ysr@777 | 519 | assert(blk_end > threshold, "should be past threshold"); |
ysr@777 | 520 | assert(blk_start <= threshold, "blk_start should be at or before threshold") |
ysr@777 | 521 | assert(pointer_delta(threshold, blk_start) <= N_words, |
ysr@777 | 522 | "offset should be <= BlockOffsetSharedArray::N"); |
ysr@777 | 523 | assert(Universe::heap()->is_in_reserved(blk_start), |
ysr@777 | 524 | "reference must be into the heap"); |
ysr@777 | 525 | assert(Universe::heap()->is_in_reserved(blk_end-1), |
ysr@777 | 526 | "limit must be within the heap"); |
ysr@777 | 527 | assert(threshold == _array->_reserved.start() + index*N_words, |
ysr@777 | 528 | "index must agree with threshold"); |
ysr@777 | 529 | |
ysr@777 | 530 | DEBUG_ONLY(size_t orig_index = index;) |
ysr@777 | 531 | |
ysr@777 | 532 | // Mark the card that holds the offset into the block. Note |
ysr@777 | 533 | // that _next_offset_index and _next_offset_threshold are not |
ysr@777 | 534 | // updated until the end of this method. |
ysr@777 | 535 | _array->set_offset_array(index, threshold, blk_start); |
ysr@777 | 536 | |
ysr@777 | 537 | // We need to now mark the subsequent cards that this blk spans. |
ysr@777 | 538 | |
ysr@777 | 539 | // Index of card on which blk ends. |
ysr@777 | 540 | size_t end_index = _array->index_for(blk_end - 1); |
ysr@777 | 541 | |
ysr@777 | 542 | // Are there more cards left to be updated? |
ysr@777 | 543 | if (index + 1 <= end_index) { |
ysr@777 | 544 | HeapWord* rem_st = _array->address_for_index(index + 1); |
ysr@777 | 545 | // Calculate rem_end this way because end_index |
ysr@777 | 546 | // may be the last valid index in the covered region. |
ysr@777 | 547 | HeapWord* rem_end = _array->address_for_index(end_index) + N_words; |
ysr@777 | 548 | set_remainder_to_point_to_start(rem_st, rem_end); |
ysr@777 | 549 | } |
ysr@777 | 550 | |
ysr@777 | 551 | index = end_index + 1; |
ysr@777 | 552 | // Calculate threshold_ this way because end_index |
ysr@777 | 553 | // may be the last valid index in the covered region. |
ysr@777 | 554 | threshold = _array->address_for_index(end_index) + N_words; |
ysr@777 | 555 | assert(threshold >= blk_end, "Incorrect offset threshold"); |
ysr@777 | 556 | |
ysr@777 | 557 | // index_ and threshold_ updated here. |
ysr@777 | 558 | *threshold_ = threshold; |
ysr@777 | 559 | *index_ = index; |
ysr@777 | 560 | |
ysr@777 | 561 | #ifdef ASSERT |
ysr@777 | 562 | // The offset can be 0 if the block starts on a boundary. That |
ysr@777 | 563 | // is checked by an assertion above. |
ysr@777 | 564 | size_t start_index = _array->index_for(blk_start); |
ysr@777 | 565 | HeapWord* boundary = _array->address_for_index(start_index); |
ysr@777 | 566 | assert((_array->offset_array(orig_index) == 0 && |
ysr@777 | 567 | blk_start == boundary) || |
ysr@777 | 568 | (_array->offset_array(orig_index) > 0 && |
ysr@777 | 569 | _array->offset_array(orig_index) <= N_words), |
ysr@777 | 570 | "offset array should have been set"); |
ysr@777 | 571 | for (size_t j = orig_index + 1; j <= end_index; j++) { |
ysr@777 | 572 | assert(_array->offset_array(j) > 0 && |
ysr@777 | 573 | _array->offset_array(j) <= |
ysr@777 | 574 | (u_char) (N_words+BlockOffsetArray::N_powers-1), |
ysr@777 | 575 | "offset array should have been set"); |
ysr@777 | 576 | } |
ysr@777 | 577 | #endif |
ysr@777 | 578 | } |
ysr@777 | 579 | |
ysr@777 | 580 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 581 | // G1BlockOffsetArrayContigSpace |
ysr@777 | 582 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 583 | |
ysr@777 | 584 | HeapWord* |
ysr@777 | 585 | G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) { |
ysr@777 | 586 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 587 | "addr must be covered by this Array"); |
ysr@777 | 588 | HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); |
ysr@777 | 589 | return forward_to_block_containing_addr(q, addr); |
ysr@777 | 590 | } |
ysr@777 | 591 | |
ysr@777 | 592 | HeapWord* |
ysr@777 | 593 | G1BlockOffsetArrayContigSpace:: |
ysr@777 | 594 | block_start_unsafe_const(const void* addr) const { |
ysr@777 | 595 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 596 | "addr must be covered by this Array"); |
ysr@777 | 597 | HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); |
ysr@777 | 598 | HeapWord* n = q + _sp->block_size(q); |
ysr@777 | 599 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 600 | } |
ysr@777 | 601 | |
ysr@777 | 602 | G1BlockOffsetArrayContigSpace:: |
ysr@777 | 603 | G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, |
ysr@777 | 604 | MemRegion mr) : |
ysr@777 | 605 | G1BlockOffsetArray(array, mr, true) |
ysr@777 | 606 | { |
ysr@777 | 607 | _next_offset_threshold = NULL; |
ysr@777 | 608 | _next_offset_index = 0; |
ysr@777 | 609 | } |
ysr@777 | 610 | |
ysr@777 | 611 | HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() { |
ysr@777 | 612 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
ysr@777 | 613 | "just checking"); |
ysr@777 | 614 | _next_offset_index = _array->index_for(_bottom); |
ysr@777 | 615 | _next_offset_index++; |
ysr@777 | 616 | _next_offset_threshold = |
ysr@777 | 617 | _array->address_for_index(_next_offset_index); |
ysr@777 | 618 | return _next_offset_threshold; |
ysr@777 | 619 | } |
ysr@777 | 620 | |
ysr@777 | 621 | void G1BlockOffsetArrayContigSpace::zero_bottom_entry() { |
ysr@777 | 622 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
ysr@777 | 623 | "just checking"); |
ysr@777 | 624 | size_t bottom_index = _array->index_for(_bottom); |
ysr@777 | 625 | assert(_array->address_for_index(bottom_index) == _bottom, |
ysr@777 | 626 | "Precondition of call"); |
ysr@777 | 627 | _array->set_offset_array(bottom_index, 0); |
ysr@777 | 628 | } |