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 | #include "precompiled.hpp" |
stefank@2314 | 26 | #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" |
mgerdin@6987 | 27 | #include "gc_implementation/g1/heapRegion.hpp" |
stefank@2314 | 28 | #include "memory/space.hpp" |
stefank@2314 | 29 | #include "oops/oop.inline.hpp" |
stefank@2314 | 30 | #include "runtime/java.hpp" |
zgu@3900 | 31 | #include "services/memTracker.hpp" |
ysr@777 | 32 | |
drchase@6680 | 33 | PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
drchase@6680 | 34 | |
tschatzl@7051 | 35 | void G1BlockOffsetSharedArrayMappingChangedListener::on_commit(uint start_idx, size_t num_regions) { |
tschatzl@7051 | 36 | // Nothing to do. The BOT is hard-wired to be part of the HeapRegion, and we cannot |
tschatzl@7051 | 37 | // retrieve it here since this would cause firing of several asserts. The code |
tschatzl@7051 | 38 | // executed after commit of a region already needs to do some re-initialization of |
tschatzl@7051 | 39 | // the HeapRegion, so we combine that. |
tschatzl@7051 | 40 | } |
tschatzl@7051 | 41 | |
ysr@777 | 42 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 43 | // G1BlockOffsetSharedArray |
ysr@777 | 44 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 45 | |
tschatzl@7051 | 46 | G1BlockOffsetSharedArray::G1BlockOffsetSharedArray(MemRegion heap, G1RegionToSpaceMapper* storage) : |
tschatzl@7051 | 47 | _reserved(), _end(NULL), _listener(), _offset_array(NULL) { |
zgu@3900 | 48 | |
tschatzl@7051 | 49 | _reserved = heap; |
tschatzl@7051 | 50 | _end = NULL; |
zgu@3900 | 51 | |
tschatzl@7051 | 52 | MemRegion bot_reserved = storage->reserved(); |
tschatzl@7051 | 53 | |
tschatzl@7051 | 54 | _offset_array = (u_char*)bot_reserved.start(); |
tschatzl@7051 | 55 | _end = _reserved.end(); |
tschatzl@7051 | 56 | |
tschatzl@7051 | 57 | storage->set_mapping_changed_listener(&_listener); |
tschatzl@7051 | 58 | |
ysr@777 | 59 | if (TraceBlockOffsetTable) { |
ysr@777 | 60 | gclog_or_tty->print_cr("G1BlockOffsetSharedArray::G1BlockOffsetSharedArray: "); |
ysr@777 | 61 | gclog_or_tty->print_cr(" " |
ysr@777 | 62 | " rs.base(): " INTPTR_FORMAT |
ysr@777 | 63 | " rs.size(): " INTPTR_FORMAT |
ysr@777 | 64 | " rs end(): " INTPTR_FORMAT, |
tschatzl@7051 | 65 | bot_reserved.start(), bot_reserved.byte_size(), bot_reserved.end()); |
ysr@777 | 66 | } |
ysr@777 | 67 | } |
ysr@777 | 68 | |
ysr@777 | 69 | bool G1BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const { |
ysr@777 | 70 | assert(p >= _reserved.start(), "just checking"); |
ysr@777 | 71 | size_t delta = pointer_delta(p, _reserved.start()); |
ysr@777 | 72 | return (delta & right_n_bits(LogN_words)) == (size_t)NoBits; |
ysr@777 | 73 | } |
ysr@777 | 74 | |
mgerdin@6987 | 75 | void G1BlockOffsetSharedArray::set_offset_array(HeapWord* left, HeapWord* right, u_char offset) { |
tschatzl@7051 | 76 | set_offset_array(index_for(left), index_for(right -1), offset); |
mgerdin@6987 | 77 | } |
ysr@777 | 78 | |
ysr@777 | 79 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 80 | // G1BlockOffsetArray |
ysr@777 | 81 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 82 | |
ysr@777 | 83 | G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array, |
ysr@777 | 84 | MemRegion mr, bool init_to_zero) : |
ysr@777 | 85 | G1BlockOffsetTable(mr.start(), mr.end()), |
ysr@777 | 86 | _unallocated_block(_bottom), |
mgerdin@6987 | 87 | _array(array), _gsp(NULL), |
ysr@777 | 88 | _init_to_zero(init_to_zero) { |
ysr@777 | 89 | assert(_bottom <= _end, "arguments out of order"); |
ysr@777 | 90 | if (!_init_to_zero) { |
ysr@777 | 91 | // initialize cards to point back to mr.start() |
ysr@777 | 92 | set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); |
ysr@777 | 93 | _array->set_offset_array(0, 0); // set first card to 0 |
ysr@777 | 94 | } |
ysr@777 | 95 | } |
ysr@777 | 96 | |
mgerdin@6987 | 97 | void G1BlockOffsetArray::set_space(G1OffsetTableContigSpace* sp) { |
mgerdin@6987 | 98 | _gsp = sp; |
ysr@777 | 99 | } |
ysr@777 | 100 | |
ysr@777 | 101 | // The arguments follow the normal convention of denoting |
ysr@777 | 102 | // a right-open interval: [start, end) |
ysr@777 | 103 | void |
ysr@777 | 104 | G1BlockOffsetArray:: set_remainder_to_point_to_start(HeapWord* start, HeapWord* end) { |
ysr@777 | 105 | |
ysr@777 | 106 | if (start >= end) { |
ysr@777 | 107 | // The start address is equal to the end address (or to |
ysr@777 | 108 | // the right of the end address) so there are not cards |
ysr@777 | 109 | // that need to be updated.. |
ysr@777 | 110 | return; |
ysr@777 | 111 | } |
ysr@777 | 112 | |
ysr@777 | 113 | // Write the backskip value for each region. |
ysr@777 | 114 | // |
ysr@777 | 115 | // offset |
ysr@777 | 116 | // card 2nd 3rd |
ysr@777 | 117 | // | +- 1st | | |
ysr@777 | 118 | // v v v v |
ysr@777 | 119 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- |
ysr@777 | 120 | // |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 | 121 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- |
ysr@777 | 122 | // 11 19 75 |
ysr@777 | 123 | // 12 |
ysr@777 | 124 | // |
ysr@777 | 125 | // offset card is the card that points to the start of an object |
ysr@777 | 126 | // x - offset value of offset card |
ysr@777 | 127 | // 1st - start of first logarithmic region |
ysr@777 | 128 | // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 |
ysr@777 | 129 | // 2nd - start of second logarithmic region |
ysr@777 | 130 | // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 |
ysr@777 | 131 | // 3rd - start of third logarithmic region |
ysr@777 | 132 | // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 |
ysr@777 | 133 | // |
ysr@777 | 134 | // integer below the block offset entry is an example of |
ysr@777 | 135 | // the index of the entry |
ysr@777 | 136 | // |
ysr@777 | 137 | // Given an address, |
ysr@777 | 138 | // Find the index for the address |
ysr@777 | 139 | // Find the block offset table entry |
ysr@777 | 140 | // Convert the entry to a back slide |
ysr@777 | 141 | // (e.g., with today's, offset = 0x81 => |
ysr@777 | 142 | // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 |
ysr@777 | 143 | // Move back N (e.g., 8) entries and repeat with the |
ysr@777 | 144 | // value of the new entry |
ysr@777 | 145 | // |
ysr@777 | 146 | size_t start_card = _array->index_for(start); |
ysr@777 | 147 | size_t end_card = _array->index_for(end-1); |
ysr@777 | 148 | assert(start ==_array->address_for_index(start_card), "Precondition"); |
ysr@777 | 149 | assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); |
ysr@777 | 150 | set_remainder_to_point_to_start_incl(start_card, end_card); // closed interval |
ysr@777 | 151 | } |
ysr@777 | 152 | |
ysr@777 | 153 | // Unlike the normal convention in this code, the argument here denotes |
ysr@777 | 154 | // a closed, inclusive interval: [start_card, end_card], cf set_remainder_to_point_to_start() |
ysr@777 | 155 | // above. |
ysr@777 | 156 | void |
ysr@777 | 157 | G1BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card) { |
ysr@777 | 158 | if (start_card > end_card) { |
ysr@777 | 159 | return; |
ysr@777 | 160 | } |
ysr@777 | 161 | assert(start_card > _array->index_for(_bottom), "Cannot be first card"); |
ysr@777 | 162 | assert(_array->offset_array(start_card-1) <= N_words, |
tonyp@2241 | 163 | "Offset card has an unexpected value"); |
ysr@777 | 164 | size_t start_card_for_region = start_card; |
ysr@777 | 165 | u_char offset = max_jubyte; |
ysr@777 | 166 | for (int i = 0; i < BlockOffsetArray::N_powers; i++) { |
ysr@777 | 167 | // -1 so that the the card with the actual offset is counted. Another -1 |
ysr@777 | 168 | // so that the reach ends in this region and not at the start |
ysr@777 | 169 | // of the next. |
ysr@777 | 170 | size_t reach = start_card - 1 + (BlockOffsetArray::power_to_cards_back(i+1) - 1); |
ysr@777 | 171 | offset = N_words + i; |
ysr@777 | 172 | if (reach >= end_card) { |
ysr@777 | 173 | _array->set_offset_array(start_card_for_region, end_card, offset); |
ysr@777 | 174 | start_card_for_region = reach + 1; |
ysr@777 | 175 | break; |
ysr@777 | 176 | } |
ysr@777 | 177 | _array->set_offset_array(start_card_for_region, reach, offset); |
ysr@777 | 178 | start_card_for_region = reach + 1; |
ysr@777 | 179 | } |
ysr@777 | 180 | assert(start_card_for_region > end_card, "Sanity check"); |
ysr@777 | 181 | DEBUG_ONLY(check_all_cards(start_card, end_card);) |
ysr@777 | 182 | } |
ysr@777 | 183 | |
ysr@777 | 184 | // The block [blk_start, blk_end) has been allocated; |
ysr@777 | 185 | // adjust the block offset table to represent this information; |
ysr@777 | 186 | // right-open interval: [blk_start, blk_end) |
ysr@777 | 187 | void |
ysr@777 | 188 | G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 189 | mark_block(blk_start, blk_end); |
ysr@777 | 190 | allocated(blk_start, blk_end); |
ysr@777 | 191 | } |
ysr@777 | 192 | |
ysr@777 | 193 | // Adjust BOT to show that a previously whole block has been split |
ysr@777 | 194 | // into two. |
ysr@777 | 195 | void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size, |
ysr@777 | 196 | size_t left_blk_size) { |
ysr@777 | 197 | // Verify that the BOT shows [blk, blk + blk_size) to be one block. |
ysr@777 | 198 | verify_single_block(blk, blk_size); |
ysr@777 | 199 | // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) |
ysr@777 | 200 | // is one single block. |
ysr@777 | 201 | mark_block(blk + left_blk_size, blk + blk_size); |
ysr@777 | 202 | } |
ysr@777 | 203 | |
ysr@777 | 204 | |
ysr@777 | 205 | // Action_mark - update the BOT for the block [blk_start, blk_end). |
ysr@777 | 206 | // Current typical use is for splitting a block. |
tonyp@2453 | 207 | // Action_single - update the BOT for an allocation. |
ysr@777 | 208 | // Action_verify - BOT verification. |
ysr@777 | 209 | void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start, |
ysr@777 | 210 | HeapWord* blk_end, |
ysr@777 | 211 | Action action) { |
ysr@777 | 212 | assert(Universe::heap()->is_in_reserved(blk_start), |
ysr@777 | 213 | "reference must be into the heap"); |
ysr@777 | 214 | assert(Universe::heap()->is_in_reserved(blk_end-1), |
ysr@777 | 215 | "limit must be within the heap"); |
ysr@777 | 216 | // This is optimized to make the test fast, assuming we only rarely |
ysr@777 | 217 | // cross boundaries. |
ysr@777 | 218 | uintptr_t end_ui = (uintptr_t)(blk_end - 1); |
ysr@777 | 219 | uintptr_t start_ui = (uintptr_t)blk_start; |
ysr@777 | 220 | // Calculate the last card boundary preceding end of blk |
ysr@777 | 221 | intptr_t boundary_before_end = (intptr_t)end_ui; |
ysr@777 | 222 | clear_bits(boundary_before_end, right_n_bits(LogN)); |
ysr@777 | 223 | if (start_ui <= (uintptr_t)boundary_before_end) { |
ysr@777 | 224 | // blk starts at or crosses a boundary |
ysr@777 | 225 | // Calculate index of card on which blk begins |
ysr@777 | 226 | size_t start_index = _array->index_for(blk_start); |
ysr@777 | 227 | // Index of card on which blk ends |
ysr@777 | 228 | size_t end_index = _array->index_for(blk_end - 1); |
ysr@777 | 229 | // Start address of card on which blk begins |
ysr@777 | 230 | HeapWord* boundary = _array->address_for_index(start_index); |
ysr@777 | 231 | assert(boundary <= blk_start, "blk should start at or after boundary"); |
ysr@777 | 232 | if (blk_start != boundary) { |
ysr@777 | 233 | // blk starts strictly after boundary |
ysr@777 | 234 | // adjust card boundary and start_index forward to next card |
ysr@777 | 235 | boundary += N_words; |
ysr@777 | 236 | start_index++; |
ysr@777 | 237 | } |
ysr@777 | 238 | assert(start_index <= end_index, "monotonicity of index_for()"); |
ysr@777 | 239 | assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); |
ysr@777 | 240 | switch (action) { |
ysr@777 | 241 | case Action_mark: { |
ysr@777 | 242 | if (init_to_zero()) { |
ysr@777 | 243 | _array->set_offset_array(start_index, boundary, blk_start); |
ysr@777 | 244 | break; |
ysr@777 | 245 | } // Else fall through to the next case |
ysr@777 | 246 | } |
ysr@777 | 247 | case Action_single: { |
ysr@777 | 248 | _array->set_offset_array(start_index, boundary, blk_start); |
ysr@777 | 249 | // We have finished marking the "offset card". We need to now |
ysr@777 | 250 | // mark the subsequent cards that this blk spans. |
ysr@777 | 251 | if (start_index < end_index) { |
ysr@777 | 252 | HeapWord* rem_st = _array->address_for_index(start_index) + N_words; |
ysr@777 | 253 | HeapWord* rem_end = _array->address_for_index(end_index) + N_words; |
ysr@777 | 254 | set_remainder_to_point_to_start(rem_st, rem_end); |
ysr@777 | 255 | } |
ysr@777 | 256 | break; |
ysr@777 | 257 | } |
ysr@777 | 258 | case Action_check: { |
ysr@777 | 259 | _array->check_offset_array(start_index, boundary, blk_start); |
ysr@777 | 260 | // We have finished checking the "offset card". We need to now |
ysr@777 | 261 | // check the subsequent cards that this blk spans. |
ysr@777 | 262 | check_all_cards(start_index + 1, end_index); |
ysr@777 | 263 | break; |
ysr@777 | 264 | } |
ysr@777 | 265 | default: |
ysr@777 | 266 | ShouldNotReachHere(); |
ysr@777 | 267 | } |
ysr@777 | 268 | } |
ysr@777 | 269 | } |
ysr@777 | 270 | |
ysr@777 | 271 | // The card-interval [start_card, end_card] is a closed interval; this |
ysr@777 | 272 | // is an expensive check -- use with care and only under protection of |
ysr@777 | 273 | // suitable flag. |
ysr@777 | 274 | void G1BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { |
ysr@777 | 275 | |
ysr@777 | 276 | if (end_card < start_card) { |
ysr@777 | 277 | return; |
ysr@777 | 278 | } |
ysr@777 | 279 | guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); |
ysr@777 | 280 | for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { |
ysr@777 | 281 | u_char entry = _array->offset_array(c); |
ysr@777 | 282 | if (c - start_card > BlockOffsetArray::power_to_cards_back(1)) { |
johnc@4300 | 283 | guarantee(entry > N_words, |
johnc@4300 | 284 | err_msg("Should be in logarithmic region - " |
johnc@4300 | 285 | "entry: " UINT32_FORMAT ", " |
johnc@4300 | 286 | "_array->offset_array(c): " UINT32_FORMAT ", " |
johnc@4300 | 287 | "N_words: " UINT32_FORMAT, |
johnc@4300 | 288 | entry, _array->offset_array(c), N_words)); |
ysr@777 | 289 | } |
ysr@777 | 290 | size_t backskip = BlockOffsetArray::entry_to_cards_back(entry); |
ysr@777 | 291 | size_t landing_card = c - backskip; |
ysr@777 | 292 | guarantee(landing_card >= (start_card - 1), "Inv"); |
ysr@777 | 293 | if (landing_card >= start_card) { |
johnc@4300 | 294 | guarantee(_array->offset_array(landing_card) <= entry, |
johnc@4300 | 295 | err_msg("Monotonicity - landing_card offset: " UINT32_FORMAT ", " |
johnc@4300 | 296 | "entry: " UINT32_FORMAT, |
johnc@4300 | 297 | _array->offset_array(landing_card), entry)); |
ysr@777 | 298 | } else { |
ysr@777 | 299 | guarantee(landing_card == start_card - 1, "Tautology"); |
johnc@4300 | 300 | // Note that N_words is the maximum offset value |
johnc@4300 | 301 | guarantee(_array->offset_array(landing_card) <= N_words, |
johnc@4300 | 302 | err_msg("landing card offset: " UINT32_FORMAT ", " |
johnc@4300 | 303 | "N_words: " UINT32_FORMAT, |
johnc@4300 | 304 | _array->offset_array(landing_card), N_words)); |
ysr@777 | 305 | } |
ysr@777 | 306 | } |
ysr@777 | 307 | } |
ysr@777 | 308 | |
ysr@777 | 309 | // The range [blk_start, blk_end) represents a single contiguous block |
ysr@777 | 310 | // of storage; modify the block offset table to represent this |
ysr@777 | 311 | // information; Right-open interval: [blk_start, blk_end) |
ysr@777 | 312 | // NOTE: this method does _not_ adjust _unallocated_block. |
ysr@777 | 313 | void |
ysr@777 | 314 | G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 315 | do_block_internal(blk_start, blk_end, Action_single); |
ysr@777 | 316 | } |
ysr@777 | 317 | |
ysr@777 | 318 | // Mark the BOT such that if [blk_start, blk_end) straddles a card |
ysr@777 | 319 | // boundary, the card following the first such boundary is marked |
ysr@777 | 320 | // with the appropriate offset. |
ysr@777 | 321 | // NOTE: this method does _not_ adjust _unallocated_block or |
ysr@777 | 322 | // any cards subsequent to the first one. |
ysr@777 | 323 | void |
ysr@777 | 324 | G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 325 | do_block_internal(blk_start, blk_end, Action_mark); |
ysr@777 | 326 | } |
ysr@777 | 327 | |
ysr@777 | 328 | HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) { |
ysr@777 | 329 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 330 | "addr must be covered by this Array"); |
ysr@777 | 331 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 332 | // allocation. |
ysr@777 | 333 | HeapWord* ub = _unallocated_block; |
ysr@777 | 334 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 335 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 336 | return ub; |
ysr@777 | 337 | } |
ysr@777 | 338 | // Otherwise, find the block start using the table. |
ysr@777 | 339 | HeapWord* q = block_at_or_preceding(addr, false, 0); |
ysr@777 | 340 | return forward_to_block_containing_addr(q, addr); |
ysr@777 | 341 | } |
ysr@777 | 342 | |
ysr@777 | 343 | // This duplicates a little code from the above: unavoidable. |
ysr@777 | 344 | HeapWord* |
ysr@777 | 345 | G1BlockOffsetArray::block_start_unsafe_const(const void* addr) const { |
ysr@777 | 346 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 347 | "addr must be covered by this Array"); |
ysr@777 | 348 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 349 | // allocation. |
ysr@777 | 350 | HeapWord* ub = _unallocated_block; |
ysr@777 | 351 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 352 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 353 | return ub; |
ysr@777 | 354 | } |
ysr@777 | 355 | // Otherwise, find the block start using the table. |
ysr@777 | 356 | HeapWord* q = block_at_or_preceding(addr, false, 0); |
mgerdin@6987 | 357 | HeapWord* n = q + block_size(q); |
ysr@777 | 358 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 359 | } |
ysr@777 | 360 | |
ysr@777 | 361 | |
ysr@777 | 362 | HeapWord* |
ysr@777 | 363 | G1BlockOffsetArray::forward_to_block_containing_addr_slow(HeapWord* q, |
ysr@777 | 364 | HeapWord* n, |
ysr@777 | 365 | const void* addr) { |
ysr@777 | 366 | // We're not in the normal case. We need to handle an important subcase |
ysr@777 | 367 | // here: LAB allocation. An allocation previously recorded in the |
ysr@777 | 368 | // offset table was actually a lab allocation, and was divided into |
ysr@777 | 369 | // several objects subsequently. Fix this situation as we answer the |
ysr@777 | 370 | // query, by updating entries as we cross them. |
iveresov@787 | 371 | |
iveresov@787 | 372 | // If the fist object's end q is at the card boundary. Start refining |
iveresov@787 | 373 | // with the corresponding card (the value of the entry will be basically |
iveresov@787 | 374 | // set to 0). If the object crosses the boundary -- start from the next card. |
coleenp@4037 | 375 | size_t n_index = _array->index_for(n); |
iveresov@787 | 376 | size_t next_index = _array->index_for(n) + !_array->is_card_boundary(n); |
coleenp@4037 | 377 | // Calculate a consistent next boundary. If "n" is not at the boundary |
coleenp@4037 | 378 | // already, step to the boundary. |
coleenp@4037 | 379 | HeapWord* next_boundary = _array->address_for_index(n_index) + |
coleenp@4037 | 380 | (n_index == next_index ? 0 : N_words); |
coleenp@4037 | 381 | assert(next_boundary <= _array->_end, |
coleenp@4037 | 382 | err_msg("next_boundary is beyond the end of the covered region " |
coleenp@4037 | 383 | " next_boundary " PTR_FORMAT " _array->_end " PTR_FORMAT, |
coleenp@4037 | 384 | next_boundary, _array->_end)); |
mgerdin@6987 | 385 | if (addr >= gsp()->top()) return gsp()->top(); |
mgerdin@6987 | 386 | while (next_boundary < addr) { |
mgerdin@6987 | 387 | while (n <= next_boundary) { |
mgerdin@6987 | 388 | q = n; |
mgerdin@6987 | 389 | oop obj = oop(q); |
mgerdin@6987 | 390 | if (obj->klass_or_null() == NULL) return q; |
stefank@6992 | 391 | n += block_size(q); |
ysr@777 | 392 | } |
mgerdin@6987 | 393 | assert(q <= next_boundary && n > next_boundary, "Consequence of loop"); |
mgerdin@6987 | 394 | // [q, n) is the block that crosses the boundary. |
mgerdin@6987 | 395 | alloc_block_work2(&next_boundary, &next_index, q, n); |
ysr@777 | 396 | } |
ysr@777 | 397 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 398 | } |
ysr@777 | 399 | |
ysr@777 | 400 | HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const { |
ysr@777 | 401 | assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); |
ysr@777 | 402 | |
ysr@777 | 403 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 404 | "addr must be covered by this Array"); |
ysr@777 | 405 | // Must read this exactly once because it can be modified by parallel |
ysr@777 | 406 | // allocation. |
ysr@777 | 407 | HeapWord* ub = _unallocated_block; |
ysr@777 | 408 | if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { |
ysr@777 | 409 | assert(ub < _end, "tautology (see above)"); |
ysr@777 | 410 | return ub; |
ysr@777 | 411 | } |
ysr@777 | 412 | |
ysr@777 | 413 | // Otherwise, find the block start using the table, but taking |
ysr@777 | 414 | // care (cf block_start_unsafe() above) not to parse any objects/blocks |
ysr@777 | 415 | // on the cards themsleves. |
ysr@777 | 416 | size_t index = _array->index_for(addr); |
ysr@777 | 417 | assert(_array->address_for_index(index) == addr, |
ysr@777 | 418 | "arg should be start of card"); |
ysr@777 | 419 | |
ysr@777 | 420 | HeapWord* q = (HeapWord*)addr; |
ysr@777 | 421 | uint offset; |
ysr@777 | 422 | do { |
ysr@777 | 423 | offset = _array->offset_array(index--); |
ysr@777 | 424 | q -= offset; |
ysr@777 | 425 | } while (offset == N_words); |
ysr@777 | 426 | assert(q <= addr, "block start should be to left of arg"); |
ysr@777 | 427 | return q; |
ysr@777 | 428 | } |
ysr@777 | 429 | |
ysr@777 | 430 | // Note that the committed size of the covered space may have changed, |
ysr@777 | 431 | // so the table size might also wish to change. |
ysr@777 | 432 | void G1BlockOffsetArray::resize(size_t new_word_size) { |
ysr@777 | 433 | HeapWord* new_end = _bottom + new_word_size; |
ysr@777 | 434 | if (_end < new_end && !init_to_zero()) { |
ysr@777 | 435 | // verify that the old and new boundaries are also card boundaries |
ysr@777 | 436 | assert(_array->is_card_boundary(_end), |
ysr@777 | 437 | "_end not a card boundary"); |
ysr@777 | 438 | assert(_array->is_card_boundary(new_end), |
ysr@777 | 439 | "new _end would not be a card boundary"); |
ysr@777 | 440 | // set all the newly added cards |
ysr@777 | 441 | _array->set_offset_array(_end, new_end, N_words); |
ysr@777 | 442 | } |
ysr@777 | 443 | _end = new_end; // update _end |
ysr@777 | 444 | } |
ysr@777 | 445 | |
ysr@777 | 446 | void G1BlockOffsetArray::set_region(MemRegion mr) { |
ysr@777 | 447 | _bottom = mr.start(); |
ysr@777 | 448 | _end = mr.end(); |
ysr@777 | 449 | } |
ysr@777 | 450 | |
ysr@777 | 451 | // |
ysr@777 | 452 | // threshold_ |
ysr@777 | 453 | // | _index_ |
ysr@777 | 454 | // v v |
ysr@777 | 455 | // +-------+-------+-------+-------+-------+ |
ysr@777 | 456 | // | i-1 | i | i+1 | i+2 | i+3 | |
ysr@777 | 457 | // +-------+-------+-------+-------+-------+ |
ysr@777 | 458 | // ( ^ ] |
ysr@777 | 459 | // block-start |
ysr@777 | 460 | // |
ysr@777 | 461 | void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_, |
ysr@777 | 462 | HeapWord* blk_start, HeapWord* blk_end) { |
ysr@777 | 463 | // For efficiency, do copy-in/copy-out. |
ysr@777 | 464 | HeapWord* threshold = *threshold_; |
ysr@777 | 465 | size_t index = *index_; |
ysr@777 | 466 | |
ysr@777 | 467 | assert(blk_start != NULL && blk_end > blk_start, |
ysr@777 | 468 | "phantom block"); |
ysr@777 | 469 | assert(blk_end > threshold, "should be past threshold"); |
jcoomes@1844 | 470 | assert(blk_start <= threshold, "blk_start should be at or before threshold"); |
ysr@777 | 471 | assert(pointer_delta(threshold, blk_start) <= N_words, |
ysr@777 | 472 | "offset should be <= BlockOffsetSharedArray::N"); |
ysr@777 | 473 | assert(Universe::heap()->is_in_reserved(blk_start), |
ysr@777 | 474 | "reference must be into the heap"); |
ysr@777 | 475 | assert(Universe::heap()->is_in_reserved(blk_end-1), |
ysr@777 | 476 | "limit must be within the heap"); |
ysr@777 | 477 | assert(threshold == _array->_reserved.start() + index*N_words, |
ysr@777 | 478 | "index must agree with threshold"); |
ysr@777 | 479 | |
ysr@777 | 480 | DEBUG_ONLY(size_t orig_index = index;) |
ysr@777 | 481 | |
ysr@777 | 482 | // Mark the card that holds the offset into the block. Note |
ysr@777 | 483 | // that _next_offset_index and _next_offset_threshold are not |
ysr@777 | 484 | // updated until the end of this method. |
ysr@777 | 485 | _array->set_offset_array(index, threshold, blk_start); |
ysr@777 | 486 | |
ysr@777 | 487 | // We need to now mark the subsequent cards that this blk spans. |
ysr@777 | 488 | |
ysr@777 | 489 | // Index of card on which blk ends. |
ysr@777 | 490 | size_t end_index = _array->index_for(blk_end - 1); |
ysr@777 | 491 | |
ysr@777 | 492 | // Are there more cards left to be updated? |
ysr@777 | 493 | if (index + 1 <= end_index) { |
ysr@777 | 494 | HeapWord* rem_st = _array->address_for_index(index + 1); |
ysr@777 | 495 | // Calculate rem_end this way because end_index |
ysr@777 | 496 | // may be the last valid index in the covered region. |
ysr@777 | 497 | HeapWord* rem_end = _array->address_for_index(end_index) + N_words; |
ysr@777 | 498 | set_remainder_to_point_to_start(rem_st, rem_end); |
ysr@777 | 499 | } |
ysr@777 | 500 | |
ysr@777 | 501 | index = end_index + 1; |
ysr@777 | 502 | // Calculate threshold_ this way because end_index |
ysr@777 | 503 | // may be the last valid index in the covered region. |
ysr@777 | 504 | threshold = _array->address_for_index(end_index) + N_words; |
ysr@777 | 505 | assert(threshold >= blk_end, "Incorrect offset threshold"); |
ysr@777 | 506 | |
ysr@777 | 507 | // index_ and threshold_ updated here. |
ysr@777 | 508 | *threshold_ = threshold; |
ysr@777 | 509 | *index_ = index; |
ysr@777 | 510 | |
ysr@777 | 511 | #ifdef ASSERT |
ysr@777 | 512 | // The offset can be 0 if the block starts on a boundary. That |
ysr@777 | 513 | // is checked by an assertion above. |
ysr@777 | 514 | size_t start_index = _array->index_for(blk_start); |
johnc@4300 | 515 | HeapWord* boundary = _array->address_for_index(start_index); |
ysr@777 | 516 | assert((_array->offset_array(orig_index) == 0 && |
ysr@777 | 517 | blk_start == boundary) || |
ysr@777 | 518 | (_array->offset_array(orig_index) > 0 && |
ysr@777 | 519 | _array->offset_array(orig_index) <= N_words), |
johnc@4300 | 520 | err_msg("offset array should have been set - " |
johnc@4300 | 521 | "orig_index offset: " UINT32_FORMAT ", " |
johnc@4300 | 522 | "blk_start: " PTR_FORMAT ", " |
johnc@4300 | 523 | "boundary: " PTR_FORMAT, |
johnc@4300 | 524 | _array->offset_array(orig_index), |
johnc@4300 | 525 | blk_start, boundary)); |
ysr@777 | 526 | for (size_t j = orig_index + 1; j <= end_index; j++) { |
ysr@777 | 527 | assert(_array->offset_array(j) > 0 && |
ysr@777 | 528 | _array->offset_array(j) <= |
ysr@777 | 529 | (u_char) (N_words+BlockOffsetArray::N_powers-1), |
johnc@4300 | 530 | err_msg("offset array should have been set - " |
johnc@4300 | 531 | UINT32_FORMAT " not > 0 OR " |
johnc@4300 | 532 | UINT32_FORMAT " not <= " UINT32_FORMAT, |
johnc@4300 | 533 | _array->offset_array(j), |
johnc@4300 | 534 | _array->offset_array(j), |
johnc@4300 | 535 | (u_char) (N_words+BlockOffsetArray::N_powers-1))); |
ysr@777 | 536 | } |
ysr@777 | 537 | #endif |
ysr@777 | 538 | } |
ysr@777 | 539 | |
tonyp@2453 | 540 | bool |
tonyp@2453 | 541 | G1BlockOffsetArray::verify_for_object(HeapWord* obj_start, |
tonyp@2453 | 542 | size_t word_size) const { |
tonyp@2453 | 543 | size_t first_card = _array->index_for(obj_start); |
tonyp@2453 | 544 | size_t last_card = _array->index_for(obj_start + word_size - 1); |
tonyp@2453 | 545 | if (!_array->is_card_boundary(obj_start)) { |
tonyp@2453 | 546 | // If the object is not on a card boundary the BOT entry of the |
tonyp@2453 | 547 | // first card should point to another object so we should not |
tonyp@2453 | 548 | // check that one. |
tonyp@2453 | 549 | first_card += 1; |
tonyp@2453 | 550 | } |
tonyp@2453 | 551 | for (size_t card = first_card; card <= last_card; card += 1) { |
tonyp@2453 | 552 | HeapWord* card_addr = _array->address_for_index(card); |
tonyp@2453 | 553 | HeapWord* block_start = block_start_const(card_addr); |
tonyp@2453 | 554 | if (block_start != obj_start) { |
tonyp@2453 | 555 | gclog_or_tty->print_cr("block start: "PTR_FORMAT" is incorrect - " |
tonyp@2453 | 556 | "card index: "SIZE_FORMAT" " |
tonyp@2453 | 557 | "card addr: "PTR_FORMAT" BOT entry: %u " |
tonyp@2453 | 558 | "obj: "PTR_FORMAT" word size: "SIZE_FORMAT" " |
tonyp@2453 | 559 | "cards: ["SIZE_FORMAT","SIZE_FORMAT"]", |
tonyp@2453 | 560 | block_start, card, card_addr, |
tonyp@2453 | 561 | _array->offset_array(card), |
tonyp@2453 | 562 | obj_start, word_size, first_card, last_card); |
tonyp@2453 | 563 | return false; |
tonyp@2453 | 564 | } |
tonyp@2453 | 565 | } |
tonyp@2453 | 566 | return true; |
tonyp@2453 | 567 | } |
tonyp@2453 | 568 | |
tonyp@2453 | 569 | #ifndef PRODUCT |
tonyp@2241 | 570 | void |
tonyp@2453 | 571 | G1BlockOffsetArray::print_on(outputStream* out) { |
tonyp@2453 | 572 | size_t from_index = _array->index_for(_bottom); |
tonyp@2453 | 573 | size_t to_index = _array->index_for(_end); |
tonyp@2453 | 574 | out->print_cr(">> BOT for area ["PTR_FORMAT","PTR_FORMAT") " |
tonyp@2453 | 575 | "cards ["SIZE_FORMAT","SIZE_FORMAT")", |
tonyp@2453 | 576 | _bottom, _end, from_index, to_index); |
tonyp@2453 | 577 | for (size_t i = from_index; i < to_index; ++i) { |
tonyp@2453 | 578 | out->print_cr(" entry "SIZE_FORMAT_W(8)" | "PTR_FORMAT" : %3u", |
tonyp@2453 | 579 | i, _array->address_for_index(i), |
tonyp@2453 | 580 | (uint) _array->offset_array(i)); |
tonyp@2453 | 581 | } |
tonyp@2241 | 582 | } |
tonyp@2453 | 583 | #endif // !PRODUCT |
tonyp@2241 | 584 | |
ysr@777 | 585 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 586 | // G1BlockOffsetArrayContigSpace |
ysr@777 | 587 | ////////////////////////////////////////////////////////////////////// |
ysr@777 | 588 | |
ysr@777 | 589 | HeapWord* |
ysr@777 | 590 | G1BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) { |
ysr@777 | 591 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 592 | "addr must be covered by this Array"); |
ysr@777 | 593 | HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); |
ysr@777 | 594 | return forward_to_block_containing_addr(q, addr); |
ysr@777 | 595 | } |
ysr@777 | 596 | |
ysr@777 | 597 | HeapWord* |
ysr@777 | 598 | G1BlockOffsetArrayContigSpace:: |
ysr@777 | 599 | block_start_unsafe_const(const void* addr) const { |
ysr@777 | 600 | assert(_bottom <= addr && addr < _end, |
ysr@777 | 601 | "addr must be covered by this Array"); |
ysr@777 | 602 | HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); |
mgerdin@6987 | 603 | HeapWord* n = q + block_size(q); |
ysr@777 | 604 | return forward_to_block_containing_addr_const(q, n, addr); |
ysr@777 | 605 | } |
ysr@777 | 606 | |
ysr@777 | 607 | G1BlockOffsetArrayContigSpace:: |
ysr@777 | 608 | G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, |
ysr@777 | 609 | MemRegion mr) : |
ysr@777 | 610 | G1BlockOffsetArray(array, mr, true) |
ysr@777 | 611 | { |
ysr@777 | 612 | _next_offset_threshold = NULL; |
ysr@777 | 613 | _next_offset_index = 0; |
ysr@777 | 614 | } |
ysr@777 | 615 | |
tschatzl@7051 | 616 | HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold_raw() { |
tschatzl@7051 | 617 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
tschatzl@7051 | 618 | "just checking"); |
tschatzl@7051 | 619 | _next_offset_index = _array->index_for_raw(_bottom); |
tschatzl@7051 | 620 | _next_offset_index++; |
tschatzl@7051 | 621 | _next_offset_threshold = |
tschatzl@7051 | 622 | _array->address_for_index_raw(_next_offset_index); |
tschatzl@7051 | 623 | return _next_offset_threshold; |
tschatzl@7051 | 624 | } |
tschatzl@7051 | 625 | |
tschatzl@7051 | 626 | void G1BlockOffsetArrayContigSpace::zero_bottom_entry_raw() { |
tschatzl@7051 | 627 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
tschatzl@7051 | 628 | "just checking"); |
tschatzl@7051 | 629 | size_t bottom_index = _array->index_for_raw(_bottom); |
tschatzl@7051 | 630 | assert(_array->address_for_index_raw(bottom_index) == _bottom, |
tschatzl@7051 | 631 | "Precondition of call"); |
tschatzl@7051 | 632 | _array->set_offset_array_raw(bottom_index, 0); |
tschatzl@7051 | 633 | } |
tschatzl@7051 | 634 | |
ysr@777 | 635 | HeapWord* G1BlockOffsetArrayContigSpace::initialize_threshold() { |
ysr@777 | 636 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
ysr@777 | 637 | "just checking"); |
ysr@777 | 638 | _next_offset_index = _array->index_for(_bottom); |
ysr@777 | 639 | _next_offset_index++; |
ysr@777 | 640 | _next_offset_threshold = |
ysr@777 | 641 | _array->address_for_index(_next_offset_index); |
ysr@777 | 642 | return _next_offset_threshold; |
ysr@777 | 643 | } |
ysr@777 | 644 | |
ysr@777 | 645 | void G1BlockOffsetArrayContigSpace::zero_bottom_entry() { |
ysr@777 | 646 | assert(!Universe::heap()->is_in_reserved(_array->_offset_array), |
ysr@777 | 647 | "just checking"); |
ysr@777 | 648 | size_t bottom_index = _array->index_for(_bottom); |
ysr@777 | 649 | assert(_array->address_for_index(bottom_index) == _bottom, |
ysr@777 | 650 | "Precondition of call"); |
ysr@777 | 651 | _array->set_offset_array(bottom_index, 0); |
ysr@777 | 652 | } |
tonyp@2241 | 653 | |
tonyp@2241 | 654 | void |
tonyp@2453 | 655 | G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) { |
tonyp@2453 | 656 | assert(new_top <= _end, "_end should have already been updated"); |
tonyp@2241 | 657 | |
tonyp@2453 | 658 | // The first BOT entry should have offset 0. |
tschatzl@7050 | 659 | reset_bot(); |
tonyp@2453 | 660 | alloc_block(_bottom, new_top); |
tonyp@2453 | 661 | } |
tonyp@2453 | 662 | |
tonyp@2453 | 663 | #ifndef PRODUCT |
tonyp@2453 | 664 | void |
tonyp@2453 | 665 | G1BlockOffsetArrayContigSpace::print_on(outputStream* out) { |
tonyp@2453 | 666 | G1BlockOffsetArray::print_on(out); |
tonyp@2453 | 667 | out->print_cr(" next offset threshold: "PTR_FORMAT, _next_offset_threshold); |
tonyp@2453 | 668 | out->print_cr(" next offset index: "SIZE_FORMAT, _next_offset_index); |
tonyp@2241 | 669 | } |
tonyp@2453 | 670 | #endif // !PRODUCT |