Mercurial > hg > truffle
annotate src/share/vm/memory/blockOffsetTable.cpp @ 17524:89152779163c
Merge with jdk8-b132
| author | Gilles Duboscq <duboscq@ssw.jku.at> |
|---|---|
| date | Wed, 15 Oct 2014 11:59:32 +0200 |
| parents | 4ca6dc0799b6 |
| children | 52b4284cb496 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 17524 | 2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
| 26 #include "gc_interface/collectedHeap.inline.hpp" | |
| 27 #include "memory/blockOffsetTable.inline.hpp" | |
| 28 #include "memory/iterator.hpp" | |
| 29 #include "memory/space.inline.hpp" | |
| 30 #include "memory/universe.hpp" | |
| 31 #include "oops/oop.inline.hpp" | |
| 32 #include "runtime/java.hpp" | |
| 6197 | 33 #include "services/memTracker.hpp" |
| 0 | 34 |
| 35 ////////////////////////////////////////////////////////////////////// | |
| 36 // BlockOffsetSharedArray | |
| 37 ////////////////////////////////////////////////////////////////////// | |
| 38 | |
| 39 BlockOffsetSharedArray::BlockOffsetSharedArray(MemRegion reserved, | |
| 40 size_t init_word_size): | |
| 41 _reserved(reserved), _end(NULL) | |
| 42 { | |
| 43 size_t size = compute_size(reserved.word_size()); | |
| 44 ReservedSpace rs(size); | |
| 45 if (!rs.is_reserved()) { | |
| 46 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); | |
| 47 } | |
| 6197 | 48 |
| 49 MemTracker::record_virtual_memory_type((address)rs.base(), mtGC); | |
| 50 | |
| 0 | 51 if (!_vs.initialize(rs, 0)) { |
| 52 vm_exit_during_initialization("Could not reserve enough space for heap offset array"); | |
| 53 } | |
| 54 _offset_array = (u_char*)_vs.low_boundary(); | |
| 55 resize(init_word_size); | |
| 56 if (TraceBlockOffsetTable) { | |
| 57 gclog_or_tty->print_cr("BlockOffsetSharedArray::BlockOffsetSharedArray: "); | |
| 58 gclog_or_tty->print_cr(" " | |
| 59 " rs.base(): " INTPTR_FORMAT | |
| 60 " rs.size(): " INTPTR_FORMAT | |
| 61 " rs end(): " INTPTR_FORMAT, | |
| 62 rs.base(), rs.size(), rs.base() + rs.size()); | |
| 63 gclog_or_tty->print_cr(" " | |
| 64 " _vs.low_boundary(): " INTPTR_FORMAT | |
| 65 " _vs.high_boundary(): " INTPTR_FORMAT, | |
| 66 _vs.low_boundary(), | |
| 67 _vs.high_boundary()); | |
| 68 } | |
| 69 } | |
| 70 | |
| 71 void BlockOffsetSharedArray::resize(size_t new_word_size) { | |
| 72 assert(new_word_size <= _reserved.word_size(), "Resize larger than reserved"); | |
| 73 size_t new_size = compute_size(new_word_size); | |
| 74 size_t old_size = _vs.committed_size(); | |
| 75 size_t delta; | |
| 76 char* high = _vs.high(); | |
| 77 _end = _reserved.start() + new_word_size; | |
| 78 if (new_size > old_size) { | |
| 79 delta = ReservedSpace::page_align_size_up(new_size - old_size); | |
| 80 assert(delta > 0, "just checking"); | |
| 81 if (!_vs.expand_by(delta)) { | |
| 82 // Do better than this for Merlin | |
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83 vm_exit_out_of_memory(delta, OOM_MMAP_ERROR, "offset table expansion"); |
| 0 | 84 } |
| 85 assert(_vs.high() == high + delta, "invalid expansion"); | |
| 86 } else { | |
| 87 delta = ReservedSpace::page_align_size_down(old_size - new_size); | |
| 88 if (delta == 0) return; | |
| 89 _vs.shrink_by(delta); | |
| 90 assert(_vs.high() == high - delta, "invalid expansion"); | |
| 91 } | |
| 92 } | |
| 93 | |
| 94 bool BlockOffsetSharedArray::is_card_boundary(HeapWord* p) const { | |
| 95 assert(p >= _reserved.start(), "just checking"); | |
| 96 size_t delta = pointer_delta(p, _reserved.start()); | |
| 97 return (delta & right_n_bits(LogN_words)) == (size_t)NoBits; | |
| 98 } | |
| 99 | |
| 100 | |
| 101 ////////////////////////////////////////////////////////////////////// | |
| 102 // BlockOffsetArray | |
| 103 ////////////////////////////////////////////////////////////////////// | |
| 104 | |
| 105 BlockOffsetArray::BlockOffsetArray(BlockOffsetSharedArray* array, | |
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106 MemRegion mr, bool init_to_zero_) : |
| 0 | 107 BlockOffsetTable(mr.start(), mr.end()), |
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108 _array(array) |
| 0 | 109 { |
| 110 assert(_bottom <= _end, "arguments out of order"); | |
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111 set_init_to_zero(init_to_zero_); |
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112 if (!init_to_zero_) { |
| 0 | 113 // initialize cards to point back to mr.start() |
| 114 set_remainder_to_point_to_start(mr.start() + N_words, mr.end()); | |
| 115 _array->set_offset_array(0, 0); // set first card to 0 | |
| 116 } | |
| 117 } | |
| 118 | |
| 119 | |
| 120 // The arguments follow the normal convention of denoting | |
| 121 // a right-open interval: [start, end) | |
| 122 void | |
| 123 BlockOffsetArray:: | |
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124 set_remainder_to_point_to_start(HeapWord* start, HeapWord* end, bool reducing) { |
| 0 | 125 |
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126 check_reducing_assertion(reducing); |
| 0 | 127 if (start >= end) { |
| 128 // The start address is equal to the end address (or to | |
| 129 // the right of the end address) so there are not cards | |
| 130 // that need to be updated.. | |
| 131 return; | |
| 132 } | |
| 133 | |
| 134 // Write the backskip value for each region. | |
| 135 // | |
| 136 // offset | |
| 137 // card 2nd 3rd | |
| 138 // | +- 1st | | | |
| 139 // v v v v | |
| 140 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
| 141 // |x|0|0|0|0|0|0|0|1|1|1|1|1|1| ... |1|1|1|1|2|2|2|2|2|2| ... | |
| 142 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+- | |
| 143 // 11 19 75 | |
| 144 // 12 | |
| 145 // | |
| 146 // offset card is the card that points to the start of an object | |
| 147 // x - offset value of offset card | |
| 148 // 1st - start of first logarithmic region | |
| 149 // 0 corresponds to logarithmic value N_words + 0 and 2**(3 * 0) = 1 | |
| 150 // 2nd - start of second logarithmic region | |
| 151 // 1 corresponds to logarithmic value N_words + 1 and 2**(3 * 1) = 8 | |
| 152 // 3rd - start of third logarithmic region | |
| 153 // 2 corresponds to logarithmic value N_words + 2 and 2**(3 * 2) = 64 | |
| 154 // | |
| 155 // integer below the block offset entry is an example of | |
| 156 // the index of the entry | |
| 157 // | |
| 158 // Given an address, | |
| 159 // Find the index for the address | |
| 160 // Find the block offset table entry | |
| 161 // Convert the entry to a back slide | |
| 162 // (e.g., with today's, offset = 0x81 => | |
| 163 // back slip = 2**(3*(0x81 - N_words)) = 2**3) = 8 | |
| 164 // Move back N (e.g., 8) entries and repeat with the | |
| 165 // value of the new entry | |
| 166 // | |
| 167 size_t start_card = _array->index_for(start); | |
| 168 size_t end_card = _array->index_for(end-1); | |
| 169 assert(start ==_array->address_for_index(start_card), "Precondition"); | |
| 170 assert(end ==_array->address_for_index(end_card)+N_words, "Precondition"); | |
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171 set_remainder_to_point_to_start_incl(start_card, end_card, reducing); // closed interval |
| 0 | 172 } |
| 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 | |
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179 BlockOffsetArray::set_remainder_to_point_to_start_incl(size_t start_card, size_t end_card, bool reducing) { |
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180 |
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181 check_reducing_assertion(reducing); |
| 0 | 182 if (start_card > end_card) { |
| 183 return; | |
| 184 } | |
| 185 assert(start_card > _array->index_for(_bottom), "Cannot be first card"); | |
| 186 assert(_array->offset_array(start_card-1) <= N_words, | |
| 187 "Offset card has an unexpected value"); | |
| 188 size_t start_card_for_region = start_card; | |
| 189 u_char offset = max_jubyte; | |
| 342 | 190 for (int i = 0; i < N_powers; i++) { |
| 0 | 191 // -1 so that the the card with the actual offset is counted. Another -1 |
| 192 // so that the reach ends in this region and not at the start | |
| 193 // of the next. | |
| 194 size_t reach = start_card - 1 + (power_to_cards_back(i+1) - 1); | |
| 195 offset = N_words + i; | |
| 196 if (reach >= end_card) { | |
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197 _array->set_offset_array(start_card_for_region, end_card, offset, reducing); |
| 0 | 198 start_card_for_region = reach + 1; |
| 199 break; | |
| 200 } | |
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201 _array->set_offset_array(start_card_for_region, reach, offset, reducing); |
| 0 | 202 start_card_for_region = reach + 1; |
| 203 } | |
| 204 assert(start_card_for_region > end_card, "Sanity check"); | |
| 205 DEBUG_ONLY(check_all_cards(start_card, end_card);) | |
| 206 } | |
| 207 | |
| 208 // The card-interval [start_card, end_card] is a closed interval; this | |
| 209 // is an expensive check -- use with care and only under protection of | |
| 210 // suitable flag. | |
| 211 void BlockOffsetArray::check_all_cards(size_t start_card, size_t end_card) const { | |
| 212 | |
| 213 if (end_card < start_card) { | |
| 214 return; | |
| 215 } | |
| 216 guarantee(_array->offset_array(start_card) == N_words, "Wrong value in second card"); | |
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217 u_char last_entry = N_words; |
| 0 | 218 for (size_t c = start_card + 1; c <= end_card; c++ /* yeah! */) { |
| 219 u_char entry = _array->offset_array(c); | |
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220 guarantee(entry >= last_entry, "Monotonicity"); |
| 0 | 221 if (c - start_card > power_to_cards_back(1)) { |
| 222 guarantee(entry > N_words, "Should be in logarithmic region"); | |
| 223 } | |
| 224 size_t backskip = entry_to_cards_back(entry); | |
| 225 size_t landing_card = c - backskip; | |
| 226 guarantee(landing_card >= (start_card - 1), "Inv"); | |
| 227 if (landing_card >= start_card) { | |
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228 guarantee(_array->offset_array(landing_card) <= entry, "Monotonicity"); |
| 0 | 229 } else { |
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230 guarantee(landing_card == (start_card - 1), "Tautology"); |
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231 // Note that N_words is the maximum offset value |
| 0 | 232 guarantee(_array->offset_array(landing_card) <= N_words, "Offset value"); |
| 233 } | |
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234 last_entry = entry; // remember for monotonicity test |
| 0 | 235 } |
| 236 } | |
| 237 | |
| 238 | |
| 239 void | |
| 240 BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) { | |
| 241 assert(blk_start != NULL && blk_end > blk_start, | |
| 242 "phantom block"); | |
| 243 single_block(blk_start, blk_end); | |
| 244 } | |
| 245 | |
| 246 // Action_mark - update the BOT for the block [blk_start, blk_end). | |
| 247 // Current typical use is for splitting a block. | |
| 248 // Action_single - udpate the BOT for an allocation. | |
| 249 // Action_verify - BOT verification. | |
| 250 void | |
| 251 BlockOffsetArray::do_block_internal(HeapWord* blk_start, | |
| 252 HeapWord* blk_end, | |
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253 Action action, bool reducing) { |
| 0 | 254 assert(Universe::heap()->is_in_reserved(blk_start), |
| 255 "reference must be into the heap"); | |
| 256 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
| 257 "limit must be within the heap"); | |
| 258 // This is optimized to make the test fast, assuming we only rarely | |
| 259 // cross boundaries. | |
| 260 uintptr_t end_ui = (uintptr_t)(blk_end - 1); | |
| 261 uintptr_t start_ui = (uintptr_t)blk_start; | |
| 262 // Calculate the last card boundary preceding end of blk | |
| 263 intptr_t boundary_before_end = (intptr_t)end_ui; | |
| 264 clear_bits(boundary_before_end, right_n_bits(LogN)); | |
| 265 if (start_ui <= (uintptr_t)boundary_before_end) { | |
| 266 // blk starts at or crosses a boundary | |
| 267 // Calculate index of card on which blk begins | |
| 268 size_t start_index = _array->index_for(blk_start); | |
| 269 // Index of card on which blk ends | |
| 270 size_t end_index = _array->index_for(blk_end - 1); | |
| 271 // Start address of card on which blk begins | |
| 272 HeapWord* boundary = _array->address_for_index(start_index); | |
| 273 assert(boundary <= blk_start, "blk should start at or after boundary"); | |
| 274 if (blk_start != boundary) { | |
| 275 // blk starts strictly after boundary | |
| 276 // adjust card boundary and start_index forward to next card | |
| 277 boundary += N_words; | |
| 278 start_index++; | |
| 279 } | |
| 280 assert(start_index <= end_index, "monotonicity of index_for()"); | |
| 281 assert(boundary <= (HeapWord*)boundary_before_end, "tautology"); | |
| 282 switch (action) { | |
| 283 case Action_mark: { | |
| 284 if (init_to_zero()) { | |
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285 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
| 0 | 286 break; |
| 287 } // Else fall through to the next case | |
| 288 } | |
| 289 case Action_single: { | |
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290 _array->set_offset_array(start_index, boundary, blk_start, reducing); |
| 0 | 291 // We have finished marking the "offset card". We need to now |
| 292 // mark the subsequent cards that this blk spans. | |
| 293 if (start_index < end_index) { | |
| 294 HeapWord* rem_st = _array->address_for_index(start_index) + N_words; | |
| 295 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
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296 set_remainder_to_point_to_start(rem_st, rem_end, reducing); |
| 0 | 297 } |
| 298 break; | |
| 299 } | |
| 300 case Action_check: { | |
| 301 _array->check_offset_array(start_index, boundary, blk_start); | |
| 302 // We have finished checking the "offset card". We need to now | |
| 303 // check the subsequent cards that this blk spans. | |
| 304 check_all_cards(start_index + 1, end_index); | |
| 305 break; | |
| 306 } | |
| 307 default: | |
| 308 ShouldNotReachHere(); | |
| 309 } | |
| 310 } | |
| 311 } | |
| 312 | |
| 313 // The range [blk_start, blk_end) represents a single contiguous block | |
| 314 // of storage; modify the block offset table to represent this | |
| 315 // information; Right-open interval: [blk_start, blk_end) | |
| 316 // NOTE: this method does _not_ adjust _unallocated_block. | |
| 317 void | |
| 318 BlockOffsetArray::single_block(HeapWord* blk_start, | |
| 319 HeapWord* blk_end) { | |
| 320 do_block_internal(blk_start, blk_end, Action_single); | |
| 321 } | |
| 322 | |
| 323 void BlockOffsetArray::verify() const { | |
| 324 // For each entry in the block offset table, verify that | |
| 325 // the entry correctly finds the start of an object at the | |
| 326 // first address covered by the block or to the left of that | |
| 327 // first address. | |
| 328 | |
| 329 size_t next_index = 1; | |
| 330 size_t last_index = last_active_index(); | |
| 331 | |
| 332 // Use for debugging. Initialize to NULL to distinguish the | |
| 333 // first iteration through the while loop. | |
| 334 HeapWord* last_p = NULL; | |
| 335 HeapWord* last_start = NULL; | |
| 336 oop last_o = NULL; | |
| 337 | |
| 338 while (next_index <= last_index) { | |
| 339 // Use an address past the start of the address for | |
| 340 // the entry. | |
| 341 HeapWord* p = _array->address_for_index(next_index) + 1; | |
| 342 if (p >= _end) { | |
| 343 // That's all of the allocated block table. | |
| 344 return; | |
| 345 } | |
| 346 // block_start() asserts that start <= p. | |
| 347 HeapWord* start = block_start(p); | |
| 348 // First check if the start is an allocated block and only | |
| 349 // then if it is a valid object. | |
| 350 oop o = oop(start); | |
| 351 assert(!Universe::is_fully_initialized() || | |
| 352 _sp->is_free_block(start) || | |
| 353 o->is_oop_or_null(), "Bad object was found"); | |
| 354 next_index++; | |
| 355 last_p = p; | |
| 356 last_start = start; | |
| 357 last_o = o; | |
| 358 } | |
| 359 } | |
| 360 | |
| 361 ////////////////////////////////////////////////////////////////////// | |
| 362 // BlockOffsetArrayNonContigSpace | |
| 363 ////////////////////////////////////////////////////////////////////// | |
| 364 | |
| 365 // The block [blk_start, blk_end) has been allocated; | |
| 366 // adjust the block offset table to represent this information; | |
| 367 // NOTE: Clients of BlockOffsetArrayNonContigSpace: consider using | |
| 368 // the somewhat more lightweight split_block() or | |
| 369 // (when init_to_zero()) mark_block() wherever possible. | |
| 370 // right-open interval: [blk_start, blk_end) | |
| 371 void | |
| 372 BlockOffsetArrayNonContigSpace::alloc_block(HeapWord* blk_start, | |
| 373 HeapWord* blk_end) { | |
| 374 assert(blk_start != NULL && blk_end > blk_start, | |
| 375 "phantom block"); | |
| 376 single_block(blk_start, blk_end); | |
| 377 allocated(blk_start, blk_end); | |
| 378 } | |
| 379 | |
| 380 // Adjust BOT to show that a previously whole block has been split | |
| 381 // into two. We verify the BOT for the first part (prefix) and | |
| 382 // update the BOT for the second part (suffix). | |
| 383 // blk is the start of the block | |
| 384 // blk_size is the size of the original block | |
| 385 // left_blk_size is the size of the first part of the split | |
| 386 void BlockOffsetArrayNonContigSpace::split_block(HeapWord* blk, | |
| 387 size_t blk_size, | |
| 388 size_t left_blk_size) { | |
| 389 // Verify that the BOT shows [blk, blk + blk_size) to be one block. | |
| 390 verify_single_block(blk, blk_size); | |
| 391 // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size) | |
| 392 // is one single block. | |
| 393 assert(blk_size > 0, "Should be positive"); | |
| 394 assert(left_blk_size > 0, "Should be positive"); | |
| 395 assert(left_blk_size < blk_size, "Not a split"); | |
| 396 | |
| 397 // Start addresses of prefix block and suffix block. | |
| 398 HeapWord* pref_addr = blk; | |
| 399 HeapWord* suff_addr = blk + left_blk_size; | |
| 400 HeapWord* end_addr = blk + blk_size; | |
| 401 | |
| 402 // Indices for starts of prefix block and suffix block. | |
| 403 size_t pref_index = _array->index_for(pref_addr); | |
| 404 if (_array->address_for_index(pref_index) != pref_addr) { | |
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405 // pref_addr does not begin pref_index |
| 0 | 406 pref_index++; |
| 407 } | |
| 408 | |
| 409 size_t suff_index = _array->index_for(suff_addr); | |
| 410 if (_array->address_for_index(suff_index) != suff_addr) { | |
| 411 // suff_addr does not begin suff_index | |
| 412 suff_index++; | |
| 413 } | |
| 414 | |
| 415 // Definition: A block B, denoted [B_start, B_end) __starts__ | |
| 416 // a card C, denoted [C_start, C_end), where C_start and C_end | |
| 417 // are the heap addresses that card C covers, iff | |
| 418 // B_start <= C_start < B_end. | |
| 419 // | |
| 420 // We say that a card C "is started by" a block B, iff | |
| 421 // B "starts" C. | |
| 422 // | |
| 423 // Note that the cardinality of the set of cards {C} | |
| 424 // started by a block B can be 0, 1, or more. | |
| 425 // | |
| 426 // Below, pref_index and suff_index are, respectively, the | |
| 427 // first (least) card indices that the prefix and suffix of | |
| 428 // the split start; end_index is one more than the index of | |
| 429 // the last (greatest) card that blk starts. | |
| 430 size_t end_index = _array->index_for(end_addr - 1) + 1; | |
| 431 | |
| 432 // Calculate the # cards that the prefix and suffix affect. | |
| 433 size_t num_pref_cards = suff_index - pref_index; | |
| 434 | |
| 435 size_t num_suff_cards = end_index - suff_index; | |
| 436 // Change the cards that need changing | |
| 437 if (num_suff_cards > 0) { | |
| 438 HeapWord* boundary = _array->address_for_index(suff_index); | |
| 439 // Set the offset card for suffix block | |
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440 _array->set_offset_array(suff_index, boundary, suff_addr, true /* reducing */); |
| 0 | 441 // Change any further cards that need changing in the suffix |
| 442 if (num_pref_cards > 0) { | |
| 443 if (num_pref_cards >= num_suff_cards) { | |
| 444 // Unilaterally fix all of the suffix cards: closed card | |
| 445 // index interval in args below. | |
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446 set_remainder_to_point_to_start_incl(suff_index + 1, end_index - 1, true /* reducing */); |
| 0 | 447 } else { |
| 448 // Unilaterally fix the first (num_pref_cards - 1) following | |
| 449 // the "offset card" in the suffix block. | |
| 450 set_remainder_to_point_to_start_incl(suff_index + 1, | |
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451 suff_index + num_pref_cards - 1, true /* reducing */); |
| 0 | 452 // Fix the appropriate cards in the remainder of the |
| 453 // suffix block -- these are the last num_pref_cards | |
| 454 // cards in each power block of the "new" range plumbed | |
| 455 // from suff_addr. | |
| 456 bool more = true; | |
| 457 uint i = 1; | |
| 458 while (more && (i < N_powers)) { | |
| 459 size_t back_by = power_to_cards_back(i); | |
| 460 size_t right_index = suff_index + back_by - 1; | |
| 461 size_t left_index = right_index - num_pref_cards + 1; | |
| 462 if (right_index >= end_index - 1) { // last iteration | |
| 463 right_index = end_index - 1; | |
| 464 more = false; | |
| 465 } | |
| 466 if (back_by > num_pref_cards) { | |
| 467 // Fill in the remainder of this "power block", if it | |
| 468 // is non-null. | |
| 469 if (left_index <= right_index) { | |
| 470 _array->set_offset_array(left_index, right_index, | |
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471 N_words + i - 1, true /* reducing */); |
| 0 | 472 } else { |
| 473 more = false; // we are done | |
| 474 } | |
| 475 i++; | |
| 476 break; | |
| 477 } | |
| 478 i++; | |
| 479 } | |
| 480 while (more && (i < N_powers)) { | |
| 481 size_t back_by = power_to_cards_back(i); | |
| 482 size_t right_index = suff_index + back_by - 1; | |
| 483 size_t left_index = right_index - num_pref_cards + 1; | |
| 484 if (right_index >= end_index - 1) { // last iteration | |
| 485 right_index = end_index - 1; | |
| 486 if (left_index > right_index) { | |
| 487 break; | |
| 488 } | |
| 489 more = false; | |
| 490 } | |
| 491 assert(left_index <= right_index, "Error"); | |
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492 _array->set_offset_array(left_index, right_index, N_words + i - 1, true /* reducing */); |
| 0 | 493 i++; |
| 494 } | |
| 495 } | |
| 496 } // else no more cards to fix in suffix | |
| 497 } // else nothing needs to be done | |
| 498 // Verify that we did the right thing | |
| 499 verify_single_block(pref_addr, left_blk_size); | |
| 500 verify_single_block(suff_addr, blk_size - left_blk_size); | |
| 501 } | |
| 502 | |
| 503 | |
| 504 // Mark the BOT such that if [blk_start, blk_end) straddles a card | |
| 505 // boundary, the card following the first such boundary is marked | |
| 506 // with the appropriate offset. | |
| 507 // NOTE: this method does _not_ adjust _unallocated_block or | |
| 508 // any cards subsequent to the first one. | |
| 509 void | |
| 510 BlockOffsetArrayNonContigSpace::mark_block(HeapWord* blk_start, | |
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511 HeapWord* blk_end, bool reducing) { |
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512 do_block_internal(blk_start, blk_end, Action_mark, reducing); |
| 0 | 513 } |
| 514 | |
| 515 HeapWord* BlockOffsetArrayNonContigSpace::block_start_unsafe( | |
| 516 const void* addr) const { | |
| 517 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
| 518 assert(_bottom <= addr && addr < _end, | |
| 519 "addr must be covered by this Array"); | |
| 520 // Must read this exactly once because it can be modified by parallel | |
| 521 // allocation. | |
| 522 HeapWord* ub = _unallocated_block; | |
| 523 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
| 524 assert(ub < _end, "tautology (see above)"); | |
| 525 return ub; | |
| 526 } | |
| 527 | |
| 528 // Otherwise, find the block start using the table. | |
| 529 size_t index = _array->index_for(addr); | |
| 530 HeapWord* q = _array->address_for_index(index); | |
| 531 | |
| 532 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
| 533 while (offset >= N_words) { | |
| 534 // The excess of the offset from N_words indicates a power of Base | |
| 535 // to go back by. | |
| 536 size_t n_cards_back = entry_to_cards_back(offset); | |
| 537 q -= (N_words * n_cards_back); | |
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538 assert(q >= _sp->bottom(), |
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539 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
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540 q, _sp->bottom())); |
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541 assert(q < _sp->end(), |
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542 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
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543 q, _sp->end())); |
| 0 | 544 index -= n_cards_back; |
| 545 offset = _array->offset_array(index); | |
| 546 } | |
| 547 assert(offset < N_words, "offset too large"); | |
| 548 index--; | |
| 549 q -= offset; | |
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550 assert(q >= _sp->bottom(), |
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551 err_msg("q = " PTR_FORMAT " crossed below bottom = " PTR_FORMAT, |
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552 q, _sp->bottom())); |
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553 assert(q < _sp->end(), |
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554 err_msg("q = " PTR_FORMAT " crossed above end = " PTR_FORMAT, |
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555 q, _sp->end())); |
| 0 | 556 HeapWord* n = q; |
| 557 | |
| 558 while (n <= addr) { | |
| 559 debug_only(HeapWord* last = q); // for debugging | |
| 560 q = n; | |
| 561 n += _sp->block_size(n); | |
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562 assert(n > q, |
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563 err_msg("Looping at n = " PTR_FORMAT " with last = " PTR_FORMAT"," |
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564 " while querying blk_start(" PTR_FORMAT ")" |
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565 " on _sp = [" PTR_FORMAT "," PTR_FORMAT ")", |
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566 n, last, addr, _sp->bottom(), _sp->end())); |
| 0 | 567 } |
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568 assert(q <= addr, |
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569 err_msg("wrong order for current (" INTPTR_FORMAT ")" " <= arg (" INTPTR_FORMAT ")", |
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570 q, addr)); |
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571 assert(addr <= n, |
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572 err_msg("wrong order for arg (" INTPTR_FORMAT ") <= next (" INTPTR_FORMAT ")", |
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573 addr, n)); |
| 0 | 574 return q; |
| 575 } | |
| 576 | |
| 577 HeapWord* BlockOffsetArrayNonContigSpace::block_start_careful( | |
| 578 const void* addr) const { | |
| 579 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
| 580 | |
| 581 assert(_bottom <= addr && addr < _end, | |
| 582 "addr must be covered by this Array"); | |
| 583 // Must read this exactly once because it can be modified by parallel | |
| 584 // allocation. | |
| 585 HeapWord* ub = _unallocated_block; | |
| 586 if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) { | |
| 587 assert(ub < _end, "tautology (see above)"); | |
| 588 return ub; | |
| 589 } | |
| 590 | |
| 591 // Otherwise, find the block start using the table, but taking | |
| 592 // care (cf block_start_unsafe() above) not to parse any objects/blocks | |
| 14909 | 593 // on the cards themsleves. |
| 0 | 594 size_t index = _array->index_for(addr); |
| 595 assert(_array->address_for_index(index) == addr, | |
| 596 "arg should be start of card"); | |
| 597 | |
| 598 HeapWord* q = (HeapWord*)addr; | |
| 599 uint offset; | |
| 600 do { | |
| 601 offset = _array->offset_array(index); | |
| 602 if (offset < N_words) { | |
| 603 q -= offset; | |
| 604 } else { | |
| 605 size_t n_cards_back = entry_to_cards_back(offset); | |
| 606 q -= (n_cards_back * N_words); | |
| 607 index -= n_cards_back; | |
| 608 } | |
| 609 } while (offset >= N_words); | |
| 610 assert(q <= addr, "block start should be to left of arg"); | |
| 611 return q; | |
| 612 } | |
| 613 | |
| 614 #ifndef PRODUCT | |
| 615 // Verification & debugging - ensure that the offset table reflects the fact | |
| 616 // that the block [blk_start, blk_end) or [blk, blk + size) is a | |
| 617 // single block of storage. NOTE: can't const this because of | |
| 618 // call to non-const do_block_internal() below. | |
| 619 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
| 620 HeapWord* blk_start, HeapWord* blk_end) { | |
| 621 if (VerifyBlockOffsetArray) { | |
| 622 do_block_internal(blk_start, blk_end, Action_check); | |
| 623 } | |
| 624 } | |
| 625 | |
| 626 void BlockOffsetArrayNonContigSpace::verify_single_block( | |
| 627 HeapWord* blk, size_t size) { | |
| 628 verify_single_block(blk, blk + size); | |
| 629 } | |
| 630 | |
| 631 // Verify that the given block is before _unallocated_block | |
| 632 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
| 633 HeapWord* blk_start, HeapWord* blk_end) const { | |
| 634 if (BlockOffsetArrayUseUnallocatedBlock) { | |
| 635 assert(blk_start < blk_end, "Block inconsistency?"); | |
| 636 assert(blk_end <= _unallocated_block, "_unallocated_block problem"); | |
| 637 } | |
| 638 } | |
| 639 | |
| 640 void BlockOffsetArrayNonContigSpace::verify_not_unallocated( | |
| 641 HeapWord* blk, size_t size) const { | |
| 642 verify_not_unallocated(blk, blk + size); | |
| 643 } | |
| 644 #endif // PRODUCT | |
| 645 | |
| 646 size_t BlockOffsetArrayNonContigSpace::last_active_index() const { | |
| 647 if (_unallocated_block == _bottom) { | |
| 648 return 0; | |
| 649 } else { | |
| 650 return _array->index_for(_unallocated_block - 1); | |
| 651 } | |
| 652 } | |
| 653 | |
| 654 ////////////////////////////////////////////////////////////////////// | |
| 655 // BlockOffsetArrayContigSpace | |
| 656 ////////////////////////////////////////////////////////////////////// | |
| 657 | |
| 658 HeapWord* BlockOffsetArrayContigSpace::block_start_unsafe(const void* addr) const { | |
| 659 assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); | |
| 660 | |
| 661 // Otherwise, find the block start using the table. | |
| 662 assert(_bottom <= addr && addr < _end, | |
| 663 "addr must be covered by this Array"); | |
| 664 size_t index = _array->index_for(addr); | |
| 665 // We must make sure that the offset table entry we use is valid. If | |
| 666 // "addr" is past the end, start at the last known one and go forward. | |
| 667 index = MIN2(index, _next_offset_index-1); | |
| 668 HeapWord* q = _array->address_for_index(index); | |
| 669 | |
| 670 uint offset = _array->offset_array(index); // Extend u_char to uint. | |
| 671 while (offset > N_words) { | |
| 672 // The excess of the offset from N_words indicates a power of Base | |
| 673 // to go back by. | |
| 674 size_t n_cards_back = entry_to_cards_back(offset); | |
| 675 q -= (N_words * n_cards_back); | |
| 676 assert(q >= _sp->bottom(), "Went below bottom!"); | |
| 677 index -= n_cards_back; | |
| 678 offset = _array->offset_array(index); | |
| 679 } | |
| 680 while (offset == N_words) { | |
| 681 assert(q >= _sp->bottom(), "Went below bottom!"); | |
| 682 q -= N_words; | |
| 683 index--; | |
| 684 offset = _array->offset_array(index); | |
| 685 } | |
| 686 assert(offset < N_words, "offset too large"); | |
| 687 q -= offset; | |
| 688 HeapWord* n = q; | |
| 689 | |
| 690 while (n <= addr) { | |
| 691 debug_only(HeapWord* last = q); // for debugging | |
| 692 q = n; | |
| 693 n += _sp->block_size(n); | |
| 694 } | |
| 695 assert(q <= addr, "wrong order for current and arg"); | |
| 696 assert(addr <= n, "wrong order for arg and next"); | |
| 697 return q; | |
| 698 } | |
| 699 | |
| 700 // | |
| 701 // _next_offset_threshold | |
| 702 // | _next_offset_index | |
| 703 // v v | |
| 704 // +-------+-------+-------+-------+-------+ | |
| 705 // | i-1 | i | i+1 | i+2 | i+3 | | |
| 706 // +-------+-------+-------+-------+-------+ | |
| 707 // ( ^ ] | |
| 708 // block-start | |
| 709 // | |
| 710 | |
| 711 void BlockOffsetArrayContigSpace::alloc_block_work(HeapWord* blk_start, | |
| 712 HeapWord* blk_end) { | |
| 713 assert(blk_start != NULL && blk_end > blk_start, | |
| 714 "phantom block"); | |
| 715 assert(blk_end > _next_offset_threshold, | |
| 716 "should be past threshold"); | |
| 717 assert(blk_start <= _next_offset_threshold, | |
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718 "blk_start should be at or before threshold"); |
| 0 | 719 assert(pointer_delta(_next_offset_threshold, blk_start) <= N_words, |
| 720 "offset should be <= BlockOffsetSharedArray::N"); | |
| 721 assert(Universe::heap()->is_in_reserved(blk_start), | |
| 722 "reference must be into the heap"); | |
| 723 assert(Universe::heap()->is_in_reserved(blk_end-1), | |
| 724 "limit must be within the heap"); | |
| 725 assert(_next_offset_threshold == | |
| 726 _array->_reserved.start() + _next_offset_index*N_words, | |
| 727 "index must agree with threshold"); | |
| 728 | |
| 729 debug_only(size_t orig_next_offset_index = _next_offset_index;) | |
| 730 | |
| 731 // Mark the card that holds the offset into the block. Note | |
| 732 // that _next_offset_index and _next_offset_threshold are not | |
| 733 // updated until the end of this method. | |
| 734 _array->set_offset_array(_next_offset_index, | |
| 735 _next_offset_threshold, | |
| 736 blk_start); | |
| 737 | |
| 738 // We need to now mark the subsequent cards that this blk spans. | |
| 739 | |
| 740 // Index of card on which blk ends. | |
| 741 size_t end_index = _array->index_for(blk_end - 1); | |
| 742 | |
| 743 // Are there more cards left to be updated? | |
| 744 if (_next_offset_index + 1 <= end_index) { | |
| 745 HeapWord* rem_st = _array->address_for_index(_next_offset_index + 1); | |
| 746 // Calculate rem_end this way because end_index | |
| 747 // may be the last valid index in the covered region. | |
| 748 HeapWord* rem_end = _array->address_for_index(end_index) + N_words; | |
| 749 set_remainder_to_point_to_start(rem_st, rem_end); | |
| 750 } | |
| 751 | |
| 752 // _next_offset_index and _next_offset_threshold updated here. | |
| 753 _next_offset_index = end_index + 1; | |
| 754 // Calculate _next_offset_threshold this way because end_index | |
| 755 // may be the last valid index in the covered region. | |
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756 _next_offset_threshold = _array->address_for_index(end_index) + N_words; |
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757 assert(_next_offset_threshold >= blk_end, "Incorrect offset threshold"); |
| 0 | 758 |
| 759 #ifdef ASSERT | |
| 760 // The offset can be 0 if the block starts on a boundary. That | |
| 761 // is checked by an assertion above. | |
| 762 size_t start_index = _array->index_for(blk_start); | |
| 763 HeapWord* boundary = _array->address_for_index(start_index); | |
| 764 assert((_array->offset_array(orig_next_offset_index) == 0 && | |
| 765 blk_start == boundary) || | |
| 766 (_array->offset_array(orig_next_offset_index) > 0 && | |
| 767 _array->offset_array(orig_next_offset_index) <= N_words), | |
| 768 "offset array should have been set"); | |
| 769 for (size_t j = orig_next_offset_index + 1; j <= end_index; j++) { | |
| 770 assert(_array->offset_array(j) > 0 && | |
| 771 _array->offset_array(j) <= (u_char) (N_words+N_powers-1), | |
| 772 "offset array should have been set"); | |
| 773 } | |
| 774 #endif | |
| 775 } | |
| 776 | |
| 777 HeapWord* BlockOffsetArrayContigSpace::initialize_threshold() { | |
| 778 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
| 779 "just checking"); | |
| 780 _next_offset_index = _array->index_for(_bottom); | |
| 781 _next_offset_index++; | |
| 782 _next_offset_threshold = | |
| 783 _array->address_for_index(_next_offset_index); | |
| 784 return _next_offset_threshold; | |
| 785 } | |
| 786 | |
| 787 void BlockOffsetArrayContigSpace::zero_bottom_entry() { | |
| 788 assert(!Universe::heap()->is_in_reserved(_array->_offset_array), | |
| 789 "just checking"); | |
| 790 size_t bottom_index = _array->index_for(_bottom); | |
| 791 _array->set_offset_array(bottom_index, 0); | |
| 792 } | |
| 793 | |
| 794 size_t BlockOffsetArrayContigSpace::last_active_index() const { | |
| 795 size_t result = _next_offset_index - 1; | |
| 796 return result >= 0 ? result : 0; | |
| 797 } |