bitMap.cpp revision 6683:08a2164660fb
1153838Sdfr/* 2153838Sdfr * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. 3153838Sdfr * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4153838Sdfr * 5153838Sdfr * This code is free software; you can redistribute it and/or modify it 6153838Sdfr * under the terms of the GNU General Public License version 2 only, as 7153838Sdfr * published by the Free Software Foundation. 8153838Sdfr * 9153838Sdfr * This code is distributed in the hope that it will be useful, but WITHOUT 10153838Sdfr * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11153838Sdfr * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12153838Sdfr * version 2 for more details (a copy is included in the LICENSE file that 13153838Sdfr * accompanied this code). 14153838Sdfr * 15153838Sdfr * You should have received a copy of the GNU General Public License version 16153838Sdfr * 2 along with this work; if not, write to the Free Software Foundation, 17153838Sdfr * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18153838Sdfr * 19153838Sdfr * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20153838Sdfr * or visit www.oracle.com if you need additional information or have any 21153838Sdfr * questions. 22153838Sdfr * 23153838Sdfr */ 24153838Sdfr 25153838Sdfr#include "precompiled.hpp" 26153838Sdfr#include "memory/allocation.inline.hpp" 27153838Sdfr#include "memory/resourceArea.hpp" 28153838Sdfr#include "runtime/atomic.inline.hpp" 29153838Sdfr#include "utilities/bitMap.inline.hpp" 30153838Sdfr#include "utilities/copy.hpp" 31153838Sdfr 32153838SdfrBitMap::BitMap(bm_word_t* map, idx_t size_in_bits) : 33153838Sdfr _map(map), _size(size_in_bits), _map_allocator(false) 34153838Sdfr{ 35153838Sdfr assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption."); 36153838Sdfr assert(size_in_bits >= 0, "just checking"); 37153838Sdfr} 38153838Sdfr 39153838Sdfr 40153838SdfrBitMap::BitMap(idx_t size_in_bits, bool in_resource_area) : 41153838Sdfr _map(NULL), _size(0), _map_allocator(false) 42153838Sdfr{ 43153838Sdfr assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption."); 44153838Sdfr resize(size_in_bits, in_resource_area); 45153838Sdfr} 46153838Sdfr 47153838Sdfrvoid BitMap::resize(idx_t size_in_bits, bool in_resource_area) { 48153838Sdfr assert(size_in_bits >= 0, "just checking"); 49153838Sdfr idx_t old_size_in_words = size_in_words(); 50153838Sdfr bm_word_t* old_map = map(); 51153838Sdfr 52178828Sdfr _size = size_in_bits; 53178828Sdfr idx_t new_size_in_words = size_in_words(); 54178828Sdfr if (in_resource_area) { 55178828Sdfr _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words); 56178828Sdfr Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map, 57178828Sdfr MIN2(old_size_in_words, new_size_in_words)); 58178828Sdfr } else { 59178828Sdfr _map = _map_allocator.reallocate(new_size_in_words); 60178828Sdfr } 61178828Sdfr 62178828Sdfr if (new_size_in_words > old_size_in_words) { 63178828Sdfr clear_range_of_words(old_size_in_words, new_size_in_words); 64178828Sdfr } 65178828Sdfr} 66178828Sdfr 67153838Sdfrvoid BitMap::set_range_within_word(idx_t beg, idx_t end) { 68153838Sdfr // With a valid range (beg <= end), this test ensures that end != 0, as 69178828Sdfr // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 70178828Sdfr if (beg != end) { 71153838Sdfr bm_word_t mask = inverted_bit_mask_for_range(beg, end); 72153838Sdfr *word_addr(beg) |= ~mask; 73153838Sdfr } 74153838Sdfr} 75153838Sdfr 76153838Sdfrvoid BitMap::clear_range_within_word(idx_t beg, idx_t end) { 77153838Sdfr // With a valid range (beg <= end), this test ensures that end != 0, as 78178828Sdfr // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 79153838Sdfr if (beg != end) { 80153838Sdfr bm_word_t mask = inverted_bit_mask_for_range(beg, end); 81153838Sdfr *word_addr(beg) &= mask; 82153838Sdfr } 83153838Sdfr} 84153838Sdfr 85178828Sdfrvoid BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) { 86178828Sdfr assert(value == 0 || value == 1, "0 for clear, 1 for set"); 87178828Sdfr // With a valid range (beg <= end), this test ensures that end != 0, as 88178828Sdfr // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 89153838Sdfr if (beg != end) { 90153838Sdfr intptr_t* pw = (intptr_t*)word_addr(beg); 91153838Sdfr intptr_t w = *pw; 92153838Sdfr intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end); 93153838Sdfr intptr_t nw = value ? (w | ~mr) : (w & mr); 94153838Sdfr while (true) { 95153838Sdfr intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w); 96153838Sdfr if (res == w) break; 97178828Sdfr w = res; 98178828Sdfr nw = value ? (w | ~mr) : (w & mr); 99178828Sdfr } 100178828Sdfr } 101178828Sdfr} 102153838Sdfr 103153838Sdfrvoid BitMap::set_range(idx_t beg, idx_t end) { 104153838Sdfr verify_range(beg, end); 105153838Sdfr 106153838Sdfr idx_t beg_full_word = word_index_round_up(beg); 107153838Sdfr idx_t end_full_word = word_index(end); 108153838Sdfr 109153838Sdfr if (beg_full_word < end_full_word) { 110 // The range includes at least one full word. 111 set_range_within_word(beg, bit_index(beg_full_word)); 112 set_range_of_words(beg_full_word, end_full_word); 113 set_range_within_word(bit_index(end_full_word), end); 114 } else { 115 // The range spans at most 2 partial words. 116 idx_t boundary = MIN2(bit_index(beg_full_word), end); 117 set_range_within_word(beg, boundary); 118 set_range_within_word(boundary, end); 119 } 120} 121 122void BitMap::clear_range(idx_t beg, idx_t end) { 123 verify_range(beg, end); 124 125 idx_t beg_full_word = word_index_round_up(beg); 126 idx_t end_full_word = word_index(end); 127 128 if (beg_full_word < end_full_word) { 129 // The range includes at least one full word. 130 clear_range_within_word(beg, bit_index(beg_full_word)); 131 clear_range_of_words(beg_full_word, end_full_word); 132 clear_range_within_word(bit_index(end_full_word), end); 133 } else { 134 // The range spans at most 2 partial words. 135 idx_t boundary = MIN2(bit_index(beg_full_word), end); 136 clear_range_within_word(beg, boundary); 137 clear_range_within_word(boundary, end); 138 } 139} 140 141void BitMap::set_large_range(idx_t beg, idx_t end) { 142 verify_range(beg, end); 143 144 idx_t beg_full_word = word_index_round_up(beg); 145 idx_t end_full_word = word_index(end); 146 147 assert(end_full_word - beg_full_word >= 32, 148 "the range must include at least 32 bytes"); 149 150 // The range includes at least one full word. 151 set_range_within_word(beg, bit_index(beg_full_word)); 152 set_large_range_of_words(beg_full_word, end_full_word); 153 set_range_within_word(bit_index(end_full_word), end); 154} 155 156void BitMap::clear_large_range(idx_t beg, idx_t end) { 157 verify_range(beg, end); 158 159 idx_t beg_full_word = word_index_round_up(beg); 160 idx_t end_full_word = word_index(end); 161 162 assert(end_full_word - beg_full_word >= 32, 163 "the range must include at least 32 bytes"); 164 165 // The range includes at least one full word. 166 clear_range_within_word(beg, bit_index(beg_full_word)); 167 clear_large_range_of_words(beg_full_word, end_full_word); 168 clear_range_within_word(bit_index(end_full_word), end); 169} 170 171void BitMap::at_put(idx_t offset, bool value) { 172 if (value) { 173 set_bit(offset); 174 } else { 175 clear_bit(offset); 176 } 177} 178 179// Return true to indicate that this thread changed 180// the bit, false to indicate that someone else did. 181// In either case, the requested bit is in the 182// requested state some time during the period that 183// this thread is executing this call. More importantly, 184// if no other thread is executing an action to 185// change the requested bit to a state other than 186// the one that this thread is trying to set it to, 187// then the the bit is in the expected state 188// at exit from this method. However, rather than 189// make such a strong assertion here, based on 190// assuming such constrained use (which though true 191// today, could change in the future to service some 192// funky parallel algorithm), we encourage callers 193// to do such verification, as and when appropriate. 194bool BitMap::par_at_put(idx_t bit, bool value) { 195 return value ? par_set_bit(bit) : par_clear_bit(bit); 196} 197 198void BitMap::at_put_grow(idx_t offset, bool value) { 199 if (offset >= size()) { 200 resize(2 * MAX2(size(), offset)); 201 } 202 at_put(offset, value); 203} 204 205void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) { 206 if (value) { 207 set_range(start_offset, end_offset); 208 } else { 209 clear_range(start_offset, end_offset); 210 } 211} 212 213void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) { 214 verify_range(beg, end); 215 216 idx_t beg_full_word = word_index_round_up(beg); 217 idx_t end_full_word = word_index(end); 218 219 if (beg_full_word < end_full_word) { 220 // The range includes at least one full word. 221 par_put_range_within_word(beg, bit_index(beg_full_word), value); 222 if (value) { 223 set_range_of_words(beg_full_word, end_full_word); 224 } else { 225 clear_range_of_words(beg_full_word, end_full_word); 226 } 227 par_put_range_within_word(bit_index(end_full_word), end, value); 228 } else { 229 // The range spans at most 2 partial words. 230 idx_t boundary = MIN2(bit_index(beg_full_word), end); 231 par_put_range_within_word(beg, boundary, value); 232 par_put_range_within_word(boundary, end, value); 233 } 234 235} 236 237void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) { 238 if (value) { 239 set_large_range(beg, end); 240 } else { 241 clear_large_range(beg, end); 242 } 243} 244 245void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) { 246 verify_range(beg, end); 247 248 idx_t beg_full_word = word_index_round_up(beg); 249 idx_t end_full_word = word_index(end); 250 251 assert(end_full_word - beg_full_word >= 32, 252 "the range must include at least 32 bytes"); 253 254 // The range includes at least one full word. 255 par_put_range_within_word(beg, bit_index(beg_full_word), value); 256 if (value) { 257 set_large_range_of_words(beg_full_word, end_full_word); 258 } else { 259 clear_large_range_of_words(beg_full_word, end_full_word); 260 } 261 par_put_range_within_word(bit_index(end_full_word), end, value); 262} 263 264bool BitMap::contains(const BitMap other) const { 265 assert(size() == other.size(), "must have same size"); 266 bm_word_t* dest_map = map(); 267 bm_word_t* other_map = other.map(); 268 idx_t size = size_in_words(); 269 for (idx_t index = 0; index < size_in_words(); index++) { 270 bm_word_t word_union = dest_map[index] | other_map[index]; 271 // If this has more bits set than dest_map[index], then other is not a 272 // subset. 273 if (word_union != dest_map[index]) return false; 274 } 275 return true; 276} 277 278bool BitMap::intersects(const BitMap other) const { 279 assert(size() == other.size(), "must have same size"); 280 bm_word_t* dest_map = map(); 281 bm_word_t* other_map = other.map(); 282 idx_t size = size_in_words(); 283 for (idx_t index = 0; index < size_in_words(); index++) { 284 if ((dest_map[index] & other_map[index]) != 0) return true; 285 } 286 // Otherwise, no intersection. 287 return false; 288} 289 290void BitMap::set_union(BitMap other) { 291 assert(size() == other.size(), "must have same size"); 292 bm_word_t* dest_map = map(); 293 bm_word_t* other_map = other.map(); 294 idx_t size = size_in_words(); 295 for (idx_t index = 0; index < size_in_words(); index++) { 296 dest_map[index] = dest_map[index] | other_map[index]; 297 } 298} 299 300 301void BitMap::set_difference(BitMap other) { 302 assert(size() == other.size(), "must have same size"); 303 bm_word_t* dest_map = map(); 304 bm_word_t* other_map = other.map(); 305 idx_t size = size_in_words(); 306 for (idx_t index = 0; index < size_in_words(); index++) { 307 dest_map[index] = dest_map[index] & ~(other_map[index]); 308 } 309} 310 311 312void BitMap::set_intersection(BitMap other) { 313 assert(size() == other.size(), "must have same size"); 314 bm_word_t* dest_map = map(); 315 bm_word_t* other_map = other.map(); 316 idx_t size = size_in_words(); 317 for (idx_t index = 0; index < size; index++) { 318 dest_map[index] = dest_map[index] & other_map[index]; 319 } 320} 321 322 323void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) { 324 assert(other.size() >= offset, "offset not in range"); 325 assert(other.size() - offset >= size(), "other not large enough"); 326 // XXX Ideally, we would remove this restriction. 327 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0, 328 "Only handle aligned cases so far."); 329 bm_word_t* dest_map = map(); 330 bm_word_t* other_map = other.map(); 331 idx_t offset_word_ind = word_index(offset); 332 idx_t size = size_in_words(); 333 for (idx_t index = 0; index < size; index++) { 334 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index]; 335 } 336} 337 338bool BitMap::set_union_with_result(BitMap other) { 339 assert(size() == other.size(), "must have same size"); 340 bool changed = false; 341 bm_word_t* dest_map = map(); 342 bm_word_t* other_map = other.map(); 343 idx_t size = size_in_words(); 344 for (idx_t index = 0; index < size; index++) { 345 idx_t temp = map(index) | other_map[index]; 346 changed = changed || (temp != map(index)); 347 map()[index] = temp; 348 } 349 return changed; 350} 351 352 353bool BitMap::set_difference_with_result(BitMap other) { 354 assert(size() == other.size(), "must have same size"); 355 bool changed = false; 356 bm_word_t* dest_map = map(); 357 bm_word_t* other_map = other.map(); 358 idx_t size = size_in_words(); 359 for (idx_t index = 0; index < size; index++) { 360 bm_word_t temp = dest_map[index] & ~(other_map[index]); 361 changed = changed || (temp != dest_map[index]); 362 dest_map[index] = temp; 363 } 364 return changed; 365} 366 367 368bool BitMap::set_intersection_with_result(BitMap other) { 369 assert(size() == other.size(), "must have same size"); 370 bool changed = false; 371 bm_word_t* dest_map = map(); 372 bm_word_t* other_map = other.map(); 373 idx_t size = size_in_words(); 374 for (idx_t index = 0; index < size; index++) { 375 bm_word_t orig = dest_map[index]; 376 bm_word_t temp = orig & other_map[index]; 377 changed = changed || (temp != orig); 378 dest_map[index] = temp; 379 } 380 return changed; 381} 382 383 384void BitMap::set_from(BitMap other) { 385 assert(size() == other.size(), "must have same size"); 386 bm_word_t* dest_map = map(); 387 bm_word_t* other_map = other.map(); 388 idx_t size = size_in_words(); 389 for (idx_t index = 0; index < size; index++) { 390 dest_map[index] = other_map[index]; 391 } 392} 393 394 395bool BitMap::is_same(BitMap other) { 396 assert(size() == other.size(), "must have same size"); 397 bm_word_t* dest_map = map(); 398 bm_word_t* other_map = other.map(); 399 idx_t size = size_in_words(); 400 for (idx_t index = 0; index < size; index++) { 401 if (dest_map[index] != other_map[index]) return false; 402 } 403 return true; 404} 405 406bool BitMap::is_full() const { 407 bm_word_t* word = map(); 408 idx_t rest = size(); 409 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { 410 if (*word != (bm_word_t) AllBits) return false; 411 word++; 412 } 413 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits; 414} 415 416 417bool BitMap::is_empty() const { 418 bm_word_t* word = map(); 419 idx_t rest = size(); 420 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { 421 if (*word != (bm_word_t) NoBits) return false; 422 word++; 423 } 424 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits; 425} 426 427void BitMap::clear_large() { 428 clear_large_range_of_words(0, size_in_words()); 429} 430 431// Note that if the closure itself modifies the bitmap 432// then modifications in and to the left of the _bit_ being 433// currently sampled will not be seen. Note also that the 434// interval [leftOffset, rightOffset) is right open. 435bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) { 436 verify_range(leftOffset, rightOffset); 437 438 idx_t startIndex = word_index(leftOffset); 439 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words()); 440 for (idx_t index = startIndex, offset = leftOffset; 441 offset < rightOffset && index < endIndex; 442 offset = (++index) << LogBitsPerWord) { 443 idx_t rest = map(index) >> (offset & (BitsPerWord - 1)); 444 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) { 445 if (rest & 1) { 446 if (!blk->do_bit(offset)) return false; 447 // resample at each closure application 448 // (see, for instance, CMS bug 4525989) 449 rest = map(index) >> (offset & (BitsPerWord -1)); 450 } 451 rest = rest >> 1; 452 } 453 } 454 return true; 455} 456 457BitMap::idx_t* BitMap::_pop_count_table = NULL; 458 459void BitMap::init_pop_count_table() { 460 if (_pop_count_table == NULL) { 461 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal); 462 for (uint i = 0; i < 256; i++) { 463 table[i] = num_set_bits(i); 464 } 465 466 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table, 467 (intptr_t*) &_pop_count_table, 468 (intptr_t) NULL_WORD); 469 if (res != NULL_WORD) { 470 guarantee( _pop_count_table == (void*) res, "invariant" ); 471 FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal); 472 } 473 } 474} 475 476BitMap::idx_t BitMap::num_set_bits(bm_word_t w) { 477 idx_t bits = 0; 478 479 while (w != 0) { 480 while ((w & 1) == 0) { 481 w >>= 1; 482 } 483 bits++; 484 w >>= 1; 485 } 486 return bits; 487} 488 489BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) { 490 assert(_pop_count_table != NULL, "precondition"); 491 return _pop_count_table[c]; 492} 493 494BitMap::idx_t BitMap::count_one_bits() const { 495 init_pop_count_table(); // If necessary. 496 idx_t sum = 0; 497 typedef unsigned char uchar; 498 for (idx_t i = 0; i < size_in_words(); i++) { 499 bm_word_t w = map()[i]; 500 for (size_t j = 0; j < sizeof(bm_word_t); j++) { 501 sum += num_set_bits_from_table(uchar(w & 255)); 502 w >>= 8; 503 } 504 } 505 return sum; 506} 507 508void BitMap::print_on_error(outputStream* st, const char* prefix) const { 509 st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")", 510 prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte))); 511} 512 513#ifndef PRODUCT 514 515void BitMap::print_on(outputStream* st) const { 516 tty->print("Bitmap(" SIZE_FORMAT "):", size()); 517 for (idx_t index = 0; index < size(); index++) { 518 tty->print("%c", at(index) ? '1' : '0'); 519 } 520 tty->cr(); 521} 522 523class TestBitMap : public AllStatic { 524 const static BitMap::idx_t BITMAP_SIZE = 1024; 525 static void fillBitMap(BitMap& map) { 526 map.set_bit(1); 527 map.set_bit(3); 528 map.set_bit(17); 529 map.set_bit(512); 530 } 531 532 static void testResize(bool in_resource_area) { 533 { 534 BitMap map(0, in_resource_area); 535 map.resize(BITMAP_SIZE, in_resource_area); 536 fillBitMap(map); 537 538 BitMap map2(BITMAP_SIZE, in_resource_area); 539 fillBitMap(map2); 540 assert(map.is_same(map2), "could be"); 541 } 542 543 { 544 BitMap map(128, in_resource_area); 545 map.resize(BITMAP_SIZE, in_resource_area); 546 fillBitMap(map); 547 548 BitMap map2(BITMAP_SIZE, in_resource_area); 549 fillBitMap(map2); 550 assert(map.is_same(map2), "could be"); 551 } 552 553 { 554 BitMap map(BITMAP_SIZE, in_resource_area); 555 map.resize(BITMAP_SIZE, in_resource_area); 556 fillBitMap(map); 557 558 BitMap map2(BITMAP_SIZE, in_resource_area); 559 fillBitMap(map2); 560 assert(map.is_same(map2), "could be"); 561 } 562 } 563 564 static void testResizeResource() { 565 ResourceMark rm; 566 testResize(true); 567 } 568 569 static void testResizeNonResource() { 570 const uintx bitmap_bytes = BITMAP_SIZE / BitsPerByte; 571 572 // Test the default behavior 573 testResize(false); 574 575 { 576 // Make sure that AllocatorMallocLimit is larger than our allocation request 577 // forcing it to call standard malloc() 578 UIntFlagSetting fs(ArrayAllocatorMallocLimit, bitmap_bytes * 4); 579 testResize(false); 580 } 581 { 582 // Make sure that AllocatorMallocLimit is smaller than our allocation request 583 // forcing it to call mmap() (or equivalent) 584 UIntFlagSetting fs(ArrayAllocatorMallocLimit, bitmap_bytes / 4); 585 testResize(false); 586 } 587 } 588 589 public: 590 static void test() { 591 testResizeResource(); 592 testResizeNonResource(); 593 } 594 595}; 596 597void TestBitMap_test() { 598 TestBitMap::test(); 599} 600#endif 601 602 603BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot) 604 : _bits_per_slot(bits_per_slot) 605 , _map(map, size_in_slots * bits_per_slot) 606{ 607} 608 609 610BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot) 611 : _bits_per_slot(bits_per_slot) 612 , _map(size_in_slots * bits_per_slot) 613{ 614} 615