1 /* 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/allocation.inline.hpp" 27 #include "utilities/bitMap.inline.hpp" 28 #include "utilities/copy.hpp" 29 #ifdef TARGET_OS_FAMILY_linux 30 # include "os_linux.inline.hpp" 31 #endif 32 #ifdef TARGET_OS_FAMILY_solaris 33 # include "os_solaris.inline.hpp" 34 #endif 35 #ifdef TARGET_OS_FAMILY_windows 36 # include "os_windows.inline.hpp" 37 #endif 38 #ifdef TARGET_OS_FAMILY_aix 39 # include "os_aix.inline.hpp" 40 #endif 41 #ifdef TARGET_OS_FAMILY_bsd 42 # include "os_bsd.inline.hpp" 43 #endif 44 45 46 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) : 47 _map(map), _size(size_in_bits), _map_allocator(false) 48 { 49 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption."); 50 assert(size_in_bits >= 0, "just checking"); 51 } 52 53 54 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) : 55 _map(NULL), _size(0), _map_allocator(false) 56 { 57 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption."); 58 resize(size_in_bits, in_resource_area); 59 } 60 61 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) { 62 assert(size_in_bits >= 0, "just checking"); 63 idx_t old_size_in_words = size_in_words(); 64 bm_word_t* old_map = map(); 65 66 _size = size_in_bits; 67 idx_t new_size_in_words = size_in_words(); 68 if (in_resource_area) { 69 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words); 70 } else { 71 if (old_map != NULL) { 72 _map_allocator.free(); 73 } 74 _map = _map_allocator.allocate(new_size_in_words); 75 } 76 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map, 77 MIN2(old_size_in_words, new_size_in_words)); 78 if (new_size_in_words > old_size_in_words) { 79 clear_range_of_words(old_size_in_words, size_in_words()); 80 } 81 } 82 83 void BitMap::set_range_within_word(idx_t beg, idx_t end) { 84 // With a valid range (beg <= end), this test ensures that end != 0, as 85 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 86 if (beg != end) { 87 bm_word_t mask = inverted_bit_mask_for_range(beg, end); 88 *word_addr(beg) |= ~mask; 89 } 90 } 91 92 void BitMap::clear_range_within_word(idx_t beg, idx_t end) { 93 // With a valid range (beg <= end), this test ensures that end != 0, as 94 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 95 if (beg != end) { 96 bm_word_t mask = inverted_bit_mask_for_range(beg, end); 97 *word_addr(beg) &= mask; 98 } 99 } 100 101 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) { 102 assert(value == 0 || value == 1, "0 for clear, 1 for set"); 103 // With a valid range (beg <= end), this test ensures that end != 0, as 104 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write. 105 if (beg != end) { 106 intptr_t* pw = (intptr_t*)word_addr(beg); 107 intptr_t w = *pw; 108 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end); 109 intptr_t nw = value ? (w | ~mr) : (w & mr); 110 while (true) { 111 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w); 112 if (res == w) break; 113 w = res; 114 nw = value ? (w | ~mr) : (w & mr); 115 } 116 } 117 } 118 119 void BitMap::set_range(idx_t beg, idx_t end) { 120 verify_range(beg, end); 121 122 idx_t beg_full_word = word_index_round_up(beg); 123 idx_t end_full_word = word_index(end); 124 125 if (beg_full_word < end_full_word) { 126 // The range includes at least one full word. 127 set_range_within_word(beg, bit_index(beg_full_word)); 128 set_range_of_words(beg_full_word, end_full_word); 129 set_range_within_word(bit_index(end_full_word), end); 130 } else { 131 // The range spans at most 2 partial words. 132 idx_t boundary = MIN2(bit_index(beg_full_word), end); 133 set_range_within_word(beg, boundary); 134 set_range_within_word(boundary, end); 135 } 136 } 137 138 void BitMap::clear_range(idx_t beg, idx_t end) { 139 verify_range(beg, end); 140 141 idx_t beg_full_word = word_index_round_up(beg); 142 idx_t end_full_word = word_index(end); 143 144 if (beg_full_word < end_full_word) { 145 // The range includes at least one full word. 146 clear_range_within_word(beg, bit_index(beg_full_word)); 147 clear_range_of_words(beg_full_word, end_full_word); 148 clear_range_within_word(bit_index(end_full_word), end); 149 } else { 150 // The range spans at most 2 partial words. 151 idx_t boundary = MIN2(bit_index(beg_full_word), end); 152 clear_range_within_word(beg, boundary); 153 clear_range_within_word(boundary, end); 154 } 155 } 156 157 void BitMap::set_large_range(idx_t beg, idx_t end) { 158 verify_range(beg, end); 159 160 idx_t beg_full_word = word_index_round_up(beg); 161 idx_t end_full_word = word_index(end); 162 163 assert(end_full_word - beg_full_word >= 32, 164 "the range must include at least 32 bytes"); 165 166 // The range includes at least one full word. 167 set_range_within_word(beg, bit_index(beg_full_word)); 168 set_large_range_of_words(beg_full_word, end_full_word); 169 set_range_within_word(bit_index(end_full_word), end); 170 } 171 172 void BitMap::clear_large_range(idx_t beg, idx_t end) { 173 verify_range(beg, end); 174 175 idx_t beg_full_word = word_index_round_up(beg); 176 idx_t end_full_word = word_index(end); 177 178 assert(end_full_word - beg_full_word >= 32, 179 "the range must include at least 32 bytes"); 180 181 // The range includes at least one full word. 182 clear_range_within_word(beg, bit_index(beg_full_word)); 183 clear_large_range_of_words(beg_full_word, end_full_word); 184 clear_range_within_word(bit_index(end_full_word), end); 185 } 186 187 void BitMap::at_put(idx_t offset, bool value) { 188 if (value) { 189 set_bit(offset); 190 } else { 191 clear_bit(offset); 192 } 193 } 194 195 // Return true to indicate that this thread changed 196 // the bit, false to indicate that someone else did. 197 // In either case, the requested bit is in the 198 // requested state some time during the period that 199 // this thread is executing this call. More importantly, 200 // if no other thread is executing an action to 201 // change the requested bit to a state other than 202 // the one that this thread is trying to set it to, 203 // then the the bit is in the expected state 204 // at exit from this method. However, rather than 205 // make such a strong assertion here, based on 206 // assuming such constrained use (which though true 207 // today, could change in the future to service some 208 // funky parallel algorithm), we encourage callers 209 // to do such verification, as and when appropriate. 210 bool BitMap::par_at_put(idx_t bit, bool value) { 211 return value ? par_set_bit(bit) : par_clear_bit(bit); 212 } 213 214 void BitMap::at_put_grow(idx_t offset, bool value) { 215 if (offset >= size()) { 216 resize(2 * MAX2(size(), offset)); 217 } 218 at_put(offset, value); 219 } 220 221 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) { 222 if (value) { 223 set_range(start_offset, end_offset); 224 } else { 225 clear_range(start_offset, end_offset); 226 } 227 } 228 229 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) { 230 verify_range(beg, end); 231 232 idx_t beg_full_word = word_index_round_up(beg); 233 idx_t end_full_word = word_index(end); 234 235 if (beg_full_word < end_full_word) { 236 // The range includes at least one full word. 237 par_put_range_within_word(beg, bit_index(beg_full_word), value); 238 if (value) { 239 set_range_of_words(beg_full_word, end_full_word); 240 } else { 241 clear_range_of_words(beg_full_word, end_full_word); 242 } 243 par_put_range_within_word(bit_index(end_full_word), end, value); 244 } else { 245 // The range spans at most 2 partial words. 246 idx_t boundary = MIN2(bit_index(beg_full_word), end); 247 par_put_range_within_word(beg, boundary, value); 248 par_put_range_within_word(boundary, end, value); 249 } 250 251 } 252 253 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) { 254 if (value) { 255 set_large_range(beg, end); 256 } else { 257 clear_large_range(beg, end); 258 } 259 } 260 261 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) { 262 verify_range(beg, end); 263 264 idx_t beg_full_word = word_index_round_up(beg); 265 idx_t end_full_word = word_index(end); 266 267 assert(end_full_word - beg_full_word >= 32, 268 "the range must include at least 32 bytes"); 269 270 // The range includes at least one full word. 271 par_put_range_within_word(beg, bit_index(beg_full_word), value); 272 if (value) { 273 set_large_range_of_words(beg_full_word, end_full_word); 274 } else { 275 clear_large_range_of_words(beg_full_word, end_full_word); 276 } 277 par_put_range_within_word(bit_index(end_full_word), end, value); 278 } 279 280 bool BitMap::contains(const BitMap other) const { 281 assert(size() == other.size(), "must have same size"); 282 bm_word_t* dest_map = map(); 283 bm_word_t* other_map = other.map(); 284 idx_t size = size_in_words(); 285 for (idx_t index = 0; index < size_in_words(); index++) { 286 bm_word_t word_union = dest_map[index] | other_map[index]; 287 // If this has more bits set than dest_map[index], then other is not a 288 // subset. 289 if (word_union != dest_map[index]) return false; 290 } 291 return true; 292 } 293 294 bool BitMap::intersects(const BitMap other) const { 295 assert(size() == other.size(), "must have same size"); 296 bm_word_t* dest_map = map(); 297 bm_word_t* other_map = other.map(); 298 idx_t size = size_in_words(); 299 for (idx_t index = 0; index < size_in_words(); index++) { 300 if ((dest_map[index] & other_map[index]) != 0) return true; 301 } 302 // Otherwise, no intersection. 303 return false; 304 } 305 306 void BitMap::set_union(BitMap other) { 307 assert(size() == other.size(), "must have same size"); 308 bm_word_t* dest_map = map(); 309 bm_word_t* other_map = other.map(); 310 idx_t size = size_in_words(); 311 for (idx_t index = 0; index < size_in_words(); index++) { 312 dest_map[index] = dest_map[index] | other_map[index]; 313 } 314 } 315 316 317 void BitMap::set_difference(BitMap other) { 318 assert(size() == other.size(), "must have same size"); 319 bm_word_t* dest_map = map(); 320 bm_word_t* other_map = other.map(); 321 idx_t size = size_in_words(); 322 for (idx_t index = 0; index < size_in_words(); index++) { 323 dest_map[index] = dest_map[index] & ~(other_map[index]); 324 } 325 } 326 327 328 void BitMap::set_intersection(BitMap other) { 329 assert(size() == other.size(), "must have same size"); 330 bm_word_t* dest_map = map(); 331 bm_word_t* other_map = other.map(); 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[index]; 335 } 336 } 337 338 339 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) { 340 assert(other.size() >= offset, "offset not in range"); 341 assert(other.size() - offset >= size(), "other not large enough"); 342 // XXX Ideally, we would remove this restriction. 343 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0, 344 "Only handle aligned cases so far."); 345 bm_word_t* dest_map = map(); 346 bm_word_t* other_map = other.map(); 347 idx_t offset_word_ind = word_index(offset); 348 idx_t size = size_in_words(); 349 for (idx_t index = 0; index < size; index++) { 350 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index]; 351 } 352 } 353 354 bool BitMap::set_union_with_result(BitMap other) { 355 assert(size() == other.size(), "must have same size"); 356 bool changed = false; 357 bm_word_t* dest_map = map(); 358 bm_word_t* other_map = other.map(); 359 idx_t size = size_in_words(); 360 for (idx_t index = 0; index < size; index++) { 361 idx_t temp = map(index) | other_map[index]; 362 changed = changed || (temp != map(index)); 363 map()[index] = temp; 364 } 365 return changed; 366 } 367 368 369 bool BitMap::set_difference_with_result(BitMap other) { 370 assert(size() == other.size(), "must have same size"); 371 bool changed = false; 372 bm_word_t* dest_map = map(); 373 bm_word_t* other_map = other.map(); 374 idx_t size = size_in_words(); 375 for (idx_t index = 0; index < size; index++) { 376 bm_word_t temp = dest_map[index] & ~(other_map[index]); 377 changed = changed || (temp != dest_map[index]); 378 dest_map[index] = temp; 379 } 380 return changed; 381 } 382 383 384 bool BitMap::set_intersection_with_result(BitMap other) { 385 assert(size() == other.size(), "must have same size"); 386 bool changed = false; 387 bm_word_t* dest_map = map(); 388 bm_word_t* other_map = other.map(); 389 idx_t size = size_in_words(); 390 for (idx_t index = 0; index < size; index++) { 391 bm_word_t orig = dest_map[index]; 392 bm_word_t temp = orig & other_map[index]; 393 changed = changed || (temp != orig); 394 dest_map[index] = temp; 395 } 396 return changed; 397 } 398 399 400 void BitMap::set_from(BitMap other) { 401 assert(size() == other.size(), "must have same size"); 402 bm_word_t* dest_map = map(); 403 bm_word_t* other_map = other.map(); 404 idx_t size = size_in_words(); 405 for (idx_t index = 0; index < size; index++) { 406 dest_map[index] = other_map[index]; 407 } 408 } 409 410 411 bool BitMap::is_same(BitMap other) { 412 assert(size() == other.size(), "must have same size"); 413 bm_word_t* dest_map = map(); 414 bm_word_t* other_map = other.map(); 415 idx_t size = size_in_words(); 416 for (idx_t index = 0; index < size; index++) { 417 if (dest_map[index] != other_map[index]) return false; 418 } 419 return true; 420 } 421 422 bool BitMap::is_full() const { 423 bm_word_t* word = map(); 424 idx_t rest = size(); 425 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { 426 if (*word != (bm_word_t) AllBits) return false; 427 word++; 428 } 429 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits; 430 } 431 432 433 bool BitMap::is_empty() const { 434 bm_word_t* word = map(); 435 idx_t rest = size(); 436 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) { 437 if (*word != (bm_word_t) NoBits) return false; 438 word++; 439 } 440 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits; 441 } 442 443 void BitMap::clear_large() { 444 clear_large_range_of_words(0, size_in_words()); 445 } 446 447 // Note that if the closure itself modifies the bitmap 448 // then modifications in and to the left of the _bit_ being 449 // currently sampled will not be seen. Note also that the 450 // interval [leftOffset, rightOffset) is right open. 451 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) { 452 verify_range(leftOffset, rightOffset); 453 454 idx_t startIndex = word_index(leftOffset); 455 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words()); 456 for (idx_t index = startIndex, offset = leftOffset; 457 offset < rightOffset && index < endIndex; 458 offset = (++index) << LogBitsPerWord) { 459 idx_t rest = map(index) >> (offset & (BitsPerWord - 1)); 460 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) { 461 if (rest & 1) { 462 if (!blk->do_bit(offset)) return false; 463 // resample at each closure application 464 // (see, for instance, CMS bug 4525989) 465 rest = map(index) >> (offset & (BitsPerWord -1)); 466 } 467 rest = rest >> 1; 468 } 469 } 470 return true; 471 } 472 473 BitMap::idx_t* BitMap::_pop_count_table = NULL; 474 475 void BitMap::init_pop_count_table() { 476 if (_pop_count_table == NULL) { 477 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal); 478 for (uint i = 0; i < 256; i++) { 479 table[i] = num_set_bits(i); 480 } 481 482 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table, 483 (intptr_t*) &_pop_count_table, 484 (intptr_t) NULL_WORD); 485 if (res != NULL_WORD) { 486 guarantee( _pop_count_table == (void*) res, "invariant" ); 487 FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal); 488 } 489 } 490 } 491 492 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) { 493 idx_t bits = 0; 494 495 while (w != 0) { 496 while ((w & 1) == 0) { 497 w >>= 1; 498 } 499 bits++; 500 w >>= 1; 501 } 502 return bits; 503 } 504 505 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) { 506 assert(_pop_count_table != NULL, "precondition"); 507 return _pop_count_table[c]; 508 } 509 510 BitMap::idx_t BitMap::count_one_bits() const { 511 init_pop_count_table(); // If necessary. 512 idx_t sum = 0; 513 typedef unsigned char uchar; 514 for (idx_t i = 0; i < size_in_words(); i++) { 515 bm_word_t w = map()[i]; 516 for (size_t j = 0; j < sizeof(bm_word_t); j++) { 517 sum += num_set_bits_from_table(uchar(w & 255)); 518 w >>= 8; 519 } 520 } 521 return sum; 522 } 523 524 void BitMap::print_on_error(outputStream* st, const char* prefix) const { 525 st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")", 526 prefix, map(), (char*)map() + (size() >> LogBitsPerByte)); 527 } 528 529 #ifndef PRODUCT 530 531 void BitMap::print_on(outputStream* st) const { 532 tty->print("Bitmap(%d):", size()); 533 for (idx_t index = 0; index < size(); index++) { 534 tty->print("%c", at(index) ? '1' : '0'); 535 } 536 tty->cr(); 537 } 538 539 #endif 540 541 542 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot) 543 : _bits_per_slot(bits_per_slot) 544 , _map(map, size_in_slots * bits_per_slot) 545 { 546 } 547 548 549 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot) 550 : _bits_per_slot(bits_per_slot) 551 , _map(size_in_slots * bits_per_slot) 552 { 553 }