src/share/vm/utilities/bitMap.cpp

Sat, 11 Dec 2010 13:20:56 -0500

author
zgu
date
Sat, 11 Dec 2010 13:20:56 -0500
changeset 2364
2d4762ec74af
parent 2314
f95d63e2154a
child 3156
f08d439fab8c
permissions
-rw-r--r--

7003748: Decode C stack frames when symbols are presented (PhoneHome project)
Summary: Implemented in-process C native stack frame decoding when symbols are available.
Reviewed-by: coleenp, never

duke@435 1 /*
stefank@2314 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 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.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "memory/allocation.inline.hpp"
stefank@2314 27 #include "utilities/bitMap.inline.hpp"
stefank@2314 28 #include "utilities/copy.hpp"
stefank@2314 29 #ifdef TARGET_OS_FAMILY_linux
stefank@2314 30 # include "os_linux.inline.hpp"
stefank@2314 31 #endif
stefank@2314 32 #ifdef TARGET_OS_FAMILY_solaris
stefank@2314 33 # include "os_solaris.inline.hpp"
stefank@2314 34 #endif
stefank@2314 35 #ifdef TARGET_OS_FAMILY_windows
stefank@2314 36 # include "os_windows.inline.hpp"
stefank@2314 37 #endif
duke@435 38
duke@435 39
ysr@777 40 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
ysr@777 41 _map(map), _size(size_in_bits)
ysr@777 42 {
ysr@777 43 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
duke@435 44 assert(size_in_bits >= 0, "just checking");
duke@435 45 }
duke@435 46
duke@435 47
ysr@777 48 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
ysr@777 49 _map(NULL), _size(0)
ysr@777 50 {
ysr@777 51 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
ysr@777 52 resize(size_in_bits, in_resource_area);
duke@435 53 }
duke@435 54
ysr@777 55 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
duke@435 56 assert(size_in_bits >= 0, "just checking");
ysr@777 57 idx_t old_size_in_words = size_in_words();
ysr@777 58 bm_word_t* old_map = map();
ysr@777 59
duke@435 60 _size = size_in_bits;
ysr@777 61 idx_t new_size_in_words = size_in_words();
ysr@777 62 if (in_resource_area) {
ysr@777 63 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
ysr@777 64 } else {
ysr@777 65 if (old_map != NULL) FREE_C_HEAP_ARRAY(bm_word_t, _map);
ysr@777 66 _map = NEW_C_HEAP_ARRAY(bm_word_t, new_size_in_words);
ysr@777 67 }
ysr@777 68 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
ysr@777 69 MIN2(old_size_in_words, new_size_in_words));
duke@435 70 if (new_size_in_words > old_size_in_words) {
duke@435 71 clear_range_of_words(old_size_in_words, size_in_words());
duke@435 72 }
duke@435 73 }
duke@435 74
duke@435 75 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
duke@435 76 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 77 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 78 if (beg != end) {
ysr@777 79 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 80 *word_addr(beg) |= ~mask;
duke@435 81 }
duke@435 82 }
duke@435 83
duke@435 84 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
duke@435 85 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 86 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 87 if (beg != end) {
ysr@777 88 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
duke@435 89 *word_addr(beg) &= mask;
duke@435 90 }
duke@435 91 }
duke@435 92
duke@435 93 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
duke@435 94 assert(value == 0 || value == 1, "0 for clear, 1 for set");
duke@435 95 // With a valid range (beg <= end), this test ensures that end != 0, as
duke@435 96 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
duke@435 97 if (beg != end) {
duke@435 98 intptr_t* pw = (intptr_t*)word_addr(beg);
duke@435 99 intptr_t w = *pw;
duke@435 100 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
duke@435 101 intptr_t nw = value ? (w | ~mr) : (w & mr);
duke@435 102 while (true) {
duke@435 103 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
duke@435 104 if (res == w) break;
duke@435 105 w = *pw;
duke@435 106 nw = value ? (w | ~mr) : (w & mr);
duke@435 107 }
duke@435 108 }
duke@435 109 }
duke@435 110
duke@435 111 void BitMap::set_range(idx_t beg, idx_t end) {
duke@435 112 verify_range(beg, end);
duke@435 113
duke@435 114 idx_t beg_full_word = word_index_round_up(beg);
duke@435 115 idx_t end_full_word = word_index(end);
duke@435 116
duke@435 117 if (beg_full_word < end_full_word) {
duke@435 118 // The range includes at least one full word.
duke@435 119 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 120 set_range_of_words(beg_full_word, end_full_word);
duke@435 121 set_range_within_word(bit_index(end_full_word), end);
duke@435 122 } else {
duke@435 123 // The range spans at most 2 partial words.
duke@435 124 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 125 set_range_within_word(beg, boundary);
duke@435 126 set_range_within_word(boundary, end);
duke@435 127 }
duke@435 128 }
duke@435 129
duke@435 130 void BitMap::clear_range(idx_t beg, idx_t end) {
duke@435 131 verify_range(beg, end);
duke@435 132
duke@435 133 idx_t beg_full_word = word_index_round_up(beg);
duke@435 134 idx_t end_full_word = word_index(end);
duke@435 135
duke@435 136 if (beg_full_word < end_full_word) {
duke@435 137 // The range includes at least one full word.
duke@435 138 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 139 clear_range_of_words(beg_full_word, end_full_word);
duke@435 140 clear_range_within_word(bit_index(end_full_word), end);
duke@435 141 } else {
duke@435 142 // The range spans at most 2 partial words.
duke@435 143 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 144 clear_range_within_word(beg, boundary);
duke@435 145 clear_range_within_word(boundary, end);
duke@435 146 }
duke@435 147 }
duke@435 148
duke@435 149 void BitMap::set_large_range(idx_t beg, idx_t end) {
duke@435 150 verify_range(beg, end);
duke@435 151
duke@435 152 idx_t beg_full_word = word_index_round_up(beg);
duke@435 153 idx_t end_full_word = word_index(end);
duke@435 154
duke@435 155 assert(end_full_word - beg_full_word >= 32,
duke@435 156 "the range must include at least 32 bytes");
duke@435 157
duke@435 158 // The range includes at least one full word.
duke@435 159 set_range_within_word(beg, bit_index(beg_full_word));
duke@435 160 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 161 set_range_within_word(bit_index(end_full_word), end);
duke@435 162 }
duke@435 163
duke@435 164 void BitMap::clear_large_range(idx_t beg, idx_t end) {
duke@435 165 verify_range(beg, end);
duke@435 166
duke@435 167 idx_t beg_full_word = word_index_round_up(beg);
duke@435 168 idx_t end_full_word = word_index(end);
duke@435 169
duke@435 170 assert(end_full_word - beg_full_word >= 32,
duke@435 171 "the range must include at least 32 bytes");
duke@435 172
duke@435 173 // The range includes at least one full word.
duke@435 174 clear_range_within_word(beg, bit_index(beg_full_word));
duke@435 175 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 176 clear_range_within_word(bit_index(end_full_word), end);
duke@435 177 }
duke@435 178
ysr@777 179 void BitMap::mostly_disjoint_range_union(BitMap* from_bitmap,
ysr@777 180 idx_t from_start_index,
ysr@777 181 idx_t to_start_index,
ysr@777 182 size_t word_num) {
ysr@777 183 // Ensure that the parameters are correct.
ysr@777 184 // These shouldn't be that expensive to check, hence I left them as
ysr@777 185 // guarantees.
ysr@777 186 guarantee(from_bitmap->bit_in_word(from_start_index) == 0,
ysr@777 187 "it should be aligned on a word boundary");
ysr@777 188 guarantee(bit_in_word(to_start_index) == 0,
ysr@777 189 "it should be aligned on a word boundary");
ysr@777 190 guarantee(word_num >= 2, "word_num should be at least 2");
ysr@777 191
ysr@777 192 intptr_t* from = (intptr_t*) from_bitmap->word_addr(from_start_index);
ysr@777 193 intptr_t* to = (intptr_t*) word_addr(to_start_index);
ysr@777 194
ysr@777 195 if (*from != 0) {
ysr@777 196 // if it's 0, then there's no point in doing the CAS
ysr@777 197 while (true) {
ysr@777 198 intptr_t old_value = *to;
ysr@777 199 intptr_t new_value = old_value | *from;
ysr@777 200 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 201 if (res == old_value) break;
ysr@777 202 }
ysr@777 203 }
ysr@777 204 ++from;
ysr@777 205 ++to;
ysr@777 206
ysr@777 207 for (size_t i = 0; i < word_num - 2; ++i) {
ysr@777 208 if (*from != 0) {
ysr@777 209 // if it's 0, then there's no point in doing the CAS
ysr@777 210 assert(*to == 0, "nobody else should be writing here");
ysr@777 211 intptr_t new_value = *from;
ysr@777 212 *to = new_value;
ysr@777 213 }
ysr@777 214
ysr@777 215 ++from;
ysr@777 216 ++to;
ysr@777 217 }
ysr@777 218
ysr@777 219 if (*from != 0) {
ysr@777 220 // if it's 0, then there's no point in doing the CAS
ysr@777 221 while (true) {
ysr@777 222 intptr_t old_value = *to;
ysr@777 223 intptr_t new_value = old_value | *from;
ysr@777 224 intptr_t res = Atomic::cmpxchg_ptr(new_value, to, old_value);
ysr@777 225 if (res == old_value) break;
ysr@777 226 }
ysr@777 227 }
ysr@777 228
ysr@777 229 // the -1 is because we didn't advance them after the final CAS
ysr@777 230 assert(from ==
ysr@777 231 (intptr_t*) from_bitmap->word_addr(from_start_index) + word_num - 1,
ysr@777 232 "invariant");
ysr@777 233 assert(to == (intptr_t*) word_addr(to_start_index) + word_num - 1,
ysr@777 234 "invariant");
ysr@777 235 }
ysr@777 236
duke@435 237 void BitMap::at_put(idx_t offset, bool value) {
duke@435 238 if (value) {
duke@435 239 set_bit(offset);
duke@435 240 } else {
duke@435 241 clear_bit(offset);
duke@435 242 }
duke@435 243 }
duke@435 244
duke@435 245 // Return true to indicate that this thread changed
duke@435 246 // the bit, false to indicate that someone else did.
duke@435 247 // In either case, the requested bit is in the
duke@435 248 // requested state some time during the period that
duke@435 249 // this thread is executing this call. More importantly,
duke@435 250 // if no other thread is executing an action to
duke@435 251 // change the requested bit to a state other than
duke@435 252 // the one that this thread is trying to set it to,
duke@435 253 // then the the bit is in the expected state
duke@435 254 // at exit from this method. However, rather than
duke@435 255 // make such a strong assertion here, based on
duke@435 256 // assuming such constrained use (which though true
duke@435 257 // today, could change in the future to service some
duke@435 258 // funky parallel algorithm), we encourage callers
duke@435 259 // to do such verification, as and when appropriate.
duke@435 260 bool BitMap::par_at_put(idx_t bit, bool value) {
duke@435 261 return value ? par_set_bit(bit) : par_clear_bit(bit);
duke@435 262 }
duke@435 263
duke@435 264 void BitMap::at_put_grow(idx_t offset, bool value) {
duke@435 265 if (offset >= size()) {
duke@435 266 resize(2 * MAX2(size(), offset));
duke@435 267 }
duke@435 268 at_put(offset, value);
duke@435 269 }
duke@435 270
duke@435 271 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
duke@435 272 if (value) {
duke@435 273 set_range(start_offset, end_offset);
duke@435 274 } else {
duke@435 275 clear_range(start_offset, end_offset);
duke@435 276 }
duke@435 277 }
duke@435 278
duke@435 279 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
duke@435 280 verify_range(beg, end);
duke@435 281
duke@435 282 idx_t beg_full_word = word_index_round_up(beg);
duke@435 283 idx_t end_full_word = word_index(end);
duke@435 284
duke@435 285 if (beg_full_word < end_full_word) {
duke@435 286 // The range includes at least one full word.
duke@435 287 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 288 if (value) {
duke@435 289 set_range_of_words(beg_full_word, end_full_word);
duke@435 290 } else {
duke@435 291 clear_range_of_words(beg_full_word, end_full_word);
duke@435 292 }
duke@435 293 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 294 } else {
duke@435 295 // The range spans at most 2 partial words.
duke@435 296 idx_t boundary = MIN2(bit_index(beg_full_word), end);
duke@435 297 par_put_range_within_word(beg, boundary, value);
duke@435 298 par_put_range_within_word(boundary, end, value);
duke@435 299 }
duke@435 300
duke@435 301 }
duke@435 302
duke@435 303 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 304 if (value) {
duke@435 305 set_large_range(beg, end);
duke@435 306 } else {
duke@435 307 clear_large_range(beg, end);
duke@435 308 }
duke@435 309 }
duke@435 310
duke@435 311 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
duke@435 312 verify_range(beg, end);
duke@435 313
duke@435 314 idx_t beg_full_word = word_index_round_up(beg);
duke@435 315 idx_t end_full_word = word_index(end);
duke@435 316
duke@435 317 assert(end_full_word - beg_full_word >= 32,
duke@435 318 "the range must include at least 32 bytes");
duke@435 319
duke@435 320 // The range includes at least one full word.
duke@435 321 par_put_range_within_word(beg, bit_index(beg_full_word), value);
duke@435 322 if (value) {
duke@435 323 set_large_range_of_words(beg_full_word, end_full_word);
duke@435 324 } else {
duke@435 325 clear_large_range_of_words(beg_full_word, end_full_word);
duke@435 326 }
duke@435 327 par_put_range_within_word(bit_index(end_full_word), end, value);
duke@435 328 }
duke@435 329
duke@435 330 bool BitMap::contains(const BitMap other) const {
duke@435 331 assert(size() == other.size(), "must have same size");
ysr@777 332 bm_word_t* dest_map = map();
ysr@777 333 bm_word_t* other_map = other.map();
duke@435 334 idx_t size = size_in_words();
duke@435 335 for (idx_t index = 0; index < size_in_words(); index++) {
ysr@777 336 bm_word_t word_union = dest_map[index] | other_map[index];
duke@435 337 // If this has more bits set than dest_map[index], then other is not a
duke@435 338 // subset.
duke@435 339 if (word_union != dest_map[index]) return false;
duke@435 340 }
duke@435 341 return true;
duke@435 342 }
duke@435 343
duke@435 344 bool BitMap::intersects(const BitMap other) const {
duke@435 345 assert(size() == other.size(), "must have same size");
ysr@777 346 bm_word_t* dest_map = map();
ysr@777 347 bm_word_t* other_map = other.map();
duke@435 348 idx_t size = size_in_words();
duke@435 349 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 350 if ((dest_map[index] & other_map[index]) != 0) return true;
duke@435 351 }
duke@435 352 // Otherwise, no intersection.
duke@435 353 return false;
duke@435 354 }
duke@435 355
duke@435 356 void BitMap::set_union(BitMap other) {
duke@435 357 assert(size() == other.size(), "must have same size");
ysr@777 358 bm_word_t* dest_map = map();
ysr@777 359 bm_word_t* other_map = other.map();
duke@435 360 idx_t size = size_in_words();
duke@435 361 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 362 dest_map[index] = dest_map[index] | other_map[index];
duke@435 363 }
duke@435 364 }
duke@435 365
duke@435 366
duke@435 367 void BitMap::set_difference(BitMap other) {
duke@435 368 assert(size() == other.size(), "must have same size");
ysr@777 369 bm_word_t* dest_map = map();
ysr@777 370 bm_word_t* other_map = other.map();
duke@435 371 idx_t size = size_in_words();
duke@435 372 for (idx_t index = 0; index < size_in_words(); index++) {
duke@435 373 dest_map[index] = dest_map[index] & ~(other_map[index]);
duke@435 374 }
duke@435 375 }
duke@435 376
duke@435 377
duke@435 378 void BitMap::set_intersection(BitMap other) {
duke@435 379 assert(size() == other.size(), "must have same size");
ysr@777 380 bm_word_t* dest_map = map();
ysr@777 381 bm_word_t* other_map = other.map();
duke@435 382 idx_t size = size_in_words();
duke@435 383 for (idx_t index = 0; index < size; index++) {
duke@435 384 dest_map[index] = dest_map[index] & other_map[index];
duke@435 385 }
duke@435 386 }
duke@435 387
duke@435 388
ysr@777 389 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
ysr@777 390 assert(other.size() >= offset, "offset not in range");
ysr@777 391 assert(other.size() - offset >= size(), "other not large enough");
ysr@777 392 // XXX Ideally, we would remove this restriction.
ysr@777 393 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
ysr@777 394 "Only handle aligned cases so far.");
ysr@777 395 bm_word_t* dest_map = map();
ysr@777 396 bm_word_t* other_map = other.map();
ysr@777 397 idx_t offset_word_ind = word_index(offset);
ysr@777 398 idx_t size = size_in_words();
ysr@777 399 for (idx_t index = 0; index < size; index++) {
ysr@777 400 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
ysr@777 401 }
ysr@777 402 }
ysr@777 403
duke@435 404 bool BitMap::set_union_with_result(BitMap other) {
duke@435 405 assert(size() == other.size(), "must have same size");
duke@435 406 bool changed = false;
ysr@777 407 bm_word_t* dest_map = map();
ysr@777 408 bm_word_t* other_map = other.map();
duke@435 409 idx_t size = size_in_words();
duke@435 410 for (idx_t index = 0; index < size; index++) {
duke@435 411 idx_t temp = map(index) | other_map[index];
duke@435 412 changed = changed || (temp != map(index));
duke@435 413 map()[index] = temp;
duke@435 414 }
duke@435 415 return changed;
duke@435 416 }
duke@435 417
duke@435 418
duke@435 419 bool BitMap::set_difference_with_result(BitMap other) {
duke@435 420 assert(size() == other.size(), "must have same size");
duke@435 421 bool changed = false;
ysr@777 422 bm_word_t* dest_map = map();
ysr@777 423 bm_word_t* other_map = other.map();
duke@435 424 idx_t size = size_in_words();
duke@435 425 for (idx_t index = 0; index < size; index++) {
ysr@777 426 bm_word_t temp = dest_map[index] & ~(other_map[index]);
duke@435 427 changed = changed || (temp != dest_map[index]);
duke@435 428 dest_map[index] = temp;
duke@435 429 }
duke@435 430 return changed;
duke@435 431 }
duke@435 432
duke@435 433
duke@435 434 bool BitMap::set_intersection_with_result(BitMap other) {
duke@435 435 assert(size() == other.size(), "must have same size");
duke@435 436 bool changed = false;
ysr@777 437 bm_word_t* dest_map = map();
ysr@777 438 bm_word_t* other_map = other.map();
duke@435 439 idx_t size = size_in_words();
duke@435 440 for (idx_t index = 0; index < size; index++) {
ysr@777 441 bm_word_t orig = dest_map[index];
ysr@777 442 bm_word_t temp = orig & other_map[index];
duke@435 443 changed = changed || (temp != orig);
duke@435 444 dest_map[index] = temp;
duke@435 445 }
duke@435 446 return changed;
duke@435 447 }
duke@435 448
duke@435 449
duke@435 450 void BitMap::set_from(BitMap other) {
duke@435 451 assert(size() == other.size(), "must have same size");
ysr@777 452 bm_word_t* dest_map = map();
ysr@777 453 bm_word_t* other_map = other.map();
duke@435 454 idx_t size = size_in_words();
duke@435 455 for (idx_t index = 0; index < size; index++) {
duke@435 456 dest_map[index] = other_map[index];
duke@435 457 }
duke@435 458 }
duke@435 459
duke@435 460
duke@435 461 bool BitMap::is_same(BitMap other) {
duke@435 462 assert(size() == other.size(), "must have same size");
ysr@777 463 bm_word_t* dest_map = map();
ysr@777 464 bm_word_t* other_map = other.map();
duke@435 465 idx_t size = size_in_words();
duke@435 466 for (idx_t index = 0; index < size; index++) {
duke@435 467 if (dest_map[index] != other_map[index]) return false;
duke@435 468 }
duke@435 469 return true;
duke@435 470 }
duke@435 471
duke@435 472 bool BitMap::is_full() const {
ysr@777 473 bm_word_t* word = map();
duke@435 474 idx_t rest = size();
duke@435 475 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 476 if (*word != (bm_word_t) AllBits) return false;
duke@435 477 word++;
duke@435 478 }
ysr@777 479 return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
duke@435 480 }
duke@435 481
duke@435 482
duke@435 483 bool BitMap::is_empty() const {
ysr@777 484 bm_word_t* word = map();
duke@435 485 idx_t rest = size();
duke@435 486 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
ysr@777 487 if (*word != (bm_word_t) NoBits) return false;
duke@435 488 word++;
duke@435 489 }
ysr@777 490 return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
duke@435 491 }
duke@435 492
duke@435 493 void BitMap::clear_large() {
duke@435 494 clear_large_range_of_words(0, size_in_words());
duke@435 495 }
duke@435 496
duke@435 497 // Note that if the closure itself modifies the bitmap
duke@435 498 // then modifications in and to the left of the _bit_ being
duke@435 499 // currently sampled will not be seen. Note also that the
duke@435 500 // interval [leftOffset, rightOffset) is right open.
ysr@777 501 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
duke@435 502 verify_range(leftOffset, rightOffset);
duke@435 503
duke@435 504 idx_t startIndex = word_index(leftOffset);
duke@435 505 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
duke@435 506 for (idx_t index = startIndex, offset = leftOffset;
duke@435 507 offset < rightOffset && index < endIndex;
duke@435 508 offset = (++index) << LogBitsPerWord) {
duke@435 509 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
ysr@777 510 for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
duke@435 511 if (rest & 1) {
ysr@777 512 if (!blk->do_bit(offset)) return false;
duke@435 513 // resample at each closure application
duke@435 514 // (see, for instance, CMS bug 4525989)
duke@435 515 rest = map(index) >> (offset & (BitsPerWord -1));
duke@435 516 }
duke@435 517 rest = rest >> 1;
duke@435 518 }
duke@435 519 }
ysr@777 520 return true;
duke@435 521 }
duke@435 522
ysr@777 523 BitMap::idx_t* BitMap::_pop_count_table = NULL;
duke@435 524
ysr@777 525 void BitMap::init_pop_count_table() {
ysr@777 526 if (_pop_count_table == NULL) {
ysr@777 527 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256);
ysr@777 528 for (uint i = 0; i < 256; i++) {
ysr@777 529 table[i] = num_set_bits(i);
ysr@777 530 }
duke@435 531
ysr@777 532 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table,
ysr@777 533 (intptr_t*) &_pop_count_table,
ysr@777 534 (intptr_t) NULL_WORD);
ysr@777 535 if (res != NULL_WORD) {
ysr@777 536 guarantee( _pop_count_table == (void*) res, "invariant" );
ysr@777 537 FREE_C_HEAP_ARRAY(bm_word_t, table);
duke@435 538 }
duke@435 539 }
duke@435 540 }
duke@435 541
ysr@777 542 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
ysr@777 543 idx_t bits = 0;
duke@435 544
ysr@777 545 while (w != 0) {
ysr@777 546 while ((w & 1) == 0) {
ysr@777 547 w >>= 1;
ysr@777 548 }
ysr@777 549 bits++;
ysr@777 550 w >>= 1;
duke@435 551 }
ysr@777 552 return bits;
ysr@777 553 }
duke@435 554
ysr@777 555 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
ysr@777 556 assert(_pop_count_table != NULL, "precondition");
ysr@777 557 return _pop_count_table[c];
ysr@777 558 }
duke@435 559
ysr@777 560 BitMap::idx_t BitMap::count_one_bits() const {
ysr@777 561 init_pop_count_table(); // If necessary.
ysr@777 562 idx_t sum = 0;
ysr@777 563 typedef unsigned char uchar;
ysr@777 564 for (idx_t i = 0; i < size_in_words(); i++) {
ysr@777 565 bm_word_t w = map()[i];
ysr@777 566 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
ysr@777 567 sum += num_set_bits_from_table(uchar(w & 255));
ysr@777 568 w >>= 8;
duke@435 569 }
duke@435 570 }
ysr@777 571 return sum;
duke@435 572 }
duke@435 573
ysr@777 574
duke@435 575 #ifndef PRODUCT
duke@435 576
duke@435 577 void BitMap::print_on(outputStream* st) const {
duke@435 578 tty->print("Bitmap(%d):", size());
duke@435 579 for (idx_t index = 0; index < size(); index++) {
duke@435 580 tty->print("%c", at(index) ? '1' : '0');
duke@435 581 }
duke@435 582 tty->cr();
duke@435 583 }
duke@435 584
duke@435 585 #endif
duke@435 586
duke@435 587
ysr@777 588 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
duke@435 589 : _bits_per_slot(bits_per_slot)
duke@435 590 , _map(map, size_in_slots * bits_per_slot)
duke@435 591 {
duke@435 592 }
duke@435 593
duke@435 594
duke@435 595 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
duke@435 596 : _bits_per_slot(bits_per_slot)
duke@435 597 , _map(size_in_slots * bits_per_slot)
duke@435 598 {
duke@435 599 }

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