Tue, 25 Feb 2014 15:11:18 -0800
Merge
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 */
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
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 }
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 }
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();
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 }
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 }
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 }
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 }
119 void BitMap::set_range(idx_t beg, idx_t end) {
120 verify_range(beg, end);
122 idx_t beg_full_word = word_index_round_up(beg);
123 idx_t end_full_word = word_index(end);
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 }
138 void BitMap::clear_range(idx_t beg, idx_t end) {
139 verify_range(beg, end);
141 idx_t beg_full_word = word_index_round_up(beg);
142 idx_t end_full_word = word_index(end);
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 }
157 void BitMap::set_large_range(idx_t beg, idx_t end) {
158 verify_range(beg, end);
160 idx_t beg_full_word = word_index_round_up(beg);
161 idx_t end_full_word = word_index(end);
163 assert(end_full_word - beg_full_word >= 32,
164 "the range must include at least 32 bytes");
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 }
172 void BitMap::clear_large_range(idx_t beg, idx_t end) {
173 verify_range(beg, end);
175 idx_t beg_full_word = word_index_round_up(beg);
176 idx_t end_full_word = word_index(end);
178 assert(end_full_word - beg_full_word >= 32,
179 "the range must include at least 32 bytes");
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 }
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 }
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 }
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 }
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 }
229 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
230 verify_range(beg, end);
232 idx_t beg_full_word = word_index_round_up(beg);
233 idx_t end_full_word = word_index(end);
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 }
251 }
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 }
261 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
262 verify_range(beg, end);
264 idx_t beg_full_word = word_index_round_up(beg);
265 idx_t end_full_word = word_index(end);
267 assert(end_full_word - beg_full_word >= 32,
268 "the range must include at least 32 bytes");
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
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 }
443 void BitMap::clear_large() {
444 clear_large_range_of_words(0, size_in_words());
445 }
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);
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 }
473 BitMap::idx_t* BitMap::_pop_count_table = NULL;
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 }
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 }
492 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
493 idx_t bits = 0;
495 while (w != 0) {
496 while ((w & 1) == 0) {
497 w >>= 1;
498 }
499 bits++;
500 w >>= 1;
501 }
502 return bits;
503 }
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 }
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 }
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 }
529 #ifndef PRODUCT
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 }
539 #endif
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 }
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 }