1 /*
2 * Copyright (c) 1997, 2015, 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 "memory/resourceArea.hpp"
28 #include "runtime/atomic.inline.hpp"
29 #include "utilities/bitMap.inline.hpp"
30 #include "utilities/copy.hpp"
31
32 BitMap::BitMap(bm_word_t* map, idx_t size_in_bits) :
33 _map(map), _size(size_in_bits)
34 {
35 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
36 }
37
38
39 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
40 _map(NULL), _size(0)
41 {
42 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
43 resize(size_in_bits, in_resource_area);
44 }
45
46 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
47 idx_t old_size_in_words = size_in_words();
48 bm_word_t* old_map = map();
49
50 _size = size_in_bits;
51 idx_t new_size_in_words = size_in_words();
52 if (in_resource_area) {
53 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
54 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
55 MIN2(old_size_in_words, new_size_in_words));
56 } else {
57 _map = ArrayAllocator<bm_word_t, mtInternal>::reallocate(old_map, old_size_in_words, new_size_in_words);
58 }
59
60 if (new_size_in_words > old_size_in_words) {
61 clear_range_of_words(old_size_in_words, new_size_in_words);
62 }
63 }
64
65 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
66 // With a valid range (beg <= end), this test ensures that end != 0, as
67 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
68 if (beg != end) {
69 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
70 *word_addr(beg) |= ~mask;
71 }
72 }
73
74 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
75 // With a valid range (beg <= end), this test ensures that end != 0, as
76 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
77 if (beg != end) {
78 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
79 *word_addr(beg) &= mask;
80 }
81 }
82
83 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
84 assert(value == 0 || value == 1, "0 for clear, 1 for set");
85 // With a valid range (beg <= end), this test ensures that end != 0, as
86 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
87 if (beg != end) {
88 intptr_t* pw = (intptr_t*)word_addr(beg);
89 intptr_t w = *pw;
90 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
91 intptr_t nw = value ? (w | ~mr) : (w & mr);
92 while (true) {
93 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
94 if (res == w) break;
95 w = res;
96 nw = value ? (w | ~mr) : (w & mr);
97 }
98 }
99 }
100
101 void BitMap::set_range(idx_t beg, idx_t end) {
102 verify_range(beg, end);
103
104 idx_t beg_full_word = word_index_round_up(beg);
105 idx_t end_full_word = word_index(end);
106
107 if (beg_full_word < end_full_word) {
108 // The range includes at least one full word.
109 set_range_within_word(beg, bit_index(beg_full_word));
110 set_range_of_words(beg_full_word, end_full_word);
111 set_range_within_word(bit_index(end_full_word), end);
112 } else {
113 // The range spans at most 2 partial words.
114 idx_t boundary = MIN2(bit_index(beg_full_word), end);
115 set_range_within_word(beg, boundary);
116 set_range_within_word(boundary, end);
117 }
118 }
119
120 void BitMap::clear_range(idx_t beg, idx_t end) {
121 verify_range(beg, end);
122
123 idx_t beg_full_word = word_index_round_up(beg);
124 idx_t end_full_word = word_index(end);
125
126 if (beg_full_word < end_full_word) {
127 // The range includes at least one full word.
128 clear_range_within_word(beg, bit_index(beg_full_word));
129 clear_range_of_words(beg_full_word, end_full_word);
130 clear_range_within_word(bit_index(end_full_word), end);
131 } else {
132 // The range spans at most 2 partial words.
133 idx_t boundary = MIN2(bit_index(beg_full_word), end);
134 clear_range_within_word(beg, boundary);
135 clear_range_within_word(boundary, end);
136 }
137 }
138
139 void BitMap::set_large_range(idx_t beg, idx_t end) {
140 verify_range(beg, end);
141
142 idx_t beg_full_word = word_index_round_up(beg);
143 idx_t end_full_word = word_index(end);
144
145 assert(end_full_word - beg_full_word >= 32,
146 "the range must include at least 32 bytes");
147
148 // The range includes at least one full word.
149 set_range_within_word(beg, bit_index(beg_full_word));
150 set_large_range_of_words(beg_full_word, end_full_word);
151 set_range_within_word(bit_index(end_full_word), end);
152 }
153
154 void BitMap::clear_large_range(idx_t beg, idx_t end) {
155 verify_range(beg, end);
156
157 idx_t beg_full_word = word_index_round_up(beg);
158 idx_t end_full_word = word_index(end);
159
160 assert(end_full_word - beg_full_word >= 32,
161 "the range must include at least 32 bytes");
162
163 // The range includes at least one full word.
164 clear_range_within_word(beg, bit_index(beg_full_word));
165 clear_large_range_of_words(beg_full_word, end_full_word);
166 clear_range_within_word(bit_index(end_full_word), end);
167 }
168
169 void BitMap::at_put(idx_t offset, bool value) {
170 if (value) {
171 set_bit(offset);
172 } else {
173 clear_bit(offset);
174 }
175 }
176
177 // Return true to indicate that this thread changed
178 // the bit, false to indicate that someone else did.
179 // In either case, the requested bit is in the
180 // requested state some time during the period that
181 // this thread is executing this call. More importantly,
182 // if no other thread is executing an action to
183 // change the requested bit to a state other than
184 // the one that this thread is trying to set it to,
185 // then the the bit is in the expected state
186 // at exit from this method. However, rather than
187 // make such a strong assertion here, based on
188 // assuming such constrained use (which though true
189 // today, could change in the future to service some
190 // funky parallel algorithm), we encourage callers
191 // to do such verification, as and when appropriate.
192 bool BitMap::par_at_put(idx_t bit, bool value) {
193 return value ? par_set_bit(bit) : par_clear_bit(bit);
194 }
195
196 void BitMap::at_put_grow(idx_t offset, bool value) {
197 if (offset >= size()) {
198 resize(2 * MAX2(size(), offset));
199 }
200 at_put(offset, value);
201 }
202
203 void BitMap::at_put_range(idx_t start_offset, idx_t end_offset, bool value) {
204 if (value) {
205 set_range(start_offset, end_offset);
206 } else {
207 clear_range(start_offset, end_offset);
208 }
209 }
210
211 void BitMap::par_at_put_range(idx_t beg, idx_t end, bool value) {
212 verify_range(beg, end);
213
214 idx_t beg_full_word = word_index_round_up(beg);
215 idx_t end_full_word = word_index(end);
216
217 if (beg_full_word < end_full_word) {
218 // The range includes at least one full word.
219 par_put_range_within_word(beg, bit_index(beg_full_word), value);
220 if (value) {
221 set_range_of_words(beg_full_word, end_full_word);
222 } else {
223 clear_range_of_words(beg_full_word, end_full_word);
224 }
225 par_put_range_within_word(bit_index(end_full_word), end, value);
226 } else {
227 // The range spans at most 2 partial words.
228 idx_t boundary = MIN2(bit_index(beg_full_word), end);
229 par_put_range_within_word(beg, boundary, value);
230 par_put_range_within_word(boundary, end, value);
231 }
232
233 }
234
235 void BitMap::at_put_large_range(idx_t beg, idx_t end, bool value) {
236 if (value) {
237 set_large_range(beg, end);
238 } else {
239 clear_large_range(beg, end);
240 }
241 }
242
243 void BitMap::par_at_put_large_range(idx_t beg, idx_t end, bool value) {
244 verify_range(beg, end);
245
246 idx_t beg_full_word = word_index_round_up(beg);
247 idx_t end_full_word = word_index(end);
248
249 assert(end_full_word - beg_full_word >= 32,
250 "the range must include at least 32 bytes");
251
252 // The range includes at least one full word.
253 par_put_range_within_word(beg, bit_index(beg_full_word), value);
254 if (value) {
255 set_large_range_of_words(beg_full_word, end_full_word);
256 } else {
257 clear_large_range_of_words(beg_full_word, end_full_word);
258 }
259 par_put_range_within_word(bit_index(end_full_word), end, value);
260 }
261
262 bool BitMap::contains(const BitMap other) const {
263 assert(size() == other.size(), "must have same size");
264 bm_word_t* dest_map = map();
265 bm_word_t* other_map = other.map();
266 idx_t size = size_in_words();
267 for (idx_t index = 0; index < size_in_words(); index++) {
268 bm_word_t word_union = dest_map[index] | other_map[index];
269 // If this has more bits set than dest_map[index], then other is not a
270 // subset.
271 if (word_union != dest_map[index]) return false;
272 }
273 return true;
274 }
275
276 bool BitMap::intersects(const BitMap other) const {
277 assert(size() == other.size(), "must have same size");
278 bm_word_t* dest_map = map();
279 bm_word_t* other_map = other.map();
280 idx_t size = size_in_words();
281 for (idx_t index = 0; index < size_in_words(); index++) {
282 if ((dest_map[index] & other_map[index]) != 0) return true;
283 }
284 // Otherwise, no intersection.
285 return false;
286 }
287
288 void BitMap::set_union(BitMap other) {
289 assert(size() == other.size(), "must have same size");
290 bm_word_t* dest_map = map();
291 bm_word_t* other_map = other.map();
292 idx_t size = size_in_words();
293 for (idx_t index = 0; index < size_in_words(); index++) {
294 dest_map[index] = dest_map[index] | other_map[index];
295 }
296 }
297
298
299 void BitMap::set_difference(BitMap other) {
300 assert(size() == other.size(), "must have same size");
301 bm_word_t* dest_map = map();
302 bm_word_t* other_map = other.map();
303 idx_t size = size_in_words();
304 for (idx_t index = 0; index < size_in_words(); index++) {
305 dest_map[index] = dest_map[index] & ~(other_map[index]);
306 }
307 }
308
309
310 void BitMap::set_intersection(BitMap other) {
311 assert(size() == other.size(), "must have same size");
312 bm_word_t* dest_map = map();
313 bm_word_t* other_map = other.map();
314 idx_t size = size_in_words();
315 for (idx_t index = 0; index < size; index++) {
316 dest_map[index] = dest_map[index] & other_map[index];
317 }
318 }
319
320
321 void BitMap::set_intersection_at_offset(BitMap other, idx_t offset) {
322 assert(other.size() >= offset, "offset not in range");
323 assert(other.size() - offset >= size(), "other not large enough");
324 // XXX Ideally, we would remove this restriction.
325 guarantee((offset % (sizeof(bm_word_t) * BitsPerByte)) == 0,
326 "Only handle aligned cases so far.");
327 bm_word_t* dest_map = map();
328 bm_word_t* other_map = other.map();
329 idx_t offset_word_ind = word_index(offset);
330 idx_t size = size_in_words();
331 for (idx_t index = 0; index < size; index++) {
332 dest_map[index] = dest_map[index] & other_map[offset_word_ind + index];
333 }
334 }
335
336 bool BitMap::set_union_with_result(BitMap other) {
337 assert(size() == other.size(), "must have same size");
338 bool changed = false;
339 bm_word_t* dest_map = map();
340 bm_word_t* other_map = other.map();
341 idx_t size = size_in_words();
342 for (idx_t index = 0; index < size; index++) {
343 idx_t temp = dest_map[index] | other_map[index];
344 changed = changed || (temp != dest_map[index]);
345 dest_map[index] = temp;
346 }
347 return changed;
348 }
349
350
351 bool BitMap::set_difference_with_result(BitMap other) {
352 assert(size() == other.size(), "must have same size");
353 bool changed = false;
354 bm_word_t* dest_map = map();
355 bm_word_t* other_map = other.map();
356 idx_t size = size_in_words();
357 for (idx_t index = 0; index < size; index++) {
358 bm_word_t temp = dest_map[index] & ~(other_map[index]);
359 changed = changed || (temp != dest_map[index]);
360 dest_map[index] = temp;
361 }
362 return changed;
363 }
364
365
366 bool BitMap::set_intersection_with_result(BitMap other) {
367 assert(size() == other.size(), "must have same size");
368 bool changed = false;
369 bm_word_t* dest_map = map();
370 bm_word_t* other_map = other.map();
371 idx_t size = size_in_words();
372 for (idx_t index = 0; index < size; index++) {
373 bm_word_t orig = dest_map[index];
374 bm_word_t temp = orig & other_map[index];
375 changed = changed || (temp != orig);
376 dest_map[index] = temp;
377 }
378 return changed;
379 }
380
381
382 void BitMap::set_from(BitMap other) {
383 assert(size() == other.size(), "must have same size");
384 bm_word_t* dest_map = map();
385 bm_word_t* other_map = other.map();
386 idx_t size = size_in_words();
387 for (idx_t index = 0; index < size; index++) {
388 dest_map[index] = other_map[index];
389 }
390 }
391
392
393 bool BitMap::is_same(BitMap other) {
394 assert(size() == other.size(), "must have same size");
395 bm_word_t* dest_map = map();
396 bm_word_t* other_map = other.map();
397 idx_t size = size_in_words();
398 for (idx_t index = 0; index < size; index++) {
399 if (dest_map[index] != other_map[index]) return false;
400 }
401 return true;
402 }
403
404 bool BitMap::is_full() const {
405 bm_word_t* word = map();
406 idx_t rest = size();
407 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
408 if (*word != ~(bm_word_t)0) return false;
409 word++;
410 }
411 return rest == 0 || (*word | ~right_n_bits((int)rest)) == ~(bm_word_t)0;
412 }
413
414
415 bool BitMap::is_empty() const {
416 bm_word_t* word = map();
417 idx_t rest = size();
418 for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
419 if (*word != 0) return false;
420 word++;
421 }
422 return rest == 0 || (*word & right_n_bits((int)rest)) == 0;
423 }
424
425 void BitMap::clear_large() {
426 clear_large_range_of_words(0, size_in_words());
427 }
428
429 // Note that if the closure itself modifies the bitmap
430 // then modifications in and to the left of the _bit_ being
431 // currently sampled will not be seen. Note also that the
432 // interval [leftOffset, rightOffset) is right open.
433 bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
434 verify_range(leftOffset, rightOffset);
435
436 idx_t startIndex = word_index(leftOffset);
437 idx_t endIndex = MIN2(word_index(rightOffset) + 1, size_in_words());
438 for (idx_t index = startIndex, offset = leftOffset;
439 offset < rightOffset && index < endIndex;
440 offset = (++index) << LogBitsPerWord) {
441 idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
442 for (; offset < rightOffset && rest != 0; offset++) {
443 if (rest & 1) {
444 if (!blk->do_bit(offset)) return false;
445 // resample at each closure application
446 // (see, for instance, CMS bug 4525989)
447 rest = map(index) >> (offset & (BitsPerWord -1));
448 }
449 rest = rest >> 1;
450 }
451 }
452 return true;
453 }
454
455 BitMap::idx_t* BitMap::_pop_count_table = NULL;
456
457 void BitMap::init_pop_count_table() {
458 if (_pop_count_table == NULL) {
459 BitMap::idx_t *table = NEW_C_HEAP_ARRAY(idx_t, 256, mtInternal);
460 for (uint i = 0; i < 256; i++) {
461 table[i] = num_set_bits(i);
462 }
463
464 intptr_t res = Atomic::cmpxchg_ptr((intptr_t) table,
465 (intptr_t*) &_pop_count_table,
466 (intptr_t) NULL_WORD);
467 if (res != NULL_WORD) {
468 guarantee( _pop_count_table == (void*) res, "invariant" );
469 FREE_C_HEAP_ARRAY(idx_t, table);
470 }
471 }
472 }
473
474 BitMap::idx_t BitMap::num_set_bits(bm_word_t w) {
475 idx_t bits = 0;
476
477 while (w != 0) {
478 while ((w & 1) == 0) {
479 w >>= 1;
480 }
481 bits++;
482 w >>= 1;
483 }
484 return bits;
485 }
486
487 BitMap::idx_t BitMap::num_set_bits_from_table(unsigned char c) {
488 assert(_pop_count_table != NULL, "precondition");
489 return _pop_count_table[c];
490 }
491
492 BitMap::idx_t BitMap::count_one_bits() const {
493 init_pop_count_table(); // If necessary.
494 idx_t sum = 0;
495 typedef unsigned char uchar;
496 for (idx_t i = 0; i < size_in_words(); i++) {
497 bm_word_t w = map()[i];
498 for (size_t j = 0; j < sizeof(bm_word_t); j++) {
499 sum += num_set_bits_from_table(uchar(w & 255));
500 w >>= 8;
501 }
502 }
503 return sum;
504 }
505
506 void BitMap::print_on_error(outputStream* st, const char* prefix) const {
507 st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")",
508 prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte)));
509 }
510
511 #ifndef PRODUCT
512
513 void BitMap::print_on(outputStream* st) const {
514 tty->print("Bitmap(" SIZE_FORMAT "):", size());
515 for (idx_t index = 0; index < size(); index++) {
516 tty->print("%c", at(index) ? '1' : '0');
517 }
518 tty->cr();
519 }
520
521 class TestBitMap : public AllStatic {
522 const static BitMap::idx_t BITMAP_SIZE = 1024;
523 static void fillBitMap(BitMap& map) {
524 map.set_bit(1);
525 map.set_bit(3);
526 map.set_bit(17);
527 map.set_bit(512);
528 }
529
530 static void testResize(bool in_resource_area) {
531 {
532 BitMap map(0, in_resource_area);
533 map.resize(BITMAP_SIZE, in_resource_area);
534 fillBitMap(map);
535
536 BitMap map2(BITMAP_SIZE, in_resource_area);
537 fillBitMap(map2);
538 assert(map.is_same(map2), "could be");
539 }
540
541 {
542 BitMap map(128, in_resource_area);
543 map.resize(BITMAP_SIZE, in_resource_area);
544 fillBitMap(map);
545
546 BitMap map2(BITMAP_SIZE, in_resource_area);
547 fillBitMap(map2);
548 assert(map.is_same(map2), "could be");
549 }
550
551 {
552 BitMap map(BITMAP_SIZE, in_resource_area);
553 map.resize(BITMAP_SIZE, in_resource_area);
554 fillBitMap(map);
555
556 BitMap map2(BITMAP_SIZE, in_resource_area);
557 fillBitMap(map2);
558 assert(map.is_same(map2), "could be");
559 }
560 }
561
562 static void testResizeResource() {
563 ResourceMark rm;
564 testResize(true);
565 }
566
567 static void testResizeNonResource() {
568 const size_t bitmap_bytes = BITMAP_SIZE / BitsPerByte;
569
570 // Test the default behavior
571 testResize(false);
572
573 {
574 // Make sure that AllocatorMallocLimit is larger than our allocation request
575 // forcing it to call standard malloc()
576 SizeTFlagSetting fs(ArrayAllocatorMallocLimit, bitmap_bytes * 4);
577 testResize(false);
578 }
579 {
580 // Make sure that AllocatorMallocLimit is smaller than our allocation request
581 // forcing it to call mmap() (or equivalent)
582 SizeTFlagSetting fs(ArrayAllocatorMallocLimit, bitmap_bytes / 4);
583 testResize(false);
584 }
585 }
586
587 public:
588 static void test() {
589 testResizeResource();
590 testResizeNonResource();
591 }
592
593 };
594
595 void TestBitMap_test() {
596 TestBitMap::test();
597 }
598 #endif
599
600
601 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
602 : _bits_per_slot(bits_per_slot)
603 , _map(map, size_in_slots * bits_per_slot)
604 {
605 }
606
607
608 BitMap2D::BitMap2D(idx_t size_in_slots, idx_t bits_per_slot)
609 : _bits_per_slot(bits_per_slot)
610 , _map(size_in_slots * bits_per_slot)
611 {
612 }