1 /*
2 * Copyright (c) 1997, 2014, 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), _map_allocator(false)
34 {
35 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
36 assert(size_in_bits >= 0, "just checking");
37 }
38
39
40 BitMap::BitMap(idx_t size_in_bits, bool in_resource_area) :
41 _map(NULL), _size(0), _map_allocator(false)
42 {
43 assert(sizeof(bm_word_t) == BytesPerWord, "Implementation assumption.");
44 resize(size_in_bits, in_resource_area);
45 }
46
47 void BitMap::resize(idx_t size_in_bits, bool in_resource_area) {
48 assert(size_in_bits >= 0, "just checking");
49 idx_t old_size_in_words = size_in_words();
50 bm_word_t* old_map = map();
51
52 _size = size_in_bits;
53 idx_t new_size_in_words = size_in_words();
54 if (in_resource_area) {
55 _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
56 Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
57 MIN2(old_size_in_words, new_size_in_words));
58 } else {
59 _map = _map_allocator.reallocate(new_size_in_words);
60 }
61
62 if (new_size_in_words > old_size_in_words) {
63 clear_range_of_words(old_size_in_words, new_size_in_words);
64 }
65 }
66
67 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
68 // With a valid range (beg <= end), this test ensures that end != 0, as
69 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
70 if (beg != end) {
71 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
72 *word_addr(beg) |= ~mask;
73 }
74 }
75
76 void BitMap::clear_range_within_word(idx_t beg, idx_t end) {
77 // With a valid range (beg <= end), this test ensures that end != 0, as
78 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
79 if (beg != end) {
80 bm_word_t mask = inverted_bit_mask_for_range(beg, end);
81 *word_addr(beg) &= mask;
82 }
83 }
84
85 void BitMap::par_put_range_within_word(idx_t beg, idx_t end, bool value) {
86 assert(value == 0 || value == 1, "0 for clear, 1 for set");
87 // With a valid range (beg <= end), this test ensures that end != 0, as
88 // required by inverted_bit_mask_for_range. Also avoids an unnecessary write.
89 if (beg != end) {
90 intptr_t* pw = (intptr_t*)word_addr(beg);
91 intptr_t w = *pw;
92 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end);
93 intptr_t nw = value ? (w | ~mr) : (w & mr);
94 while (true) {
95 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w);
96 if (res == w) break;
97 w = res;
98 nw = value ? (w | ~mr) : (w & mr);
99 }
100 }
101 }
102
103 void BitMap::set_range(idx_t beg, idx_t end) {
104 verify_range(beg, end);
105
106 idx_t beg_full_word = word_index_round_up(beg);
107 idx_t end_full_word = word_index(end);
108
109 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
122 void 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
141 void 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
156 void 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
171 void 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.
194 bool BitMap::par_at_put(idx_t bit, bool value) {
195 return value ? par_set_bit(bit) : par_clear_bit(bit);
196 }
197
198 void 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
205 void 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
213 void 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
237 void 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
245 void 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
264 bool 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
278 bool 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
290 void 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
301 void 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
312 void 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
323 void 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
338 bool 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
353 bool 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
368 bool 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
384 void 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
395 bool 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
406 bool 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
417 bool 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
427 void 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.
435 bool 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
457 BitMap::idx_t* BitMap::_pop_count_table = NULL;
458
459 void 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
476 BitMap::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
489 BitMap::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
494 BitMap::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
508 void 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
515 void 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
523 class 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 size_t 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 SizeTFlagSetting 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 SizeTFlagSetting 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
597 void TestBitMap_test() {
598 TestBitMap::test();
599 }
600 #endif
601
602
603 BitMap2D::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
610 BitMap2D::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 }