comparison src/share/vm/utilities/bitMap.hpp @ 0:a61af66fc99e jdk7-b24

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date Sat, 01 Dec 2007 00:00:00 +0000
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1 /*
2 * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 // Closure for iterating over BitMaps
26
27 class BitMapClosure VALUE_OBJ_CLASS_SPEC {
28 public:
29 // Callback when bit in map is set
30 virtual void do_bit(size_t offset) = 0;
31 };
32
33
34 // Operations for bitmaps represented as arrays of unsigned 32- or 64-bit
35 // integers (uintptr_t).
36 //
37 // Bit offsets are numbered from 0 to size-1
38
39 class BitMap VALUE_OBJ_CLASS_SPEC {
40 friend class BitMap2D;
41
42 public:
43 typedef size_t idx_t; // Type used for bit and word indices.
44
45 // Hints for range sizes.
46 typedef enum {
47 unknown_range, small_range, large_range
48 } RangeSizeHint;
49
50 private:
51 idx_t* _map; // First word in bitmap
52 idx_t _size; // Size of bitmap (in bits)
53
54 // Puts the given value at the given offset, using resize() to size
55 // the bitmap appropriately if needed using factor-of-two expansion.
56 void at_put_grow(idx_t index, bool value);
57
58 protected:
59 // Return the position of bit within the word that contains it (e.g., if
60 // bitmap words are 32 bits, return a number 0 <= n <= 31).
61 static idx_t bit_in_word(idx_t bit) { return bit & (BitsPerWord - 1); }
62
63 // Return a mask that will select the specified bit, when applied to the word
64 // containing the bit.
65 static idx_t bit_mask(idx_t bit) { return (idx_t)1 << bit_in_word(bit); }
66
67 // Return the index of the word containing the specified bit.
68 static idx_t word_index(idx_t bit) { return bit >> LogBitsPerWord; }
69
70 // Return the bit number of the first bit in the specified word.
71 static idx_t bit_index(idx_t word) { return word << LogBitsPerWord; }
72
73 // Return the array of bitmap words, or a specific word from it.
74 idx_t* map() const { return _map; }
75 idx_t map(idx_t word) const { return _map[word]; }
76
77 // Return a pointer to the word containing the specified bit.
78 idx_t* word_addr(idx_t bit) const { return map() + word_index(bit); }
79
80 // Set a word to a specified value or to all ones; clear a word.
81 void set_word (idx_t word, idx_t val) { _map[word] = val; }
82 void set_word (idx_t word) { set_word(word, ~(uintptr_t)0); }
83 void clear_word(idx_t word) { _map[word] = 0; }
84
85 // Utilities for ranges of bits. Ranges are half-open [beg, end).
86
87 // Ranges within a single word.
88 inline idx_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const;
89 inline void set_range_within_word (idx_t beg, idx_t end);
90 inline void clear_range_within_word (idx_t beg, idx_t end);
91 inline void par_put_range_within_word (idx_t beg, idx_t end, bool value);
92
93 // Ranges spanning entire words.
94 inline void set_range_of_words (idx_t beg, idx_t end);
95 inline void clear_range_of_words (idx_t beg, idx_t end);
96 inline void set_large_range_of_words (idx_t beg, idx_t end);
97 inline void clear_large_range_of_words (idx_t beg, idx_t end);
98
99 // The index of the first full word in a range.
100 inline idx_t word_index_round_up(idx_t bit) const;
101
102 // Verification, statistics.
103 void verify_index(idx_t index) const {
104 assert(index < _size, "BitMap index out of bounds");
105 }
106
107 void verify_range(idx_t beg_index, idx_t end_index) const {
108 #ifdef ASSERT
109 assert(beg_index <= end_index, "BitMap range error");
110 // Note that [0,0) and [size,size) are both valid ranges.
111 if (end_index != _size) verify_index(end_index);
112 #endif
113 }
114
115 public:
116
117 // Constructs a bitmap with no map, and size 0.
118 BitMap() : _map(NULL), _size(0) {}
119
120 // Construction
121 BitMap(idx_t* map, idx_t size_in_bits);
122
123 // Allocates necessary data structure in resource area
124 BitMap(idx_t size_in_bits);
125
126 void set_map(idx_t* map) { _map = map; }
127 void set_size(idx_t size_in_bits) { _size = size_in_bits; }
128
129 // Allocates necessary data structure in resource area.
130 // Preserves state currently in bit map by copying data.
131 // Zeros any newly-addressable bits.
132 // Does not perform any frees (i.e., of current _map).
133 void resize(idx_t size_in_bits);
134
135 // Accessing
136 idx_t size() const { return _size; }
137 idx_t size_in_words() const {
138 return word_index(size() + BitsPerWord - 1);
139 }
140
141 bool at(idx_t index) const {
142 verify_index(index);
143 return (*word_addr(index) & bit_mask(index)) != 0;
144 }
145
146 // Align bit index up or down to the next bitmap word boundary, or check
147 // alignment.
148 static idx_t word_align_up(idx_t bit) {
149 return align_size_up(bit, BitsPerWord);
150 }
151 static idx_t word_align_down(idx_t bit) {
152 return align_size_down(bit, BitsPerWord);
153 }
154 static bool is_word_aligned(idx_t bit) {
155 return word_align_up(bit) == bit;
156 }
157
158 // Set or clear the specified bit.
159 inline void set_bit(idx_t bit);
160 inline void clear_bit(idx_t bit);
161
162 // Atomically set or clear the specified bit.
163 inline bool par_set_bit(idx_t bit);
164 inline bool par_clear_bit(idx_t bit);
165
166 // Put the given value at the given offset. The parallel version
167 // will CAS the value into the bitmap and is quite a bit slower.
168 // The parallel version also returns a value indicating if the
169 // calling thread was the one that changed the value of the bit.
170 void at_put(idx_t index, bool value);
171 bool par_at_put(idx_t index, bool value);
172
173 // Update a range of bits. Ranges are half-open [beg, end).
174 void set_range (idx_t beg, idx_t end);
175 void clear_range (idx_t beg, idx_t end);
176 void set_large_range (idx_t beg, idx_t end);
177 void clear_large_range (idx_t beg, idx_t end);
178 void at_put_range(idx_t beg, idx_t end, bool value);
179 void par_at_put_range(idx_t beg, idx_t end, bool value);
180 void at_put_large_range(idx_t beg, idx_t end, bool value);
181 void par_at_put_large_range(idx_t beg, idx_t end, bool value);
182
183 // Update a range of bits, using a hint about the size. Currently only
184 // inlines the predominant case of a 1-bit range. Works best when hint is a
185 // compile-time constant.
186 inline void set_range(idx_t beg, idx_t end, RangeSizeHint hint);
187 inline void clear_range(idx_t beg, idx_t end, RangeSizeHint hint);
188 inline void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint);
189 inline void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint);
190
191 // Clearing
192 void clear();
193 void clear_large();
194
195 // Iteration support
196 void iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex);
197 inline void iterate(BitMapClosure* blk) {
198 // call the version that takes an interval
199 iterate(blk, 0, size());
200 }
201
202 // Looking for 1's and 0's to the "right"
203 idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const;
204 idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const;
205
206 idx_t get_next_one_offset(idx_t offset) const {
207 return get_next_one_offset(offset, size());
208 }
209 idx_t get_next_zero_offset(idx_t offset) const {
210 return get_next_zero_offset(offset, size());
211 }
212
213
214
215 // Find the next one bit in the range [beg_bit, end_bit), or return end_bit if
216 // no one bit is found. Equivalent to get_next_one_offset(), but inline for
217 // use in performance-critical code.
218 inline idx_t find_next_one_bit(idx_t beg_bit, idx_t end_bit) const;
219
220 // Set operations.
221 void set_union(BitMap bits);
222 void set_difference(BitMap bits);
223 void set_intersection(BitMap bits);
224 // Returns true iff "this" is a superset of "bits".
225 bool contains(const BitMap bits) const;
226 // Returns true iff "this and "bits" have a non-empty intersection.
227 bool intersects(const BitMap bits) const;
228
229 // Returns result of whether this map changed
230 // during the operation
231 bool set_union_with_result(BitMap bits);
232 bool set_difference_with_result(BitMap bits);
233 bool set_intersection_with_result(BitMap bits);
234
235 void set_from(BitMap bits);
236
237 bool is_same(BitMap bits);
238
239 // Test if all bits are set or cleared
240 bool is_full() const;
241 bool is_empty() const;
242
243
244 #ifndef PRODUCT
245 public:
246 // Printing
247 void print_on(outputStream* st) const;
248 #endif
249 };
250
251 inline void BitMap::set_bit(idx_t bit) {
252 verify_index(bit);
253 *word_addr(bit) |= bit_mask(bit);
254 }
255
256 inline void BitMap::clear_bit(idx_t bit) {
257 verify_index(bit);
258 *word_addr(bit) &= ~bit_mask(bit);
259 }
260
261 inline void BitMap::set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
262 if (hint == small_range && end - beg == 1) {
263 set_bit(beg);
264 } else {
265 if (hint == large_range) {
266 set_large_range(beg, end);
267 } else {
268 set_range(beg, end);
269 }
270 }
271 }
272
273 inline void BitMap::clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
274 if (hint == small_range && end - beg == 1) {
275 clear_bit(beg);
276 } else {
277 if (hint == large_range) {
278 clear_large_range(beg, end);
279 } else {
280 clear_range(beg, end);
281 }
282 }
283 }
284
285 inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
286 if (hint == small_range && end - beg == 1) {
287 par_at_put(beg, true);
288 } else {
289 if (hint == large_range) {
290 par_at_put_large_range(beg, end, true);
291 } else {
292 par_at_put_range(beg, end, true);
293 }
294 }
295 }
296
297
298 // Convenience class wrapping BitMap which provides multiple bits per slot.
299 class BitMap2D VALUE_OBJ_CLASS_SPEC {
300 public:
301 typedef size_t idx_t; // Type used for bit and word indices.
302
303 private:
304 BitMap _map;
305 idx_t _bits_per_slot;
306
307 idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const {
308 return slot_index * _bits_per_slot + bit_within_slot_index;
309 }
310
311 void verify_bit_within_slot_index(idx_t index) const {
312 assert(index < _bits_per_slot, "bit_within_slot index out of bounds");
313 }
314
315 public:
316 // Construction. bits_per_slot must be greater than 0.
317 BitMap2D(uintptr_t* map, idx_t size_in_slots, idx_t bits_per_slot);
318
319 // Allocates necessary data structure in resource area. bits_per_slot must be greater than 0.
320 BitMap2D(idx_t size_in_slots, idx_t bits_per_slot);
321
322 idx_t size_in_bits() {
323 return _map.size();
324 }
325
326 // Returns number of full slots that have been allocated
327 idx_t size_in_slots() {
328 // Round down
329 return _map.size() / _bits_per_slot;
330 }
331
332 bool is_valid_index(idx_t slot_index, idx_t bit_within_slot_index) {
333 verify_bit_within_slot_index(bit_within_slot_index);
334 return (bit_index(slot_index, bit_within_slot_index) < size_in_bits());
335 }
336
337 bool at(idx_t slot_index, idx_t bit_within_slot_index) const {
338 verify_bit_within_slot_index(bit_within_slot_index);
339 return _map.at(bit_index(slot_index, bit_within_slot_index));
340 }
341
342 void set_bit(idx_t slot_index, idx_t bit_within_slot_index) {
343 verify_bit_within_slot_index(bit_within_slot_index);
344 _map.set_bit(bit_index(slot_index, bit_within_slot_index));
345 }
346
347 void clear_bit(idx_t slot_index, idx_t bit_within_slot_index) {
348 verify_bit_within_slot_index(bit_within_slot_index);
349 _map.clear_bit(bit_index(slot_index, bit_within_slot_index));
350 }
351
352 void at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
353 verify_bit_within_slot_index(bit_within_slot_index);
354 _map.at_put(bit_index(slot_index, bit_within_slot_index), value);
355 }
356
357 void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) {
358 verify_bit_within_slot_index(bit_within_slot_index);
359 _map.at_put_grow(bit_index(slot_index, bit_within_slot_index), value);
360 }
361
362 void clear() {
363 _map.clear();
364 }
365 };
366
367
368
369 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {
370 uintptr_t* map = _map;
371 for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0;
372 }
373
374
375 inline void BitMap::clear_range_of_words(idx_t beg, idx_t end) {
376 uintptr_t* map = _map;
377 for (idx_t i = beg; i < end; ++i) map[i] = 0;
378 }
379
380
381 inline void BitMap::clear() {
382 clear_range_of_words(0, size_in_words());
383 }
384
385
386 inline void BitMap::par_clear_range(idx_t beg, idx_t end, RangeSizeHint hint) {
387 if (hint == small_range && end - beg == 1) {
388 par_at_put(beg, false);
389 } else {
390 if (hint == large_range) {
391 par_at_put_large_range(beg, end, false);
392 } else {
393 par_at_put_range(beg, end, false);
394 }
395 }
396 }