Mercurial > hg > truffle
annotate src/share/vm/utilities/bitMap.hpp @ 2177:3582bf76420e
6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank
| author | coleenp |
|---|---|
| date | Thu, 27 Jan 2011 16:11:27 -0800 |
| parents | f95d63e2154a |
| children | 842b840e67db |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 1972 | 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_UTILITIES_BITMAP_HPP |
| 26 #define SHARE_VM_UTILITIES_BITMAP_HPP | |
| 27 | |
| 28 #include "memory/allocation.hpp" | |
| 29 #include "utilities/top.hpp" | |
| 30 | |
| 342 | 31 // Forward decl; |
| 32 class BitMapClosure; | |
| 0 | 33 |
| 342 | 34 // Operations for bitmaps represented as arrays of unsigned integers. |
| 35 // Bit offsets are numbered from 0 to size-1. | |
| 0 | 36 |
| 37 class BitMap VALUE_OBJ_CLASS_SPEC { | |
| 38 friend class BitMap2D; | |
| 39 | |
| 40 public: | |
| 41 typedef size_t idx_t; // Type used for bit and word indices. | |
| 342 | 42 typedef uintptr_t bm_word_t; // Element type of array that represents |
| 43 // the bitmap. | |
| 0 | 44 |
| 45 // Hints for range sizes. | |
| 46 typedef enum { | |
| 47 unknown_range, small_range, large_range | |
| 48 } RangeSizeHint; | |
| 49 | |
| 50 private: | |
| 342 | 51 bm_word_t* _map; // First word in bitmap |
| 52 idx_t _size; // Size of bitmap (in bits) | |
| 0 | 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. | |
| 342 | 65 static bm_word_t bit_mask(idx_t bit) { return (bm_word_t)1 << bit_in_word(bit); } |
| 0 | 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. | |
| 342 | 74 bm_word_t* map() const { return _map; } |
| 75 bm_word_t map(idx_t word) const { return _map[word]; } | |
| 0 | 76 |
| 77 // Return a pointer to the word containing the specified bit. | |
| 342 | 78 bm_word_t* word_addr(idx_t bit) const { return map() + word_index(bit); } |
| 0 | 79 |
| 80 // Set a word to a specified value or to all ones; clear a word. | |
| 342 | 81 void set_word (idx_t word, bm_word_t val) { _map[word] = val; } |
| 0 | 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. | |
| 342 | 88 bm_word_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const; |
| 89 void set_range_within_word (idx_t beg, idx_t end); | |
| 90 void clear_range_within_word (idx_t beg, idx_t end); | |
| 91 void par_put_range_within_word (idx_t beg, idx_t end, bool value); | |
| 0 | 92 |
| 93 // Ranges spanning entire words. | |
| 342 | 94 void set_range_of_words (idx_t beg, idx_t end); |
| 95 void clear_range_of_words (idx_t beg, idx_t end); | |
| 96 void set_large_range_of_words (idx_t beg, idx_t end); | |
| 97 void clear_large_range_of_words (idx_t beg, idx_t end); | |
| 0 | 98 |
| 99 // The index of the first full word in a range. | |
| 342 | 100 idx_t word_index_round_up(idx_t bit) const; |
| 0 | 101 |
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102 // Verification. |
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103 inline void verify_index(idx_t index) const NOT_DEBUG_RETURN; |
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104 inline void verify_range(idx_t beg_index, idx_t end_index) const |
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105 NOT_DEBUG_RETURN; |
| 0 | 106 |
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107 // Statistics. |
| 342 | 108 static idx_t* _pop_count_table; |
| 109 static void init_pop_count_table(); | |
| 110 static idx_t num_set_bits(bm_word_t w); | |
| 111 static idx_t num_set_bits_from_table(unsigned char c); | |
| 0 | 112 |
| 113 public: | |
| 114 | |
| 115 // Constructs a bitmap with no map, and size 0. | |
| 116 BitMap() : _map(NULL), _size(0) {} | |
| 117 | |
| 342 | 118 // Constructs a bitmap with the given map and size. |
| 119 BitMap(bm_word_t* map, idx_t size_in_bits); | |
| 0 | 120 |
| 342 | 121 // Constructs an empty bitmap of the given size (that is, this clears the |
| 122 // new bitmap). Allocates the map array in resource area if | |
| 123 // "in_resource_area" is true, else in the C heap. | |
| 124 BitMap(idx_t size_in_bits, bool in_resource_area = true); | |
| 0 | 125 |
| 342 | 126 // Set the map and size. |
| 127 void set_map(bm_word_t* map) { _map = map; } | |
| 0 | 128 void set_size(idx_t size_in_bits) { _size = size_in_bits; } |
| 129 | |
| 342 | 130 // Allocates necessary data structure, either in the resource area |
| 131 // or in the C heap, as indicated by "in_resource_area." | |
| 0 | 132 // Preserves state currently in bit map by copying data. |
| 133 // Zeros any newly-addressable bits. | |
| 342 | 134 // If "in_resource_area" is false, frees the current map. |
| 135 // (Note that this assumes that all calls to "resize" on the same BitMap | |
| 136 // use the same value for "in_resource_area".) | |
| 137 void resize(idx_t size_in_bits, bool in_resource_area = true); | |
| 0 | 138 |
| 139 // Accessing | |
| 140 idx_t size() const { return _size; } | |
| 141 idx_t size_in_words() const { | |
| 142 return word_index(size() + BitsPerWord - 1); | |
| 143 } | |
| 144 | |
| 145 bool at(idx_t index) const { | |
| 146 verify_index(index); | |
| 147 return (*word_addr(index) & bit_mask(index)) != 0; | |
| 148 } | |
| 149 | |
| 150 // Align bit index up or down to the next bitmap word boundary, or check | |
| 151 // alignment. | |
| 152 static idx_t word_align_up(idx_t bit) { | |
| 153 return align_size_up(bit, BitsPerWord); | |
| 154 } | |
| 155 static idx_t word_align_down(idx_t bit) { | |
| 156 return align_size_down(bit, BitsPerWord); | |
| 157 } | |
| 158 static bool is_word_aligned(idx_t bit) { | |
| 159 return word_align_up(bit) == bit; | |
| 160 } | |
| 161 | |
| 162 // Set or clear the specified bit. | |
| 163 inline void set_bit(idx_t bit); | |
| 342 | 164 void clear_bit(idx_t bit); |
| 0 | 165 |
| 166 // Atomically set or clear the specified bit. | |
| 342 | 167 bool par_set_bit(idx_t bit); |
| 168 bool par_clear_bit(idx_t bit); | |
| 0 | 169 |
| 170 // Put the given value at the given offset. The parallel version | |
| 171 // will CAS the value into the bitmap and is quite a bit slower. | |
| 172 // The parallel version also returns a value indicating if the | |
| 173 // calling thread was the one that changed the value of the bit. | |
| 174 void at_put(idx_t index, bool value); | |
| 175 bool par_at_put(idx_t index, bool value); | |
| 176 | |
| 177 // Update a range of bits. Ranges are half-open [beg, end). | |
| 178 void set_range (idx_t beg, idx_t end); | |
| 179 void clear_range (idx_t beg, idx_t end); | |
| 180 void set_large_range (idx_t beg, idx_t end); | |
| 181 void clear_large_range (idx_t beg, idx_t end); | |
| 182 void at_put_range(idx_t beg, idx_t end, bool value); | |
| 183 void par_at_put_range(idx_t beg, idx_t end, bool value); | |
| 184 void at_put_large_range(idx_t beg, idx_t end, bool value); | |
| 185 void par_at_put_large_range(idx_t beg, idx_t end, bool value); | |
| 186 | |
| 187 // Update a range of bits, using a hint about the size. Currently only | |
| 188 // inlines the predominant case of a 1-bit range. Works best when hint is a | |
| 189 // compile-time constant. | |
| 342 | 190 void set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
| 191 void clear_range(idx_t beg, idx_t end, RangeSizeHint hint); | |
| 192 void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint); | |
| 193 void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint); | |
| 194 | |
| 195 // It performs the union operation between subsets of equal length | |
| 196 // of two bitmaps (the target bitmap of the method and the | |
| 197 // from_bitmap) and stores the result to the target bitmap. The | |
| 198 // from_start_index represents the first bit index of the subrange | |
| 199 // of the from_bitmap. The to_start_index is the equivalent of the | |
| 200 // target bitmap. Both indexes should be word-aligned, i.e. they | |
| 201 // should correspond to the first bit on a bitmap word (it's up to | |
| 202 // the caller to ensure this; the method does check it). The length | |
| 203 // of the subset is specified with word_num and it is in number of | |
| 204 // bitmap words. The caller should ensure that this is at least 2 | |
| 205 // (smaller ranges are not support to save extra checks). Again, | |
| 206 // this is checked in the method. | |
| 207 // | |
| 208 // Atomicity concerns: it is assumed that any contention on the | |
| 209 // target bitmap with other threads will happen on the first and | |
| 210 // last words; the ones in between will be "owned" exclusively by | |
| 211 // the calling thread and, in fact, they will already be 0. So, the | |
| 212 // method performs a CAS on the first word, copies the next | |
| 213 // word_num-2 words, and finally performs a CAS on the last word. | |
| 214 void mostly_disjoint_range_union(BitMap* from_bitmap, | |
| 215 idx_t from_start_index, | |
| 216 idx_t to_start_index, | |
| 217 size_t word_num); | |
| 218 | |
| 0 | 219 |
| 220 // Clearing | |
| 221 void clear_large(); | |
| 342 | 222 inline void clear(); |
| 0 | 223 |
| 342 | 224 // Iteration support. Returns "true" if the iteration completed, false |
| 225 // if the iteration terminated early (because the closure "blk" returned | |
| 226 // false). | |
| 227 bool iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex); | |
| 228 bool iterate(BitMapClosure* blk) { | |
| 0 | 229 // call the version that takes an interval |
| 342 | 230 return iterate(blk, 0, size()); |
| 0 | 231 } |
| 232 | |
| 342 | 233 // Looking for 1's and 0's at indices equal to or greater than "l_index", |
| 234 // stopping if none has been found before "r_index", and returning | |
| 235 // "r_index" (which must be at most "size") in that case. | |
| 236 idx_t get_next_one_offset_inline (idx_t l_index, idx_t r_index) const; | |
| 237 idx_t get_next_zero_offset_inline(idx_t l_index, idx_t r_index) const; | |
| 238 | |
| 239 // Like "get_next_one_offset_inline", except requires that "r_index" is | |
| 240 // aligned to bitsizeof(bm_word_t). | |
| 241 idx_t get_next_one_offset_inline_aligned_right(idx_t l_index, | |
| 242 idx_t r_index) const; | |
| 243 | |
| 244 // Non-inline versionsof the above. | |
| 0 | 245 idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const; |
| 246 idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const; | |
| 247 | |
| 248 idx_t get_next_one_offset(idx_t offset) const { | |
| 249 return get_next_one_offset(offset, size()); | |
| 250 } | |
| 251 idx_t get_next_zero_offset(idx_t offset) const { | |
| 252 return get_next_zero_offset(offset, size()); | |
| 253 } | |
| 254 | |
| 342 | 255 // Returns the number of bits set in the bitmap. |
| 256 idx_t count_one_bits() const; | |
| 0 | 257 |
| 258 // Set operations. | |
| 259 void set_union(BitMap bits); | |
| 260 void set_difference(BitMap bits); | |
| 261 void set_intersection(BitMap bits); | |
| 262 // Returns true iff "this" is a superset of "bits". | |
| 263 bool contains(const BitMap bits) const; | |
| 264 // Returns true iff "this and "bits" have a non-empty intersection. | |
| 265 bool intersects(const BitMap bits) const; | |
| 266 | |
| 267 // Returns result of whether this map changed | |
| 268 // during the operation | |
| 269 bool set_union_with_result(BitMap bits); | |
| 270 bool set_difference_with_result(BitMap bits); | |
| 271 bool set_intersection_with_result(BitMap bits); | |
| 272 | |
| 342 | 273 // Requires the submap of "bits" starting at offset to be at least as |
| 274 // large as "this". Modifies "this" to be the intersection of its | |
| 275 // current contents and the submap of "bits" starting at "offset" of the | |
| 276 // same length as "this." | |
| 277 // (For expedience, currently requires the offset to be aligned to the | |
| 278 // bitsize of a uintptr_t. This should go away in the future though it | |
| 279 // will probably remain a good case to optimize.) | |
| 280 void set_intersection_at_offset(BitMap bits, idx_t offset); | |
| 281 | |
| 0 | 282 void set_from(BitMap bits); |
| 283 | |
| 284 bool is_same(BitMap bits); | |
| 285 | |
| 286 // Test if all bits are set or cleared | |
| 287 bool is_full() const; | |
| 288 bool is_empty() const; | |
| 289 | |
| 290 | |
| 291 #ifndef PRODUCT | |
| 292 public: | |
| 293 // Printing | |
| 294 void print_on(outputStream* st) const; | |
| 295 #endif | |
| 296 }; | |
| 297 | |
| 298 // Convenience class wrapping BitMap which provides multiple bits per slot. | |
| 299 class BitMap2D VALUE_OBJ_CLASS_SPEC { | |
| 300 public: | |
| 342 | 301 typedef BitMap::idx_t idx_t; // Type used for bit and word indices. |
| 302 typedef BitMap::bm_word_t bm_word_t; // Element type of array that | |
| 303 // represents the bitmap. | |
| 0 | 304 private: |
| 305 BitMap _map; | |
| 306 idx_t _bits_per_slot; | |
| 307 | |
| 308 idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const { | |
| 309 return slot_index * _bits_per_slot + bit_within_slot_index; | |
| 310 } | |
| 311 | |
| 312 void verify_bit_within_slot_index(idx_t index) const { | |
| 313 assert(index < _bits_per_slot, "bit_within_slot index out of bounds"); | |
| 314 } | |
| 315 | |
| 316 public: | |
| 317 // Construction. bits_per_slot must be greater than 0. | |
| 342 | 318 BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot); |
| 0 | 319 |
| 320 // Allocates necessary data structure in resource area. bits_per_slot must be greater than 0. | |
| 321 BitMap2D(idx_t size_in_slots, idx_t bits_per_slot); | |
| 322 | |
| 323 idx_t size_in_bits() { | |
| 324 return _map.size(); | |
| 325 } | |
| 326 | |
| 327 // Returns number of full slots that have been allocated | |
| 328 idx_t size_in_slots() { | |
| 329 // Round down | |
| 330 return _map.size() / _bits_per_slot; | |
| 331 } | |
| 332 | |
| 333 bool is_valid_index(idx_t slot_index, idx_t bit_within_slot_index) { | |
| 334 verify_bit_within_slot_index(bit_within_slot_index); | |
| 335 return (bit_index(slot_index, bit_within_slot_index) < size_in_bits()); | |
| 336 } | |
| 337 | |
| 338 bool at(idx_t slot_index, idx_t bit_within_slot_index) const { | |
| 339 verify_bit_within_slot_index(bit_within_slot_index); | |
| 340 return _map.at(bit_index(slot_index, bit_within_slot_index)); | |
| 341 } | |
| 342 | |
| 343 void set_bit(idx_t slot_index, idx_t bit_within_slot_index) { | |
| 344 verify_bit_within_slot_index(bit_within_slot_index); | |
| 345 _map.set_bit(bit_index(slot_index, bit_within_slot_index)); | |
| 346 } | |
| 347 | |
| 348 void clear_bit(idx_t slot_index, idx_t bit_within_slot_index) { | |
| 349 verify_bit_within_slot_index(bit_within_slot_index); | |
| 350 _map.clear_bit(bit_index(slot_index, bit_within_slot_index)); | |
| 351 } | |
| 352 | |
| 353 void at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value) { | |
| 354 verify_bit_within_slot_index(bit_within_slot_index); | |
| 355 _map.at_put(bit_index(slot_index, bit_within_slot_index), value); | |
| 356 } | |
| 357 | |
| 358 void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value) { | |
| 359 verify_bit_within_slot_index(bit_within_slot_index); | |
| 360 _map.at_put_grow(bit_index(slot_index, bit_within_slot_index), value); | |
| 361 } | |
| 362 | |
| 342 | 363 void clear(); |
| 0 | 364 }; |
| 365 | |
| 342 | 366 // Closure for iterating over BitMaps |
| 0 | 367 |
| 342 | 368 class BitMapClosure VALUE_OBJ_CLASS_SPEC { |
| 369 public: | |
| 370 // Callback when bit in map is set. Should normally return "true"; | |
| 371 // return of false indicates that the bitmap iteration should terminate. | |
| 372 virtual bool do_bit(BitMap::idx_t offset) = 0; | |
| 373 }; | |
| 1972 | 374 |
| 375 #endif // SHARE_VM_UTILITIES_BITMAP_HPP |