src/share/vm/gc_implementation/parallelScavenge/parMarkBitMap.hpp

Fri, 16 Jul 2010 21:33:21 -0700

author
jcoomes
date
Fri, 16 Jul 2010 21:33:21 -0700
changeset 2020
a93a9eda13f7
parent 1907
c18cbe5936b8
child 2314
f95d63e2154a
permissions
-rw-r--r--

6962947: shared TaskQueue statistics
Reviewed-by: tonyp, ysr

duke@435 1 /*
trims@1907 2 * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 class oopDesc;
duke@435 26 class ParMarkBitMapClosure;
duke@435 27
duke@435 28 class ParMarkBitMap: public CHeapObj
duke@435 29 {
duke@435 30 public:
duke@435 31 typedef BitMap::idx_t idx_t;
duke@435 32
duke@435 33 // Values returned by the iterate() methods.
duke@435 34 enum IterationStatus { incomplete, complete, full, would_overflow };
duke@435 35
duke@435 36 inline ParMarkBitMap();
duke@435 37 inline ParMarkBitMap(MemRegion covered_region);
duke@435 38 bool initialize(MemRegion covered_region);
duke@435 39
duke@435 40 // Atomically mark an object as live.
duke@435 41 bool mark_obj(HeapWord* addr, size_t size);
duke@435 42 inline bool mark_obj(oop obj, int size);
duke@435 43 inline bool mark_obj(oop obj);
duke@435 44
duke@435 45 // Return whether the specified begin or end bit is set.
duke@435 46 inline bool is_obj_beg(idx_t bit) const;
duke@435 47 inline bool is_obj_end(idx_t bit) const;
duke@435 48
duke@435 49 // Traditional interface for testing whether an object is marked or not (these
duke@435 50 // test only the begin bits).
duke@435 51 inline bool is_marked(idx_t bit) const;
duke@435 52 inline bool is_marked(HeapWord* addr) const;
duke@435 53 inline bool is_marked(oop obj) const;
duke@435 54
duke@435 55 inline bool is_unmarked(idx_t bit) const;
duke@435 56 inline bool is_unmarked(HeapWord* addr) const;
duke@435 57 inline bool is_unmarked(oop obj) const;
duke@435 58
duke@435 59 // Convert sizes from bits to HeapWords and back. An object that is n bits
duke@435 60 // long will be bits_to_words(n) words long. An object that is m words long
duke@435 61 // will take up words_to_bits(m) bits in the bitmap.
duke@435 62 inline static size_t bits_to_words(idx_t bits);
duke@435 63 inline static idx_t words_to_bits(size_t words);
duke@435 64
duke@435 65 // Return the size in words of an object given a begin bit and an end bit, or
duke@435 66 // the equivalent beg_addr and end_addr.
duke@435 67 inline size_t obj_size(idx_t beg_bit, idx_t end_bit) const;
duke@435 68 inline size_t obj_size(HeapWord* beg_addr, HeapWord* end_addr) const;
duke@435 69
duke@435 70 // Return the size in words of the object (a search is done for the end bit).
duke@435 71 inline size_t obj_size(idx_t beg_bit) const;
duke@435 72 inline size_t obj_size(HeapWord* addr) const;
duke@435 73 inline size_t obj_size(oop obj) const;
duke@435 74
duke@435 75 // Synonyms for the above.
duke@435 76 size_t obj_size_in_words(oop obj) const { return obj_size((HeapWord*)obj); }
duke@435 77 size_t obj_size_in_words(HeapWord* addr) const { return obj_size(addr); }
duke@435 78
duke@435 79 // Apply live_closure to each live object that lies completely within the
duke@435 80 // range [live_range_beg, live_range_end). This is used to iterate over the
duke@435 81 // compacted region of the heap. Return values:
duke@435 82 //
duke@435 83 // incomplete The iteration is not complete. The last object that
duke@435 84 // begins in the range does not end in the range;
duke@435 85 // closure->source() is set to the start of that object.
duke@435 86 //
duke@435 87 // complete The iteration is complete. All objects in the range
duke@435 88 // were processed and the closure is not full;
duke@435 89 // closure->source() is set one past the end of the range.
duke@435 90 //
duke@435 91 // full The closure is full; closure->source() is set to one
duke@435 92 // past the end of the last object processed.
duke@435 93 //
duke@435 94 // would_overflow The next object in the range would overflow the closure;
duke@435 95 // closure->source() is set to the start of that object.
duke@435 96 IterationStatus iterate(ParMarkBitMapClosure* live_closure,
duke@435 97 idx_t range_beg, idx_t range_end) const;
duke@435 98 inline IterationStatus iterate(ParMarkBitMapClosure* live_closure,
duke@435 99 HeapWord* range_beg,
duke@435 100 HeapWord* range_end) const;
duke@435 101
duke@435 102 // Apply live closure as above and additionally apply dead_closure to all dead
duke@435 103 // space in the range [range_beg, dead_range_end). Note that dead_range_end
duke@435 104 // must be >= range_end. This is used to iterate over the dense prefix.
duke@435 105 //
duke@435 106 // This method assumes that if the first bit in the range (range_beg) is not
duke@435 107 // marked, then dead space begins at that point and the dead_closure is
duke@435 108 // applied. Thus callers must ensure that range_beg is not in the middle of a
duke@435 109 // live object.
duke@435 110 IterationStatus iterate(ParMarkBitMapClosure* live_closure,
duke@435 111 ParMarkBitMapClosure* dead_closure,
duke@435 112 idx_t range_beg, idx_t range_end,
duke@435 113 idx_t dead_range_end) const;
duke@435 114 inline IterationStatus iterate(ParMarkBitMapClosure* live_closure,
duke@435 115 ParMarkBitMapClosure* dead_closure,
duke@435 116 HeapWord* range_beg,
duke@435 117 HeapWord* range_end,
duke@435 118 HeapWord* dead_range_end) const;
duke@435 119
duke@435 120 // Return the number of live words in the range [beg_addr, end_addr) due to
duke@435 121 // objects that start in the range. If a live object extends onto the range,
duke@435 122 // the caller must detect and account for any live words due to that object.
duke@435 123 // If a live object extends beyond the end of the range, only the words within
duke@435 124 // the range are included in the result.
duke@435 125 size_t live_words_in_range(HeapWord* beg_addr, HeapWord* end_addr) const;
duke@435 126
duke@435 127 // Same as the above, except the end of the range must be a live object, which
duke@435 128 // is the case when updating pointers. This allows a branch to be removed
duke@435 129 // from inside the loop.
duke@435 130 size_t live_words_in_range(HeapWord* beg_addr, oop end_obj) const;
duke@435 131
duke@435 132 inline HeapWord* region_start() const;
duke@435 133 inline HeapWord* region_end() const;
duke@435 134 inline size_t region_size() const;
duke@435 135 inline size_t size() const;
duke@435 136
duke@435 137 // Convert a heap address to/from a bit index.
duke@435 138 inline idx_t addr_to_bit(HeapWord* addr) const;
duke@435 139 inline HeapWord* bit_to_addr(idx_t bit) const;
duke@435 140
duke@435 141 // Return the bit index of the first marked object that begins (or ends,
duke@435 142 // respectively) in the range [beg, end). If no object is found, return end.
duke@435 143 inline idx_t find_obj_beg(idx_t beg, idx_t end) const;
duke@435 144 inline idx_t find_obj_end(idx_t beg, idx_t end) const;
duke@435 145
duke@435 146 inline HeapWord* find_obj_beg(HeapWord* beg, HeapWord* end) const;
duke@435 147 inline HeapWord* find_obj_end(HeapWord* beg, HeapWord* end) const;
duke@435 148
duke@435 149 // Clear a range of bits or the entire bitmap (both begin and end bits are
duke@435 150 // cleared).
duke@435 151 inline void clear_range(idx_t beg, idx_t end);
duke@435 152 inline void clear() { clear_range(0, size()); }
duke@435 153
duke@435 154 // Return the number of bits required to represent the specified number of
duke@435 155 // HeapWords, or the specified region.
duke@435 156 static inline idx_t bits_required(size_t words);
duke@435 157 static inline idx_t bits_required(MemRegion covered_region);
duke@435 158 static inline idx_t words_required(MemRegion covered_region);
duke@435 159
duke@435 160 #ifndef PRODUCT
duke@435 161 // CAS statistics.
duke@435 162 size_t cas_tries() { return _cas_tries; }
duke@435 163 size_t cas_retries() { return _cas_retries; }
duke@435 164 size_t cas_by_another() { return _cas_by_another; }
duke@435 165
duke@435 166 void reset_counters();
duke@435 167 #endif // #ifndef PRODUCT
duke@435 168
duke@435 169 #ifdef ASSERT
duke@435 170 void verify_clear() const;
duke@435 171 inline void verify_bit(idx_t bit) const;
duke@435 172 inline void verify_addr(HeapWord* addr) const;
duke@435 173 #endif // #ifdef ASSERT
duke@435 174
duke@435 175 private:
duke@435 176 // Each bit in the bitmap represents one unit of 'object granularity.' Objects
duke@435 177 // are double-word aligned in 32-bit VMs, but not in 64-bit VMs, so the 32-bit
duke@435 178 // granularity is 2, 64-bit is 1.
duke@435 179 static inline size_t obj_granularity() { return size_t(MinObjAlignment); }
jcoomes@1243 180 static inline int obj_granularity_shift() { return LogMinObjAlignment; }
duke@435 181
duke@435 182 HeapWord* _region_start;
duke@435 183 size_t _region_size;
duke@435 184 BitMap _beg_bits;
duke@435 185 BitMap _end_bits;
duke@435 186 PSVirtualSpace* _virtual_space;
duke@435 187
duke@435 188 #ifndef PRODUCT
duke@435 189 size_t _cas_tries;
duke@435 190 size_t _cas_retries;
duke@435 191 size_t _cas_by_another;
duke@435 192 #endif // #ifndef PRODUCT
duke@435 193 };
duke@435 194
duke@435 195 inline ParMarkBitMap::ParMarkBitMap():
ysr@777 196 _beg_bits(),
ysr@777 197 _end_bits()
duke@435 198 {
duke@435 199 _region_start = 0;
duke@435 200 _virtual_space = 0;
duke@435 201 }
duke@435 202
duke@435 203 inline ParMarkBitMap::ParMarkBitMap(MemRegion covered_region):
ysr@777 204 _beg_bits(),
ysr@777 205 _end_bits()
duke@435 206 {
duke@435 207 initialize(covered_region);
duke@435 208 }
duke@435 209
duke@435 210 inline void ParMarkBitMap::clear_range(idx_t beg, idx_t end)
duke@435 211 {
duke@435 212 _beg_bits.clear_range(beg, end);
duke@435 213 _end_bits.clear_range(beg, end);
duke@435 214 }
duke@435 215
duke@435 216 inline ParMarkBitMap::idx_t
duke@435 217 ParMarkBitMap::bits_required(size_t words)
duke@435 218 {
duke@435 219 // Need two bits (one begin bit, one end bit) for each unit of 'object
duke@435 220 // granularity' in the heap.
duke@435 221 return words_to_bits(words * 2);
duke@435 222 }
duke@435 223
duke@435 224 inline ParMarkBitMap::idx_t
duke@435 225 ParMarkBitMap::bits_required(MemRegion covered_region)
duke@435 226 {
duke@435 227 return bits_required(covered_region.word_size());
duke@435 228 }
duke@435 229
duke@435 230 inline ParMarkBitMap::idx_t
duke@435 231 ParMarkBitMap::words_required(MemRegion covered_region)
duke@435 232 {
duke@435 233 return bits_required(covered_region) / BitsPerWord;
duke@435 234 }
duke@435 235
duke@435 236 inline HeapWord*
duke@435 237 ParMarkBitMap::region_start() const
duke@435 238 {
duke@435 239 return _region_start;
duke@435 240 }
duke@435 241
duke@435 242 inline HeapWord*
duke@435 243 ParMarkBitMap::region_end() const
duke@435 244 {
duke@435 245 return region_start() + region_size();
duke@435 246 }
duke@435 247
duke@435 248 inline size_t
duke@435 249 ParMarkBitMap::region_size() const
duke@435 250 {
duke@435 251 return _region_size;
duke@435 252 }
duke@435 253
duke@435 254 inline size_t
duke@435 255 ParMarkBitMap::size() const
duke@435 256 {
duke@435 257 return _beg_bits.size();
duke@435 258 }
duke@435 259
duke@435 260 inline bool ParMarkBitMap::is_obj_beg(idx_t bit) const
duke@435 261 {
duke@435 262 return _beg_bits.at(bit);
duke@435 263 }
duke@435 264
duke@435 265 inline bool ParMarkBitMap::is_obj_end(idx_t bit) const
duke@435 266 {
duke@435 267 return _end_bits.at(bit);
duke@435 268 }
duke@435 269
duke@435 270 inline bool ParMarkBitMap::is_marked(idx_t bit) const
duke@435 271 {
duke@435 272 return is_obj_beg(bit);
duke@435 273 }
duke@435 274
duke@435 275 inline bool ParMarkBitMap::is_marked(HeapWord* addr) const
duke@435 276 {
duke@435 277 return is_marked(addr_to_bit(addr));
duke@435 278 }
duke@435 279
duke@435 280 inline bool ParMarkBitMap::is_marked(oop obj) const
duke@435 281 {
duke@435 282 return is_marked((HeapWord*)obj);
duke@435 283 }
duke@435 284
duke@435 285 inline bool ParMarkBitMap::is_unmarked(idx_t bit) const
duke@435 286 {
duke@435 287 return !is_marked(bit);
duke@435 288 }
duke@435 289
duke@435 290 inline bool ParMarkBitMap::is_unmarked(HeapWord* addr) const
duke@435 291 {
duke@435 292 return !is_marked(addr);
duke@435 293 }
duke@435 294
duke@435 295 inline bool ParMarkBitMap::is_unmarked(oop obj) const
duke@435 296 {
duke@435 297 return !is_marked(obj);
duke@435 298 }
duke@435 299
duke@435 300 inline size_t
duke@435 301 ParMarkBitMap::bits_to_words(idx_t bits)
duke@435 302 {
jcoomes@1243 303 return bits << obj_granularity_shift();
duke@435 304 }
duke@435 305
duke@435 306 inline ParMarkBitMap::idx_t
duke@435 307 ParMarkBitMap::words_to_bits(size_t words)
duke@435 308 {
jcoomes@1243 309 return words >> obj_granularity_shift();
duke@435 310 }
duke@435 311
duke@435 312 inline size_t ParMarkBitMap::obj_size(idx_t beg_bit, idx_t end_bit) const
duke@435 313 {
duke@435 314 DEBUG_ONLY(verify_bit(beg_bit);)
duke@435 315 DEBUG_ONLY(verify_bit(end_bit);)
duke@435 316 return bits_to_words(end_bit - beg_bit + 1);
duke@435 317 }
duke@435 318
duke@435 319 inline size_t
duke@435 320 ParMarkBitMap::obj_size(HeapWord* beg_addr, HeapWord* end_addr) const
duke@435 321 {
duke@435 322 DEBUG_ONLY(verify_addr(beg_addr);)
duke@435 323 DEBUG_ONLY(verify_addr(end_addr);)
duke@435 324 return pointer_delta(end_addr, beg_addr) + obj_granularity();
duke@435 325 }
duke@435 326
duke@435 327 inline size_t ParMarkBitMap::obj_size(idx_t beg_bit) const
duke@435 328 {
ysr@777 329 const idx_t end_bit = _end_bits.get_next_one_offset_inline(beg_bit, size());
duke@435 330 assert(is_marked(beg_bit), "obj not marked");
duke@435 331 assert(end_bit < size(), "end bit missing");
duke@435 332 return obj_size(beg_bit, end_bit);
duke@435 333 }
duke@435 334
duke@435 335 inline size_t ParMarkBitMap::obj_size(HeapWord* addr) const
duke@435 336 {
duke@435 337 return obj_size(addr_to_bit(addr));
duke@435 338 }
duke@435 339
duke@435 340 inline size_t ParMarkBitMap::obj_size(oop obj) const
duke@435 341 {
duke@435 342 return obj_size((HeapWord*)obj);
duke@435 343 }
duke@435 344
duke@435 345 inline ParMarkBitMap::IterationStatus
duke@435 346 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
duke@435 347 HeapWord* range_beg,
duke@435 348 HeapWord* range_end) const
duke@435 349 {
duke@435 350 return iterate(live_closure, addr_to_bit(range_beg), addr_to_bit(range_end));
duke@435 351 }
duke@435 352
duke@435 353 inline ParMarkBitMap::IterationStatus
duke@435 354 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
duke@435 355 ParMarkBitMapClosure* dead_closure,
duke@435 356 HeapWord* range_beg,
duke@435 357 HeapWord* range_end,
duke@435 358 HeapWord* dead_range_end) const
duke@435 359 {
duke@435 360 return iterate(live_closure, dead_closure,
duke@435 361 addr_to_bit(range_beg), addr_to_bit(range_end),
duke@435 362 addr_to_bit(dead_range_end));
duke@435 363 }
duke@435 364
duke@435 365 inline bool
duke@435 366 ParMarkBitMap::mark_obj(oop obj, int size)
duke@435 367 {
duke@435 368 return mark_obj((HeapWord*)obj, (size_t)size);
duke@435 369 }
duke@435 370
duke@435 371 inline BitMap::idx_t
duke@435 372 ParMarkBitMap::addr_to_bit(HeapWord* addr) const
duke@435 373 {
duke@435 374 DEBUG_ONLY(verify_addr(addr);)
duke@435 375 return words_to_bits(pointer_delta(addr, region_start()));
duke@435 376 }
duke@435 377
duke@435 378 inline HeapWord*
duke@435 379 ParMarkBitMap::bit_to_addr(idx_t bit) const
duke@435 380 {
duke@435 381 DEBUG_ONLY(verify_bit(bit);)
duke@435 382 return region_start() + bits_to_words(bit);
duke@435 383 }
duke@435 384
duke@435 385 inline ParMarkBitMap::idx_t
duke@435 386 ParMarkBitMap::find_obj_beg(idx_t beg, idx_t end) const
duke@435 387 {
ysr@777 388 return _beg_bits.get_next_one_offset_inline_aligned_right(beg, end);
duke@435 389 }
duke@435 390
duke@435 391 inline ParMarkBitMap::idx_t
duke@435 392 ParMarkBitMap::find_obj_end(idx_t beg, idx_t end) const
duke@435 393 {
ysr@777 394 return _end_bits.get_next_one_offset_inline_aligned_right(beg, end);
duke@435 395 }
duke@435 396
duke@435 397 inline HeapWord*
duke@435 398 ParMarkBitMap::find_obj_beg(HeapWord* beg, HeapWord* end) const
duke@435 399 {
duke@435 400 const idx_t beg_bit = addr_to_bit(beg);
duke@435 401 const idx_t end_bit = addr_to_bit(end);
duke@435 402 const idx_t search_end = BitMap::word_align_up(end_bit);
duke@435 403 const idx_t res_bit = MIN2(find_obj_beg(beg_bit, search_end), end_bit);
duke@435 404 return bit_to_addr(res_bit);
duke@435 405 }
duke@435 406
duke@435 407 inline HeapWord*
duke@435 408 ParMarkBitMap::find_obj_end(HeapWord* beg, HeapWord* end) const
duke@435 409 {
duke@435 410 const idx_t beg_bit = addr_to_bit(beg);
duke@435 411 const idx_t end_bit = addr_to_bit(end);
duke@435 412 const idx_t search_end = BitMap::word_align_up(end_bit);
duke@435 413 const idx_t res_bit = MIN2(find_obj_end(beg_bit, search_end), end_bit);
duke@435 414 return bit_to_addr(res_bit);
duke@435 415 }
duke@435 416
duke@435 417 #ifdef ASSERT
duke@435 418 inline void ParMarkBitMap::verify_bit(idx_t bit) const {
duke@435 419 // Allow one past the last valid bit; useful for loop bounds.
duke@435 420 assert(bit <= _beg_bits.size(), "bit out of range");
duke@435 421 }
duke@435 422
duke@435 423 inline void ParMarkBitMap::verify_addr(HeapWord* addr) const {
duke@435 424 // Allow one past the last valid address; useful for loop bounds.
duke@435 425 assert(addr >= region_start(), "addr too small");
duke@435 426 assert(addr <= region_start() + region_size(), "addr too big");
duke@435 427 }
duke@435 428 #endif // #ifdef ASSERT

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