Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/parallelScavenge/parMarkBitMap.hpp @ 1286:ab75c83d7c37
Merge
author | johnc |
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date | Tue, 02 Mar 2010 13:57:46 -0800 |
parents | bd02caa94611 |
children | c18cbe5936b8 |
rev | line source |
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0 | 1 /* |
844 | 2 * Copyright 2005-2009 Sun Microsystems, Inc. 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 * | |
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 class oopDesc; | |
26 class ParMarkBitMapClosure; | |
27 | |
28 class ParMarkBitMap: public CHeapObj | |
29 { | |
30 public: | |
31 typedef BitMap::idx_t idx_t; | |
32 | |
33 // Values returned by the iterate() methods. | |
34 enum IterationStatus { incomplete, complete, full, would_overflow }; | |
35 | |
36 inline ParMarkBitMap(); | |
37 inline ParMarkBitMap(MemRegion covered_region); | |
38 bool initialize(MemRegion covered_region); | |
39 | |
40 // Atomically mark an object as live. | |
41 bool mark_obj(HeapWord* addr, size_t size); | |
42 inline bool mark_obj(oop obj, int size); | |
43 inline bool mark_obj(oop obj); | |
44 | |
45 // Return whether the specified begin or end bit is set. | |
46 inline bool is_obj_beg(idx_t bit) const; | |
47 inline bool is_obj_end(idx_t bit) const; | |
48 | |
49 // Traditional interface for testing whether an object is marked or not (these | |
50 // test only the begin bits). | |
51 inline bool is_marked(idx_t bit) const; | |
52 inline bool is_marked(HeapWord* addr) const; | |
53 inline bool is_marked(oop obj) const; | |
54 | |
55 inline bool is_unmarked(idx_t bit) const; | |
56 inline bool is_unmarked(HeapWord* addr) const; | |
57 inline bool is_unmarked(oop obj) const; | |
58 | |
59 // Convert sizes from bits to HeapWords and back. An object that is n bits | |
60 // long will be bits_to_words(n) words long. An object that is m words long | |
61 // will take up words_to_bits(m) bits in the bitmap. | |
62 inline static size_t bits_to_words(idx_t bits); | |
63 inline static idx_t words_to_bits(size_t words); | |
64 | |
65 // Return the size in words of an object given a begin bit and an end bit, or | |
66 // the equivalent beg_addr and end_addr. | |
67 inline size_t obj_size(idx_t beg_bit, idx_t end_bit) const; | |
68 inline size_t obj_size(HeapWord* beg_addr, HeapWord* end_addr) const; | |
69 | |
70 // Return the size in words of the object (a search is done for the end bit). | |
71 inline size_t obj_size(idx_t beg_bit) const; | |
72 inline size_t obj_size(HeapWord* addr) const; | |
73 inline size_t obj_size(oop obj) const; | |
74 | |
75 // Synonyms for the above. | |
76 size_t obj_size_in_words(oop obj) const { return obj_size((HeapWord*)obj); } | |
77 size_t obj_size_in_words(HeapWord* addr) const { return obj_size(addr); } | |
78 | |
79 // Apply live_closure to each live object that lies completely within the | |
80 // range [live_range_beg, live_range_end). This is used to iterate over the | |
81 // compacted region of the heap. Return values: | |
82 // | |
83 // incomplete The iteration is not complete. The last object that | |
84 // begins in the range does not end in the range; | |
85 // closure->source() is set to the start of that object. | |
86 // | |
87 // complete The iteration is complete. All objects in the range | |
88 // were processed and the closure is not full; | |
89 // closure->source() is set one past the end of the range. | |
90 // | |
91 // full The closure is full; closure->source() is set to one | |
92 // past the end of the last object processed. | |
93 // | |
94 // would_overflow The next object in the range would overflow the closure; | |
95 // closure->source() is set to the start of that object. | |
96 IterationStatus iterate(ParMarkBitMapClosure* live_closure, | |
97 idx_t range_beg, idx_t range_end) const; | |
98 inline IterationStatus iterate(ParMarkBitMapClosure* live_closure, | |
99 HeapWord* range_beg, | |
100 HeapWord* range_end) const; | |
101 | |
102 // Apply live closure as above and additionally apply dead_closure to all dead | |
103 // space in the range [range_beg, dead_range_end). Note that dead_range_end | |
104 // must be >= range_end. This is used to iterate over the dense prefix. | |
105 // | |
106 // This method assumes that if the first bit in the range (range_beg) is not | |
107 // marked, then dead space begins at that point and the dead_closure is | |
108 // applied. Thus callers must ensure that range_beg is not in the middle of a | |
109 // live object. | |
110 IterationStatus iterate(ParMarkBitMapClosure* live_closure, | |
111 ParMarkBitMapClosure* dead_closure, | |
112 idx_t range_beg, idx_t range_end, | |
113 idx_t dead_range_end) const; | |
114 inline IterationStatus iterate(ParMarkBitMapClosure* live_closure, | |
115 ParMarkBitMapClosure* dead_closure, | |
116 HeapWord* range_beg, | |
117 HeapWord* range_end, | |
118 HeapWord* dead_range_end) const; | |
119 | |
120 // Return the number of live words in the range [beg_addr, end_addr) due to | |
121 // objects that start in the range. If a live object extends onto the range, | |
122 // the caller must detect and account for any live words due to that object. | |
123 // If a live object extends beyond the end of the range, only the words within | |
124 // the range are included in the result. | |
125 size_t live_words_in_range(HeapWord* beg_addr, HeapWord* end_addr) const; | |
126 | |
127 // Same as the above, except the end of the range must be a live object, which | |
128 // is the case when updating pointers. This allows a branch to be removed | |
129 // from inside the loop. | |
130 size_t live_words_in_range(HeapWord* beg_addr, oop end_obj) const; | |
131 | |
132 inline HeapWord* region_start() const; | |
133 inline HeapWord* region_end() const; | |
134 inline size_t region_size() const; | |
135 inline size_t size() const; | |
136 | |
137 // Convert a heap address to/from a bit index. | |
138 inline idx_t addr_to_bit(HeapWord* addr) const; | |
139 inline HeapWord* bit_to_addr(idx_t bit) const; | |
140 | |
141 // Return the bit index of the first marked object that begins (or ends, | |
142 // respectively) in the range [beg, end). If no object is found, return end. | |
143 inline idx_t find_obj_beg(idx_t beg, idx_t end) const; | |
144 inline idx_t find_obj_end(idx_t beg, idx_t end) const; | |
145 | |
146 inline HeapWord* find_obj_beg(HeapWord* beg, HeapWord* end) const; | |
147 inline HeapWord* find_obj_end(HeapWord* beg, HeapWord* end) const; | |
148 | |
149 // Clear a range of bits or the entire bitmap (both begin and end bits are | |
150 // cleared). | |
151 inline void clear_range(idx_t beg, idx_t end); | |
152 inline void clear() { clear_range(0, size()); } | |
153 | |
154 // Return the number of bits required to represent the specified number of | |
155 // HeapWords, or the specified region. | |
156 static inline idx_t bits_required(size_t words); | |
157 static inline idx_t bits_required(MemRegion covered_region); | |
158 static inline idx_t words_required(MemRegion covered_region); | |
159 | |
160 #ifndef PRODUCT | |
161 // CAS statistics. | |
162 size_t cas_tries() { return _cas_tries; } | |
163 size_t cas_retries() { return _cas_retries; } | |
164 size_t cas_by_another() { return _cas_by_another; } | |
165 | |
166 void reset_counters(); | |
167 #endif // #ifndef PRODUCT | |
168 | |
169 #ifdef ASSERT | |
170 void verify_clear() const; | |
171 inline void verify_bit(idx_t bit) const; | |
172 inline void verify_addr(HeapWord* addr) const; | |
173 #endif // #ifdef ASSERT | |
174 | |
175 private: | |
176 // Each bit in the bitmap represents one unit of 'object granularity.' Objects | |
177 // are double-word aligned in 32-bit VMs, but not in 64-bit VMs, so the 32-bit | |
178 // granularity is 2, 64-bit is 1. | |
179 static inline size_t obj_granularity() { return size_t(MinObjAlignment); } | |
808
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180 static inline int obj_granularity_shift() { return LogMinObjAlignment; } |
0 | 181 |
182 HeapWord* _region_start; | |
183 size_t _region_size; | |
184 BitMap _beg_bits; | |
185 BitMap _end_bits; | |
186 PSVirtualSpace* _virtual_space; | |
187 | |
188 #ifndef PRODUCT | |
189 size_t _cas_tries; | |
190 size_t _cas_retries; | |
191 size_t _cas_by_another; | |
192 #endif // #ifndef PRODUCT | |
193 }; | |
194 | |
195 inline ParMarkBitMap::ParMarkBitMap(): | |
342 | 196 _beg_bits(), |
197 _end_bits() | |
0 | 198 { |
199 _region_start = 0; | |
200 _virtual_space = 0; | |
201 } | |
202 | |
203 inline ParMarkBitMap::ParMarkBitMap(MemRegion covered_region): | |
342 | 204 _beg_bits(), |
205 _end_bits() | |
0 | 206 { |
207 initialize(covered_region); | |
208 } | |
209 | |
210 inline void ParMarkBitMap::clear_range(idx_t beg, idx_t end) | |
211 { | |
212 _beg_bits.clear_range(beg, end); | |
213 _end_bits.clear_range(beg, end); | |
214 } | |
215 | |
216 inline ParMarkBitMap::idx_t | |
217 ParMarkBitMap::bits_required(size_t words) | |
218 { | |
219 // Need two bits (one begin bit, one end bit) for each unit of 'object | |
220 // granularity' in the heap. | |
221 return words_to_bits(words * 2); | |
222 } | |
223 | |
224 inline ParMarkBitMap::idx_t | |
225 ParMarkBitMap::bits_required(MemRegion covered_region) | |
226 { | |
227 return bits_required(covered_region.word_size()); | |
228 } | |
229 | |
230 inline ParMarkBitMap::idx_t | |
231 ParMarkBitMap::words_required(MemRegion covered_region) | |
232 { | |
233 return bits_required(covered_region) / BitsPerWord; | |
234 } | |
235 | |
236 inline HeapWord* | |
237 ParMarkBitMap::region_start() const | |
238 { | |
239 return _region_start; | |
240 } | |
241 | |
242 inline HeapWord* | |
243 ParMarkBitMap::region_end() const | |
244 { | |
245 return region_start() + region_size(); | |
246 } | |
247 | |
248 inline size_t | |
249 ParMarkBitMap::region_size() const | |
250 { | |
251 return _region_size; | |
252 } | |
253 | |
254 inline size_t | |
255 ParMarkBitMap::size() const | |
256 { | |
257 return _beg_bits.size(); | |
258 } | |
259 | |
260 inline bool ParMarkBitMap::is_obj_beg(idx_t bit) const | |
261 { | |
262 return _beg_bits.at(bit); | |
263 } | |
264 | |
265 inline bool ParMarkBitMap::is_obj_end(idx_t bit) const | |
266 { | |
267 return _end_bits.at(bit); | |
268 } | |
269 | |
270 inline bool ParMarkBitMap::is_marked(idx_t bit) const | |
271 { | |
272 return is_obj_beg(bit); | |
273 } | |
274 | |
275 inline bool ParMarkBitMap::is_marked(HeapWord* addr) const | |
276 { | |
277 return is_marked(addr_to_bit(addr)); | |
278 } | |
279 | |
280 inline bool ParMarkBitMap::is_marked(oop obj) const | |
281 { | |
282 return is_marked((HeapWord*)obj); | |
283 } | |
284 | |
285 inline bool ParMarkBitMap::is_unmarked(idx_t bit) const | |
286 { | |
287 return !is_marked(bit); | |
288 } | |
289 | |
290 inline bool ParMarkBitMap::is_unmarked(HeapWord* addr) const | |
291 { | |
292 return !is_marked(addr); | |
293 } | |
294 | |
295 inline bool ParMarkBitMap::is_unmarked(oop obj) const | |
296 { | |
297 return !is_marked(obj); | |
298 } | |
299 | |
300 inline size_t | |
301 ParMarkBitMap::bits_to_words(idx_t bits) | |
302 { | |
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303 return bits << obj_granularity_shift(); |
0 | 304 } |
305 | |
306 inline ParMarkBitMap::idx_t | |
307 ParMarkBitMap::words_to_bits(size_t words) | |
308 { | |
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309 return words >> obj_granularity_shift(); |
0 | 310 } |
311 | |
312 inline size_t ParMarkBitMap::obj_size(idx_t beg_bit, idx_t end_bit) const | |
313 { | |
314 DEBUG_ONLY(verify_bit(beg_bit);) | |
315 DEBUG_ONLY(verify_bit(end_bit);) | |
316 return bits_to_words(end_bit - beg_bit + 1); | |
317 } | |
318 | |
319 inline size_t | |
320 ParMarkBitMap::obj_size(HeapWord* beg_addr, HeapWord* end_addr) const | |
321 { | |
322 DEBUG_ONLY(verify_addr(beg_addr);) | |
323 DEBUG_ONLY(verify_addr(end_addr);) | |
324 return pointer_delta(end_addr, beg_addr) + obj_granularity(); | |
325 } | |
326 | |
327 inline size_t ParMarkBitMap::obj_size(idx_t beg_bit) const | |
328 { | |
342 | 329 const idx_t end_bit = _end_bits.get_next_one_offset_inline(beg_bit, size()); |
0 | 330 assert(is_marked(beg_bit), "obj not marked"); |
331 assert(end_bit < size(), "end bit missing"); | |
332 return obj_size(beg_bit, end_bit); | |
333 } | |
334 | |
335 inline size_t ParMarkBitMap::obj_size(HeapWord* addr) const | |
336 { | |
337 return obj_size(addr_to_bit(addr)); | |
338 } | |
339 | |
340 inline size_t ParMarkBitMap::obj_size(oop obj) const | |
341 { | |
342 return obj_size((HeapWord*)obj); | |
343 } | |
344 | |
345 inline ParMarkBitMap::IterationStatus | |
346 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, | |
347 HeapWord* range_beg, | |
348 HeapWord* range_end) const | |
349 { | |
350 return iterate(live_closure, addr_to_bit(range_beg), addr_to_bit(range_end)); | |
351 } | |
352 | |
353 inline ParMarkBitMap::IterationStatus | |
354 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, | |
355 ParMarkBitMapClosure* dead_closure, | |
356 HeapWord* range_beg, | |
357 HeapWord* range_end, | |
358 HeapWord* dead_range_end) const | |
359 { | |
360 return iterate(live_closure, dead_closure, | |
361 addr_to_bit(range_beg), addr_to_bit(range_end), | |
362 addr_to_bit(dead_range_end)); | |
363 } | |
364 | |
365 inline bool | |
366 ParMarkBitMap::mark_obj(oop obj, int size) | |
367 { | |
368 return mark_obj((HeapWord*)obj, (size_t)size); | |
369 } | |
370 | |
371 inline BitMap::idx_t | |
372 ParMarkBitMap::addr_to_bit(HeapWord* addr) const | |
373 { | |
374 DEBUG_ONLY(verify_addr(addr);) | |
375 return words_to_bits(pointer_delta(addr, region_start())); | |
376 } | |
377 | |
378 inline HeapWord* | |
379 ParMarkBitMap::bit_to_addr(idx_t bit) const | |
380 { | |
381 DEBUG_ONLY(verify_bit(bit);) | |
382 return region_start() + bits_to_words(bit); | |
383 } | |
384 | |
385 inline ParMarkBitMap::idx_t | |
386 ParMarkBitMap::find_obj_beg(idx_t beg, idx_t end) const | |
387 { | |
342 | 388 return _beg_bits.get_next_one_offset_inline_aligned_right(beg, end); |
0 | 389 } |
390 | |
391 inline ParMarkBitMap::idx_t | |
392 ParMarkBitMap::find_obj_end(idx_t beg, idx_t end) const | |
393 { | |
342 | 394 return _end_bits.get_next_one_offset_inline_aligned_right(beg, end); |
0 | 395 } |
396 | |
397 inline HeapWord* | |
398 ParMarkBitMap::find_obj_beg(HeapWord* beg, HeapWord* end) const | |
399 { | |
400 const idx_t beg_bit = addr_to_bit(beg); | |
401 const idx_t end_bit = addr_to_bit(end); | |
402 const idx_t search_end = BitMap::word_align_up(end_bit); | |
403 const idx_t res_bit = MIN2(find_obj_beg(beg_bit, search_end), end_bit); | |
404 return bit_to_addr(res_bit); | |
405 } | |
406 | |
407 inline HeapWord* | |
408 ParMarkBitMap::find_obj_end(HeapWord* beg, HeapWord* end) const | |
409 { | |
410 const idx_t beg_bit = addr_to_bit(beg); | |
411 const idx_t end_bit = addr_to_bit(end); | |
412 const idx_t search_end = BitMap::word_align_up(end_bit); | |
413 const idx_t res_bit = MIN2(find_obj_end(beg_bit, search_end), end_bit); | |
414 return bit_to_addr(res_bit); | |
415 } | |
416 | |
417 #ifdef ASSERT | |
418 inline void ParMarkBitMap::verify_bit(idx_t bit) const { | |
419 // Allow one past the last valid bit; useful for loop bounds. | |
420 assert(bit <= _beg_bits.size(), "bit out of range"); | |
421 } | |
422 | |
423 inline void ParMarkBitMap::verify_addr(HeapWord* addr) const { | |
424 // Allow one past the last valid address; useful for loop bounds. | |
425 assert(addr >= region_start(), "addr too small"); | |
426 assert(addr <= region_start() + region_size(), "addr too big"); | |
427 } | |
428 #endif // #ifdef ASSERT |