Mercurial > hg > truffle
comparison src/share/vm/memory/space.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | ba764ed4b6f2 |
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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 # include "incls/_precompiled.incl" | |
26 # include "incls/_space.cpp.incl" | |
27 | |
28 HeapWord* DirtyCardToOopClosure::get_actual_top(HeapWord* top, | |
29 HeapWord* top_obj) { | |
30 if (top_obj != NULL) { | |
31 if (_sp->block_is_obj(top_obj)) { | |
32 if (_precision == CardTableModRefBS::ObjHeadPreciseArray) { | |
33 if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) { | |
34 // An arrayOop is starting on the dirty card - since we do exact | |
35 // store checks for objArrays we are done. | |
36 } else { | |
37 // Otherwise, it is possible that the object starting on the dirty | |
38 // card spans the entire card, and that the store happened on a | |
39 // later card. Figure out where the object ends. | |
40 // Use the block_size() method of the space over which | |
41 // the iteration is being done. That space (e.g. CMS) may have | |
42 // specific requirements on object sizes which will | |
43 // be reflected in the block_size() method. | |
44 top = top_obj + oop(top_obj)->size(); | |
45 } | |
46 } | |
47 } else { | |
48 top = top_obj; | |
49 } | |
50 } else { | |
51 assert(top == _sp->end(), "only case where top_obj == NULL"); | |
52 } | |
53 return top; | |
54 } | |
55 | |
56 void DirtyCardToOopClosure::walk_mem_region(MemRegion mr, | |
57 HeapWord* bottom, | |
58 HeapWord* top) { | |
59 // 1. Blocks may or may not be objects. | |
60 // 2. Even when a block_is_obj(), it may not entirely | |
61 // occupy the block if the block quantum is larger than | |
62 // the object size. | |
63 // We can and should try to optimize by calling the non-MemRegion | |
64 // version of oop_iterate() for all but the extremal objects | |
65 // (for which we need to call the MemRegion version of | |
66 // oop_iterate()) To be done post-beta XXX | |
67 for (; bottom < top; bottom += _sp->block_size(bottom)) { | |
68 // As in the case of contiguous space above, we'd like to | |
69 // just use the value returned by oop_iterate to increment the | |
70 // current pointer; unfortunately, that won't work in CMS because | |
71 // we'd need an interface change (it seems) to have the space | |
72 // "adjust the object size" (for instance pad it up to its | |
73 // block alignment or minimum block size restrictions. XXX | |
74 if (_sp->block_is_obj(bottom) && | |
75 !_sp->obj_allocated_since_save_marks(oop(bottom))) { | |
76 oop(bottom)->oop_iterate(_cl, mr); | |
77 } | |
78 } | |
79 } | |
80 | |
81 void DirtyCardToOopClosure::do_MemRegion(MemRegion mr) { | |
82 | |
83 // Some collectors need to do special things whenever their dirty | |
84 // cards are processed. For instance, CMS must remember mutator updates | |
85 // (i.e. dirty cards) so as to re-scan mutated objects. | |
86 // Such work can be piggy-backed here on dirty card scanning, so as to make | |
87 // it slightly more efficient than doing a complete non-detructive pre-scan | |
88 // of the card table. | |
89 MemRegionClosure* pCl = _sp->preconsumptionDirtyCardClosure(); | |
90 if (pCl != NULL) { | |
91 pCl->do_MemRegion(mr); | |
92 } | |
93 | |
94 HeapWord* bottom = mr.start(); | |
95 HeapWord* last = mr.last(); | |
96 HeapWord* top = mr.end(); | |
97 HeapWord* bottom_obj; | |
98 HeapWord* top_obj; | |
99 | |
100 assert(_precision == CardTableModRefBS::ObjHeadPreciseArray || | |
101 _precision == CardTableModRefBS::Precise, | |
102 "Only ones we deal with for now."); | |
103 | |
104 assert(_precision != CardTableModRefBS::ObjHeadPreciseArray || | |
105 _last_bottom == NULL || | |
106 top <= _last_bottom, | |
107 "Not decreasing"); | |
108 NOT_PRODUCT(_last_bottom = mr.start()); | |
109 | |
110 bottom_obj = _sp->block_start(bottom); | |
111 top_obj = _sp->block_start(last); | |
112 | |
113 assert(bottom_obj <= bottom, "just checking"); | |
114 assert(top_obj <= top, "just checking"); | |
115 | |
116 // Given what we think is the top of the memory region and | |
117 // the start of the object at the top, get the actual | |
118 // value of the top. | |
119 top = get_actual_top(top, top_obj); | |
120 | |
121 // If the previous call did some part of this region, don't redo. | |
122 if (_precision == CardTableModRefBS::ObjHeadPreciseArray && | |
123 _min_done != NULL && | |
124 _min_done < top) { | |
125 top = _min_done; | |
126 } | |
127 | |
128 // Top may have been reset, and in fact may be below bottom, | |
129 // e.g. the dirty card region is entirely in a now free object | |
130 // -- something that could happen with a concurrent sweeper. | |
131 bottom = MIN2(bottom, top); | |
132 mr = MemRegion(bottom, top); | |
133 assert(bottom <= top && | |
134 (_precision != CardTableModRefBS::ObjHeadPreciseArray || | |
135 _min_done == NULL || | |
136 top <= _min_done), | |
137 "overlap!"); | |
138 | |
139 // Walk the region if it is not empty; otherwise there is nothing to do. | |
140 if (!mr.is_empty()) { | |
141 walk_mem_region(mr, bottom_obj, top); | |
142 } | |
143 | |
144 _min_done = bottom; | |
145 } | |
146 | |
147 DirtyCardToOopClosure* Space::new_dcto_cl(OopClosure* cl, | |
148 CardTableModRefBS::PrecisionStyle precision, | |
149 HeapWord* boundary) { | |
150 return new DirtyCardToOopClosure(this, cl, precision, boundary); | |
151 } | |
152 | |
153 void FilteringClosure::do_oop(oop* p) { | |
154 do_oop_nv(p); | |
155 } | |
156 | |
157 HeapWord* ContiguousSpaceDCTOC::get_actual_top(HeapWord* top, | |
158 HeapWord* top_obj) { | |
159 if (top_obj != NULL && top_obj < (_sp->toContiguousSpace())->top()) { | |
160 if (_precision == CardTableModRefBS::ObjHeadPreciseArray) { | |
161 if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) { | |
162 // An arrayOop is starting on the dirty card - since we do exact | |
163 // store checks for objArrays we are done. | |
164 } else { | |
165 // Otherwise, it is possible that the object starting on the dirty | |
166 // card spans the entire card, and that the store happened on a | |
167 // later card. Figure out where the object ends. | |
168 assert(_sp->block_size(top_obj) == (size_t) oop(top_obj)->size(), | |
169 "Block size and object size mismatch"); | |
170 top = top_obj + oop(top_obj)->size(); | |
171 } | |
172 } | |
173 } else { | |
174 top = (_sp->toContiguousSpace())->top(); | |
175 } | |
176 return top; | |
177 } | |
178 | |
179 void Filtering_DCTOC::walk_mem_region(MemRegion mr, | |
180 HeapWord* bottom, | |
181 HeapWord* top) { | |
182 // Note that this assumption won't hold if we have a concurrent | |
183 // collector in this space, which may have freed up objects after | |
184 // they were dirtied and before the stop-the-world GC that is | |
185 // examining cards here. | |
186 assert(bottom < top, "ought to be at least one obj on a dirty card."); | |
187 | |
188 if (_boundary != NULL) { | |
189 // We have a boundary outside of which we don't want to look | |
190 // at objects, so create a filtering closure around the | |
191 // oop closure before walking the region. | |
192 FilteringClosure filter(_boundary, _cl); | |
193 walk_mem_region_with_cl(mr, bottom, top, &filter); | |
194 } else { | |
195 // No boundary, simply walk the heap with the oop closure. | |
196 walk_mem_region_with_cl(mr, bottom, top, _cl); | |
197 } | |
198 | |
199 } | |
200 | |
201 // We must replicate this so that the static type of "FilteringClosure" | |
202 // (see above) is apparent at the oop_iterate calls. | |
203 #define ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \ | |
204 void ContiguousSpaceDCTOC::walk_mem_region_with_cl(MemRegion mr, \ | |
205 HeapWord* bottom, \ | |
206 HeapWord* top, \ | |
207 ClosureType* cl) { \ | |
208 bottom += oop(bottom)->oop_iterate(cl, mr); \ | |
209 if (bottom < top) { \ | |
210 HeapWord* next_obj = bottom + oop(bottom)->size(); \ | |
211 while (next_obj < top) { \ | |
212 /* Bottom lies entirely below top, so we can call the */ \ | |
213 /* non-memRegion version of oop_iterate below. */ \ | |
214 oop(bottom)->oop_iterate(cl); \ | |
215 bottom = next_obj; \ | |
216 next_obj = bottom + oop(bottom)->size(); \ | |
217 } \ | |
218 /* Last object. */ \ | |
219 oop(bottom)->oop_iterate(cl, mr); \ | |
220 } \ | |
221 } | |
222 | |
223 // (There are only two of these, rather than N, because the split is due | |
224 // only to the introduction of the FilteringClosure, a local part of the | |
225 // impl of this abstraction.) | |
226 ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(OopClosure) | |
227 ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure) | |
228 | |
229 DirtyCardToOopClosure* | |
230 ContiguousSpace::new_dcto_cl(OopClosure* cl, | |
231 CardTableModRefBS::PrecisionStyle precision, | |
232 HeapWord* boundary) { | |
233 return new ContiguousSpaceDCTOC(this, cl, precision, boundary); | |
234 } | |
235 | |
236 void Space::initialize(MemRegion mr, bool clear_space) { | |
237 HeapWord* bottom = mr.start(); | |
238 HeapWord* end = mr.end(); | |
239 assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end), | |
240 "invalid space boundaries"); | |
241 set_bottom(bottom); | |
242 set_end(end); | |
243 if (clear_space) clear(); | |
244 } | |
245 | |
246 void Space::clear() { | |
247 if (ZapUnusedHeapArea) mangle_unused_area(); | |
248 } | |
249 | |
250 void ContiguousSpace::initialize(MemRegion mr, bool clear_space) | |
251 { | |
252 CompactibleSpace::initialize(mr, clear_space); | |
253 _concurrent_iteration_safe_limit = top(); | |
254 } | |
255 | |
256 void ContiguousSpace::clear() { | |
257 set_top(bottom()); | |
258 set_saved_mark(); | |
259 Space::clear(); | |
260 } | |
261 | |
262 bool Space::is_in(const void* p) const { | |
263 HeapWord* b = block_start(p); | |
264 return b != NULL && block_is_obj(b); | |
265 } | |
266 | |
267 bool ContiguousSpace::is_in(const void* p) const { | |
268 return _bottom <= p && p < _top; | |
269 } | |
270 | |
271 bool ContiguousSpace::is_free_block(const HeapWord* p) const { | |
272 return p >= _top; | |
273 } | |
274 | |
275 void OffsetTableContigSpace::clear() { | |
276 ContiguousSpace::clear(); | |
277 _offsets.initialize_threshold(); | |
278 } | |
279 | |
280 void OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) { | |
281 Space::set_bottom(new_bottom); | |
282 _offsets.set_bottom(new_bottom); | |
283 } | |
284 | |
285 void OffsetTableContigSpace::set_end(HeapWord* new_end) { | |
286 // Space should not advertize an increase in size | |
287 // until after the underlying offest table has been enlarged. | |
288 _offsets.resize(pointer_delta(new_end, bottom())); | |
289 Space::set_end(new_end); | |
290 } | |
291 | |
292 void ContiguousSpace::mangle_unused_area() { | |
293 // to-space is used for storing marks during mark-sweep | |
294 mangle_region(MemRegion(top(), end())); | |
295 } | |
296 | |
297 void ContiguousSpace::mangle_region(MemRegion mr) { | |
298 debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord)); | |
299 } | |
300 | |
301 void CompactibleSpace::initialize(MemRegion mr, bool clear_space) { | |
302 Space::initialize(mr, clear_space); | |
303 _compaction_top = bottom(); | |
304 _next_compaction_space = NULL; | |
305 } | |
306 | |
307 HeapWord* CompactibleSpace::forward(oop q, size_t size, | |
308 CompactPoint* cp, HeapWord* compact_top) { | |
309 // q is alive | |
310 // First check if we should switch compaction space | |
311 assert(this == cp->space, "'this' should be current compaction space."); | |
312 size_t compaction_max_size = pointer_delta(end(), compact_top); | |
313 while (size > compaction_max_size) { | |
314 // switch to next compaction space | |
315 cp->space->set_compaction_top(compact_top); | |
316 cp->space = cp->space->next_compaction_space(); | |
317 if (cp->space == NULL) { | |
318 cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen); | |
319 assert(cp->gen != NULL, "compaction must succeed"); | |
320 cp->space = cp->gen->first_compaction_space(); | |
321 assert(cp->space != NULL, "generation must have a first compaction space"); | |
322 } | |
323 compact_top = cp->space->bottom(); | |
324 cp->space->set_compaction_top(compact_top); | |
325 cp->threshold = cp->space->initialize_threshold(); | |
326 compaction_max_size = pointer_delta(cp->space->end(), compact_top); | |
327 } | |
328 | |
329 // store the forwarding pointer into the mark word | |
330 if ((HeapWord*)q != compact_top) { | |
331 q->forward_to(oop(compact_top)); | |
332 assert(q->is_gc_marked(), "encoding the pointer should preserve the mark"); | |
333 } else { | |
334 // if the object isn't moving we can just set the mark to the default | |
335 // mark and handle it specially later on. | |
336 q->init_mark(); | |
337 assert(q->forwardee() == NULL, "should be forwarded to NULL"); | |
338 } | |
339 | |
340 debug_only(MarkSweep::register_live_oop(q, size)); | |
341 compact_top += size; | |
342 | |
343 // we need to update the offset table so that the beginnings of objects can be | |
344 // found during scavenge. Note that we are updating the offset table based on | |
345 // where the object will be once the compaction phase finishes. | |
346 if (compact_top > cp->threshold) | |
347 cp->threshold = | |
348 cp->space->cross_threshold(compact_top - size, compact_top); | |
349 return compact_top; | |
350 } | |
351 | |
352 | |
353 bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words, | |
354 HeapWord* q, size_t deadlength) { | |
355 if (allowed_deadspace_words >= deadlength) { | |
356 allowed_deadspace_words -= deadlength; | |
357 oop(q)->set_mark(markOopDesc::prototype()->set_marked()); | |
358 const size_t min_int_array_size = typeArrayOopDesc::header_size(T_INT); | |
359 if (deadlength >= min_int_array_size) { | |
360 oop(q)->set_klass(Universe::intArrayKlassObj()); | |
361 typeArrayOop(q)->set_length((int)((deadlength - min_int_array_size) | |
362 * (HeapWordSize/sizeof(jint)))); | |
363 } else { | |
364 assert((int) deadlength == instanceOopDesc::header_size(), | |
365 "size for smallest fake dead object doesn't match"); | |
366 oop(q)->set_klass(SystemDictionary::object_klass()); | |
367 } | |
368 assert((int) deadlength == oop(q)->size(), | |
369 "make sure size for fake dead object match"); | |
370 // Recall that we required "q == compaction_top". | |
371 return true; | |
372 } else { | |
373 allowed_deadspace_words = 0; | |
374 return false; | |
375 } | |
376 } | |
377 | |
378 #define block_is_always_obj(q) true | |
379 #define obj_size(q) oop(q)->size() | |
380 #define adjust_obj_size(s) s | |
381 | |
382 void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) { | |
383 SCAN_AND_FORWARD(cp, end, block_is_obj, block_size); | |
384 } | |
385 | |
386 // Faster object search. | |
387 void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) { | |
388 SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size); | |
389 } | |
390 | |
391 void Space::adjust_pointers() { | |
392 // adjust all the interior pointers to point at the new locations of objects | |
393 // Used by MarkSweep::mark_sweep_phase3() | |
394 | |
395 // First check to see if there is any work to be done. | |
396 if (used() == 0) { | |
397 return; // Nothing to do. | |
398 } | |
399 | |
400 // Otherwise... | |
401 HeapWord* q = bottom(); | |
402 HeapWord* t = end(); | |
403 | |
404 debug_only(HeapWord* prev_q = NULL); | |
405 while (q < t) { | |
406 if (oop(q)->is_gc_marked()) { | |
407 // q is alive | |
408 | |
409 debug_only(MarkSweep::track_interior_pointers(oop(q))); | |
410 // point all the oops to the new location | |
411 size_t size = oop(q)->adjust_pointers(); | |
412 debug_only(MarkSweep::check_interior_pointers()); | |
413 | |
414 debug_only(prev_q = q); | |
415 debug_only(MarkSweep::validate_live_oop(oop(q), size)); | |
416 | |
417 q += size; | |
418 } else { | |
419 // q is not a live object. But we're not in a compactible space, | |
420 // So we don't have live ranges. | |
421 debug_only(prev_q = q); | |
422 q += block_size(q); | |
423 assert(q > prev_q, "we should be moving forward through memory"); | |
424 } | |
425 } | |
426 assert(q == t, "just checking"); | |
427 } | |
428 | |
429 void CompactibleSpace::adjust_pointers() { | |
430 // Check first is there is any work to do. | |
431 if (used() == 0) { | |
432 return; // Nothing to do. | |
433 } | |
434 | |
435 SCAN_AND_ADJUST_POINTERS(adjust_obj_size); | |
436 } | |
437 | |
438 void CompactibleSpace::compact() { | |
439 SCAN_AND_COMPACT(obj_size); | |
440 } | |
441 | |
442 void Space::print_short() const { print_short_on(tty); } | |
443 | |
444 void Space::print_short_on(outputStream* st) const { | |
445 st->print(" space " SIZE_FORMAT "K, %3d%% used", capacity() / K, | |
446 (int) ((double) used() * 100 / capacity())); | |
447 } | |
448 | |
449 void Space::print() const { print_on(tty); } | |
450 | |
451 void Space::print_on(outputStream* st) const { | |
452 print_short_on(st); | |
453 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ")", | |
454 bottom(), end()); | |
455 } | |
456 | |
457 void ContiguousSpace::print_on(outputStream* st) const { | |
458 print_short_on(st); | |
459 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")", | |
460 bottom(), top(), end()); | |
461 } | |
462 | |
463 void OffsetTableContigSpace::print_on(outputStream* st) const { | |
464 print_short_on(st); | |
465 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " | |
466 INTPTR_FORMAT ", " INTPTR_FORMAT ")", | |
467 bottom(), top(), _offsets.threshold(), end()); | |
468 } | |
469 | |
470 void ContiguousSpace::verify(bool allow_dirty) const { | |
471 HeapWord* p = bottom(); | |
472 HeapWord* t = top(); | |
473 HeapWord* prev_p = NULL; | |
474 while (p < t) { | |
475 oop(p)->verify(); | |
476 prev_p = p; | |
477 p += oop(p)->size(); | |
478 } | |
479 guarantee(p == top(), "end of last object must match end of space"); | |
480 if (top() != end()) { | |
481 guarantee(top() == block_start(end()-1) && | |
482 top() == block_start(top()), | |
483 "top should be start of unallocated block, if it exists"); | |
484 } | |
485 } | |
486 | |
487 void Space::oop_iterate(OopClosure* blk) { | |
488 ObjectToOopClosure blk2(blk); | |
489 object_iterate(&blk2); | |
490 } | |
491 | |
492 HeapWord* Space::object_iterate_careful(ObjectClosureCareful* cl) { | |
493 guarantee(false, "NYI"); | |
494 return bottom(); | |
495 } | |
496 | |
497 HeapWord* Space::object_iterate_careful_m(MemRegion mr, | |
498 ObjectClosureCareful* cl) { | |
499 guarantee(false, "NYI"); | |
500 return bottom(); | |
501 } | |
502 | |
503 | |
504 void Space::object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl) { | |
505 assert(!mr.is_empty(), "Should be non-empty"); | |
506 // We use MemRegion(bottom(), end()) rather than used_region() below | |
507 // because the two are not necessarily equal for some kinds of | |
508 // spaces, in particular, certain kinds of free list spaces. | |
509 // We could use the more complicated but more precise: | |
510 // MemRegion(used_region().start(), round_to(used_region().end(), CardSize)) | |
511 // but the slight imprecision seems acceptable in the assertion check. | |
512 assert(MemRegion(bottom(), end()).contains(mr), | |
513 "Should be within used space"); | |
514 HeapWord* prev = cl->previous(); // max address from last time | |
515 if (prev >= mr.end()) { // nothing to do | |
516 return; | |
517 } | |
518 // This assert will not work when we go from cms space to perm | |
519 // space, and use same closure. Easy fix deferred for later. XXX YSR | |
520 // assert(prev == NULL || contains(prev), "Should be within space"); | |
521 | |
522 bool last_was_obj_array = false; | |
523 HeapWord *blk_start_addr, *region_start_addr; | |
524 if (prev > mr.start()) { | |
525 region_start_addr = prev; | |
526 blk_start_addr = prev; | |
527 assert(blk_start_addr == block_start(region_start_addr), "invariant"); | |
528 } else { | |
529 region_start_addr = mr.start(); | |
530 blk_start_addr = block_start(region_start_addr); | |
531 } | |
532 HeapWord* region_end_addr = mr.end(); | |
533 MemRegion derived_mr(region_start_addr, region_end_addr); | |
534 while (blk_start_addr < region_end_addr) { | |
535 const size_t size = block_size(blk_start_addr); | |
536 if (block_is_obj(blk_start_addr)) { | |
537 last_was_obj_array = cl->do_object_bm(oop(blk_start_addr), derived_mr); | |
538 } else { | |
539 last_was_obj_array = false; | |
540 } | |
541 blk_start_addr += size; | |
542 } | |
543 if (!last_was_obj_array) { | |
544 assert((bottom() <= blk_start_addr) && (blk_start_addr <= end()), | |
545 "Should be within (closed) used space"); | |
546 assert(blk_start_addr > prev, "Invariant"); | |
547 cl->set_previous(blk_start_addr); // min address for next time | |
548 } | |
549 } | |
550 | |
551 bool Space::obj_is_alive(const HeapWord* p) const { | |
552 assert (block_is_obj(p), "The address should point to an object"); | |
553 return true; | |
554 } | |
555 | |
556 void ContiguousSpace::object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl) { | |
557 assert(!mr.is_empty(), "Should be non-empty"); | |
558 assert(used_region().contains(mr), "Should be within used space"); | |
559 HeapWord* prev = cl->previous(); // max address from last time | |
560 if (prev >= mr.end()) { // nothing to do | |
561 return; | |
562 } | |
563 // See comment above (in more general method above) in case you | |
564 // happen to use this method. | |
565 assert(prev == NULL || is_in_reserved(prev), "Should be within space"); | |
566 | |
567 bool last_was_obj_array = false; | |
568 HeapWord *obj_start_addr, *region_start_addr; | |
569 if (prev > mr.start()) { | |
570 region_start_addr = prev; | |
571 obj_start_addr = prev; | |
572 assert(obj_start_addr == block_start(region_start_addr), "invariant"); | |
573 } else { | |
574 region_start_addr = mr.start(); | |
575 obj_start_addr = block_start(region_start_addr); | |
576 } | |
577 HeapWord* region_end_addr = mr.end(); | |
578 MemRegion derived_mr(region_start_addr, region_end_addr); | |
579 while (obj_start_addr < region_end_addr) { | |
580 oop obj = oop(obj_start_addr); | |
581 const size_t size = obj->size(); | |
582 last_was_obj_array = cl->do_object_bm(obj, derived_mr); | |
583 obj_start_addr += size; | |
584 } | |
585 if (!last_was_obj_array) { | |
586 assert((bottom() <= obj_start_addr) && (obj_start_addr <= end()), | |
587 "Should be within (closed) used space"); | |
588 assert(obj_start_addr > prev, "Invariant"); | |
589 cl->set_previous(obj_start_addr); // min address for next time | |
590 } | |
591 } | |
592 | |
593 #ifndef SERIALGC | |
594 #define ContigSpace_PAR_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ | |
595 \ | |
596 void ContiguousSpace::par_oop_iterate(MemRegion mr, OopClosureType* blk) {\ | |
597 HeapWord* obj_addr = mr.start(); \ | |
598 HeapWord* t = mr.end(); \ | |
599 while (obj_addr < t) { \ | |
600 assert(oop(obj_addr)->is_oop(), "Should be an oop"); \ | |
601 obj_addr += oop(obj_addr)->oop_iterate(blk); \ | |
602 } \ | |
603 } | |
604 | |
605 ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DEFN) | |
606 | |
607 #undef ContigSpace_PAR_OOP_ITERATE_DEFN | |
608 #endif // SERIALGC | |
609 | |
610 void ContiguousSpace::oop_iterate(OopClosure* blk) { | |
611 if (is_empty()) return; | |
612 HeapWord* obj_addr = bottom(); | |
613 HeapWord* t = top(); | |
614 // Could call objects iterate, but this is easier. | |
615 while (obj_addr < t) { | |
616 obj_addr += oop(obj_addr)->oop_iterate(blk); | |
617 } | |
618 } | |
619 | |
620 void ContiguousSpace::oop_iterate(MemRegion mr, OopClosure* blk) { | |
621 if (is_empty()) { | |
622 return; | |
623 } | |
624 MemRegion cur = MemRegion(bottom(), top()); | |
625 mr = mr.intersection(cur); | |
626 if (mr.is_empty()) { | |
627 return; | |
628 } | |
629 if (mr.equals(cur)) { | |
630 oop_iterate(blk); | |
631 return; | |
632 } | |
633 assert(mr.end() <= top(), "just took an intersection above"); | |
634 HeapWord* obj_addr = block_start(mr.start()); | |
635 HeapWord* t = mr.end(); | |
636 | |
637 // Handle first object specially. | |
638 oop obj = oop(obj_addr); | |
639 SpaceMemRegionOopsIterClosure smr_blk(blk, mr); | |
640 obj_addr += obj->oop_iterate(&smr_blk); | |
641 while (obj_addr < t) { | |
642 oop obj = oop(obj_addr); | |
643 assert(obj->is_oop(), "expected an oop"); | |
644 obj_addr += obj->size(); | |
645 // If "obj_addr" is not greater than top, then the | |
646 // entire object "obj" is within the region. | |
647 if (obj_addr <= t) { | |
648 obj->oop_iterate(blk); | |
649 } else { | |
650 // "obj" extends beyond end of region | |
651 obj->oop_iterate(&smr_blk); | |
652 break; | |
653 } | |
654 }; | |
655 } | |
656 | |
657 void ContiguousSpace::object_iterate(ObjectClosure* blk) { | |
658 if (is_empty()) return; | |
659 WaterMark bm = bottom_mark(); | |
660 object_iterate_from(bm, blk); | |
661 } | |
662 | |
663 void ContiguousSpace::object_iterate_from(WaterMark mark, ObjectClosure* blk) { | |
664 assert(mark.space() == this, "Mark does not match space"); | |
665 HeapWord* p = mark.point(); | |
666 while (p < top()) { | |
667 blk->do_object(oop(p)); | |
668 p += oop(p)->size(); | |
669 } | |
670 } | |
671 | |
672 HeapWord* | |
673 ContiguousSpace::object_iterate_careful(ObjectClosureCareful* blk) { | |
674 HeapWord * limit = concurrent_iteration_safe_limit(); | |
675 assert(limit <= top(), "sanity check"); | |
676 for (HeapWord* p = bottom(); p < limit;) { | |
677 size_t size = blk->do_object_careful(oop(p)); | |
678 if (size == 0) { | |
679 return p; // failed at p | |
680 } else { | |
681 p += size; | |
682 } | |
683 } | |
684 return NULL; // all done | |
685 } | |
686 | |
687 #define ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ | |
688 \ | |
689 void ContiguousSpace:: \ | |
690 oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ | |
691 HeapWord* t; \ | |
692 HeapWord* p = saved_mark_word(); \ | |
693 assert(p != NULL, "expected saved mark"); \ | |
694 \ | |
695 const intx interval = PrefetchScanIntervalInBytes; \ | |
696 do { \ | |
697 t = top(); \ | |
698 while (p < t) { \ | |
699 Prefetch::write(p, interval); \ | |
700 debug_only(HeapWord* prev = p); \ | |
701 oop m = oop(p); \ | |
702 p += m->oop_iterate(blk); \ | |
703 } \ | |
704 } while (t < top()); \ | |
705 \ | |
706 set_saved_mark_word(p); \ | |
707 } | |
708 | |
709 ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN) | |
710 | |
711 #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN | |
712 | |
713 // Very general, slow implementation. | |
714 HeapWord* ContiguousSpace::block_start(const void* p) const { | |
715 assert(MemRegion(bottom(), end()).contains(p), "p not in space"); | |
716 if (p >= top()) { | |
717 return top(); | |
718 } else { | |
719 HeapWord* last = bottom(); | |
720 HeapWord* cur = last; | |
721 while (cur <= p) { | |
722 last = cur; | |
723 cur += oop(cur)->size(); | |
724 } | |
725 assert(oop(last)->is_oop(), "Should be an object start"); | |
726 return last; | |
727 } | |
728 } | |
729 | |
730 size_t ContiguousSpace::block_size(const HeapWord* p) const { | |
731 assert(MemRegion(bottom(), end()).contains(p), "p not in space"); | |
732 HeapWord* current_top = top(); | |
733 assert(p <= current_top, "p is not a block start"); | |
734 assert(p == current_top || oop(p)->is_oop(), "p is not a block start"); | |
735 if (p < current_top) | |
736 return oop(p)->size(); | |
737 else { | |
738 assert(p == current_top, "just checking"); | |
739 return pointer_delta(end(), (HeapWord*) p); | |
740 } | |
741 } | |
742 | |
743 // This version requires locking. | |
744 inline HeapWord* ContiguousSpace::allocate_impl(size_t size, | |
745 HeapWord* const end_value) { | |
746 assert(Heap_lock->owned_by_self() || | |
747 (SafepointSynchronize::is_at_safepoint() && | |
748 Thread::current()->is_VM_thread()), | |
749 "not locked"); | |
750 HeapWord* obj = top(); | |
751 if (pointer_delta(end_value, obj) >= size) { | |
752 HeapWord* new_top = obj + size; | |
753 set_top(new_top); | |
754 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); | |
755 return obj; | |
756 } else { | |
757 return NULL; | |
758 } | |
759 } | |
760 | |
761 // This version is lock-free. | |
762 inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size, | |
763 HeapWord* const end_value) { | |
764 do { | |
765 HeapWord* obj = top(); | |
766 if (pointer_delta(end_value, obj) >= size) { | |
767 HeapWord* new_top = obj + size; | |
768 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); | |
769 // result can be one of two: | |
770 // the old top value: the exchange succeeded | |
771 // otherwise: the new value of the top is returned. | |
772 if (result == obj) { | |
773 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); | |
774 return obj; | |
775 } | |
776 } else { | |
777 return NULL; | |
778 } | |
779 } while (true); | |
780 } | |
781 | |
782 // Requires locking. | |
783 HeapWord* ContiguousSpace::allocate(size_t size) { | |
784 return allocate_impl(size, end()); | |
785 } | |
786 | |
787 // Lock-free. | |
788 HeapWord* ContiguousSpace::par_allocate(size_t size) { | |
789 return par_allocate_impl(size, end()); | |
790 } | |
791 | |
792 void ContiguousSpace::allocate_temporary_filler(int factor) { | |
793 // allocate temporary type array decreasing free size with factor 'factor' | |
794 assert(factor >= 0, "just checking"); | |
795 size_t size = pointer_delta(end(), top()); | |
796 | |
797 // if space is full, return | |
798 if (size == 0) return; | |
799 | |
800 if (factor > 0) { | |
801 size -= size/factor; | |
802 } | |
803 size = align_object_size(size); | |
804 | |
805 const size_t min_int_array_size = typeArrayOopDesc::header_size(T_INT); | |
806 if (size >= min_int_array_size) { | |
807 size_t length = (size - min_int_array_size) * (HeapWordSize / sizeof(jint)); | |
808 // allocate uninitialized int array | |
809 typeArrayOop t = (typeArrayOop) allocate(size); | |
810 assert(t != NULL, "allocation should succeed"); | |
811 t->set_mark(markOopDesc::prototype()); | |
812 t->set_klass(Universe::intArrayKlassObj()); | |
813 t->set_length((int)length); | |
814 } else { | |
815 assert((int) size == instanceOopDesc::header_size(), | |
816 "size for smallest fake object doesn't match"); | |
817 instanceOop obj = (instanceOop) allocate(size); | |
818 obj->set_mark(markOopDesc::prototype()); | |
819 obj->set_klass(SystemDictionary::object_klass()); | |
820 } | |
821 } | |
822 | |
823 void EdenSpace::clear() { | |
824 ContiguousSpace::clear(); | |
825 set_soft_end(end()); | |
826 } | |
827 | |
828 // Requires locking. | |
829 HeapWord* EdenSpace::allocate(size_t size) { | |
830 return allocate_impl(size, soft_end()); | |
831 } | |
832 | |
833 // Lock-free. | |
834 HeapWord* EdenSpace::par_allocate(size_t size) { | |
835 return par_allocate_impl(size, soft_end()); | |
836 } | |
837 | |
838 HeapWord* ConcEdenSpace::par_allocate(size_t size) | |
839 { | |
840 do { | |
841 // The invariant is top() should be read before end() because | |
842 // top() can't be greater than end(), so if an update of _soft_end | |
843 // occurs between 'end_val = end();' and 'top_val = top();' top() | |
844 // also can grow up to the new end() and the condition | |
845 // 'top_val > end_val' is true. To ensure the loading order | |
846 // OrderAccess::loadload() is required after top() read. | |
847 HeapWord* obj = top(); | |
848 OrderAccess::loadload(); | |
849 if (pointer_delta(*soft_end_addr(), obj) >= size) { | |
850 HeapWord* new_top = obj + size; | |
851 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); | |
852 // result can be one of two: | |
853 // the old top value: the exchange succeeded | |
854 // otherwise: the new value of the top is returned. | |
855 if (result == obj) { | |
856 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); | |
857 return obj; | |
858 } | |
859 } else { | |
860 return NULL; | |
861 } | |
862 } while (true); | |
863 } | |
864 | |
865 | |
866 HeapWord* OffsetTableContigSpace::initialize_threshold() { | |
867 return _offsets.initialize_threshold(); | |
868 } | |
869 | |
870 HeapWord* OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) { | |
871 _offsets.alloc_block(start, end); | |
872 return _offsets.threshold(); | |
873 } | |
874 | |
875 OffsetTableContigSpace::OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray, | |
876 MemRegion mr) : | |
877 _offsets(sharedOffsetArray, mr), | |
878 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true) | |
879 { | |
880 _offsets.set_contig_space(this); | |
881 initialize(mr, true); | |
882 } | |
883 | |
884 | |
885 class VerifyOldOopClosure : public OopClosure { | |
886 public: | |
887 oop the_obj; | |
888 bool allow_dirty; | |
889 void do_oop(oop* p) { | |
890 the_obj->verify_old_oop(p, allow_dirty); | |
891 } | |
892 }; | |
893 | |
894 #define OBJ_SAMPLE_INTERVAL 0 | |
895 #define BLOCK_SAMPLE_INTERVAL 100 | |
896 | |
897 void OffsetTableContigSpace::verify(bool allow_dirty) const { | |
898 HeapWord* p = bottom(); | |
899 HeapWord* prev_p = NULL; | |
900 VerifyOldOopClosure blk; // Does this do anything? | |
901 blk.allow_dirty = allow_dirty; | |
902 int objs = 0; | |
903 int blocks = 0; | |
904 | |
905 if (VerifyObjectStartArray) { | |
906 _offsets.verify(); | |
907 } | |
908 | |
909 while (p < top()) { | |
910 size_t size = oop(p)->size(); | |
911 // For a sampling of objects in the space, find it using the | |
912 // block offset table. | |
913 if (blocks == BLOCK_SAMPLE_INTERVAL) { | |
914 guarantee(p == block_start(p + (size/2)), "check offset computation"); | |
915 blocks = 0; | |
916 } else { | |
917 blocks++; | |
918 } | |
919 | |
920 if (objs == OBJ_SAMPLE_INTERVAL) { | |
921 oop(p)->verify(); | |
922 blk.the_obj = oop(p); | |
923 oop(p)->oop_iterate(&blk); | |
924 objs = 0; | |
925 } else { | |
926 objs++; | |
927 } | |
928 prev_p = p; | |
929 p += size; | |
930 } | |
931 guarantee(p == top(), "end of last object must match end of space"); | |
932 } | |
933 | |
934 void OffsetTableContigSpace::serialize_block_offset_array_offsets( | |
935 SerializeOopClosure* soc) { | |
936 _offsets.serialize(soc); | |
937 } | |
938 | |
939 | |
940 int TenuredSpace::allowed_dead_ratio() const { | |
941 return MarkSweepDeadRatio; | |
942 } | |
943 | |
944 | |
945 int ContigPermSpace::allowed_dead_ratio() const { | |
946 return PermMarkSweepDeadRatio; | |
947 } |