Mercurial > hg > truffle
comparison src/share/vm/gc_implementation/g1/heapRegion.cpp @ 342:37f87013dfd8
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author | ysr |
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date | Thu, 05 Jun 2008 15:57:56 -0700 |
parents | |
children | 9bb2c10ac07b |
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1 /* | |
2 * Copyright 2001-2007 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/_heapRegion.cpp.incl" | |
27 | |
28 HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1, | |
29 HeapRegion* hr, OopClosure* cl, | |
30 CardTableModRefBS::PrecisionStyle precision, | |
31 FilterKind fk) : | |
32 ContiguousSpaceDCTOC(hr, cl, precision, NULL), | |
33 _hr(hr), _fk(fk), _g1(g1) | |
34 {} | |
35 | |
36 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r, | |
37 OopClosure* oc) : | |
38 _r_bottom(r->bottom()), _r_end(r->end()), | |
39 _oc(oc), _out_of_region(0) | |
40 {} | |
41 | |
42 class VerifyLiveClosure: public OopClosure { | |
43 G1CollectedHeap* _g1h; | |
44 CardTableModRefBS* _bs; | |
45 oop _containing_obj; | |
46 bool _failures; | |
47 int _n_failures; | |
48 public: | |
49 VerifyLiveClosure(G1CollectedHeap* g1h) : | |
50 _g1h(g1h), _bs(NULL), _containing_obj(NULL), | |
51 _failures(false), _n_failures(0) | |
52 { | |
53 BarrierSet* bs = _g1h->barrier_set(); | |
54 if (bs->is_a(BarrierSet::CardTableModRef)) | |
55 _bs = (CardTableModRefBS*)bs; | |
56 } | |
57 | |
58 void set_containing_obj(oop obj) { | |
59 _containing_obj = obj; | |
60 } | |
61 | |
62 bool failures() { return _failures; } | |
63 int n_failures() { return _n_failures; } | |
64 | |
65 virtual void do_oop(narrowOop* p) { | |
66 guarantee(false, "NYI"); | |
67 } | |
68 | |
69 void do_oop(oop* p) { | |
70 assert(_containing_obj != NULL, "Precondition"); | |
71 assert(!_g1h->is_obj_dead(_containing_obj), "Precondition"); | |
72 oop obj = *p; | |
73 if (obj != NULL) { | |
74 bool failed = false; | |
75 if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead(obj)) { | |
76 if (!_failures) { | |
77 gclog_or_tty->print_cr(""); | |
78 gclog_or_tty->print_cr("----------"); | |
79 } | |
80 if (!_g1h->is_in_closed_subset(obj)) { | |
81 gclog_or_tty->print_cr("Field "PTR_FORMAT | |
82 " of live obj "PTR_FORMAT | |
83 " points to obj "PTR_FORMAT | |
84 " not in the heap.", | |
85 p, (void*) _containing_obj, (void*) obj); | |
86 } else { | |
87 gclog_or_tty->print_cr("Field "PTR_FORMAT | |
88 " of live obj "PTR_FORMAT | |
89 " points to dead obj "PTR_FORMAT".", | |
90 p, (void*) _containing_obj, (void*) obj); | |
91 } | |
92 gclog_or_tty->print_cr("Live obj:"); | |
93 _containing_obj->print_on(gclog_or_tty); | |
94 gclog_or_tty->print_cr("Bad referent:"); | |
95 obj->print_on(gclog_or_tty); | |
96 gclog_or_tty->print_cr("----------"); | |
97 _failures = true; | |
98 failed = true; | |
99 _n_failures++; | |
100 } | |
101 | |
102 if (!_g1h->full_collection()) { | |
103 HeapRegion* from = _g1h->heap_region_containing(p); | |
104 HeapRegion* to = _g1h->heap_region_containing(*p); | |
105 if (from != NULL && to != NULL && | |
106 from != to && | |
107 !to->popular() && | |
108 !to->isHumongous()) { | |
109 jbyte cv_obj = *_bs->byte_for_const(_containing_obj); | |
110 jbyte cv_field = *_bs->byte_for_const(p); | |
111 const jbyte dirty = CardTableModRefBS::dirty_card_val(); | |
112 | |
113 bool is_bad = !(from->is_young() | |
114 || to->rem_set()->contains_reference(p) | |
115 || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed | |
116 (_containing_obj->is_objArray() ? | |
117 cv_field == dirty | |
118 : cv_obj == dirty || cv_field == dirty)); | |
119 if (is_bad) { | |
120 if (!_failures) { | |
121 gclog_or_tty->print_cr(""); | |
122 gclog_or_tty->print_cr("----------"); | |
123 } | |
124 gclog_or_tty->print_cr("Missing rem set entry:"); | |
125 gclog_or_tty->print_cr("Field "PTR_FORMAT | |
126 " of obj "PTR_FORMAT | |
127 ", in region %d ["PTR_FORMAT | |
128 ", "PTR_FORMAT"),", | |
129 p, (void*) _containing_obj, | |
130 from->hrs_index(), | |
131 from->bottom(), | |
132 from->end()); | |
133 _containing_obj->print_on(gclog_or_tty); | |
134 gclog_or_tty->print_cr("points to obj "PTR_FORMAT | |
135 " in region %d ["PTR_FORMAT | |
136 ", "PTR_FORMAT").", | |
137 (void*) obj, to->hrs_index(), | |
138 to->bottom(), to->end()); | |
139 obj->print_on(gclog_or_tty); | |
140 gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.", | |
141 cv_obj, cv_field); | |
142 gclog_or_tty->print_cr("----------"); | |
143 _failures = true; | |
144 if (!failed) _n_failures++; | |
145 } | |
146 } | |
147 } | |
148 } | |
149 } | |
150 }; | |
151 | |
152 template<class ClosureType> | |
153 HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h, | |
154 HeapRegion* hr, | |
155 HeapWord* cur, HeapWord* top) { | |
156 oop cur_oop = oop(cur); | |
157 int oop_size = cur_oop->size(); | |
158 HeapWord* next_obj = cur + oop_size; | |
159 while (next_obj < top) { | |
160 // Keep filtering the remembered set. | |
161 if (!g1h->is_obj_dead(cur_oop, hr)) { | |
162 // Bottom lies entirely below top, so we can call the | |
163 // non-memRegion version of oop_iterate below. | |
164 #ifndef PRODUCT | |
165 if (G1VerifyMarkingInEvac) { | |
166 VerifyLiveClosure vl_cl(g1h); | |
167 cur_oop->oop_iterate(&vl_cl); | |
168 } | |
169 #endif | |
170 cur_oop->oop_iterate(cl); | |
171 } | |
172 cur = next_obj; | |
173 cur_oop = oop(cur); | |
174 oop_size = cur_oop->size(); | |
175 next_obj = cur + oop_size; | |
176 } | |
177 return cur; | |
178 } | |
179 | |
180 void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr, | |
181 HeapWord* bottom, | |
182 HeapWord* top, | |
183 OopClosure* cl) { | |
184 G1CollectedHeap* g1h = _g1; | |
185 | |
186 int oop_size; | |
187 | |
188 OopClosure* cl2 = cl; | |
189 FilterIntoCSClosure intoCSFilt(this, g1h, cl); | |
190 FilterOutOfRegionClosure outOfRegionFilt(_hr, cl); | |
191 switch (_fk) { | |
192 case IntoCSFilterKind: cl2 = &intoCSFilt; break; | |
193 case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break; | |
194 } | |
195 | |
196 // Start filtering what we add to the remembered set. If the object is | |
197 // not considered dead, either because it is marked (in the mark bitmap) | |
198 // or it was allocated after marking finished, then we add it. Otherwise | |
199 // we can safely ignore the object. | |
200 if (!g1h->is_obj_dead(oop(bottom), _hr)) { | |
201 #ifndef PRODUCT | |
202 if (G1VerifyMarkingInEvac) { | |
203 VerifyLiveClosure vl_cl(g1h); | |
204 oop(bottom)->oop_iterate(&vl_cl, mr); | |
205 } | |
206 #endif | |
207 oop_size = oop(bottom)->oop_iterate(cl2, mr); | |
208 } else { | |
209 oop_size = oop(bottom)->size(); | |
210 } | |
211 | |
212 bottom += oop_size; | |
213 | |
214 if (bottom < top) { | |
215 // We replicate the loop below for several kinds of possible filters. | |
216 switch (_fk) { | |
217 case NoFilterKind: | |
218 bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top); | |
219 break; | |
220 case IntoCSFilterKind: { | |
221 FilterIntoCSClosure filt(this, g1h, cl); | |
222 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top); | |
223 break; | |
224 } | |
225 case OutOfRegionFilterKind: { | |
226 FilterOutOfRegionClosure filt(_hr, cl); | |
227 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top); | |
228 break; | |
229 } | |
230 default: | |
231 ShouldNotReachHere(); | |
232 } | |
233 | |
234 // Last object. Need to do dead-obj filtering here too. | |
235 if (!g1h->is_obj_dead(oop(bottom), _hr)) { | |
236 #ifndef PRODUCT | |
237 if (G1VerifyMarkingInEvac) { | |
238 VerifyLiveClosure vl_cl(g1h); | |
239 oop(bottom)->oop_iterate(&vl_cl, mr); | |
240 } | |
241 #endif | |
242 oop(bottom)->oop_iterate(cl2, mr); | |
243 } | |
244 } | |
245 } | |
246 | |
247 void HeapRegion::reset_after_compaction() { | |
248 G1OffsetTableContigSpace::reset_after_compaction(); | |
249 // After a compaction the mark bitmap is invalid, so we must | |
250 // treat all objects as being inside the unmarked area. | |
251 zero_marked_bytes(); | |
252 init_top_at_mark_start(); | |
253 } | |
254 | |
255 | |
256 | |
257 DirtyCardToOopClosure* | |
258 HeapRegion::new_dcto_closure(OopClosure* cl, | |
259 CardTableModRefBS::PrecisionStyle precision, | |
260 HeapRegionDCTOC::FilterKind fk) { | |
261 return new HeapRegionDCTOC(G1CollectedHeap::heap(), | |
262 this, cl, precision, fk); | |
263 } | |
264 | |
265 void HeapRegion::hr_clear(bool par, bool clear_space) { | |
266 _humongous = false; | |
267 _humongous_start = false; | |
268 _humongous_start_region = NULL; | |
269 _in_collection_set = false; | |
270 _is_gc_alloc_region = false; | |
271 | |
272 // Age stuff (if parallel, this will be done separately, since it needs | |
273 // to be sequential). | |
274 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
275 | |
276 set_young_index_in_cset(-1); | |
277 uninstall_surv_rate_group(); | |
278 set_young_type(NotYoung); | |
279 | |
280 // In case it had been the start of a humongous sequence, reset its end. | |
281 set_end(_orig_end); | |
282 | |
283 if (!par) { | |
284 // If this is parallel, this will be done later. | |
285 HeapRegionRemSet* hrrs = rem_set(); | |
286 if (hrrs != NULL) hrrs->clear(); | |
287 _claimed = 0; | |
288 } | |
289 zero_marked_bytes(); | |
290 set_sort_index(-1); | |
291 if ((uintptr_t)bottom() >= (uintptr_t)g1h->popular_object_boundary()) | |
292 set_popular(false); | |
293 | |
294 _offsets.resize(HeapRegion::GrainWords); | |
295 init_top_at_mark_start(); | |
296 if (clear_space) clear(); | |
297 } | |
298 | |
299 // <PREDICTION> | |
300 void HeapRegion::calc_gc_efficiency() { | |
301 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
302 _gc_efficiency = (double) garbage_bytes() / | |
303 g1h->predict_region_elapsed_time_ms(this, false); | |
304 } | |
305 // </PREDICTION> | |
306 | |
307 void HeapRegion::set_startsHumongous() { | |
308 _humongous_start = true; _humongous = true; | |
309 _humongous_start_region = this; | |
310 assert(end() == _orig_end, "Should be normal before alloc."); | |
311 } | |
312 | |
313 bool HeapRegion::claimHeapRegion(jint claimValue) { | |
314 jint current = _claimed; | |
315 if (current != claimValue) { | |
316 jint res = Atomic::cmpxchg(claimValue, &_claimed, current); | |
317 if (res == current) { | |
318 return true; | |
319 } | |
320 } | |
321 return false; | |
322 } | |
323 | |
324 HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) { | |
325 HeapWord* low = addr; | |
326 HeapWord* high = end(); | |
327 while (low < high) { | |
328 size_t diff = pointer_delta(high, low); | |
329 // Must add one below to bias toward the high amount. Otherwise, if | |
330 // "high" were at the desired value, and "low" were one less, we | |
331 // would not converge on "high". This is not symmetric, because | |
332 // we set "high" to a block start, which might be the right one, | |
333 // which we don't do for "low". | |
334 HeapWord* middle = low + (diff+1)/2; | |
335 if (middle == high) return high; | |
336 HeapWord* mid_bs = block_start_careful(middle); | |
337 if (mid_bs < addr) { | |
338 low = middle; | |
339 } else { | |
340 high = mid_bs; | |
341 } | |
342 } | |
343 assert(low == high && low >= addr, "Didn't work."); | |
344 return low; | |
345 } | |
346 | |
347 void HeapRegion::set_next_on_unclean_list(HeapRegion* r) { | |
348 assert(r == NULL || r->is_on_unclean_list(), "Malformed unclean list."); | |
349 _next_in_special_set = r; | |
350 } | |
351 | |
352 void HeapRegion::set_on_unclean_list(bool b) { | |
353 _is_on_unclean_list = b; | |
354 } | |
355 | |
356 void HeapRegion::initialize(MemRegion mr, bool clear_space) { | |
357 G1OffsetTableContigSpace::initialize(mr, false); | |
358 hr_clear(false/*par*/, clear_space); | |
359 } | |
360 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away | |
361 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list | |
362 #endif // _MSC_VER | |
363 | |
364 | |
365 HeapRegion:: | |
366 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray, | |
367 MemRegion mr, bool is_zeroed) | |
368 : G1OffsetTableContigSpace(sharedOffsetArray, mr, is_zeroed), | |
369 _next_fk(HeapRegionDCTOC::NoFilterKind), | |
370 _hrs_index(-1), | |
371 _humongous(false), _humongous_start(false), _humongous_start_region(NULL), | |
372 _in_collection_set(false), _is_gc_alloc_region(false), | |
373 _is_on_free_list(false), _is_on_unclean_list(false), | |
374 _next_in_special_set(NULL), _orig_end(NULL), | |
375 _claimed(0), _evacuation_failed(false), | |
376 _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1), | |
377 _popularity(NotPopular), | |
378 _young_type(NotYoung), _next_young_region(NULL), | |
379 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1), | |
380 _rem_set(NULL), _zfs(NotZeroFilled) | |
381 { | |
382 _orig_end = mr.end(); | |
383 // Note that initialize() will set the start of the unmarked area of the | |
384 // region. | |
385 this->initialize(mr, !is_zeroed); | |
386 | |
387 _rem_set = new HeapRegionRemSet(sharedOffsetArray, this); | |
388 | |
389 assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant."); | |
390 // In case the region is allocated during a pause, note the top. | |
391 // We haven't done any counting on a brand new region. | |
392 _top_at_conc_mark_count = bottom(); | |
393 } | |
394 | |
395 class NextCompactionHeapRegionClosure: public HeapRegionClosure { | |
396 const HeapRegion* _target; | |
397 bool _target_seen; | |
398 HeapRegion* _last; | |
399 CompactibleSpace* _res; | |
400 public: | |
401 NextCompactionHeapRegionClosure(const HeapRegion* target) : | |
402 _target(target), _target_seen(false), _res(NULL) {} | |
403 bool doHeapRegion(HeapRegion* cur) { | |
404 if (_target_seen) { | |
405 if (!cur->isHumongous()) { | |
406 _res = cur; | |
407 return true; | |
408 } | |
409 } else if (cur == _target) { | |
410 _target_seen = true; | |
411 } | |
412 return false; | |
413 } | |
414 CompactibleSpace* result() { return _res; } | |
415 }; | |
416 | |
417 CompactibleSpace* HeapRegion::next_compaction_space() const { | |
418 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
419 // cast away const-ness | |
420 HeapRegion* r = (HeapRegion*) this; | |
421 NextCompactionHeapRegionClosure blk(r); | |
422 g1h->heap_region_iterate_from(r, &blk); | |
423 return blk.result(); | |
424 } | |
425 | |
426 void HeapRegion::set_continuesHumongous(HeapRegion* start) { | |
427 // The order is important here. | |
428 start->add_continuingHumongousRegion(this); | |
429 _humongous = true; _humongous_start = false; | |
430 _humongous_start_region = start; | |
431 } | |
432 | |
433 void HeapRegion::add_continuingHumongousRegion(HeapRegion* cont) { | |
434 // Must join the blocks of the current H region seq with the block of the | |
435 // added region. | |
436 offsets()->join_blocks(bottom(), cont->bottom()); | |
437 arrayOop obj = (arrayOop)(bottom()); | |
438 obj->set_length((int) (obj->length() + cont->capacity()/jintSize)); | |
439 set_end(cont->end()); | |
440 set_top(cont->end()); | |
441 } | |
442 | |
443 void HeapRegion::save_marks() { | |
444 set_saved_mark(); | |
445 } | |
446 | |
447 void HeapRegion::oops_in_mr_iterate(MemRegion mr, OopClosure* cl) { | |
448 HeapWord* p = mr.start(); | |
449 HeapWord* e = mr.end(); | |
450 oop obj; | |
451 while (p < e) { | |
452 obj = oop(p); | |
453 p += obj->oop_iterate(cl); | |
454 } | |
455 assert(p == e, "bad memregion: doesn't end on obj boundary"); | |
456 } | |
457 | |
458 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ | |
459 void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \ | |
460 ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl); \ | |
461 } | |
462 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN) | |
463 | |
464 | |
465 void HeapRegion::oop_before_save_marks_iterate(OopClosure* cl) { | |
466 oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl); | |
467 } | |
468 | |
469 #ifdef DEBUG | |
470 HeapWord* HeapRegion::allocate(size_t size) { | |
471 jint state = zero_fill_state(); | |
472 assert(!G1CollectedHeap::heap()->allocs_are_zero_filled() || | |
473 zero_fill_is_allocated(), | |
474 "When ZF is on, only alloc in ZF'd regions"); | |
475 return G1OffsetTableContigSpace::allocate(size); | |
476 } | |
477 #endif | |
478 | |
479 void HeapRegion::set_zero_fill_state_work(ZeroFillState zfs) { | |
480 assert(top() == bottom() || zfs == Allocated, | |
481 "Region must be empty, or we must be setting it to allocated."); | |
482 assert(ZF_mon->owned_by_self() || | |
483 Universe::heap()->is_gc_active(), | |
484 "Must hold the lock or be a full GC to modify."); | |
485 _zfs = zfs; | |
486 } | |
487 | |
488 void HeapRegion::set_zero_fill_complete() { | |
489 set_zero_fill_state_work(ZeroFilled); | |
490 if (ZF_mon->owned_by_self()) { | |
491 ZF_mon->notify_all(); | |
492 } | |
493 } | |
494 | |
495 | |
496 void HeapRegion::ensure_zero_filled() { | |
497 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag); | |
498 ensure_zero_filled_locked(); | |
499 } | |
500 | |
501 void HeapRegion::ensure_zero_filled_locked() { | |
502 assert(ZF_mon->owned_by_self(), "Precondition"); | |
503 bool should_ignore_zf = SafepointSynchronize::is_at_safepoint(); | |
504 assert(should_ignore_zf || Heap_lock->is_locked(), | |
505 "Either we're in a GC or we're allocating a region."); | |
506 switch (zero_fill_state()) { | |
507 case HeapRegion::NotZeroFilled: | |
508 set_zero_fill_in_progress(Thread::current()); | |
509 { | |
510 ZF_mon->unlock(); | |
511 Copy::fill_to_words(bottom(), capacity()/HeapWordSize); | |
512 ZF_mon->lock_without_safepoint_check(); | |
513 } | |
514 // A trap. | |
515 guarantee(zero_fill_state() == HeapRegion::ZeroFilling | |
516 && zero_filler() == Thread::current(), | |
517 "AHA! Tell Dave D if you see this..."); | |
518 set_zero_fill_complete(); | |
519 // gclog_or_tty->print_cr("Did sync ZF."); | |
520 ConcurrentZFThread::note_sync_zfs(); | |
521 break; | |
522 case HeapRegion::ZeroFilling: | |
523 if (should_ignore_zf) { | |
524 // We can "break" the lock and take over the work. | |
525 Copy::fill_to_words(bottom(), capacity()/HeapWordSize); | |
526 set_zero_fill_complete(); | |
527 ConcurrentZFThread::note_sync_zfs(); | |
528 break; | |
529 } else { | |
530 ConcurrentZFThread::wait_for_ZF_completed(this); | |
531 } | |
532 case HeapRegion::ZeroFilled: | |
533 // Nothing to do. | |
534 break; | |
535 case HeapRegion::Allocated: | |
536 guarantee(false, "Should not call on allocated regions."); | |
537 } | |
538 assert(zero_fill_state() == HeapRegion::ZeroFilled, "Post"); | |
539 } | |
540 | |
541 HeapWord* | |
542 HeapRegion::object_iterate_mem_careful(MemRegion mr, | |
543 ObjectClosure* cl) { | |
544 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
545 // We used to use "block_start_careful" here. But we're actually happy | |
546 // to update the BOT while we do this... | |
547 HeapWord* cur = block_start(mr.start()); | |
548 mr = mr.intersection(used_region()); | |
549 if (mr.is_empty()) return NULL; | |
550 // Otherwise, find the obj that extends onto mr.start(). | |
551 | |
552 assert(cur <= mr.start() | |
553 && (oop(cur)->klass() == NULL || | |
554 cur + oop(cur)->size() > mr.start()), | |
555 "postcondition of block_start"); | |
556 oop obj; | |
557 while (cur < mr.end()) { | |
558 obj = oop(cur); | |
559 if (obj->klass() == NULL) { | |
560 // Ran into an unparseable point. | |
561 return cur; | |
562 } else if (!g1h->is_obj_dead(obj)) { | |
563 cl->do_object(obj); | |
564 } | |
565 if (cl->abort()) return cur; | |
566 // The check above must occur before the operation below, since an | |
567 // abort might invalidate the "size" operation. | |
568 cur += obj->size(); | |
569 } | |
570 return NULL; | |
571 } | |
572 | |
573 HeapWord* | |
574 HeapRegion:: | |
575 oops_on_card_seq_iterate_careful(MemRegion mr, | |
576 FilterOutOfRegionClosure* cl) { | |
577 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
578 | |
579 // If we're within a stop-world GC, then we might look at a card in a | |
580 // GC alloc region that extends onto a GC LAB, which may not be | |
581 // parseable. Stop such at the "saved_mark" of the region. | |
582 if (G1CollectedHeap::heap()->is_gc_active()) { | |
583 mr = mr.intersection(used_region_at_save_marks()); | |
584 } else { | |
585 mr = mr.intersection(used_region()); | |
586 } | |
587 if (mr.is_empty()) return NULL; | |
588 // Otherwise, find the obj that extends onto mr.start(). | |
589 | |
590 // We used to use "block_start_careful" here. But we're actually happy | |
591 // to update the BOT while we do this... | |
592 HeapWord* cur = block_start(mr.start()); | |
593 assert(cur <= mr.start(), "Postcondition"); | |
594 | |
595 while (cur <= mr.start()) { | |
596 if (oop(cur)->klass() == NULL) { | |
597 // Ran into an unparseable point. | |
598 return cur; | |
599 } | |
600 // Otherwise... | |
601 int sz = oop(cur)->size(); | |
602 if (cur + sz > mr.start()) break; | |
603 // Otherwise, go on. | |
604 cur = cur + sz; | |
605 } | |
606 oop obj; | |
607 obj = oop(cur); | |
608 // If we finish this loop... | |
609 assert(cur <= mr.start() | |
610 && obj->klass() != NULL | |
611 && cur + obj->size() > mr.start(), | |
612 "Loop postcondition"); | |
613 if (!g1h->is_obj_dead(obj)) { | |
614 obj->oop_iterate(cl, mr); | |
615 } | |
616 | |
617 HeapWord* next; | |
618 while (cur < mr.end()) { | |
619 obj = oop(cur); | |
620 if (obj->klass() == NULL) { | |
621 // Ran into an unparseable point. | |
622 return cur; | |
623 }; | |
624 // Otherwise: | |
625 next = (cur + obj->size()); | |
626 if (!g1h->is_obj_dead(obj)) { | |
627 if (next < mr.end()) { | |
628 obj->oop_iterate(cl); | |
629 } else { | |
630 // this obj spans the boundary. If it's an array, stop at the | |
631 // boundary. | |
632 if (obj->is_objArray()) { | |
633 obj->oop_iterate(cl, mr); | |
634 } else { | |
635 obj->oop_iterate(cl); | |
636 } | |
637 } | |
638 } | |
639 cur = next; | |
640 } | |
641 return NULL; | |
642 } | |
643 | |
644 void HeapRegion::print() const { print_on(gclog_or_tty); } | |
645 void HeapRegion::print_on(outputStream* st) const { | |
646 if (isHumongous()) { | |
647 if (startsHumongous()) | |
648 st->print(" HS"); | |
649 else | |
650 st->print(" HC"); | |
651 } else { | |
652 st->print(" "); | |
653 } | |
654 if (in_collection_set()) | |
655 st->print(" CS"); | |
656 else if (is_gc_alloc_region()) | |
657 st->print(" A "); | |
658 else | |
659 st->print(" "); | |
660 if (is_young()) | |
661 st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y ")); | |
662 else | |
663 st->print(" "); | |
664 if (is_empty()) | |
665 st->print(" F"); | |
666 else | |
667 st->print(" "); | |
668 st->print(" %d", _gc_time_stamp); | |
669 G1OffsetTableContigSpace::print_on(st); | |
670 } | |
671 | |
672 #define OBJ_SAMPLE_INTERVAL 0 | |
673 #define BLOCK_SAMPLE_INTERVAL 100 | |
674 | |
675 // This really ought to be commoned up into OffsetTableContigSpace somehow. | |
676 // We would need a mechanism to make that code skip dead objects. | |
677 | |
678 void HeapRegion::verify(bool allow_dirty) const { | |
679 G1CollectedHeap* g1 = G1CollectedHeap::heap(); | |
680 HeapWord* p = bottom(); | |
681 HeapWord* prev_p = NULL; | |
682 int objs = 0; | |
683 int blocks = 0; | |
684 VerifyLiveClosure vl_cl(g1); | |
685 while (p < top()) { | |
686 size_t size = oop(p)->size(); | |
687 if (blocks == BLOCK_SAMPLE_INTERVAL) { | |
688 guarantee(p == block_start_const(p + (size/2)), | |
689 "check offset computation"); | |
690 blocks = 0; | |
691 } else { | |
692 blocks++; | |
693 } | |
694 if (objs == OBJ_SAMPLE_INTERVAL) { | |
695 oop obj = oop(p); | |
696 if (!g1->is_obj_dead(obj, this)) { | |
697 obj->verify(); | |
698 vl_cl.set_containing_obj(obj); | |
699 obj->oop_iterate(&vl_cl); | |
700 if (G1MaxVerifyFailures >= 0 | |
701 && vl_cl.n_failures() >= G1MaxVerifyFailures) break; | |
702 } | |
703 objs = 0; | |
704 } else { | |
705 objs++; | |
706 } | |
707 prev_p = p; | |
708 p += size; | |
709 } | |
710 HeapWord* rend = end(); | |
711 HeapWord* rtop = top(); | |
712 if (rtop < rend) { | |
713 guarantee(block_start_const(rtop + (rend - rtop) / 2) == rtop, | |
714 "check offset computation"); | |
715 } | |
716 if (vl_cl.failures()) { | |
717 gclog_or_tty->print_cr("Heap:"); | |
718 G1CollectedHeap::heap()->print(); | |
719 gclog_or_tty->print_cr(""); | |
720 } | |
721 if (G1VerifyConcMark && | |
722 G1VerifyConcMarkPrintReachable && | |
723 vl_cl.failures()) { | |
724 g1->concurrent_mark()->print_prev_bitmap_reachable(); | |
725 } | |
726 guarantee(!vl_cl.failures(), "should not have had any failures"); | |
727 guarantee(p == top(), "end of last object must match end of space"); | |
728 } | |
729 | |
730 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go | |
731 // away eventually. | |
732 | |
733 void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space) { | |
734 // false ==> we'll do the clearing if there's clearing to be done. | |
735 ContiguousSpace::initialize(mr, false); | |
736 _offsets.zero_bottom_entry(); | |
737 _offsets.initialize_threshold(); | |
738 if (clear_space) clear(); | |
739 } | |
740 | |
741 void G1OffsetTableContigSpace::clear() { | |
742 ContiguousSpace::clear(); | |
743 _offsets.zero_bottom_entry(); | |
744 _offsets.initialize_threshold(); | |
745 } | |
746 | |
747 void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) { | |
748 Space::set_bottom(new_bottom); | |
749 _offsets.set_bottom(new_bottom); | |
750 } | |
751 | |
752 void G1OffsetTableContigSpace::set_end(HeapWord* new_end) { | |
753 Space::set_end(new_end); | |
754 _offsets.resize(new_end - bottom()); | |
755 } | |
756 | |
757 void G1OffsetTableContigSpace::print() const { | |
758 print_short(); | |
759 gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " | |
760 INTPTR_FORMAT ", " INTPTR_FORMAT ")", | |
761 bottom(), top(), _offsets.threshold(), end()); | |
762 } | |
763 | |
764 HeapWord* G1OffsetTableContigSpace::initialize_threshold() { | |
765 return _offsets.initialize_threshold(); | |
766 } | |
767 | |
768 HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start, | |
769 HeapWord* end) { | |
770 _offsets.alloc_block(start, end); | |
771 return _offsets.threshold(); | |
772 } | |
773 | |
774 HeapWord* G1OffsetTableContigSpace::saved_mark_word() const { | |
775 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
776 assert( _gc_time_stamp <= g1h->get_gc_time_stamp(), "invariant" ); | |
777 if (_gc_time_stamp < g1h->get_gc_time_stamp()) | |
778 return top(); | |
779 else | |
780 return ContiguousSpace::saved_mark_word(); | |
781 } | |
782 | |
783 void G1OffsetTableContigSpace::set_saved_mark() { | |
784 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
785 unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp(); | |
786 | |
787 if (_gc_time_stamp < curr_gc_time_stamp) { | |
788 // The order of these is important, as another thread might be | |
789 // about to start scanning this region. If it does so after | |
790 // set_saved_mark and before _gc_time_stamp = ..., then the latter | |
791 // will be false, and it will pick up top() as the high water mark | |
792 // of region. If it does so after _gc_time_stamp = ..., then it | |
793 // will pick up the right saved_mark_word() as the high water mark | |
794 // of the region. Either way, the behaviour will be correct. | |
795 ContiguousSpace::set_saved_mark(); | |
796 OrderAccess::release_store_ptr((volatile intptr_t*) &_gc_time_stamp, | |
797 (intptr_t) curr_gc_time_stamp); | |
798 } | |
799 } | |
800 | |
801 G1OffsetTableContigSpace:: | |
802 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, | |
803 MemRegion mr, bool is_zeroed) : | |
804 _offsets(sharedOffsetArray, mr), | |
805 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true), | |
806 _gc_time_stamp(0) | |
807 { | |
808 _offsets.set_space(this); | |
809 initialize(mr, !is_zeroed); | |
810 } | |
811 | |
812 size_t RegionList::length() { | |
813 size_t len = 0; | |
814 HeapRegion* cur = hd(); | |
815 DEBUG_ONLY(HeapRegion* last = NULL); | |
816 while (cur != NULL) { | |
817 len++; | |
818 DEBUG_ONLY(last = cur); | |
819 cur = get_next(cur); | |
820 } | |
821 assert(last == tl(), "Invariant"); | |
822 return len; | |
823 } | |
824 | |
825 void RegionList::insert_before_head(HeapRegion* r) { | |
826 assert(well_formed(), "Inv"); | |
827 set_next(r, hd()); | |
828 _hd = r; | |
829 _sz++; | |
830 if (tl() == NULL) _tl = r; | |
831 assert(well_formed(), "Inv"); | |
832 } | |
833 | |
834 void RegionList::prepend_list(RegionList* new_list) { | |
835 assert(well_formed(), "Precondition"); | |
836 assert(new_list->well_formed(), "Precondition"); | |
837 HeapRegion* new_tl = new_list->tl(); | |
838 if (new_tl != NULL) { | |
839 set_next(new_tl, hd()); | |
840 _hd = new_list->hd(); | |
841 _sz += new_list->sz(); | |
842 if (tl() == NULL) _tl = new_list->tl(); | |
843 } else { | |
844 assert(new_list->hd() == NULL && new_list->sz() == 0, "Inv"); | |
845 } | |
846 assert(well_formed(), "Inv"); | |
847 } | |
848 | |
849 void RegionList::delete_after(HeapRegion* r) { | |
850 assert(well_formed(), "Precondition"); | |
851 HeapRegion* next = get_next(r); | |
852 assert(r != NULL, "Precondition"); | |
853 HeapRegion* next_tl = get_next(next); | |
854 set_next(r, next_tl); | |
855 dec_sz(); | |
856 if (next == tl()) { | |
857 assert(next_tl == NULL, "Inv"); | |
858 _tl = r; | |
859 } | |
860 assert(well_formed(), "Inv"); | |
861 } | |
862 | |
863 HeapRegion* RegionList::pop() { | |
864 assert(well_formed(), "Inv"); | |
865 HeapRegion* res = hd(); | |
866 if (res != NULL) { | |
867 _hd = get_next(res); | |
868 _sz--; | |
869 set_next(res, NULL); | |
870 if (sz() == 0) _tl = NULL; | |
871 } | |
872 assert(well_formed(), "Inv"); | |
873 return res; | |
874 } |