Thu, 15 Apr 2010 18:45:30 -0400
6939027: G1: assertion failure during the concurrent phase of cleanup
Summary: The outgoing region map is not maintained properly and it's causing an assert failure. Given that we don't actually use it, I'm removing it. I'm piggy-backing a small change on this which removes a message that it's printed before a Full GC when DisableExplicitGC is set.
Reviewed-by: apetrusenko, ysr
1 /*
2 * Copyright 2001-2009 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.
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23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_heapRegion.cpp.incl"
28 int HeapRegion::LogOfHRGrainBytes = 0;
29 int HeapRegion::LogOfHRGrainWords = 0;
30 int HeapRegion::GrainBytes = 0;
31 int HeapRegion::GrainWords = 0;
32 int HeapRegion::CardsPerRegion = 0;
34 HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1,
35 HeapRegion* hr, OopClosure* cl,
36 CardTableModRefBS::PrecisionStyle precision,
37 FilterKind fk) :
38 ContiguousSpaceDCTOC(hr, cl, precision, NULL),
39 _hr(hr), _fk(fk), _g1(g1)
40 {}
42 FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r,
43 OopClosure* oc) :
44 _r_bottom(r->bottom()), _r_end(r->end()),
45 _oc(oc), _out_of_region(0)
46 {}
48 class VerifyLiveClosure: public OopClosure {
49 private:
50 G1CollectedHeap* _g1h;
51 CardTableModRefBS* _bs;
52 oop _containing_obj;
53 bool _failures;
54 int _n_failures;
55 bool _use_prev_marking;
56 public:
57 // use_prev_marking == true -> use "prev" marking information,
58 // use_prev_marking == false -> use "next" marking information
59 VerifyLiveClosure(G1CollectedHeap* g1h, bool use_prev_marking) :
60 _g1h(g1h), _bs(NULL), _containing_obj(NULL),
61 _failures(false), _n_failures(0), _use_prev_marking(use_prev_marking)
62 {
63 BarrierSet* bs = _g1h->barrier_set();
64 if (bs->is_a(BarrierSet::CardTableModRef))
65 _bs = (CardTableModRefBS*)bs;
66 }
68 void set_containing_obj(oop obj) {
69 _containing_obj = obj;
70 }
72 bool failures() { return _failures; }
73 int n_failures() { return _n_failures; }
75 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
76 virtual void do_oop( oop* p) { do_oop_work(p); }
78 void print_object(outputStream* out, oop obj) {
79 #ifdef PRODUCT
80 klassOop k = obj->klass();
81 const char* class_name = instanceKlass::cast(k)->external_name();
82 out->print_cr("class name %s", class_name);
83 #else // PRODUCT
84 obj->print_on(out);
85 #endif // PRODUCT
86 }
88 template <class T> void do_oop_work(T* p) {
89 assert(_containing_obj != NULL, "Precondition");
90 assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
91 "Precondition");
92 T heap_oop = oopDesc::load_heap_oop(p);
93 if (!oopDesc::is_null(heap_oop)) {
94 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
95 bool failed = false;
96 if (!_g1h->is_in_closed_subset(obj) ||
97 _g1h->is_obj_dead_cond(obj, _use_prev_marking)) {
98 if (!_failures) {
99 gclog_or_tty->print_cr("");
100 gclog_or_tty->print_cr("----------");
101 }
102 if (!_g1h->is_in_closed_subset(obj)) {
103 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
104 gclog_or_tty->print_cr("Field "PTR_FORMAT
105 " of live obj "PTR_FORMAT" in region "
106 "["PTR_FORMAT", "PTR_FORMAT")",
107 p, (void*) _containing_obj,
108 from->bottom(), from->end());
109 print_object(gclog_or_tty, _containing_obj);
110 gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap",
111 (void*) obj);
112 } else {
113 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
114 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
115 gclog_or_tty->print_cr("Field "PTR_FORMAT
116 " of live obj "PTR_FORMAT" in region "
117 "["PTR_FORMAT", "PTR_FORMAT")",
118 p, (void*) _containing_obj,
119 from->bottom(), from->end());
120 print_object(gclog_or_tty, _containing_obj);
121 gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region "
122 "["PTR_FORMAT", "PTR_FORMAT")",
123 (void*) obj, to->bottom(), to->end());
124 print_object(gclog_or_tty, obj);
125 }
126 gclog_or_tty->print_cr("----------");
127 _failures = true;
128 failed = true;
129 _n_failures++;
130 }
132 if (!_g1h->full_collection()) {
133 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
134 HeapRegion* to = _g1h->heap_region_containing(obj);
135 if (from != NULL && to != NULL &&
136 from != to &&
137 !to->isHumongous()) {
138 jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
139 jbyte cv_field = *_bs->byte_for_const(p);
140 const jbyte dirty = CardTableModRefBS::dirty_card_val();
142 bool is_bad = !(from->is_young()
143 || to->rem_set()->contains_reference(p)
144 || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed
145 (_containing_obj->is_objArray() ?
146 cv_field == dirty
147 : cv_obj == dirty || cv_field == dirty));
148 if (is_bad) {
149 if (!_failures) {
150 gclog_or_tty->print_cr("");
151 gclog_or_tty->print_cr("----------");
152 }
153 gclog_or_tty->print_cr("Missing rem set entry:");
154 gclog_or_tty->print_cr("Field "PTR_FORMAT
155 " of obj "PTR_FORMAT
156 ", in region %d ["PTR_FORMAT
157 ", "PTR_FORMAT"),",
158 p, (void*) _containing_obj,
159 from->hrs_index(),
160 from->bottom(),
161 from->end());
162 _containing_obj->print_on(gclog_or_tty);
163 gclog_or_tty->print_cr("points to obj "PTR_FORMAT
164 " in region %d ["PTR_FORMAT
165 ", "PTR_FORMAT").",
166 (void*) obj, to->hrs_index(),
167 to->bottom(), to->end());
168 obj->print_on(gclog_or_tty);
169 gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.",
170 cv_obj, cv_field);
171 gclog_or_tty->print_cr("----------");
172 _failures = true;
173 if (!failed) _n_failures++;
174 }
175 }
176 }
177 }
178 }
179 };
181 template<class ClosureType>
182 HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h,
183 HeapRegion* hr,
184 HeapWord* cur, HeapWord* top) {
185 oop cur_oop = oop(cur);
186 int oop_size = cur_oop->size();
187 HeapWord* next_obj = cur + oop_size;
188 while (next_obj < top) {
189 // Keep filtering the remembered set.
190 if (!g1h->is_obj_dead(cur_oop, hr)) {
191 // Bottom lies entirely below top, so we can call the
192 // non-memRegion version of oop_iterate below.
193 cur_oop->oop_iterate(cl);
194 }
195 cur = next_obj;
196 cur_oop = oop(cur);
197 oop_size = cur_oop->size();
198 next_obj = cur + oop_size;
199 }
200 return cur;
201 }
203 void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
204 HeapWord* bottom,
205 HeapWord* top,
206 OopClosure* cl) {
207 G1CollectedHeap* g1h = _g1;
209 int oop_size;
211 OopClosure* cl2 = cl;
212 FilterIntoCSClosure intoCSFilt(this, g1h, cl);
213 FilterOutOfRegionClosure outOfRegionFilt(_hr, cl);
214 switch (_fk) {
215 case IntoCSFilterKind: cl2 = &intoCSFilt; break;
216 case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break;
217 }
219 // Start filtering what we add to the remembered set. If the object is
220 // not considered dead, either because it is marked (in the mark bitmap)
221 // or it was allocated after marking finished, then we add it. Otherwise
222 // we can safely ignore the object.
223 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
224 oop_size = oop(bottom)->oop_iterate(cl2, mr);
225 } else {
226 oop_size = oop(bottom)->size();
227 }
229 bottom += oop_size;
231 if (bottom < top) {
232 // We replicate the loop below for several kinds of possible filters.
233 switch (_fk) {
234 case NoFilterKind:
235 bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top);
236 break;
237 case IntoCSFilterKind: {
238 FilterIntoCSClosure filt(this, g1h, cl);
239 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
240 break;
241 }
242 case OutOfRegionFilterKind: {
243 FilterOutOfRegionClosure filt(_hr, cl);
244 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
245 break;
246 }
247 default:
248 ShouldNotReachHere();
249 }
251 // Last object. Need to do dead-obj filtering here too.
252 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
253 oop(bottom)->oop_iterate(cl2, mr);
254 }
255 }
256 }
258 // Minimum region size; we won't go lower than that.
259 // We might want to decrease this in the future, to deal with small
260 // heaps a bit more efficiently.
261 #define MIN_REGION_SIZE ( 1024 * 1024 )
263 // Maximum region size; we don't go higher than that. There's a good
264 // reason for having an upper bound. We don't want regions to get too
265 // large, otherwise cleanup's effectiveness would decrease as there
266 // will be fewer opportunities to find totally empty regions after
267 // marking.
268 #define MAX_REGION_SIZE ( 32 * 1024 * 1024 )
270 // The automatic region size calculation will try to have around this
271 // many regions in the heap (based on the min heap size).
272 #define TARGET_REGION_NUMBER 2048
274 void HeapRegion::setup_heap_region_size(uintx min_heap_size) {
275 // region_size in bytes
276 uintx region_size = G1HeapRegionSize;
277 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
278 // We base the automatic calculation on the min heap size. This
279 // can be problematic if the spread between min and max is quite
280 // wide, imagine -Xms128m -Xmx32g. But, if we decided it based on
281 // the max size, the region size might be way too large for the
282 // min size. Either way, some users might have to set the region
283 // size manually for some -Xms / -Xmx combos.
285 region_size = MAX2(min_heap_size / TARGET_REGION_NUMBER,
286 (uintx) MIN_REGION_SIZE);
287 }
289 int region_size_log = log2_long((jlong) region_size);
290 // Recalculate the region size to make sure it's a power of
291 // 2. This means that region_size is the largest power of 2 that's
292 // <= what we've calculated so far.
293 region_size = 1 << region_size_log;
295 // Now make sure that we don't go over or under our limits.
296 if (region_size < MIN_REGION_SIZE) {
297 region_size = MIN_REGION_SIZE;
298 } else if (region_size > MAX_REGION_SIZE) {
299 region_size = MAX_REGION_SIZE;
300 }
302 // And recalculate the log.
303 region_size_log = log2_long((jlong) region_size);
305 // Now, set up the globals.
306 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
307 LogOfHRGrainBytes = region_size_log;
309 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
310 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
312 guarantee(GrainBytes == 0, "we should only set it once");
313 // The cast to int is safe, given that we've bounded region_size by
314 // MIN_REGION_SIZE and MAX_REGION_SIZE.
315 GrainBytes = (int) region_size;
317 guarantee(GrainWords == 0, "we should only set it once");
318 GrainWords = GrainBytes >> LogHeapWordSize;
319 guarantee(1 << LogOfHRGrainWords == GrainWords, "sanity");
321 guarantee(CardsPerRegion == 0, "we should only set it once");
322 CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift;
323 }
325 void HeapRegion::reset_after_compaction() {
326 G1OffsetTableContigSpace::reset_after_compaction();
327 // After a compaction the mark bitmap is invalid, so we must
328 // treat all objects as being inside the unmarked area.
329 zero_marked_bytes();
330 init_top_at_mark_start();
331 }
333 DirtyCardToOopClosure*
334 HeapRegion::new_dcto_closure(OopClosure* cl,
335 CardTableModRefBS::PrecisionStyle precision,
336 HeapRegionDCTOC::FilterKind fk) {
337 return new HeapRegionDCTOC(G1CollectedHeap::heap(),
338 this, cl, precision, fk);
339 }
341 void HeapRegion::hr_clear(bool par, bool clear_space) {
342 _humongous_type = NotHumongous;
343 _humongous_start_region = NULL;
344 _in_collection_set = false;
345 _is_gc_alloc_region = false;
347 // Age stuff (if parallel, this will be done separately, since it needs
348 // to be sequential).
349 G1CollectedHeap* g1h = G1CollectedHeap::heap();
351 set_young_index_in_cset(-1);
352 uninstall_surv_rate_group();
353 set_young_type(NotYoung);
355 // In case it had been the start of a humongous sequence, reset its end.
356 set_end(_orig_end);
358 if (!par) {
359 // If this is parallel, this will be done later.
360 HeapRegionRemSet* hrrs = rem_set();
361 if (hrrs != NULL) hrrs->clear();
362 _claimed = InitialClaimValue;
363 }
364 zero_marked_bytes();
365 set_sort_index(-1);
367 _offsets.resize(HeapRegion::GrainWords);
368 init_top_at_mark_start();
369 if (clear_space) clear(SpaceDecorator::Mangle);
370 }
372 // <PREDICTION>
373 void HeapRegion::calc_gc_efficiency() {
374 G1CollectedHeap* g1h = G1CollectedHeap::heap();
375 _gc_efficiency = (double) garbage_bytes() /
376 g1h->predict_region_elapsed_time_ms(this, false);
377 }
378 // </PREDICTION>
380 void HeapRegion::set_startsHumongous() {
381 _humongous_type = StartsHumongous;
382 _humongous_start_region = this;
383 assert(end() == _orig_end, "Should be normal before alloc.");
384 }
386 bool HeapRegion::claimHeapRegion(jint claimValue) {
387 jint current = _claimed;
388 if (current != claimValue) {
389 jint res = Atomic::cmpxchg(claimValue, &_claimed, current);
390 if (res == current) {
391 return true;
392 }
393 }
394 return false;
395 }
397 HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) {
398 HeapWord* low = addr;
399 HeapWord* high = end();
400 while (low < high) {
401 size_t diff = pointer_delta(high, low);
402 // Must add one below to bias toward the high amount. Otherwise, if
403 // "high" were at the desired value, and "low" were one less, we
404 // would not converge on "high". This is not symmetric, because
405 // we set "high" to a block start, which might be the right one,
406 // which we don't do for "low".
407 HeapWord* middle = low + (diff+1)/2;
408 if (middle == high) return high;
409 HeapWord* mid_bs = block_start_careful(middle);
410 if (mid_bs < addr) {
411 low = middle;
412 } else {
413 high = mid_bs;
414 }
415 }
416 assert(low == high && low >= addr, "Didn't work.");
417 return low;
418 }
420 void HeapRegion::set_next_on_unclean_list(HeapRegion* r) {
421 assert(r == NULL || r->is_on_unclean_list(), "Malformed unclean list.");
422 _next_in_special_set = r;
423 }
425 void HeapRegion::set_on_unclean_list(bool b) {
426 _is_on_unclean_list = b;
427 }
429 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
430 G1OffsetTableContigSpace::initialize(mr, false, mangle_space);
431 hr_clear(false/*par*/, clear_space);
432 }
433 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
434 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
435 #endif // _MSC_VER
438 HeapRegion::
439 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
440 MemRegion mr, bool is_zeroed)
441 : G1OffsetTableContigSpace(sharedOffsetArray, mr, is_zeroed),
442 _next_fk(HeapRegionDCTOC::NoFilterKind),
443 _hrs_index(-1),
444 _humongous_type(NotHumongous), _humongous_start_region(NULL),
445 _in_collection_set(false), _is_gc_alloc_region(false),
446 _is_on_free_list(false), _is_on_unclean_list(false),
447 _next_in_special_set(NULL), _orig_end(NULL),
448 _claimed(InitialClaimValue), _evacuation_failed(false),
449 _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1),
450 _young_type(NotYoung), _next_young_region(NULL),
451 _next_dirty_cards_region(NULL),
452 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
453 _rem_set(NULL), _zfs(NotZeroFilled)
454 {
455 _orig_end = mr.end();
456 // Note that initialize() will set the start of the unmarked area of the
457 // region.
458 this->initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
459 set_top(bottom());
460 set_saved_mark();
462 _rem_set = new HeapRegionRemSet(sharedOffsetArray, this);
464 assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant.");
465 // In case the region is allocated during a pause, note the top.
466 // We haven't done any counting on a brand new region.
467 _top_at_conc_mark_count = bottom();
468 }
470 class NextCompactionHeapRegionClosure: public HeapRegionClosure {
471 const HeapRegion* _target;
472 bool _target_seen;
473 HeapRegion* _last;
474 CompactibleSpace* _res;
475 public:
476 NextCompactionHeapRegionClosure(const HeapRegion* target) :
477 _target(target), _target_seen(false), _res(NULL) {}
478 bool doHeapRegion(HeapRegion* cur) {
479 if (_target_seen) {
480 if (!cur->isHumongous()) {
481 _res = cur;
482 return true;
483 }
484 } else if (cur == _target) {
485 _target_seen = true;
486 }
487 return false;
488 }
489 CompactibleSpace* result() { return _res; }
490 };
492 CompactibleSpace* HeapRegion::next_compaction_space() const {
493 G1CollectedHeap* g1h = G1CollectedHeap::heap();
494 // cast away const-ness
495 HeapRegion* r = (HeapRegion*) this;
496 NextCompactionHeapRegionClosure blk(r);
497 g1h->heap_region_iterate_from(r, &blk);
498 return blk.result();
499 }
501 void HeapRegion::set_continuesHumongous(HeapRegion* start) {
502 // The order is important here.
503 start->add_continuingHumongousRegion(this);
504 _humongous_type = ContinuesHumongous;
505 _humongous_start_region = start;
506 }
508 void HeapRegion::add_continuingHumongousRegion(HeapRegion* cont) {
509 // Must join the blocks of the current H region seq with the block of the
510 // added region.
511 offsets()->join_blocks(bottom(), cont->bottom());
512 arrayOop obj = (arrayOop)(bottom());
513 obj->set_length((int) (obj->length() + cont->capacity()/jintSize));
514 set_end(cont->end());
515 set_top(cont->end());
516 }
518 void HeapRegion::save_marks() {
519 set_saved_mark();
520 }
522 void HeapRegion::oops_in_mr_iterate(MemRegion mr, OopClosure* cl) {
523 HeapWord* p = mr.start();
524 HeapWord* e = mr.end();
525 oop obj;
526 while (p < e) {
527 obj = oop(p);
528 p += obj->oop_iterate(cl);
529 }
530 assert(p == e, "bad memregion: doesn't end on obj boundary");
531 }
533 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
534 void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \
535 ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl); \
536 }
537 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN)
540 void HeapRegion::oop_before_save_marks_iterate(OopClosure* cl) {
541 oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
542 }
544 #ifdef DEBUG
545 HeapWord* HeapRegion::allocate(size_t size) {
546 jint state = zero_fill_state();
547 assert(!G1CollectedHeap::heap()->allocs_are_zero_filled() ||
548 zero_fill_is_allocated(),
549 "When ZF is on, only alloc in ZF'd regions");
550 return G1OffsetTableContigSpace::allocate(size);
551 }
552 #endif
554 void HeapRegion::set_zero_fill_state_work(ZeroFillState zfs) {
555 assert(top() == bottom() || zfs == Allocated,
556 "Region must be empty, or we must be setting it to allocated.");
557 assert(ZF_mon->owned_by_self() ||
558 Universe::heap()->is_gc_active(),
559 "Must hold the lock or be a full GC to modify.");
560 _zfs = zfs;
561 }
563 void HeapRegion::set_zero_fill_complete() {
564 set_zero_fill_state_work(ZeroFilled);
565 if (ZF_mon->owned_by_self()) {
566 ZF_mon->notify_all();
567 }
568 }
571 void HeapRegion::ensure_zero_filled() {
572 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
573 ensure_zero_filled_locked();
574 }
576 void HeapRegion::ensure_zero_filled_locked() {
577 assert(ZF_mon->owned_by_self(), "Precondition");
578 bool should_ignore_zf = SafepointSynchronize::is_at_safepoint();
579 assert(should_ignore_zf || Heap_lock->is_locked(),
580 "Either we're in a GC or we're allocating a region.");
581 switch (zero_fill_state()) {
582 case HeapRegion::NotZeroFilled:
583 set_zero_fill_in_progress(Thread::current());
584 {
585 ZF_mon->unlock();
586 Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
587 ZF_mon->lock_without_safepoint_check();
588 }
589 // A trap.
590 guarantee(zero_fill_state() == HeapRegion::ZeroFilling
591 && zero_filler() == Thread::current(),
592 "AHA! Tell Dave D if you see this...");
593 set_zero_fill_complete();
594 // gclog_or_tty->print_cr("Did sync ZF.");
595 ConcurrentZFThread::note_sync_zfs();
596 break;
597 case HeapRegion::ZeroFilling:
598 if (should_ignore_zf) {
599 // We can "break" the lock and take over the work.
600 Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
601 set_zero_fill_complete();
602 ConcurrentZFThread::note_sync_zfs();
603 break;
604 } else {
605 ConcurrentZFThread::wait_for_ZF_completed(this);
606 }
607 case HeapRegion::ZeroFilled:
608 // Nothing to do.
609 break;
610 case HeapRegion::Allocated:
611 guarantee(false, "Should not call on allocated regions.");
612 }
613 assert(zero_fill_state() == HeapRegion::ZeroFilled, "Post");
614 }
616 HeapWord*
617 HeapRegion::object_iterate_mem_careful(MemRegion mr,
618 ObjectClosure* cl) {
619 G1CollectedHeap* g1h = G1CollectedHeap::heap();
620 // We used to use "block_start_careful" here. But we're actually happy
621 // to update the BOT while we do this...
622 HeapWord* cur = block_start(mr.start());
623 mr = mr.intersection(used_region());
624 if (mr.is_empty()) return NULL;
625 // Otherwise, find the obj that extends onto mr.start().
627 assert(cur <= mr.start()
628 && (oop(cur)->klass_or_null() == NULL ||
629 cur + oop(cur)->size() > mr.start()),
630 "postcondition of block_start");
631 oop obj;
632 while (cur < mr.end()) {
633 obj = oop(cur);
634 if (obj->klass_or_null() == NULL) {
635 // Ran into an unparseable point.
636 return cur;
637 } else if (!g1h->is_obj_dead(obj)) {
638 cl->do_object(obj);
639 }
640 if (cl->abort()) return cur;
641 // The check above must occur before the operation below, since an
642 // abort might invalidate the "size" operation.
643 cur += obj->size();
644 }
645 return NULL;
646 }
648 HeapWord*
649 HeapRegion::
650 oops_on_card_seq_iterate_careful(MemRegion mr,
651 FilterOutOfRegionClosure* cl) {
652 G1CollectedHeap* g1h = G1CollectedHeap::heap();
654 // If we're within a stop-world GC, then we might look at a card in a
655 // GC alloc region that extends onto a GC LAB, which may not be
656 // parseable. Stop such at the "saved_mark" of the region.
657 if (G1CollectedHeap::heap()->is_gc_active()) {
658 mr = mr.intersection(used_region_at_save_marks());
659 } else {
660 mr = mr.intersection(used_region());
661 }
662 if (mr.is_empty()) return NULL;
663 // Otherwise, find the obj that extends onto mr.start().
665 // We used to use "block_start_careful" here. But we're actually happy
666 // to update the BOT while we do this...
667 HeapWord* cur = block_start(mr.start());
668 assert(cur <= mr.start(), "Postcondition");
670 while (cur <= mr.start()) {
671 if (oop(cur)->klass_or_null() == NULL) {
672 // Ran into an unparseable point.
673 return cur;
674 }
675 // Otherwise...
676 int sz = oop(cur)->size();
677 if (cur + sz > mr.start()) break;
678 // Otherwise, go on.
679 cur = cur + sz;
680 }
681 oop obj;
682 obj = oop(cur);
683 // If we finish this loop...
684 assert(cur <= mr.start()
685 && obj->klass_or_null() != NULL
686 && cur + obj->size() > mr.start(),
687 "Loop postcondition");
688 if (!g1h->is_obj_dead(obj)) {
689 obj->oop_iterate(cl, mr);
690 }
692 HeapWord* next;
693 while (cur < mr.end()) {
694 obj = oop(cur);
695 if (obj->klass_or_null() == NULL) {
696 // Ran into an unparseable point.
697 return cur;
698 };
699 // Otherwise:
700 next = (cur + obj->size());
701 if (!g1h->is_obj_dead(obj)) {
702 if (next < mr.end()) {
703 obj->oop_iterate(cl);
704 } else {
705 // this obj spans the boundary. If it's an array, stop at the
706 // boundary.
707 if (obj->is_objArray()) {
708 obj->oop_iterate(cl, mr);
709 } else {
710 obj->oop_iterate(cl);
711 }
712 }
713 }
714 cur = next;
715 }
716 return NULL;
717 }
719 void HeapRegion::print() const { print_on(gclog_or_tty); }
720 void HeapRegion::print_on(outputStream* st) const {
721 if (isHumongous()) {
722 if (startsHumongous())
723 st->print(" HS");
724 else
725 st->print(" HC");
726 } else {
727 st->print(" ");
728 }
729 if (in_collection_set())
730 st->print(" CS");
731 else if (is_gc_alloc_region())
732 st->print(" A ");
733 else
734 st->print(" ");
735 if (is_young())
736 st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
737 else
738 st->print(" ");
739 if (is_empty())
740 st->print(" F");
741 else
742 st->print(" ");
743 st->print(" %5d", _gc_time_stamp);
744 st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT,
745 prev_top_at_mark_start(), next_top_at_mark_start());
746 G1OffsetTableContigSpace::print_on(st);
747 }
749 void HeapRegion::verify(bool allow_dirty) const {
750 bool dummy = false;
751 verify(allow_dirty, /* use_prev_marking */ true, /* failures */ &dummy);
752 }
754 #define OBJ_SAMPLE_INTERVAL 0
755 #define BLOCK_SAMPLE_INTERVAL 100
757 // This really ought to be commoned up into OffsetTableContigSpace somehow.
758 // We would need a mechanism to make that code skip dead objects.
760 void HeapRegion::verify(bool allow_dirty,
761 bool use_prev_marking,
762 bool* failures) const {
763 G1CollectedHeap* g1 = G1CollectedHeap::heap();
764 *failures = false;
765 HeapWord* p = bottom();
766 HeapWord* prev_p = NULL;
767 int objs = 0;
768 int blocks = 0;
769 VerifyLiveClosure vl_cl(g1, use_prev_marking);
770 while (p < top()) {
771 size_t size = oop(p)->size();
772 if (blocks == BLOCK_SAMPLE_INTERVAL) {
773 HeapWord* res = block_start_const(p + (size/2));
774 if (p != res) {
775 gclog_or_tty->print_cr("offset computation 1 for "PTR_FORMAT" and "
776 SIZE_FORMAT" returned "PTR_FORMAT,
777 p, size, res);
778 *failures = true;
779 return;
780 }
781 blocks = 0;
782 } else {
783 blocks++;
784 }
785 if (objs == OBJ_SAMPLE_INTERVAL) {
786 oop obj = oop(p);
787 if (!g1->is_obj_dead_cond(obj, this, use_prev_marking)) {
788 if (obj->is_oop()) {
789 klassOop klass = obj->klass();
790 if (!klass->is_perm()) {
791 gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" "
792 "not in perm", klass, obj);
793 *failures = true;
794 return;
795 } else if (!klass->is_klass()) {
796 gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" "
797 "not a klass", klass, obj);
798 *failures = true;
799 return;
800 } else {
801 vl_cl.set_containing_obj(obj);
802 obj->oop_iterate(&vl_cl);
803 if (vl_cl.failures()) {
804 *failures = true;
805 }
806 if (G1MaxVerifyFailures >= 0 &&
807 vl_cl.n_failures() >= G1MaxVerifyFailures) {
808 return;
809 }
810 }
811 } else {
812 gclog_or_tty->print_cr(PTR_FORMAT" no an oop", obj);
813 *failures = true;
814 return;
815 }
816 }
817 objs = 0;
818 } else {
819 objs++;
820 }
821 prev_p = p;
822 p += size;
823 }
824 HeapWord* rend = end();
825 HeapWord* rtop = top();
826 if (rtop < rend) {
827 HeapWord* res = block_start_const(rtop + (rend - rtop) / 2);
828 if (res != rtop) {
829 gclog_or_tty->print_cr("offset computation 2 for "PTR_FORMAT" and "
830 PTR_FORMAT" returned "PTR_FORMAT,
831 rtop, rend, res);
832 *failures = true;
833 return;
834 }
835 }
837 if (p != top()) {
838 gclog_or_tty->print_cr("end of last object "PTR_FORMAT" "
839 "does not match top "PTR_FORMAT, p, top());
840 *failures = true;
841 return;
842 }
843 }
845 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
846 // away eventually.
848 void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
849 // false ==> we'll do the clearing if there's clearing to be done.
850 ContiguousSpace::initialize(mr, false, mangle_space);
851 _offsets.zero_bottom_entry();
852 _offsets.initialize_threshold();
853 if (clear_space) clear(mangle_space);
854 }
856 void G1OffsetTableContigSpace::clear(bool mangle_space) {
857 ContiguousSpace::clear(mangle_space);
858 _offsets.zero_bottom_entry();
859 _offsets.initialize_threshold();
860 }
862 void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
863 Space::set_bottom(new_bottom);
864 _offsets.set_bottom(new_bottom);
865 }
867 void G1OffsetTableContigSpace::set_end(HeapWord* new_end) {
868 Space::set_end(new_end);
869 _offsets.resize(new_end - bottom());
870 }
872 void G1OffsetTableContigSpace::print() const {
873 print_short();
874 gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
875 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
876 bottom(), top(), _offsets.threshold(), end());
877 }
879 HeapWord* G1OffsetTableContigSpace::initialize_threshold() {
880 return _offsets.initialize_threshold();
881 }
883 HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start,
884 HeapWord* end) {
885 _offsets.alloc_block(start, end);
886 return _offsets.threshold();
887 }
889 HeapWord* G1OffsetTableContigSpace::saved_mark_word() const {
890 G1CollectedHeap* g1h = G1CollectedHeap::heap();
891 assert( _gc_time_stamp <= g1h->get_gc_time_stamp(), "invariant" );
892 if (_gc_time_stamp < g1h->get_gc_time_stamp())
893 return top();
894 else
895 return ContiguousSpace::saved_mark_word();
896 }
898 void G1OffsetTableContigSpace::set_saved_mark() {
899 G1CollectedHeap* g1h = G1CollectedHeap::heap();
900 unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp();
902 if (_gc_time_stamp < curr_gc_time_stamp) {
903 // The order of these is important, as another thread might be
904 // about to start scanning this region. If it does so after
905 // set_saved_mark and before _gc_time_stamp = ..., then the latter
906 // will be false, and it will pick up top() as the high water mark
907 // of region. If it does so after _gc_time_stamp = ..., then it
908 // will pick up the right saved_mark_word() as the high water mark
909 // of the region. Either way, the behaviour will be correct.
910 ContiguousSpace::set_saved_mark();
911 OrderAccess::storestore();
912 _gc_time_stamp = curr_gc_time_stamp;
913 // The following fence is to force a flush of the writes above, but
914 // is strictly not needed because when an allocating worker thread
915 // calls set_saved_mark() it does so under the ParGCRareEvent_lock;
916 // when the lock is released, the write will be flushed.
917 // OrderAccess::fence();
918 }
919 }
921 G1OffsetTableContigSpace::
922 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
923 MemRegion mr, bool is_zeroed) :
924 _offsets(sharedOffsetArray, mr),
925 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
926 _gc_time_stamp(0)
927 {
928 _offsets.set_space(this);
929 initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
930 }
932 size_t RegionList::length() {
933 size_t len = 0;
934 HeapRegion* cur = hd();
935 DEBUG_ONLY(HeapRegion* last = NULL);
936 while (cur != NULL) {
937 len++;
938 DEBUG_ONLY(last = cur);
939 cur = get_next(cur);
940 }
941 assert(last == tl(), "Invariant");
942 return len;
943 }
945 void RegionList::insert_before_head(HeapRegion* r) {
946 assert(well_formed(), "Inv");
947 set_next(r, hd());
948 _hd = r;
949 _sz++;
950 if (tl() == NULL) _tl = r;
951 assert(well_formed(), "Inv");
952 }
954 void RegionList::prepend_list(RegionList* new_list) {
955 assert(well_formed(), "Precondition");
956 assert(new_list->well_formed(), "Precondition");
957 HeapRegion* new_tl = new_list->tl();
958 if (new_tl != NULL) {
959 set_next(new_tl, hd());
960 _hd = new_list->hd();
961 _sz += new_list->sz();
962 if (tl() == NULL) _tl = new_list->tl();
963 } else {
964 assert(new_list->hd() == NULL && new_list->sz() == 0, "Inv");
965 }
966 assert(well_formed(), "Inv");
967 }
969 void RegionList::delete_after(HeapRegion* r) {
970 assert(well_formed(), "Precondition");
971 HeapRegion* next = get_next(r);
972 assert(r != NULL, "Precondition");
973 HeapRegion* next_tl = get_next(next);
974 set_next(r, next_tl);
975 dec_sz();
976 if (next == tl()) {
977 assert(next_tl == NULL, "Inv");
978 _tl = r;
979 }
980 assert(well_formed(), "Inv");
981 }
983 HeapRegion* RegionList::pop() {
984 assert(well_formed(), "Inv");
985 HeapRegion* res = hd();
986 if (res != NULL) {
987 _hd = get_next(res);
988 _sz--;
989 set_next(res, NULL);
990 if (sz() == 0) _tl = NULL;
991 }
992 assert(well_formed(), "Inv");
993 return res;
994 }