Mon, 31 Aug 2009 05:27:29 -0700
6841313: G1: dirty cards of survivor regions in parallel
Reviewed-by: tonyp, iveresov
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.
22 *
23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_heapRegion.cpp.incl"
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 {}
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 {}
42 class VerifyLiveClosure: public OopClosure {
43 private:
44 G1CollectedHeap* _g1h;
45 CardTableModRefBS* _bs;
46 oop _containing_obj;
47 bool _failures;
48 int _n_failures;
49 bool _use_prev_marking;
50 public:
51 // use_prev_marking == true -> use "prev" marking information,
52 // use_prev_marking == false -> use "next" marking information
53 VerifyLiveClosure(G1CollectedHeap* g1h, bool use_prev_marking) :
54 _g1h(g1h), _bs(NULL), _containing_obj(NULL),
55 _failures(false), _n_failures(0), _use_prev_marking(use_prev_marking)
56 {
57 BarrierSet* bs = _g1h->barrier_set();
58 if (bs->is_a(BarrierSet::CardTableModRef))
59 _bs = (CardTableModRefBS*)bs;
60 }
62 void set_containing_obj(oop obj) {
63 _containing_obj = obj;
64 }
66 bool failures() { return _failures; }
67 int n_failures() { return _n_failures; }
69 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
70 virtual void do_oop( oop* p) { do_oop_work(p); }
72 template <class T> void do_oop_work(T* p) {
73 assert(_containing_obj != NULL, "Precondition");
74 assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
75 "Precondition");
76 T heap_oop = oopDesc::load_heap_oop(p);
77 if (!oopDesc::is_null(heap_oop)) {
78 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
79 bool failed = false;
80 if (!_g1h->is_in_closed_subset(obj) ||
81 _g1h->is_obj_dead_cond(obj, _use_prev_marking)) {
82 if (!_failures) {
83 gclog_or_tty->print_cr("");
84 gclog_or_tty->print_cr("----------");
85 }
86 if (!_g1h->is_in_closed_subset(obj)) {
87 gclog_or_tty->print_cr("Field "PTR_FORMAT
88 " of live obj "PTR_FORMAT
89 " points to obj "PTR_FORMAT
90 " not in the heap.",
91 p, (void*) _containing_obj, (void*) obj);
92 } else {
93 gclog_or_tty->print_cr("Field "PTR_FORMAT
94 " of live obj "PTR_FORMAT
95 " points to dead obj "PTR_FORMAT".",
96 p, (void*) _containing_obj, (void*) obj);
97 }
98 gclog_or_tty->print_cr("Live obj:");
99 _containing_obj->print_on(gclog_or_tty);
100 gclog_or_tty->print_cr("Bad referent:");
101 obj->print_on(gclog_or_tty);
102 gclog_or_tty->print_cr("----------");
103 _failures = true;
104 failed = true;
105 _n_failures++;
106 }
108 if (!_g1h->full_collection()) {
109 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
110 HeapRegion* to = _g1h->heap_region_containing(obj);
111 if (from != NULL && to != NULL &&
112 from != to &&
113 !to->isHumongous()) {
114 jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
115 jbyte cv_field = *_bs->byte_for_const(p);
116 const jbyte dirty = CardTableModRefBS::dirty_card_val();
118 bool is_bad = !(from->is_young()
119 || to->rem_set()->contains_reference(p)
120 || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed
121 (_containing_obj->is_objArray() ?
122 cv_field == dirty
123 : cv_obj == dirty || cv_field == dirty));
124 if (is_bad) {
125 if (!_failures) {
126 gclog_or_tty->print_cr("");
127 gclog_or_tty->print_cr("----------");
128 }
129 gclog_or_tty->print_cr("Missing rem set entry:");
130 gclog_or_tty->print_cr("Field "PTR_FORMAT
131 " of obj "PTR_FORMAT
132 ", in region %d ["PTR_FORMAT
133 ", "PTR_FORMAT"),",
134 p, (void*) _containing_obj,
135 from->hrs_index(),
136 from->bottom(),
137 from->end());
138 _containing_obj->print_on(gclog_or_tty);
139 gclog_or_tty->print_cr("points to obj "PTR_FORMAT
140 " in region %d ["PTR_FORMAT
141 ", "PTR_FORMAT").",
142 (void*) obj, to->hrs_index(),
143 to->bottom(), to->end());
144 obj->print_on(gclog_or_tty);
145 gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.",
146 cv_obj, cv_field);
147 gclog_or_tty->print_cr("----------");
148 _failures = true;
149 if (!failed) _n_failures++;
150 }
151 }
152 }
153 }
154 }
155 };
157 template<class ClosureType>
158 HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h,
159 HeapRegion* hr,
160 HeapWord* cur, HeapWord* top) {
161 oop cur_oop = oop(cur);
162 int oop_size = cur_oop->size();
163 HeapWord* next_obj = cur + oop_size;
164 while (next_obj < top) {
165 // Keep filtering the remembered set.
166 if (!g1h->is_obj_dead(cur_oop, hr)) {
167 // Bottom lies entirely below top, so we can call the
168 // non-memRegion version of oop_iterate below.
169 cur_oop->oop_iterate(cl);
170 }
171 cur = next_obj;
172 cur_oop = oop(cur);
173 oop_size = cur_oop->size();
174 next_obj = cur + oop_size;
175 }
176 return cur;
177 }
179 void HeapRegionDCTOC::walk_mem_region_with_cl(MemRegion mr,
180 HeapWord* bottom,
181 HeapWord* top,
182 OopClosure* cl) {
183 G1CollectedHeap* g1h = _g1;
185 int oop_size;
187 OopClosure* cl2 = cl;
188 FilterIntoCSClosure intoCSFilt(this, g1h, cl);
189 FilterOutOfRegionClosure outOfRegionFilt(_hr, cl);
190 switch (_fk) {
191 case IntoCSFilterKind: cl2 = &intoCSFilt; break;
192 case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break;
193 }
195 // Start filtering what we add to the remembered set. If the object is
196 // not considered dead, either because it is marked (in the mark bitmap)
197 // or it was allocated after marking finished, then we add it. Otherwise
198 // we can safely ignore the object.
199 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
200 oop_size = oop(bottom)->oop_iterate(cl2, mr);
201 } else {
202 oop_size = oop(bottom)->size();
203 }
205 bottom += oop_size;
207 if (bottom < top) {
208 // We replicate the loop below for several kinds of possible filters.
209 switch (_fk) {
210 case NoFilterKind:
211 bottom = walk_mem_region_loop(cl, g1h, _hr, bottom, top);
212 break;
213 case IntoCSFilterKind: {
214 FilterIntoCSClosure filt(this, g1h, cl);
215 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
216 break;
217 }
218 case OutOfRegionFilterKind: {
219 FilterOutOfRegionClosure filt(_hr, cl);
220 bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top);
221 break;
222 }
223 default:
224 ShouldNotReachHere();
225 }
227 // Last object. Need to do dead-obj filtering here too.
228 if (!g1h->is_obj_dead(oop(bottom), _hr)) {
229 oop(bottom)->oop_iterate(cl2, mr);
230 }
231 }
232 }
234 void HeapRegion::reset_after_compaction() {
235 G1OffsetTableContigSpace::reset_after_compaction();
236 // After a compaction the mark bitmap is invalid, so we must
237 // treat all objects as being inside the unmarked area.
238 zero_marked_bytes();
239 init_top_at_mark_start();
240 }
242 DirtyCardToOopClosure*
243 HeapRegion::new_dcto_closure(OopClosure* cl,
244 CardTableModRefBS::PrecisionStyle precision,
245 HeapRegionDCTOC::FilterKind fk) {
246 return new HeapRegionDCTOC(G1CollectedHeap::heap(),
247 this, cl, precision, fk);
248 }
250 void HeapRegion::hr_clear(bool par, bool clear_space) {
251 _humongous_type = NotHumongous;
252 _humongous_start_region = NULL;
253 _in_collection_set = false;
254 _is_gc_alloc_region = false;
256 // Age stuff (if parallel, this will be done separately, since it needs
257 // to be sequential).
258 G1CollectedHeap* g1h = G1CollectedHeap::heap();
260 set_young_index_in_cset(-1);
261 uninstall_surv_rate_group();
262 set_young_type(NotYoung);
264 // In case it had been the start of a humongous sequence, reset its end.
265 set_end(_orig_end);
267 if (!par) {
268 // If this is parallel, this will be done later.
269 HeapRegionRemSet* hrrs = rem_set();
270 if (hrrs != NULL) hrrs->clear();
271 _claimed = InitialClaimValue;
272 }
273 zero_marked_bytes();
274 set_sort_index(-1);
276 _offsets.resize(HeapRegion::GrainWords);
277 init_top_at_mark_start();
278 if (clear_space) clear(SpaceDecorator::Mangle);
279 }
281 // <PREDICTION>
282 void HeapRegion::calc_gc_efficiency() {
283 G1CollectedHeap* g1h = G1CollectedHeap::heap();
284 _gc_efficiency = (double) garbage_bytes() /
285 g1h->predict_region_elapsed_time_ms(this, false);
286 }
287 // </PREDICTION>
289 void HeapRegion::set_startsHumongous() {
290 _humongous_type = StartsHumongous;
291 _humongous_start_region = this;
292 assert(end() == _orig_end, "Should be normal before alloc.");
293 }
295 bool HeapRegion::claimHeapRegion(jint claimValue) {
296 jint current = _claimed;
297 if (current != claimValue) {
298 jint res = Atomic::cmpxchg(claimValue, &_claimed, current);
299 if (res == current) {
300 return true;
301 }
302 }
303 return false;
304 }
306 HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) {
307 HeapWord* low = addr;
308 HeapWord* high = end();
309 while (low < high) {
310 size_t diff = pointer_delta(high, low);
311 // Must add one below to bias toward the high amount. Otherwise, if
312 // "high" were at the desired value, and "low" were one less, we
313 // would not converge on "high". This is not symmetric, because
314 // we set "high" to a block start, which might be the right one,
315 // which we don't do for "low".
316 HeapWord* middle = low + (diff+1)/2;
317 if (middle == high) return high;
318 HeapWord* mid_bs = block_start_careful(middle);
319 if (mid_bs < addr) {
320 low = middle;
321 } else {
322 high = mid_bs;
323 }
324 }
325 assert(low == high && low >= addr, "Didn't work.");
326 return low;
327 }
329 void HeapRegion::set_next_on_unclean_list(HeapRegion* r) {
330 assert(r == NULL || r->is_on_unclean_list(), "Malformed unclean list.");
331 _next_in_special_set = r;
332 }
334 void HeapRegion::set_on_unclean_list(bool b) {
335 _is_on_unclean_list = b;
336 }
338 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
339 G1OffsetTableContigSpace::initialize(mr, false, mangle_space);
340 hr_clear(false/*par*/, clear_space);
341 }
342 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
343 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
344 #endif // _MSC_VER
347 HeapRegion::
348 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
349 MemRegion mr, bool is_zeroed)
350 : G1OffsetTableContigSpace(sharedOffsetArray, mr, is_zeroed),
351 _next_fk(HeapRegionDCTOC::NoFilterKind),
352 _hrs_index(-1),
353 _humongous_type(NotHumongous), _humongous_start_region(NULL),
354 _in_collection_set(false), _is_gc_alloc_region(false),
355 _is_on_free_list(false), _is_on_unclean_list(false),
356 _next_in_special_set(NULL), _orig_end(NULL),
357 _claimed(InitialClaimValue), _evacuation_failed(false),
358 _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1),
359 _young_type(NotYoung), _next_young_region(NULL),
360 _next_dirty_cards_region(NULL),
361 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
362 _rem_set(NULL), _zfs(NotZeroFilled)
363 {
364 _orig_end = mr.end();
365 // Note that initialize() will set the start of the unmarked area of the
366 // region.
367 this->initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
368 set_top(bottom());
369 set_saved_mark();
371 _rem_set = new HeapRegionRemSet(sharedOffsetArray, this);
373 assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant.");
374 // In case the region is allocated during a pause, note the top.
375 // We haven't done any counting on a brand new region.
376 _top_at_conc_mark_count = bottom();
377 }
379 class NextCompactionHeapRegionClosure: public HeapRegionClosure {
380 const HeapRegion* _target;
381 bool _target_seen;
382 HeapRegion* _last;
383 CompactibleSpace* _res;
384 public:
385 NextCompactionHeapRegionClosure(const HeapRegion* target) :
386 _target(target), _target_seen(false), _res(NULL) {}
387 bool doHeapRegion(HeapRegion* cur) {
388 if (_target_seen) {
389 if (!cur->isHumongous()) {
390 _res = cur;
391 return true;
392 }
393 } else if (cur == _target) {
394 _target_seen = true;
395 }
396 return false;
397 }
398 CompactibleSpace* result() { return _res; }
399 };
401 CompactibleSpace* HeapRegion::next_compaction_space() const {
402 G1CollectedHeap* g1h = G1CollectedHeap::heap();
403 // cast away const-ness
404 HeapRegion* r = (HeapRegion*) this;
405 NextCompactionHeapRegionClosure blk(r);
406 g1h->heap_region_iterate_from(r, &blk);
407 return blk.result();
408 }
410 void HeapRegion::set_continuesHumongous(HeapRegion* start) {
411 // The order is important here.
412 start->add_continuingHumongousRegion(this);
413 _humongous_type = ContinuesHumongous;
414 _humongous_start_region = start;
415 }
417 void HeapRegion::add_continuingHumongousRegion(HeapRegion* cont) {
418 // Must join the blocks of the current H region seq with the block of the
419 // added region.
420 offsets()->join_blocks(bottom(), cont->bottom());
421 arrayOop obj = (arrayOop)(bottom());
422 obj->set_length((int) (obj->length() + cont->capacity()/jintSize));
423 set_end(cont->end());
424 set_top(cont->end());
425 }
427 void HeapRegion::save_marks() {
428 set_saved_mark();
429 }
431 void HeapRegion::oops_in_mr_iterate(MemRegion mr, OopClosure* cl) {
432 HeapWord* p = mr.start();
433 HeapWord* e = mr.end();
434 oop obj;
435 while (p < e) {
436 obj = oop(p);
437 p += obj->oop_iterate(cl);
438 }
439 assert(p == e, "bad memregion: doesn't end on obj boundary");
440 }
442 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
443 void HeapRegion::oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \
444 ContiguousSpace::oop_since_save_marks_iterate##nv_suffix(cl); \
445 }
446 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DEFN)
449 void HeapRegion::oop_before_save_marks_iterate(OopClosure* cl) {
450 oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
451 }
453 #ifdef DEBUG
454 HeapWord* HeapRegion::allocate(size_t size) {
455 jint state = zero_fill_state();
456 assert(!G1CollectedHeap::heap()->allocs_are_zero_filled() ||
457 zero_fill_is_allocated(),
458 "When ZF is on, only alloc in ZF'd regions");
459 return G1OffsetTableContigSpace::allocate(size);
460 }
461 #endif
463 void HeapRegion::set_zero_fill_state_work(ZeroFillState zfs) {
464 assert(top() == bottom() || zfs == Allocated,
465 "Region must be empty, or we must be setting it to allocated.");
466 assert(ZF_mon->owned_by_self() ||
467 Universe::heap()->is_gc_active(),
468 "Must hold the lock or be a full GC to modify.");
469 _zfs = zfs;
470 }
472 void HeapRegion::set_zero_fill_complete() {
473 set_zero_fill_state_work(ZeroFilled);
474 if (ZF_mon->owned_by_self()) {
475 ZF_mon->notify_all();
476 }
477 }
480 void HeapRegion::ensure_zero_filled() {
481 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
482 ensure_zero_filled_locked();
483 }
485 void HeapRegion::ensure_zero_filled_locked() {
486 assert(ZF_mon->owned_by_self(), "Precondition");
487 bool should_ignore_zf = SafepointSynchronize::is_at_safepoint();
488 assert(should_ignore_zf || Heap_lock->is_locked(),
489 "Either we're in a GC or we're allocating a region.");
490 switch (zero_fill_state()) {
491 case HeapRegion::NotZeroFilled:
492 set_zero_fill_in_progress(Thread::current());
493 {
494 ZF_mon->unlock();
495 Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
496 ZF_mon->lock_without_safepoint_check();
497 }
498 // A trap.
499 guarantee(zero_fill_state() == HeapRegion::ZeroFilling
500 && zero_filler() == Thread::current(),
501 "AHA! Tell Dave D if you see this...");
502 set_zero_fill_complete();
503 // gclog_or_tty->print_cr("Did sync ZF.");
504 ConcurrentZFThread::note_sync_zfs();
505 break;
506 case HeapRegion::ZeroFilling:
507 if (should_ignore_zf) {
508 // We can "break" the lock and take over the work.
509 Copy::fill_to_words(bottom(), capacity()/HeapWordSize);
510 set_zero_fill_complete();
511 ConcurrentZFThread::note_sync_zfs();
512 break;
513 } else {
514 ConcurrentZFThread::wait_for_ZF_completed(this);
515 }
516 case HeapRegion::ZeroFilled:
517 // Nothing to do.
518 break;
519 case HeapRegion::Allocated:
520 guarantee(false, "Should not call on allocated regions.");
521 }
522 assert(zero_fill_state() == HeapRegion::ZeroFilled, "Post");
523 }
525 HeapWord*
526 HeapRegion::object_iterate_mem_careful(MemRegion mr,
527 ObjectClosure* cl) {
528 G1CollectedHeap* g1h = G1CollectedHeap::heap();
529 // We used to use "block_start_careful" here. But we're actually happy
530 // to update the BOT while we do this...
531 HeapWord* cur = block_start(mr.start());
532 mr = mr.intersection(used_region());
533 if (mr.is_empty()) return NULL;
534 // Otherwise, find the obj that extends onto mr.start().
536 assert(cur <= mr.start()
537 && (oop(cur)->klass_or_null() == NULL ||
538 cur + oop(cur)->size() > mr.start()),
539 "postcondition of block_start");
540 oop obj;
541 while (cur < mr.end()) {
542 obj = oop(cur);
543 if (obj->klass_or_null() == NULL) {
544 // Ran into an unparseable point.
545 return cur;
546 } else if (!g1h->is_obj_dead(obj)) {
547 cl->do_object(obj);
548 }
549 if (cl->abort()) return cur;
550 // The check above must occur before the operation below, since an
551 // abort might invalidate the "size" operation.
552 cur += obj->size();
553 }
554 return NULL;
555 }
557 HeapWord*
558 HeapRegion::
559 oops_on_card_seq_iterate_careful(MemRegion mr,
560 FilterOutOfRegionClosure* cl) {
561 G1CollectedHeap* g1h = G1CollectedHeap::heap();
563 // If we're within a stop-world GC, then we might look at a card in a
564 // GC alloc region that extends onto a GC LAB, which may not be
565 // parseable. Stop such at the "saved_mark" of the region.
566 if (G1CollectedHeap::heap()->is_gc_active()) {
567 mr = mr.intersection(used_region_at_save_marks());
568 } else {
569 mr = mr.intersection(used_region());
570 }
571 if (mr.is_empty()) return NULL;
572 // Otherwise, find the obj that extends onto mr.start().
574 // We used to use "block_start_careful" here. But we're actually happy
575 // to update the BOT while we do this...
576 HeapWord* cur = block_start(mr.start());
577 assert(cur <= mr.start(), "Postcondition");
579 while (cur <= mr.start()) {
580 if (oop(cur)->klass_or_null() == NULL) {
581 // Ran into an unparseable point.
582 return cur;
583 }
584 // Otherwise...
585 int sz = oop(cur)->size();
586 if (cur + sz > mr.start()) break;
587 // Otherwise, go on.
588 cur = cur + sz;
589 }
590 oop obj;
591 obj = oop(cur);
592 // If we finish this loop...
593 assert(cur <= mr.start()
594 && obj->klass_or_null() != NULL
595 && cur + obj->size() > mr.start(),
596 "Loop postcondition");
597 if (!g1h->is_obj_dead(obj)) {
598 obj->oop_iterate(cl, mr);
599 }
601 HeapWord* next;
602 while (cur < mr.end()) {
603 obj = oop(cur);
604 if (obj->klass_or_null() == NULL) {
605 // Ran into an unparseable point.
606 return cur;
607 };
608 // Otherwise:
609 next = (cur + obj->size());
610 if (!g1h->is_obj_dead(obj)) {
611 if (next < mr.end()) {
612 obj->oop_iterate(cl);
613 } else {
614 // this obj spans the boundary. If it's an array, stop at the
615 // boundary.
616 if (obj->is_objArray()) {
617 obj->oop_iterate(cl, mr);
618 } else {
619 obj->oop_iterate(cl);
620 }
621 }
622 }
623 cur = next;
624 }
625 return NULL;
626 }
628 void HeapRegion::print() const { print_on(gclog_or_tty); }
629 void HeapRegion::print_on(outputStream* st) const {
630 if (isHumongous()) {
631 if (startsHumongous())
632 st->print(" HS");
633 else
634 st->print(" HC");
635 } else {
636 st->print(" ");
637 }
638 if (in_collection_set())
639 st->print(" CS");
640 else if (is_gc_alloc_region())
641 st->print(" A ");
642 else
643 st->print(" ");
644 if (is_young())
645 st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
646 else
647 st->print(" ");
648 if (is_empty())
649 st->print(" F");
650 else
651 st->print(" ");
652 st->print(" %d", _gc_time_stamp);
653 G1OffsetTableContigSpace::print_on(st);
654 }
656 void HeapRegion::verify(bool allow_dirty) const {
657 verify(allow_dirty, /* use_prev_marking */ true);
658 }
660 #define OBJ_SAMPLE_INTERVAL 0
661 #define BLOCK_SAMPLE_INTERVAL 100
663 // This really ought to be commoned up into OffsetTableContigSpace somehow.
664 // We would need a mechanism to make that code skip dead objects.
666 void HeapRegion::verify(bool allow_dirty, bool use_prev_marking) const {
667 G1CollectedHeap* g1 = G1CollectedHeap::heap();
668 HeapWord* p = bottom();
669 HeapWord* prev_p = NULL;
670 int objs = 0;
671 int blocks = 0;
672 VerifyLiveClosure vl_cl(g1, use_prev_marking);
673 while (p < top()) {
674 size_t size = oop(p)->size();
675 if (blocks == BLOCK_SAMPLE_INTERVAL) {
676 guarantee(p == block_start_const(p + (size/2)),
677 "check offset computation");
678 blocks = 0;
679 } else {
680 blocks++;
681 }
682 if (objs == OBJ_SAMPLE_INTERVAL) {
683 oop obj = oop(p);
684 if (!g1->is_obj_dead_cond(obj, this, use_prev_marking)) {
685 obj->verify();
686 vl_cl.set_containing_obj(obj);
687 obj->oop_iterate(&vl_cl);
688 if (G1MaxVerifyFailures >= 0
689 && vl_cl.n_failures() >= G1MaxVerifyFailures) break;
690 }
691 objs = 0;
692 } else {
693 objs++;
694 }
695 prev_p = p;
696 p += size;
697 }
698 HeapWord* rend = end();
699 HeapWord* rtop = top();
700 if (rtop < rend) {
701 guarantee(block_start_const(rtop + (rend - rtop) / 2) == rtop,
702 "check offset computation");
703 }
704 if (vl_cl.failures()) {
705 gclog_or_tty->print_cr("Heap:");
706 G1CollectedHeap::heap()->print_on(gclog_or_tty, true /* extended */);
707 gclog_or_tty->print_cr("");
708 }
709 if (VerifyDuringGC &&
710 G1VerifyConcMarkPrintReachable &&
711 vl_cl.failures()) {
712 g1->concurrent_mark()->print_prev_bitmap_reachable();
713 }
714 guarantee(!vl_cl.failures(), "region verification failed");
715 guarantee(p == top(), "end of last object must match end of space");
716 }
718 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
719 // away eventually.
721 void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) {
722 // false ==> we'll do the clearing if there's clearing to be done.
723 ContiguousSpace::initialize(mr, false, mangle_space);
724 _offsets.zero_bottom_entry();
725 _offsets.initialize_threshold();
726 if (clear_space) clear(mangle_space);
727 }
729 void G1OffsetTableContigSpace::clear(bool mangle_space) {
730 ContiguousSpace::clear(mangle_space);
731 _offsets.zero_bottom_entry();
732 _offsets.initialize_threshold();
733 }
735 void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
736 Space::set_bottom(new_bottom);
737 _offsets.set_bottom(new_bottom);
738 }
740 void G1OffsetTableContigSpace::set_end(HeapWord* new_end) {
741 Space::set_end(new_end);
742 _offsets.resize(new_end - bottom());
743 }
745 void G1OffsetTableContigSpace::print() const {
746 print_short();
747 gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
748 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
749 bottom(), top(), _offsets.threshold(), end());
750 }
752 HeapWord* G1OffsetTableContigSpace::initialize_threshold() {
753 return _offsets.initialize_threshold();
754 }
756 HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start,
757 HeapWord* end) {
758 _offsets.alloc_block(start, end);
759 return _offsets.threshold();
760 }
762 HeapWord* G1OffsetTableContigSpace::saved_mark_word() const {
763 G1CollectedHeap* g1h = G1CollectedHeap::heap();
764 assert( _gc_time_stamp <= g1h->get_gc_time_stamp(), "invariant" );
765 if (_gc_time_stamp < g1h->get_gc_time_stamp())
766 return top();
767 else
768 return ContiguousSpace::saved_mark_word();
769 }
771 void G1OffsetTableContigSpace::set_saved_mark() {
772 G1CollectedHeap* g1h = G1CollectedHeap::heap();
773 unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp();
775 if (_gc_time_stamp < curr_gc_time_stamp) {
776 // The order of these is important, as another thread might be
777 // about to start scanning this region. If it does so after
778 // set_saved_mark and before _gc_time_stamp = ..., then the latter
779 // will be false, and it will pick up top() as the high water mark
780 // of region. If it does so after _gc_time_stamp = ..., then it
781 // will pick up the right saved_mark_word() as the high water mark
782 // of the region. Either way, the behaviour will be correct.
783 ContiguousSpace::set_saved_mark();
784 OrderAccess::storestore();
785 _gc_time_stamp = curr_gc_time_stamp;
786 // The following fence is to force a flush of the writes above, but
787 // is strictly not needed because when an allocating worker thread
788 // calls set_saved_mark() it does so under the ParGCRareEvent_lock;
789 // when the lock is released, the write will be flushed.
790 // OrderAccess::fence();
791 }
792 }
794 G1OffsetTableContigSpace::
795 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
796 MemRegion mr, bool is_zeroed) :
797 _offsets(sharedOffsetArray, mr),
798 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true),
799 _gc_time_stamp(0)
800 {
801 _offsets.set_space(this);
802 initialize(mr, !is_zeroed, SpaceDecorator::Mangle);
803 }
805 size_t RegionList::length() {
806 size_t len = 0;
807 HeapRegion* cur = hd();
808 DEBUG_ONLY(HeapRegion* last = NULL);
809 while (cur != NULL) {
810 len++;
811 DEBUG_ONLY(last = cur);
812 cur = get_next(cur);
813 }
814 assert(last == tl(), "Invariant");
815 return len;
816 }
818 void RegionList::insert_before_head(HeapRegion* r) {
819 assert(well_formed(), "Inv");
820 set_next(r, hd());
821 _hd = r;
822 _sz++;
823 if (tl() == NULL) _tl = r;
824 assert(well_formed(), "Inv");
825 }
827 void RegionList::prepend_list(RegionList* new_list) {
828 assert(well_formed(), "Precondition");
829 assert(new_list->well_formed(), "Precondition");
830 HeapRegion* new_tl = new_list->tl();
831 if (new_tl != NULL) {
832 set_next(new_tl, hd());
833 _hd = new_list->hd();
834 _sz += new_list->sz();
835 if (tl() == NULL) _tl = new_list->tl();
836 } else {
837 assert(new_list->hd() == NULL && new_list->sz() == 0, "Inv");
838 }
839 assert(well_formed(), "Inv");
840 }
842 void RegionList::delete_after(HeapRegion* r) {
843 assert(well_formed(), "Precondition");
844 HeapRegion* next = get_next(r);
845 assert(r != NULL, "Precondition");
846 HeapRegion* next_tl = get_next(next);
847 set_next(r, next_tl);
848 dec_sz();
849 if (next == tl()) {
850 assert(next_tl == NULL, "Inv");
851 _tl = r;
852 }
853 assert(well_formed(), "Inv");
854 }
856 HeapRegion* RegionList::pop() {
857 assert(well_formed(), "Inv");
858 HeapRegion* res = hd();
859 if (res != NULL) {
860 _hd = get_next(res);
861 _sz--;
862 set_next(res, NULL);
863 if (sz() == 0) _tl = NULL;
864 }
865 assert(well_formed(), "Inv");
866 return res;
867 }