1 /*
2 * Copyright (c) 2001, 2019, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "code/nmethod.hpp"
27 #include "gc/g1/g1BlockOffsetTable.inline.hpp"
28 #include "gc/g1/g1CollectedHeap.inline.hpp"
29 #include "gc/g1/g1CollectionSet.hpp"
30 #include "gc/g1/g1HeapRegionTraceType.hpp"
31 #include "gc/g1/g1NUMA.hpp"
32 #include "gc/g1/g1OopClosures.inline.hpp"
33 #include "gc/g1/heapRegion.inline.hpp"
34 #include "gc/g1/heapRegionBounds.inline.hpp"
35 #include "gc/g1/heapRegionManager.inline.hpp"
36 #include "gc/g1/heapRegionRemSet.hpp"
37 #include "gc/g1/heapRegionTracer.hpp"
38 #include "gc/shared/genOopClosures.inline.hpp"
39 #include "logging/log.hpp"
40 #include "logging/logStream.hpp"
41 #include "memory/iterator.inline.hpp"
42 #include "memory/resourceArea.hpp"
43 #include "oops/access.inline.hpp"
44 #include "oops/compressedOops.inline.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "runtime/atomic.hpp"
47 #include "runtime/orderAccess.hpp"
48
49 int HeapRegion::LogOfHRGrainBytes = 0;
50 int HeapRegion::LogOfHRGrainWords = 0;
51 int HeapRegion::LogCardsPerRegion = 0;
52 size_t HeapRegion::GrainBytes = 0;
53 size_t HeapRegion::GrainWords = 0;
54 size_t HeapRegion::CardsPerRegion = 0;
55
56 size_t HeapRegion::max_region_size() {
57 return HeapRegionBounds::max_size();
58 }
59
60 size_t HeapRegion::min_region_size_in_words() {
61 return HeapRegionBounds::min_size() >> LogHeapWordSize;
62 }
63
64 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
65 size_t region_size = G1HeapRegionSize;
66 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
67 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2;
68 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(),
69 HeapRegionBounds::min_size());
70 }
71
72 int region_size_log = log2_long((jlong) region_size);
73 // Recalculate the region size to make sure it's a power of
74 // 2. This means that region_size is the largest power of 2 that's
75 // <= what we've calculated so far.
76 region_size = ((size_t)1 << region_size_log);
77
78 // Now make sure that we don't go over or under our limits.
79 if (region_size < HeapRegionBounds::min_size()) {
80 region_size = HeapRegionBounds::min_size();
81 } else if (region_size > HeapRegionBounds::max_size()) {
82 region_size = HeapRegionBounds::max_size();
83 }
84
85 // And recalculate the log.
86 region_size_log = log2_long((jlong) region_size);
87
88 // Now, set up the globals.
89 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
90 LogOfHRGrainBytes = region_size_log;
91
92 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
93 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
94
95 guarantee(GrainBytes == 0, "we should only set it once");
96 // The cast to int is safe, given that we've bounded region_size by
97 // MIN_REGION_SIZE and MAX_REGION_SIZE.
98 GrainBytes = region_size;
99 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M);
100
101 guarantee(GrainWords == 0, "we should only set it once");
102 GrainWords = GrainBytes >> LogHeapWordSize;
103 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
104
105 guarantee(CardsPerRegion == 0, "we should only set it once");
106 CardsPerRegion = GrainBytes >> G1CardTable::card_shift;
107
108 LogCardsPerRegion = log2_long((jlong) CardsPerRegion);
109
110 if (G1HeapRegionSize != GrainBytes) {
111 FLAG_SET_ERGO(G1HeapRegionSize, GrainBytes);
112 }
113 }
114
115 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) {
116 assert(_humongous_start_region == NULL,
117 "we should have already filtered out humongous regions");
118 assert(!in_collection_set(),
119 "Should not clear heap region %u in the collection set", hrm_index());
120
121 clear_young_index_in_cset();
122 clear_index_in_opt_cset();
123 uninstall_surv_rate_group();
124 set_free();
125 reset_pre_dummy_top();
126
127 if (!keep_remset) {
128 if (locked) {
129 rem_set()->clear_locked();
130 } else {
131 rem_set()->clear();
132 }
133 }
134
135 zero_marked_bytes();
136
137 init_top_at_mark_start();
138 if (clear_space) clear(SpaceDecorator::Mangle);
139
140 _evacuation_failed = false;
141 _gc_efficiency = 0.0;
142 }
143
144 void HeapRegion::clear_cardtable() {
145 G1CardTable* ct = G1CollectedHeap::heap()->card_table();
146 ct->clear(MemRegion(bottom(), end()));
147 }
148
149 void HeapRegion::calc_gc_efficiency() {
150 // GC efficiency is the ratio of how much space would be
151 // reclaimed over how long we predict it would take to reclaim it.
152 G1Policy* policy = G1CollectedHeap::heap()->policy();
153
154 // Retrieve a prediction of the elapsed time for this region for
155 // a mixed gc because the region will only be evacuated during a
156 // mixed gc.
157 double region_elapsed_time_ms = policy->predict_region_total_time_ms(this, false /* for_young_gc */);
158 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
159 }
160
161 void HeapRegion::set_free() {
162 report_region_type_change(G1HeapRegionTraceType::Free);
163 _type.set_free();
164 }
165
166 void HeapRegion::set_eden() {
167 report_region_type_change(G1HeapRegionTraceType::Eden);
168 _type.set_eden();
169 }
170
171 void HeapRegion::set_eden_pre_gc() {
172 report_region_type_change(G1HeapRegionTraceType::Eden);
173 _type.set_eden_pre_gc();
174 }
175
176 void HeapRegion::set_survivor() {
177 report_region_type_change(G1HeapRegionTraceType::Survivor);
178 _type.set_survivor();
179 }
180
181 void HeapRegion::move_to_old() {
182 if (_type.relabel_as_old()) {
183 report_region_type_change(G1HeapRegionTraceType::Old);
184 }
185 }
186
187 void HeapRegion::set_old() {
188 report_region_type_change(G1HeapRegionTraceType::Old);
189 _type.set_old();
190 }
191
192 void HeapRegion::set_open_archive() {
193 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
194 _type.set_open_archive();
195 }
196
197 void HeapRegion::set_closed_archive() {
198 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
199 _type.set_closed_archive();
200 }
201
202 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
203 assert(!is_humongous(), "sanity / pre-condition");
204 assert(top() == bottom(), "should be empty");
205
206 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
207 _type.set_starts_humongous();
208 _humongous_start_region = this;
209
210 _bot_part.set_for_starts_humongous(obj_top, fill_size);
211 }
212
213 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
214 assert(!is_humongous(), "sanity / pre-condition");
215 assert(top() == bottom(), "should be empty");
216 assert(first_hr->is_starts_humongous(), "pre-condition");
217
218 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
219 _type.set_continues_humongous();
220 _humongous_start_region = first_hr;
221
222 _bot_part.set_object_can_span(true);
223 }
224
225 void HeapRegion::clear_humongous() {
226 assert(is_humongous(), "pre-condition");
227
228 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
229 _humongous_start_region = NULL;
230
231 _bot_part.set_object_can_span(false);
232 }
233
234 HeapRegion::HeapRegion(uint hrm_index,
235 G1BlockOffsetTable* bot,
236 MemRegion mr) :
237 _bottom(mr.start()),
238 _end(mr.end()),
239 _top(NULL),
240 _compaction_top(NULL),
241 _bot_part(bot, this),
242 _par_alloc_lock(Mutex::leaf, "HeapRegion par alloc lock", true),
243 _pre_dummy_top(NULL),
244 _rem_set(NULL),
245 _hrm_index(hrm_index),
246 _type(),
247 _humongous_start_region(NULL),
248 _evacuation_failed(false),
249 _index_in_opt_cset(InvalidCSetIndex),
250 _next(NULL), _prev(NULL),
251 #ifdef ASSERT
252 _containing_set(NULL),
253 #endif
254 _prev_top_at_mark_start(NULL), _next_top_at_mark_start(NULL),
255 _prev_marked_bytes(0), _next_marked_bytes(0),
256 _young_index_in_cset(-1),
257 _surv_rate_group(NULL), _age_index(SurvRateGroup::InvalidAgeIndex), _gc_efficiency(0.0),
258 _node_index(G1NUMA::UnknownNodeIndex)
259 {
260 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
261 "invalid space boundaries");
262
263 _rem_set = new HeapRegionRemSet(bot, this);
264 initialize();
265 }
266
267 void HeapRegion::initialize(bool clear_space, bool mangle_space) {
268 assert(_rem_set->is_empty(), "Remembered set must be empty");
269
270 if (clear_space) {
271 clear(mangle_space);
272 }
273
274 set_top(bottom());
275 set_compaction_top(bottom());
276 reset_bot();
277
278 hr_clear(false /*par*/, false /*clear_space*/);
279 }
280
281 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
282 HeapRegionTracer::send_region_type_change(_hrm_index,
283 get_trace_type(),
284 to,
285 (uintptr_t)bottom(),
286 used());
287 }
288
289 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
290 bool during_conc_mark) {
291 // We always recreate the prev marking info and we'll explicitly
292 // mark all objects we find to be self-forwarded on the prev
293 // bitmap. So all objects need to be below PTAMS.
294 _prev_marked_bytes = 0;
295
296 if (during_initial_mark) {
297 // During initial-mark, we'll also explicitly mark all objects
298 // we find to be self-forwarded on the next bitmap. So all
299 // objects need to be below NTAMS.
300 _next_top_at_mark_start = top();
301 _next_marked_bytes = 0;
302 } else if (during_conc_mark) {
303 // During concurrent mark, all objects in the CSet (including
304 // the ones we find to be self-forwarded) are implicitly live.
305 // So all objects need to be above NTAMS.
306 _next_top_at_mark_start = bottom();
307 _next_marked_bytes = 0;
308 }
309 }
310
311 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
312 assert(marked_bytes <= used(),
313 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
314 _prev_top_at_mark_start = top();
315 _prev_marked_bytes = marked_bytes;
316 }
317
318 // Code roots support
319
320 void HeapRegion::add_strong_code_root(nmethod* nm) {
321 HeapRegionRemSet* hrrs = rem_set();
322 hrrs->add_strong_code_root(nm);
323 }
324
325 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
326 assert_locked_or_safepoint(CodeCache_lock);
327 HeapRegionRemSet* hrrs = rem_set();
328 hrrs->add_strong_code_root_locked(nm);
329 }
330
331 void HeapRegion::remove_strong_code_root(nmethod* nm) {
332 HeapRegionRemSet* hrrs = rem_set();
333 hrrs->remove_strong_code_root(nm);
334 }
335
336 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
337 HeapRegionRemSet* hrrs = rem_set();
338 hrrs->strong_code_roots_do(blk);
339 }
340
341 class VerifyStrongCodeRootOopClosure: public OopClosure {
342 const HeapRegion* _hr;
343 bool _failures;
344 bool _has_oops_in_region;
345
346 template <class T> void do_oop_work(T* p) {
347 T heap_oop = RawAccess<>::oop_load(p);
348 if (!CompressedOops::is_null(heap_oop)) {
349 oop obj = CompressedOops::decode_not_null(heap_oop);
350
351 // Note: not all the oops embedded in the nmethod are in the
352 // current region. We only look at those which are.
353 if (_hr->is_in(obj)) {
354 // Object is in the region. Check that its less than top
355 if (_hr->top() <= (HeapWord*)obj) {
356 // Object is above top
357 log_error(gc, verify)("Object " PTR_FORMAT " in region " HR_FORMAT " is above top ",
358 p2i(obj), HR_FORMAT_PARAMS(_hr));
359 _failures = true;
360 return;
361 }
362 // Nmethod has at least one oop in the current region
363 _has_oops_in_region = true;
364 }
365 }
366 }
367
368 public:
369 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
370 _hr(hr), _failures(false), _has_oops_in_region(false) {}
371
372 void do_oop(narrowOop* p) { do_oop_work(p); }
373 void do_oop(oop* p) { do_oop_work(p); }
374
375 bool failures() { return _failures; }
376 bool has_oops_in_region() { return _has_oops_in_region; }
377 };
378
379 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
380 const HeapRegion* _hr;
381 bool _failures;
382 public:
383 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
384 _hr(hr), _failures(false) {}
385
386 void do_code_blob(CodeBlob* cb) {
387 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
388 if (nm != NULL) {
389 // Verify that the nemthod is live
390 if (!nm->is_alive()) {
391 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
392 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
393 _failures = true;
394 } else {
395 VerifyStrongCodeRootOopClosure oop_cl(_hr);
396 nm->oops_do(&oop_cl);
397 if (!oop_cl.has_oops_in_region()) {
398 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
399 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
400 _failures = true;
401 } else if (oop_cl.failures()) {
402 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
403 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
404 _failures = true;
405 }
406 }
407 }
408 }
409
410 bool failures() { return _failures; }
411 };
412
413 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
414 if (!G1VerifyHeapRegionCodeRoots) {
415 // We're not verifying code roots.
416 return;
417 }
418 if (vo == VerifyOption_G1UseFullMarking) {
419 // Marking verification during a full GC is performed after class
420 // unloading, code cache unloading, etc so the strong code roots
421 // attached to each heap region are in an inconsistent state. They won't
422 // be consistent until the strong code roots are rebuilt after the
423 // actual GC. Skip verifying the strong code roots in this particular
424 // time.
425 assert(VerifyDuringGC, "only way to get here");
426 return;
427 }
428
429 HeapRegionRemSet* hrrs = rem_set();
430 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
431
432 // if this region is empty then there should be no entries
433 // on its strong code root list
434 if (is_empty()) {
435 if (strong_code_roots_length > 0) {
436 log_error(gc, verify)("region " HR_FORMAT " is empty but has " SIZE_FORMAT " code root entries",
437 HR_FORMAT_PARAMS(this), strong_code_roots_length);
438 *failures = true;
439 }
440 return;
441 }
442
443 if (is_continues_humongous()) {
444 if (strong_code_roots_length > 0) {
445 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
446 HR_FORMAT_PARAMS(this), strong_code_roots_length);
447 *failures = true;
448 }
449 return;
450 }
451
452 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
453 strong_code_roots_do(&cb_cl);
454
455 if (cb_cl.failures()) {
456 *failures = true;
457 }
458 }
459
460 void HeapRegion::print() const { print_on(tty); }
461
462 void HeapRegion::print_on(outputStream* st) const {
463 st->print("|%4u", this->_hrm_index);
464 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
465 p2i(bottom()), p2i(top()), p2i(end()));
466 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
467 st->print("|%2s", get_short_type_str());
468 if (in_collection_set()) {
469 st->print("|CS");
470 } else {
471 st->print("| ");
472 }
473 st->print("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ",
474 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str());
475 if (UseNUMA) {
476 G1NUMA* numa = G1NUMA::numa();
477 if (node_index() < numa->num_active_nodes()) {
478 st->print("|%d", numa->numa_id(node_index()));
479 } else {
480 st->print("|-");
481 }
482 }
483 st->print_cr("");
484 }
485
486 class G1VerificationClosure : public BasicOopIterateClosure {
487 protected:
488 G1CollectedHeap* _g1h;
489 G1CardTable *_ct;
490 oop _containing_obj;
491 bool _failures;
492 int _n_failures;
493 VerifyOption _vo;
494 public:
495 // _vo == UsePrevMarking -> use "prev" marking information,
496 // _vo == UseNextMarking -> use "next" marking information,
497 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
498 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
499 _g1h(g1h), _ct(g1h->card_table()),
500 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
501 }
502
503 void set_containing_obj(oop obj) {
504 _containing_obj = obj;
505 }
506
507 bool failures() { return _failures; }
508 int n_failures() { return _n_failures; }
509
510 void print_object(outputStream* out, oop obj) {
511 #ifdef PRODUCT
512 Klass* k = obj->klass();
513 const char* class_name = k->external_name();
514 out->print_cr("class name %s", class_name);
515 #else // PRODUCT
516 obj->print_on(out);
517 #endif // PRODUCT
518 }
519
520 // This closure provides its own oop verification code.
521 debug_only(virtual bool should_verify_oops() { return false; })
522 };
523
524 class VerifyLiveClosure : public G1VerificationClosure {
525 public:
526 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
527 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
528 virtual void do_oop(oop* p) { do_oop_work(p); }
529
530 template <class T>
531 void do_oop_work(T* p) {
532 assert(_containing_obj != NULL, "Precondition");
533 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
534 "Precondition");
535 verify_liveness(p);
536 }
537
538 template <class T>
539 void verify_liveness(T* p) {
540 T heap_oop = RawAccess<>::oop_load(p);
541 Log(gc, verify) log;
542 if (!CompressedOops::is_null(heap_oop)) {
543 oop obj = CompressedOops::decode_not_null(heap_oop);
544 bool failed = false;
545 if (!_g1h->is_in(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
546 MutexLocker x(ParGCRareEvent_lock,
547 Mutex::_no_safepoint_check_flag);
548
549 if (!_failures) {
550 log.error("----------");
551 }
552 ResourceMark rm;
553 if (!_g1h->is_in(obj)) {
554 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
555 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
556 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
557 LogStream ls(log.error());
558 print_object(&ls, _containing_obj);
559 HeapRegion* const to = _g1h->heap_region_containing(obj);
560 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
561 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
562 } else {
563 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
564 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
565 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
566 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
567 LogStream ls(log.error());
568 print_object(&ls, _containing_obj);
569 log.error("points to dead obj " PTR_FORMAT " in region " HR_FORMAT,
570 p2i(obj), HR_FORMAT_PARAMS(to));
571 print_object(&ls, obj);
572 }
573 log.error("----------");
574 _failures = true;
575 failed = true;
576 _n_failures++;
577 }
578 }
579 }
580 };
581
582 class VerifyRemSetClosure : public G1VerificationClosure {
583 public:
584 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
585 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
586 virtual void do_oop(oop* p) { do_oop_work(p); }
587
588 template <class T>
589 void do_oop_work(T* p) {
590 assert(_containing_obj != NULL, "Precondition");
591 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
592 "Precondition");
593 verify_remembered_set(p);
594 }
595
596 template <class T>
597 void verify_remembered_set(T* p) {
598 T heap_oop = RawAccess<>::oop_load(p);
599 Log(gc, verify) log;
600 if (!CompressedOops::is_null(heap_oop)) {
601 oop obj = CompressedOops::decode_not_null(heap_oop);
602 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
603 HeapRegion* to = _g1h->heap_region_containing(obj);
604 if (from != NULL && to != NULL &&
605 from != to &&
606 !to->is_pinned() &&
607 to->rem_set()->is_complete()) {
608 jbyte cv_obj = *_ct->byte_for_const(_containing_obj);
609 jbyte cv_field = *_ct->byte_for_const(p);
610 const jbyte dirty = G1CardTable::dirty_card_val();
611
612 bool is_bad = !(from->is_young()
613 || to->rem_set()->contains_reference(p)
614 || (_containing_obj->is_objArray() ?
615 cv_field == dirty :
616 cv_obj == dirty || cv_field == dirty));
617 if (is_bad) {
618 MutexLocker x(ParGCRareEvent_lock,
619 Mutex::_no_safepoint_check_flag);
620
621 if (!_failures) {
622 log.error("----------");
623 }
624 log.error("Missing rem set entry:");
625 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT,
626 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
627 ResourceMark rm;
628 LogStream ls(log.error());
629 _containing_obj->print_on(&ls);
630 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
631 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
632 if (oopDesc::is_oop(obj)) {
633 obj->print_on(&ls);
634 }
635 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
636 log.error("----------");
637 _failures = true;
638 _n_failures++;
639 }
640 }
641 }
642 }
643 };
644
645 // Closure that applies the given two closures in sequence.
646 class G1Mux2Closure : public BasicOopIterateClosure {
647 OopClosure* _c1;
648 OopClosure* _c2;
649 public:
650 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
651 template <class T> inline void do_oop_work(T* p) {
652 // Apply first closure; then apply the second.
653 _c1->do_oop(p);
654 _c2->do_oop(p);
655 }
656 virtual inline void do_oop(oop* p) { do_oop_work(p); }
657 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
658
659 // This closure provides its own oop verification code.
660 debug_only(virtual bool should_verify_oops() { return false; })
661 };
662
663 void HeapRegion::verify(VerifyOption vo,
664 bool* failures) const {
665 G1CollectedHeap* g1h = G1CollectedHeap::heap();
666 *failures = false;
667 HeapWord* p = bottom();
668 HeapWord* prev_p = NULL;
669 VerifyLiveClosure vl_cl(g1h, vo);
670 VerifyRemSetClosure vr_cl(g1h, vo);
671 bool is_region_humongous = is_humongous();
672 size_t object_num = 0;
673 while (p < top()) {
674 oop obj = oop(p);
675 size_t obj_size = block_size(p);
676 object_num += 1;
677
678 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
679 if (oopDesc::is_oop(obj)) {
680 Klass* klass = obj->klass();
681 bool is_metaspace_object = Metaspace::contains(klass);
682 if (!is_metaspace_object) {
683 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
684 "not metadata", p2i(klass), p2i(obj));
685 *failures = true;
686 return;
687 } else if (!klass->is_klass()) {
688 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
689 "not a klass", p2i(klass), p2i(obj));
690 *failures = true;
691 return;
692 } else {
693 vl_cl.set_containing_obj(obj);
694 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) {
695 // verify liveness and rem_set
696 vr_cl.set_containing_obj(obj);
697 G1Mux2Closure mux(&vl_cl, &vr_cl);
698 obj->oop_iterate(&mux);
699
700 if (vr_cl.failures()) {
701 *failures = true;
702 }
703 if (G1MaxVerifyFailures >= 0 &&
704 vr_cl.n_failures() >= G1MaxVerifyFailures) {
705 return;
706 }
707 } else {
708 // verify only liveness
709 obj->oop_iterate(&vl_cl);
710 }
711 if (vl_cl.failures()) {
712 *failures = true;
713 }
714 if (G1MaxVerifyFailures >= 0 &&
715 vl_cl.n_failures() >= G1MaxVerifyFailures) {
716 return;
717 }
718 }
719 } else {
720 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
721 *failures = true;
722 return;
723 }
724 }
725 prev_p = p;
726 p += obj_size;
727 }
728
729 if (!is_young() && !is_empty()) {
730 _bot_part.verify();
731 }
732
733 if (is_region_humongous) {
734 oop obj = oop(this->humongous_start_region()->bottom());
735 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) {
736 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
737 *failures = true;
738 return;
739 }
740 }
741
742 if (!is_region_humongous && p != top()) {
743 log_error(gc, verify)("end of last object " PTR_FORMAT " "
744 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
745 *failures = true;
746 return;
747 }
748
749 HeapWord* the_end = end();
750 // Do some extra BOT consistency checking for addresses in the
751 // range [top, end). BOT look-ups in this range should yield
752 // top. No point in doing that if top == end (there's nothing there).
753 if (p < the_end) {
754 // Look up top
755 HeapWord* addr_1 = p;
756 HeapWord* b_start_1 = block_start_const(addr_1);
757 if (b_start_1 != p) {
758 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
759 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
760 p2i(addr_1), p2i(b_start_1), p2i(p));
761 *failures = true;
762 return;
763 }
764
765 // Look up top + 1
766 HeapWord* addr_2 = p + 1;
767 if (addr_2 < the_end) {
768 HeapWord* b_start_2 = block_start_const(addr_2);
769 if (b_start_2 != p) {
770 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
771 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
772 p2i(addr_2), p2i(b_start_2), p2i(p));
773 *failures = true;
774 return;
775 }
776 }
777
778 // Look up an address between top and end
779 size_t diff = pointer_delta(the_end, p) / 2;
780 HeapWord* addr_3 = p + diff;
781 if (addr_3 < the_end) {
782 HeapWord* b_start_3 = block_start_const(addr_3);
783 if (b_start_3 != p) {
784 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
785 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
786 p2i(addr_3), p2i(b_start_3), p2i(p));
787 *failures = true;
788 return;
789 }
790 }
791
792 // Look up end - 1
793 HeapWord* addr_4 = the_end - 1;
794 HeapWord* b_start_4 = block_start_const(addr_4);
795 if (b_start_4 != p) {
796 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
797 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
798 p2i(addr_4), p2i(b_start_4), p2i(p));
799 *failures = true;
800 return;
801 }
802 }
803
804 verify_strong_code_roots(vo, failures);
805 }
806
807 void HeapRegion::verify() const {
808 bool dummy = false;
809 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
810 }
811
812 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
813 G1CollectedHeap* g1h = G1CollectedHeap::heap();
814 *failures = false;
815 HeapWord* p = bottom();
816 HeapWord* prev_p = NULL;
817 VerifyRemSetClosure vr_cl(g1h, vo);
818 while (p < top()) {
819 oop obj = oop(p);
820 size_t obj_size = block_size(p);
821
822 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
823 if (oopDesc::is_oop(obj)) {
824 vr_cl.set_containing_obj(obj);
825 obj->oop_iterate(&vr_cl);
826
827 if (vr_cl.failures()) {
828 *failures = true;
829 }
830 if (G1MaxVerifyFailures >= 0 &&
831 vr_cl.n_failures() >= G1MaxVerifyFailures) {
832 return;
833 }
834 } else {
835 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
836 *failures = true;
837 return;
838 }
839 }
840
841 prev_p = p;
842 p += obj_size;
843 }
844 }
845
846 void HeapRegion::verify_rem_set() const {
847 bool failures = false;
848 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
849 guarantee(!failures, "HeapRegion RemSet verification failed");
850 }
851
852 void HeapRegion::clear(bool mangle_space) {
853 set_top(bottom());
854 set_compaction_top(bottom());
855
856 if (ZapUnusedHeapArea && mangle_space) {
857 mangle_unused_area();
858 }
859 reset_bot();
860 }
861
862 #ifndef PRODUCT
863 void HeapRegion::mangle_unused_area() {
864 SpaceMangler::mangle_region(MemRegion(top(), end()));
865 }
866 #endif
867
868 HeapWord* HeapRegion::initialize_threshold() {
869 return _bot_part.initialize_threshold();
870 }
871
872 HeapWord* HeapRegion::cross_threshold(HeapWord* start, HeapWord* end) {
873 _bot_part.alloc_block(start, end);
874 return _bot_part.threshold();
875 }
876
877 void HeapRegion::object_iterate(ObjectClosure* blk) {
878 HeapWord* p = bottom();
879 while (p < top()) {
880 if (block_is_obj(p)) {
881 blk->do_object(oop(p));
882 }
883 p += block_size(p);
884 }
885 }