1 /*
2 * Copyright (c) 2001, 2020, 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 "utilities/powerOfTwo.hpp"
47
48 int HeapRegion::LogOfHRGrainBytes = 0;
49 int HeapRegion::LogOfHRGrainWords = 0;
50 int HeapRegion::LogCardsPerRegion = 0;
51 size_t HeapRegion::GrainBytes = 0;
52 size_t HeapRegion::GrainWords = 0;
53 size_t HeapRegion::CardsPerRegion = 0;
54
55 size_t HeapRegion::max_region_size() {
56 return HeapRegionBounds::max_size();
57 }
58
59 size_t HeapRegion::min_region_size_in_words() {
60 return HeapRegionBounds::min_size() >> LogHeapWordSize;
61 }
62
63 void HeapRegion::setup_heap_region_size(size_t max_heap_size) {
64 size_t region_size = G1HeapRegionSize;
65 // G1HeapRegionSize = 0 means decide ergonomically.
66 if (region_size == 0) {
67 region_size = MAX2(max_heap_size / HeapRegionBounds::target_number(),
68 HeapRegionBounds::min_size());
69 }
70
71 // Make sure region size is a power of 2. Rounding up since this
72 // is beneficial in most cases.
73 region_size = round_up_power_of_2(region_size);
74
75 // Now make sure that we don't go over or under our limits.
76 region_size = clamp(region_size, HeapRegionBounds::min_size(), HeapRegionBounds::max_size());
77
78 // Calculate the log for the region size.
79 int region_size_log = exact_log2_long((jlong)region_size);
80
81 // Now, set up the globals.
82 guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
83 LogOfHRGrainBytes = region_size_log;
84
85 guarantee(LogOfHRGrainWords == 0, "we should only set it once");
86 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
87
88 guarantee(GrainBytes == 0, "we should only set it once");
89 // The cast to int is safe, given that we've bounded region_size by
90 // MIN_REGION_SIZE and MAX_REGION_SIZE.
91 GrainBytes = region_size;
92
93 guarantee(GrainWords == 0, "we should only set it once");
94 GrainWords = GrainBytes >> LogHeapWordSize;
95 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
96
97 guarantee(CardsPerRegion == 0, "we should only set it once");
98 CardsPerRegion = GrainBytes >> G1CardTable::card_shift;
99
100 LogCardsPerRegion = log2_long((jlong) CardsPerRegion);
101
102 if (G1HeapRegionSize != GrainBytes) {
103 FLAG_SET_ERGO(G1HeapRegionSize, GrainBytes);
104 }
105 }
106
107 void HeapRegion::handle_evacuation_failure() {
108 uninstall_surv_rate_group();
109 clear_young_index_in_cset();
110 set_evacuation_failed(false);
111 set_old();
112 }
113
114 void HeapRegion::unlink_from_list() {
115 set_next(NULL);
116 set_prev(NULL);
117 set_containing_set(NULL);
118 }
119
120 void HeapRegion::hr_clear(bool clear_space) {
121 assert(_humongous_start_region == NULL,
122 "we should have already filtered out humongous regions");
123 assert(!in_collection_set(),
124 "Should not clear heap region %u in the collection set", hrm_index());
125
126 clear_young_index_in_cset();
127 clear_index_in_opt_cset();
128 uninstall_surv_rate_group();
129 set_free();
130 reset_pre_dummy_top();
131
132 rem_set()->clear_locked();
133
134 zero_marked_bytes();
135
136 init_top_at_mark_start();
137 if (clear_space) clear(SpaceDecorator::Mangle);
138
139 _evacuation_failed = false;
140 _gc_efficiency = 0.0;
141 }
142
143 void HeapRegion::clear_cardtable() {
144 G1CardTable* ct = G1CollectedHeap::heap()->card_table();
145 ct->clear(MemRegion(bottom(), end()));
146 }
147
148 void HeapRegion::calc_gc_efficiency() {
149 // GC efficiency is the ratio of how much space would be
150 // reclaimed over how long we predict it would take to reclaim it.
151 G1Policy* policy = G1CollectedHeap::heap()->policy();
152
153 // Retrieve a prediction of the elapsed time for this region for
154 // a mixed gc because the region will only be evacuated during a
155 // mixed gc.
156 double region_elapsed_time_ms = policy->predict_region_total_time_ms(this, false /* for_young_gc */);
157 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
158 }
159
160 void HeapRegion::set_free() {
161 report_region_type_change(G1HeapRegionTraceType::Free);
162 _type.set_free();
163 }
164
165 void HeapRegion::set_eden() {
166 report_region_type_change(G1HeapRegionTraceType::Eden);
167 _type.set_eden();
168 }
169
170 void HeapRegion::set_eden_pre_gc() {
171 report_region_type_change(G1HeapRegionTraceType::Eden);
172 _type.set_eden_pre_gc();
173 }
174
175 void HeapRegion::set_survivor() {
176 report_region_type_change(G1HeapRegionTraceType::Survivor);
177 _type.set_survivor();
178 }
179
180 void HeapRegion::move_to_old() {
181 if (_type.relabel_as_old()) {
182 report_region_type_change(G1HeapRegionTraceType::Old);
183 }
184 }
185
186 void HeapRegion::set_old() {
187 report_region_type_change(G1HeapRegionTraceType::Old);
188 _type.set_old();
189 }
190
191 void HeapRegion::set_open_archive() {
192 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
193 _type.set_open_archive();
194 }
195
196 void HeapRegion::set_closed_archive() {
197 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
198 _type.set_closed_archive();
199 }
200
201 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
202 assert(!is_humongous(), "sanity / pre-condition");
203 assert(top() == bottom(), "should be empty");
204
205 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
206 _type.set_starts_humongous();
207 _humongous_start_region = this;
208
209 _bot_part.set_for_starts_humongous(obj_top, fill_size);
210 }
211
212 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
213 assert(!is_humongous(), "sanity / pre-condition");
214 assert(top() == bottom(), "should be empty");
215 assert(first_hr->is_starts_humongous(), "pre-condition");
216
217 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
218 _type.set_continues_humongous();
219 _humongous_start_region = first_hr;
220
221 _bot_part.set_object_can_span(true);
222 }
223
224 void HeapRegion::clear_humongous() {
225 assert(is_humongous(), "pre-condition");
226
227 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
228 _humongous_start_region = NULL;
229
230 _bot_part.set_object_can_span(false);
231 }
232
233 HeapRegion::HeapRegion(uint hrm_index,
234 G1BlockOffsetTable* bot,
235 MemRegion mr) :
236 _bottom(mr.start()),
237 _end(mr.end()),
238 _top(NULL),
239 _compaction_top(NULL),
240 _bot_part(bot, this),
241 _par_alloc_lock(Mutex::leaf, "HeapRegion par alloc lock", true),
242 _pre_dummy_top(NULL),
243 _rem_set(NULL),
244 _hrm_index(hrm_index),
245 _type(),
246 _humongous_start_region(NULL),
247 _evacuation_failed(false),
248 _index_in_opt_cset(InvalidCSetIndex),
249 _next(NULL), _prev(NULL),
250 #ifdef ASSERT
251 _containing_set(NULL),
252 #endif
253 _prev_top_at_mark_start(NULL), _next_top_at_mark_start(NULL),
254 _prev_marked_bytes(0), _next_marked_bytes(0),
255 _young_index_in_cset(-1),
256 _surv_rate_group(NULL), _age_index(G1SurvRateGroup::InvalidAgeIndex), _gc_efficiency(0.0),
257 _node_index(G1NUMA::UnknownNodeIndex)
258 {
259 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
260 "invalid space boundaries");
261
262 _rem_set = new HeapRegionRemSet(bot, this);
263 initialize();
264 }
265
266 void HeapRegion::initialize(bool clear_space, bool mangle_space) {
267 assert(_rem_set->is_empty(), "Remembered set must be empty");
268
269 if (clear_space) {
270 clear(mangle_space);
271 }
272
273 set_top(bottom());
274 set_compaction_top(bottom());
275 reset_bot();
276
277 hr_clear(false /*clear_space*/);
278 }
279
280 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
281 HeapRegionTracer::send_region_type_change(_hrm_index,
282 get_trace_type(),
283 to,
284 (uintptr_t)bottom(),
285 used());
286 }
287
288 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
289 bool during_conc_mark) {
290 // We always recreate the prev marking info and we'll explicitly
291 // mark all objects we find to be self-forwarded on the prev
292 // bitmap. So all objects need to be below PTAMS.
293 _prev_marked_bytes = 0;
294
295 if (during_initial_mark) {
296 // During initial-mark, we'll also explicitly mark all objects
297 // we find to be self-forwarded on the next bitmap. So all
298 // objects need to be below NTAMS.
299 _next_top_at_mark_start = top();
300 _next_marked_bytes = 0;
301 } else if (during_conc_mark) {
302 // During concurrent mark, all objects in the CSet (including
303 // the ones we find to be self-forwarded) are implicitly live.
304 // So all objects need to be above NTAMS.
305 _next_top_at_mark_start = bottom();
306 _next_marked_bytes = 0;
307 }
308 }
309
310 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
311 assert(marked_bytes <= used(),
312 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
313 _prev_top_at_mark_start = top();
314 _prev_marked_bytes = marked_bytes;
315 }
316
317 // Code roots support
318
319 void HeapRegion::add_strong_code_root(nmethod* nm) {
320 HeapRegionRemSet* hrrs = rem_set();
321 hrrs->add_strong_code_root(nm);
322 }
323
324 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
325 assert_locked_or_safepoint(CodeCache_lock);
326 HeapRegionRemSet* hrrs = rem_set();
327 hrrs->add_strong_code_root_locked(nm);
328 }
329
330 void HeapRegion::remove_strong_code_root(nmethod* nm) {
331 HeapRegionRemSet* hrrs = rem_set();
332 hrrs->remove_strong_code_root(nm);
333 }
334
335 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
336 HeapRegionRemSet* hrrs = rem_set();
337 hrrs->strong_code_roots_do(blk);
338 }
339
340 class VerifyStrongCodeRootOopClosure: public OopClosure {
341 const HeapRegion* _hr;
342 bool _failures;
343 bool _has_oops_in_region;
344
345 template <class T> void do_oop_work(T* p) {
346 T heap_oop = RawAccess<>::oop_load(p);
347 if (!CompressedOops::is_null(heap_oop)) {
348 oop obj = CompressedOops::decode_not_null(heap_oop);
349
350 // Note: not all the oops embedded in the nmethod are in the
351 // current region. We only look at those which are.
352 if (_hr->is_in(obj)) {
353 // Object is in the region. Check that its less than top
354 if (_hr->top() <= cast_from_oop<HeapWord*>(obj)) {
355 // Object is above top
356 log_error(gc, verify)("Object " PTR_FORMAT " in region " HR_FORMAT " is above top ",
357 p2i(obj), HR_FORMAT_PARAMS(_hr));
358 _failures = true;
359 return;
360 }
361 // Nmethod has at least one oop in the current region
362 _has_oops_in_region = true;
363 }
364 }
365 }
366
367 public:
368 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
369 _hr(hr), _failures(false), _has_oops_in_region(false) {}
370
371 void do_oop(narrowOop* p) { do_oop_work(p); }
372 void do_oop(oop* p) { do_oop_work(p); }
373
374 bool failures() { return _failures; }
375 bool has_oops_in_region() { return _has_oops_in_region; }
376 };
377
378 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
379 const HeapRegion* _hr;
380 bool _failures;
381 public:
382 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
383 _hr(hr), _failures(false) {}
384
385 void do_code_blob(CodeBlob* cb) {
386 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
387 if (nm != NULL) {
388 // Verify that the nemthod is live
389 if (!nm->is_alive()) {
390 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
391 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
392 _failures = true;
393 } else {
394 VerifyStrongCodeRootOopClosure oop_cl(_hr);
395 nm->oops_do(&oop_cl);
396 if (!oop_cl.has_oops_in_region()) {
397 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
398 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
399 _failures = true;
400 } else if (oop_cl.failures()) {
401 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
402 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
403 _failures = true;
404 }
405 }
406 }
407 }
408
409 bool failures() { return _failures; }
410 };
411
412 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
413 if (!G1VerifyHeapRegionCodeRoots) {
414 // We're not verifying code roots.
415 return;
416 }
417 if (vo == VerifyOption_G1UseFullMarking) {
418 // Marking verification during a full GC is performed after class
419 // unloading, code cache unloading, etc so the strong code roots
420 // attached to each heap region are in an inconsistent state. They won't
421 // be consistent until the strong code roots are rebuilt after the
422 // actual GC. Skip verifying the strong code roots in this particular
423 // time.
424 assert(VerifyDuringGC, "only way to get here");
425 return;
426 }
427
428 HeapRegionRemSet* hrrs = rem_set();
429 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
430
431 // if this region is empty then there should be no entries
432 // on its strong code root list
433 if (is_empty()) {
434 if (strong_code_roots_length > 0) {
435 log_error(gc, verify)("region " HR_FORMAT " is empty but has " SIZE_FORMAT " code root entries",
436 HR_FORMAT_PARAMS(this), strong_code_roots_length);
437 *failures = true;
438 }
439 return;
440 }
441
442 if (is_continues_humongous()) {
443 if (strong_code_roots_length > 0) {
444 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
445 HR_FORMAT_PARAMS(this), strong_code_roots_length);
446 *failures = true;
447 }
448 return;
449 }
450
451 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
452 strong_code_roots_do(&cb_cl);
453
454 if (cb_cl.failures()) {
455 *failures = true;
456 }
457 }
458
459 void HeapRegion::print() const { print_on(tty); }
460
461 void HeapRegion::print_on(outputStream* st) const {
462 st->print("|%4u", this->_hrm_index);
463 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
464 p2i(bottom()), p2i(top()), p2i(end()));
465 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
466 st->print("|%2s", get_short_type_str());
467 if (in_collection_set()) {
468 st->print("|CS");
469 } else {
470 st->print("| ");
471 }
472 st->print("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ",
473 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str());
474 if (UseNUMA) {
475 G1NUMA* numa = G1NUMA::numa();
476 if (node_index() < numa->num_active_nodes()) {
477 st->print("|%d", numa->numa_id(node_index()));
478 } else {
479 st->print("|-");
480 }
481 }
482 st->print_cr("");
483 }
484
485 class G1VerificationClosure : public BasicOopIterateClosure {
486 protected:
487 G1CollectedHeap* _g1h;
488 G1CardTable *_ct;
489 oop _containing_obj;
490 bool _failures;
491 int _n_failures;
492 VerifyOption _vo;
493 public:
494 // _vo == UsePrevMarking -> use "prev" marking information,
495 // _vo == UseNextMarking -> use "next" marking information,
496 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
497 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
498 _g1h(g1h), _ct(g1h->card_table()),
499 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
500 }
501
502 void set_containing_obj(oop obj) {
503 _containing_obj = obj;
504 }
505
506 bool failures() { return _failures; }
507 int n_failures() { return _n_failures; }
508
509 void print_object(outputStream* out, oop obj) {
510 #ifdef PRODUCT
511 Klass* k = obj->klass();
512 const char* class_name = k->external_name();
513 out->print_cr("class name %s", class_name);
514 #else // PRODUCT
515 obj->print_on(out);
516 #endif // PRODUCT
517 }
518
519 // This closure provides its own oop verification code.
520 debug_only(virtual bool should_verify_oops() { return false; })
521 };
522
523 class VerifyLiveClosure : public G1VerificationClosure {
524 public:
525 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
526 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
527 virtual void do_oop(oop* p) { do_oop_work(p); }
528
529 template <class T>
530 void do_oop_work(T* p) {
531 assert(_containing_obj != NULL, "Precondition");
532 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
533 "Precondition");
534 verify_liveness(p);
535 }
536
537 template <class T>
538 void verify_liveness(T* p) {
539 T heap_oop = RawAccess<>::oop_load(p);
540 Log(gc, verify) log;
541 if (!CompressedOops::is_null(heap_oop)) {
542 oop obj = CompressedOops::decode_not_null(heap_oop);
543 bool failed = false;
544 if (!_g1h->is_in(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
545 MutexLocker x(ParGCRareEvent_lock,
546 Mutex::_no_safepoint_check_flag);
547
548 if (!_failures) {
549 log.error("----------");
550 }
551 ResourceMark rm;
552 if (!_g1h->is_in(obj)) {
553 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
554 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
555 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
556 LogStream ls(log.error());
557 print_object(&ls, _containing_obj);
558 HeapRegion* const to = _g1h->heap_region_containing(obj);
559 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
560 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
561 } else {
562 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
563 HeapRegion* to = _g1h->heap_region_containing(obj);
564 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
565 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
566 LogStream ls(log.error());
567 print_object(&ls, _containing_obj);
568 log.error("points to dead obj " PTR_FORMAT " in region " HR_FORMAT,
569 p2i(obj), HR_FORMAT_PARAMS(to));
570 print_object(&ls, obj);
571 }
572 log.error("----------");
573 _failures = true;
574 failed = true;
575 _n_failures++;
576 }
577 }
578 }
579 };
580
581 class VerifyRemSetClosure : public G1VerificationClosure {
582 public:
583 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
584 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
585 virtual void do_oop(oop* p) { do_oop_work(p); }
586
587 template <class T>
588 void do_oop_work(T* p) {
589 assert(_containing_obj != NULL, "Precondition");
590 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
591 "Precondition");
592 verify_remembered_set(p);
593 }
594
595 template <class T>
596 void verify_remembered_set(T* p) {
597 T heap_oop = RawAccess<>::oop_load(p);
598 Log(gc, verify) log;
599 if (!CompressedOops::is_null(heap_oop)) {
600 oop obj = CompressedOops::decode_not_null(heap_oop);
601 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
602 HeapRegion* to = _g1h->heap_region_containing(obj);
603 if (from != NULL && to != NULL &&
604 from != to &&
605 !to->is_pinned() &&
606 to->rem_set()->is_complete()) {
607 jbyte cv_obj = *_ct->byte_for_const(_containing_obj);
608 jbyte cv_field = *_ct->byte_for_const(p);
609 const jbyte dirty = G1CardTable::dirty_card_val();
610
611 bool is_bad = !(from->is_young()
612 || to->rem_set()->contains_reference(p)
613 || (_containing_obj->is_objArray() ?
614 cv_field == dirty :
615 cv_obj == dirty || cv_field == dirty));
616 if (is_bad) {
617 MutexLocker x(ParGCRareEvent_lock,
618 Mutex::_no_safepoint_check_flag);
619
620 if (!_failures) {
621 log.error("----------");
622 }
623 log.error("Missing rem set entry:");
624 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT,
625 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
626 ResourceMark rm;
627 LogStream ls(log.error());
628 _containing_obj->print_on(&ls);
629 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
630 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
631 if (oopDesc::is_oop(obj)) {
632 obj->print_on(&ls);
633 }
634 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
635 log.error("----------");
636 _failures = true;
637 _n_failures++;
638 }
639 }
640 }
641 }
642 };
643
644 // Closure that applies the given two closures in sequence.
645 class G1Mux2Closure : public BasicOopIterateClosure {
646 OopClosure* _c1;
647 OopClosure* _c2;
648 public:
649 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
650 template <class T> inline void do_oop_work(T* p) {
651 // Apply first closure; then apply the second.
652 _c1->do_oop(p);
653 _c2->do_oop(p);
654 }
655 virtual inline void do_oop(oop* p) { do_oop_work(p); }
656 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
657
658 // This closure provides its own oop verification code.
659 debug_only(virtual bool should_verify_oops() { return false; })
660 };
661
662 void HeapRegion::verify(VerifyOption vo,
663 bool* failures) const {
664 G1CollectedHeap* g1h = G1CollectedHeap::heap();
665 *failures = false;
666 HeapWord* p = bottom();
667 HeapWord* prev_p = NULL;
668 VerifyLiveClosure vl_cl(g1h, vo);
669 VerifyRemSetClosure vr_cl(g1h, vo);
670 bool is_region_humongous = is_humongous();
671 size_t object_num = 0;
672 while (p < top()) {
673 oop obj = oop(p);
674 size_t obj_size = block_size(p);
675 object_num += 1;
676
677 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
678 if (oopDesc::is_oop(obj)) {
679 Klass* klass = obj->klass();
680 bool is_metaspace_object = Metaspace::contains(klass);
681 if (!is_metaspace_object) {
682 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
683 "not metadata", p2i(klass), p2i(obj));
684 *failures = true;
685 return;
686 } else if (!klass->is_klass()) {
687 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
688 "not a klass", p2i(klass), p2i(obj));
689 *failures = true;
690 return;
691 } else {
692 vl_cl.set_containing_obj(obj);
693 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) {
694 // verify liveness and rem_set
695 vr_cl.set_containing_obj(obj);
696 G1Mux2Closure mux(&vl_cl, &vr_cl);
697 obj->oop_iterate(&mux);
698
699 if (vr_cl.failures()) {
700 *failures = true;
701 }
702 if (G1MaxVerifyFailures >= 0 &&
703 vr_cl.n_failures() >= G1MaxVerifyFailures) {
704 return;
705 }
706 } else {
707 // verify only liveness
708 obj->oop_iterate(&vl_cl);
709 }
710 if (vl_cl.failures()) {
711 *failures = true;
712 }
713 if (G1MaxVerifyFailures >= 0 &&
714 vl_cl.n_failures() >= G1MaxVerifyFailures) {
715 return;
716 }
717 }
718 } else {
719 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
720 *failures = true;
721 return;
722 }
723 }
724 prev_p = p;
725 p += obj_size;
726 }
727
728 if (!is_young() && !is_empty()) {
729 _bot_part.verify();
730 }
731
732 if (is_region_humongous) {
733 oop obj = oop(this->humongous_start_region()->bottom());
734 if (cast_from_oop<HeapWord*>(obj) > bottom() || cast_from_oop<HeapWord*>(obj) + obj->size() < bottom()) {
735 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
736 *failures = true;
737 return;
738 }
739 }
740
741 if (!is_region_humongous && p != top()) {
742 log_error(gc, verify)("end of last object " PTR_FORMAT " "
743 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
744 *failures = true;
745 return;
746 }
747
748 HeapWord* the_end = end();
749 // Do some extra BOT consistency checking for addresses in the
750 // range [top, end). BOT look-ups in this range should yield
751 // top. No point in doing that if top == end (there's nothing there).
752 if (p < the_end) {
753 // Look up top
754 HeapWord* addr_1 = p;
755 HeapWord* b_start_1 = block_start_const(addr_1);
756 if (b_start_1 != p) {
757 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
758 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
759 p2i(addr_1), p2i(b_start_1), p2i(p));
760 *failures = true;
761 return;
762 }
763
764 // Look up top + 1
765 HeapWord* addr_2 = p + 1;
766 if (addr_2 < the_end) {
767 HeapWord* b_start_2 = block_start_const(addr_2);
768 if (b_start_2 != p) {
769 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
770 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
771 p2i(addr_2), p2i(b_start_2), p2i(p));
772 *failures = true;
773 return;
774 }
775 }
776
777 // Look up an address between top and end
778 size_t diff = pointer_delta(the_end, p) / 2;
779 HeapWord* addr_3 = p + diff;
780 if (addr_3 < the_end) {
781 HeapWord* b_start_3 = block_start_const(addr_3);
782 if (b_start_3 != p) {
783 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
784 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
785 p2i(addr_3), p2i(b_start_3), p2i(p));
786 *failures = true;
787 return;
788 }
789 }
790
791 // Look up end - 1
792 HeapWord* addr_4 = the_end - 1;
793 HeapWord* b_start_4 = block_start_const(addr_4);
794 if (b_start_4 != p) {
795 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
796 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
797 p2i(addr_4), p2i(b_start_4), p2i(p));
798 *failures = true;
799 return;
800 }
801 }
802
803 verify_strong_code_roots(vo, failures);
804 }
805
806 void HeapRegion::verify() const {
807 bool dummy = false;
808 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
809 }
810
811 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
812 G1CollectedHeap* g1h = G1CollectedHeap::heap();
813 *failures = false;
814 HeapWord* p = bottom();
815 HeapWord* prev_p = NULL;
816 VerifyRemSetClosure vr_cl(g1h, vo);
817 while (p < top()) {
818 oop obj = oop(p);
819 size_t obj_size = block_size(p);
820
821 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
822 if (oopDesc::is_oop(obj)) {
823 vr_cl.set_containing_obj(obj);
824 obj->oop_iterate(&vr_cl);
825
826 if (vr_cl.failures()) {
827 *failures = true;
828 }
829 if (G1MaxVerifyFailures >= 0 &&
830 vr_cl.n_failures() >= G1MaxVerifyFailures) {
831 return;
832 }
833 } else {
834 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
835 *failures = true;
836 return;
837 }
838 }
839
840 prev_p = p;
841 p += obj_size;
842 }
843 }
844
845 void HeapRegion::verify_rem_set() const {
846 bool failures = false;
847 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
848 guarantee(!failures, "HeapRegion RemSet verification failed");
849 }
850
851 void HeapRegion::clear(bool mangle_space) {
852 set_top(bottom());
853 set_compaction_top(bottom());
854
855 if (ZapUnusedHeapArea && mangle_space) {
856 mangle_unused_area();
857 }
858 reset_bot();
859 }
860
861 #ifndef PRODUCT
862 void HeapRegion::mangle_unused_area() {
863 SpaceMangler::mangle_region(MemRegion(top(), end()));
864 }
865 #endif
866
867 HeapWord* HeapRegion::initialize_threshold() {
868 return _bot_part.initialize_threshold();
869 }
870
871 HeapWord* HeapRegion::cross_threshold(HeapWord* start, HeapWord* end) {
872 _bot_part.alloc_block(start, end);
873 return _bot_part.threshold();
874 }
875
876 void HeapRegion::object_iterate(ObjectClosure* blk) {
877 HeapWord* p = bottom();
878 while (p < top()) {
879 if (block_is_obj(p)) {
880 blk->do_object(oop(p));
881 }
882 p += block_size(p);
883 }
884 }