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::handle_evacuation_failed() {
116 uninstall_surv_rate_group();
117 clear_young_index_in_cset();
118 set_evacuation_failed(false);
119 set_old();
120 }
121
122 void HeapRegion::unlink_from_list() {
123 set_next(NULL);
124 set_prev(NULL);
125 set_containing_set(NULL);
126 }
127
128 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) {
129 assert(_humongous_start_region == NULL,
130 "we should have already filtered out humongous regions");
131 assert(!in_collection_set(),
132 "Should not clear heap region %u in the collection set", hrm_index());
133
134 clear_young_index_in_cset();
135 clear_index_in_opt_cset();
136 uninstall_surv_rate_group();
137 set_free();
138 reset_pre_dummy_top();
139
140 if (!keep_remset) {
141 if (locked) {
142 rem_set()->clear_locked();
143 } else {
144 rem_set()->clear();
145 }
146 }
147
148 zero_marked_bytes();
149
150 init_top_at_mark_start();
151 if (clear_space) clear(SpaceDecorator::Mangle);
152
153 _evacuation_failed = false;
154 _gc_efficiency = 0.0;
155 _recorded_rs_length = 0;
156 _predicted_elapsed_time_ms = 0.0;
157 }
158
159 void HeapRegion::clear_cardtable() {
160 G1CardTable* ct = G1CollectedHeap::heap()->card_table();
161 ct->clear(MemRegion(bottom(), end()));
162 }
163
164 void HeapRegion::calc_gc_efficiency() {
165 // GC efficiency is the ratio of how much space would be
166 // reclaimed over how long we predict it would take to reclaim it.
167 G1CollectedHeap* g1h = G1CollectedHeap::heap();
168 G1Policy* policy = g1h->policy();
169
170 // Retrieve a prediction of the elapsed time for this region for
171 // a mixed gc because the region will only be evacuated during a
172 // mixed gc.
173 double region_elapsed_time_ms =
174 policy->predict_region_elapsed_time_ms(this, false /* for_young_gc */);
175 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms;
176 }
177
178 void HeapRegion::set_free() {
179 report_region_type_change(G1HeapRegionTraceType::Free);
180 _type.set_free();
181 }
182
183 void HeapRegion::set_eden() {
184 report_region_type_change(G1HeapRegionTraceType::Eden);
185 _type.set_eden();
186 }
187
188 void HeapRegion::set_eden_pre_gc() {
189 report_region_type_change(G1HeapRegionTraceType::Eden);
190 _type.set_eden_pre_gc();
191 }
192
193 void HeapRegion::set_survivor() {
194 report_region_type_change(G1HeapRegionTraceType::Survivor);
195 _type.set_survivor();
196 }
197
198 void HeapRegion::move_to_old() {
199 if (_type.relabel_as_old()) {
200 report_region_type_change(G1HeapRegionTraceType::Old);
201 }
202 }
203
204 void HeapRegion::set_old() {
205 report_region_type_change(G1HeapRegionTraceType::Old);
206 _type.set_old();
207 }
208
209 void HeapRegion::set_open_archive() {
210 report_region_type_change(G1HeapRegionTraceType::OpenArchive);
211 _type.set_open_archive();
212 }
213
214 void HeapRegion::set_closed_archive() {
215 report_region_type_change(G1HeapRegionTraceType::ClosedArchive);
216 _type.set_closed_archive();
217 }
218
219 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) {
220 assert(!is_humongous(), "sanity / pre-condition");
221 assert(top() == bottom(), "should be empty");
222
223 report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
224 _type.set_starts_humongous();
225 _humongous_start_region = this;
226
227 _bot_part.set_for_starts_humongous(obj_top, fill_size);
228 }
229
230 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) {
231 assert(!is_humongous(), "sanity / pre-condition");
232 assert(top() == bottom(), "should be empty");
233 assert(first_hr->is_starts_humongous(), "pre-condition");
234
235 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
236 _type.set_continues_humongous();
237 _humongous_start_region = first_hr;
238
239 _bot_part.set_object_can_span(true);
240 }
241
242 void HeapRegion::clear_humongous() {
243 assert(is_humongous(), "pre-condition");
244
245 assert(capacity() == HeapRegion::GrainBytes, "pre-condition");
246 _humongous_start_region = NULL;
247
248 _bot_part.set_object_can_span(false);
249 }
250
251 HeapRegion::HeapRegion(uint hrm_index,
252 G1BlockOffsetTable* bot,
253 MemRegion mr) :
254 _bottom(mr.start()),
255 _end(mr.end()),
256 _top(NULL),
257 _compaction_top(NULL),
258 _bot_part(bot, this),
259 _par_alloc_lock(Mutex::leaf, "HeapRegion par alloc lock", true),
260 _pre_dummy_top(NULL),
261 _rem_set(NULL),
262 _hrm_index(hrm_index),
263 _type(),
264 _humongous_start_region(NULL),
265 _evacuation_failed(false),
266 _index_in_opt_cset(InvalidCSetIndex),
267 _next(NULL), _prev(NULL),
268 #ifdef ASSERT
269 _containing_set(NULL),
270 #endif
271 _prev_top_at_mark_start(NULL), _next_top_at_mark_start(NULL),
272 _prev_marked_bytes(0), _next_marked_bytes(0),
273 _young_index_in_cset(-1),
274 _surv_rate_group(NULL), _age_index(-1), _gc_efficiency(0.0),
275 _recorded_rs_length(0), _predicted_elapsed_time_ms(0),
276 _node_index(G1NUMA::UnknownNodeIndex)
277 {
278 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
279 "invalid space boundaries");
280
281 _rem_set = new HeapRegionRemSet(bot, this);
282 initialize();
283 }
284
285 void HeapRegion::initialize(bool clear_space, bool mangle_space) {
286 assert(_rem_set->is_empty(), "Remembered set must be empty");
287
288 if (clear_space) {
289 clear(mangle_space);
290 }
291
292 set_top(bottom());
293 set_compaction_top(bottom());
294 reset_bot();
295
296 hr_clear(false /*par*/, false /*clear_space*/);
297 }
298
299 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
300 HeapRegionTracer::send_region_type_change(_hrm_index,
301 get_trace_type(),
302 to,
303 (uintptr_t)bottom(),
304 used());
305 }
306
307 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
308 bool during_conc_mark) {
309 // We always recreate the prev marking info and we'll explicitly
310 // mark all objects we find to be self-forwarded on the prev
311 // bitmap. So all objects need to be below PTAMS.
312 _prev_marked_bytes = 0;
313
314 if (during_initial_mark) {
315 // During initial-mark, we'll also explicitly mark all objects
316 // we find to be self-forwarded on the next bitmap. So all
317 // objects need to be below NTAMS.
318 _next_top_at_mark_start = top();
319 _next_marked_bytes = 0;
320 } else if (during_conc_mark) {
321 // During concurrent mark, all objects in the CSet (including
322 // the ones we find to be self-forwarded) are implicitly live.
323 // So all objects need to be above NTAMS.
324 _next_top_at_mark_start = bottom();
325 _next_marked_bytes = 0;
326 }
327 }
328
329 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) {
330 assert(marked_bytes <= used(),
331 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used());
332 _prev_top_at_mark_start = top();
333 _prev_marked_bytes = marked_bytes;
334 }
335
336 // Code roots support
337
338 void HeapRegion::add_strong_code_root(nmethod* nm) {
339 HeapRegionRemSet* hrrs = rem_set();
340 hrrs->add_strong_code_root(nm);
341 }
342
343 void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
344 assert_locked_or_safepoint(CodeCache_lock);
345 HeapRegionRemSet* hrrs = rem_set();
346 hrrs->add_strong_code_root_locked(nm);
347 }
348
349 void HeapRegion::remove_strong_code_root(nmethod* nm) {
350 HeapRegionRemSet* hrrs = rem_set();
351 hrrs->remove_strong_code_root(nm);
352 }
353
354 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
355 HeapRegionRemSet* hrrs = rem_set();
356 hrrs->strong_code_roots_do(blk);
357 }
358
359 class VerifyStrongCodeRootOopClosure: public OopClosure {
360 const HeapRegion* _hr;
361 bool _failures;
362 bool _has_oops_in_region;
363
364 template <class T> void do_oop_work(T* p) {
365 T heap_oop = RawAccess<>::oop_load(p);
366 if (!CompressedOops::is_null(heap_oop)) {
367 oop obj = CompressedOops::decode_not_null(heap_oop);
368
369 // Note: not all the oops embedded in the nmethod are in the
370 // current region. We only look at those which are.
371 if (_hr->is_in(obj)) {
372 // Object is in the region. Check that its less than top
373 if (_hr->top() <= (HeapWord*)obj) {
374 // Object is above top
375 log_error(gc, verify)("Object " PTR_FORMAT " in region " HR_FORMAT " is above top ",
376 p2i(obj), HR_FORMAT_PARAMS(_hr));
377 _failures = true;
378 return;
379 }
380 // Nmethod has at least one oop in the current region
381 _has_oops_in_region = true;
382 }
383 }
384 }
385
386 public:
387 VerifyStrongCodeRootOopClosure(const HeapRegion* hr):
388 _hr(hr), _failures(false), _has_oops_in_region(false) {}
389
390 void do_oop(narrowOop* p) { do_oop_work(p); }
391 void do_oop(oop* p) { do_oop_work(p); }
392
393 bool failures() { return _failures; }
394 bool has_oops_in_region() { return _has_oops_in_region; }
395 };
396
397 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure {
398 const HeapRegion* _hr;
399 bool _failures;
400 public:
401 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) :
402 _hr(hr), _failures(false) {}
403
404 void do_code_blob(CodeBlob* cb) {
405 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null();
406 if (nm != NULL) {
407 // Verify that the nemthod is live
408 if (!nm->is_alive()) {
409 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots",
410 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
411 _failures = true;
412 } else {
413 VerifyStrongCodeRootOopClosure oop_cl(_hr);
414 nm->oops_do(&oop_cl);
415 if (!oop_cl.has_oops_in_region()) {
416 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region",
417 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
418 _failures = true;
419 } else if (oop_cl.failures()) {
420 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT,
421 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm));
422 _failures = true;
423 }
424 }
425 }
426 }
427
428 bool failures() { return _failures; }
429 };
430
431 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
432 if (!G1VerifyHeapRegionCodeRoots) {
433 // We're not verifying code roots.
434 return;
435 }
436 if (vo == VerifyOption_G1UseFullMarking) {
437 // Marking verification during a full GC is performed after class
438 // unloading, code cache unloading, etc so the strong code roots
439 // attached to each heap region are in an inconsistent state. They won't
440 // be consistent until the strong code roots are rebuilt after the
441 // actual GC. Skip verifying the strong code roots in this particular
442 // time.
443 assert(VerifyDuringGC, "only way to get here");
444 return;
445 }
446
447 HeapRegionRemSet* hrrs = rem_set();
448 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
449
450 // if this region is empty then there should be no entries
451 // on its strong code root list
452 if (is_empty()) {
453 if (strong_code_roots_length > 0) {
454 log_error(gc, verify)("region " HR_FORMAT " is empty but has " SIZE_FORMAT " code root entries",
455 HR_FORMAT_PARAMS(this), strong_code_roots_length);
456 *failures = true;
457 }
458 return;
459 }
460
461 if (is_continues_humongous()) {
462 if (strong_code_roots_length > 0) {
463 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries",
464 HR_FORMAT_PARAMS(this), strong_code_roots_length);
465 *failures = true;
466 }
467 return;
468 }
469
470 VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
471 strong_code_roots_do(&cb_cl);
472
473 if (cb_cl.failures()) {
474 *failures = true;
475 }
476 }
477
478 void HeapRegion::print() const { print_on(tty); }
479
480 void HeapRegion::print_on(outputStream* st) const {
481 st->print("|%4u", this->_hrm_index);
482 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT,
483 p2i(bottom()), p2i(top()), p2i(end()));
484 st->print("|%3d%%", (int) ((double) used() * 100 / capacity()));
485 st->print("|%2s", get_short_type_str());
486 if (in_collection_set()) {
487 st->print("|CS");
488 } else {
489 st->print("| ");
490 }
491 st->print("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ",
492 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str());
493 if (UseNUMA) {
494 G1NUMA* numa = G1NUMA::numa();
495 if (node_index() < numa->num_active_nodes()) {
496 st->print("|%d", numa->numa_id(node_index()));
497 } else {
498 st->print("|-");
499 }
500 }
501 st->print_cr("");
502 }
503
504 class G1VerificationClosure : public BasicOopIterateClosure {
505 protected:
506 G1CollectedHeap* _g1h;
507 G1CardTable *_ct;
508 oop _containing_obj;
509 bool _failures;
510 int _n_failures;
511 VerifyOption _vo;
512 public:
513 // _vo == UsePrevMarking -> use "prev" marking information,
514 // _vo == UseNextMarking -> use "next" marking information,
515 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
516 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) :
517 _g1h(g1h), _ct(g1h->card_table()),
518 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) {
519 }
520
521 void set_containing_obj(oop obj) {
522 _containing_obj = obj;
523 }
524
525 bool failures() { return _failures; }
526 int n_failures() { return _n_failures; }
527
528 void print_object(outputStream* out, oop obj) {
529 #ifdef PRODUCT
530 Klass* k = obj->klass();
531 const char* class_name = k->external_name();
532 out->print_cr("class name %s", class_name);
533 #else // PRODUCT
534 obj->print_on(out);
535 #endif // PRODUCT
536 }
537
538 // This closure provides its own oop verification code.
539 debug_only(virtual bool should_verify_oops() { return false; })
540 };
541
542 class VerifyLiveClosure : public G1VerificationClosure {
543 public:
544 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
545 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
546 virtual void do_oop(oop* p) { do_oop_work(p); }
547
548 template <class T>
549 void do_oop_work(T* p) {
550 assert(_containing_obj != NULL, "Precondition");
551 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
552 "Precondition");
553 verify_liveness(p);
554 }
555
556 template <class T>
557 void verify_liveness(T* p) {
558 T heap_oop = RawAccess<>::oop_load(p);
559 Log(gc, verify) log;
560 if (!CompressedOops::is_null(heap_oop)) {
561 oop obj = CompressedOops::decode_not_null(heap_oop);
562 bool failed = false;
563 if (!_g1h->is_in(obj) || _g1h->is_obj_dead_cond(obj, _vo)) {
564 MutexLocker x(ParGCRareEvent_lock,
565 Mutex::_no_safepoint_check_flag);
566
567 if (!_failures) {
568 log.error("----------");
569 }
570 ResourceMark rm;
571 if (!_g1h->is_in(obj)) {
572 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
573 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
574 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
575 LogStream ls(log.error());
576 print_object(&ls, _containing_obj);
577 HeapRegion* const to = _g1h->heap_region_containing(obj);
578 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
579 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
580 } else {
581 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
582 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj);
583 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT,
584 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
585 LogStream ls(log.error());
586 print_object(&ls, _containing_obj);
587 log.error("points to dead obj " PTR_FORMAT " in region " HR_FORMAT,
588 p2i(obj), HR_FORMAT_PARAMS(to));
589 print_object(&ls, obj);
590 }
591 log.error("----------");
592 _failures = true;
593 failed = true;
594 _n_failures++;
595 }
596 }
597 }
598 };
599
600 class VerifyRemSetClosure : public G1VerificationClosure {
601 public:
602 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {}
603 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
604 virtual void do_oop(oop* p) { do_oop_work(p); }
605
606 template <class T>
607 void do_oop_work(T* p) {
608 assert(_containing_obj != NULL, "Precondition");
609 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo),
610 "Precondition");
611 verify_remembered_set(p);
612 }
613
614 template <class T>
615 void verify_remembered_set(T* p) {
616 T heap_oop = RawAccess<>::oop_load(p);
617 Log(gc, verify) log;
618 if (!CompressedOops::is_null(heap_oop)) {
619 oop obj = CompressedOops::decode_not_null(heap_oop);
620 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
621 HeapRegion* to = _g1h->heap_region_containing(obj);
622 if (from != NULL && to != NULL &&
623 from != to &&
624 !to->is_pinned() &&
625 to->rem_set()->is_complete()) {
626 jbyte cv_obj = *_ct->byte_for_const(_containing_obj);
627 jbyte cv_field = *_ct->byte_for_const(p);
628 const jbyte dirty = G1CardTable::dirty_card_val();
629
630 bool is_bad = !(from->is_young()
631 || to->rem_set()->contains_reference(p)
632 || (_containing_obj->is_objArray() ?
633 cv_field == dirty :
634 cv_obj == dirty || cv_field == dirty));
635 if (is_bad) {
636 MutexLocker x(ParGCRareEvent_lock,
637 Mutex::_no_safepoint_check_flag);
638
639 if (!_failures) {
640 log.error("----------");
641 }
642 log.error("Missing rem set entry:");
643 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT,
644 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
645 ResourceMark rm;
646 LogStream ls(log.error());
647 _containing_obj->print_on(&ls);
648 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s",
649 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str());
650 if (oopDesc::is_oop(obj)) {
651 obj->print_on(&ls);
652 }
653 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field);
654 log.error("----------");
655 _failures = true;
656 _n_failures++;
657 }
658 }
659 }
660 }
661 };
662
663 // Closure that applies the given two closures in sequence.
664 class G1Mux2Closure : public BasicOopIterateClosure {
665 OopClosure* _c1;
666 OopClosure* _c2;
667 public:
668 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; }
669 template <class T> inline void do_oop_work(T* p) {
670 // Apply first closure; then apply the second.
671 _c1->do_oop(p);
672 _c2->do_oop(p);
673 }
674 virtual inline void do_oop(oop* p) { do_oop_work(p); }
675 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
676
677 // This closure provides its own oop verification code.
678 debug_only(virtual bool should_verify_oops() { return false; })
679 };
680
681 void HeapRegion::verify(VerifyOption vo,
682 bool* failures) const {
683 G1CollectedHeap* g1h = G1CollectedHeap::heap();
684 *failures = false;
685 HeapWord* p = bottom();
686 HeapWord* prev_p = NULL;
687 VerifyLiveClosure vl_cl(g1h, vo);
688 VerifyRemSetClosure vr_cl(g1h, vo);
689 bool is_region_humongous = is_humongous();
690 size_t object_num = 0;
691 while (p < top()) {
692 oop obj = oop(p);
693 size_t obj_size = block_size(p);
694 object_num += 1;
695
696 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
697 if (oopDesc::is_oop(obj)) {
698 Klass* klass = obj->klass();
699 bool is_metaspace_object = Metaspace::contains(klass);
700 if (!is_metaspace_object) {
701 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
702 "not metadata", p2i(klass), p2i(obj));
703 *failures = true;
704 return;
705 } else if (!klass->is_klass()) {
706 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " "
707 "not a klass", p2i(klass), p2i(obj));
708 *failures = true;
709 return;
710 } else {
711 vl_cl.set_containing_obj(obj);
712 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) {
713 // verify liveness and rem_set
714 vr_cl.set_containing_obj(obj);
715 G1Mux2Closure mux(&vl_cl, &vr_cl);
716 obj->oop_iterate(&mux);
717
718 if (vr_cl.failures()) {
719 *failures = true;
720 }
721 if (G1MaxVerifyFailures >= 0 &&
722 vr_cl.n_failures() >= G1MaxVerifyFailures) {
723 return;
724 }
725 } else {
726 // verify only liveness
727 obj->oop_iterate(&vl_cl);
728 }
729 if (vl_cl.failures()) {
730 *failures = true;
731 }
732 if (G1MaxVerifyFailures >= 0 &&
733 vl_cl.n_failures() >= G1MaxVerifyFailures) {
734 return;
735 }
736 }
737 } else {
738 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
739 *failures = true;
740 return;
741 }
742 }
743 prev_p = p;
744 p += obj_size;
745 }
746
747 if (!is_young() && !is_empty()) {
748 _bot_part.verify();
749 }
750
751 if (is_region_humongous) {
752 oop obj = oop(this->humongous_start_region()->bottom());
753 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) {
754 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj));
755 *failures = true;
756 return;
757 }
758 }
759
760 if (!is_region_humongous && p != top()) {
761 log_error(gc, verify)("end of last object " PTR_FORMAT " "
762 "does not match top " PTR_FORMAT, p2i(p), p2i(top()));
763 *failures = true;
764 return;
765 }
766
767 HeapWord* the_end = end();
768 // Do some extra BOT consistency checking for addresses in the
769 // range [top, end). BOT look-ups in this range should yield
770 // top. No point in doing that if top == end (there's nothing there).
771 if (p < the_end) {
772 // Look up top
773 HeapWord* addr_1 = p;
774 HeapWord* b_start_1 = block_start_const(addr_1);
775 if (b_start_1 != p) {
776 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " "
777 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
778 p2i(addr_1), p2i(b_start_1), p2i(p));
779 *failures = true;
780 return;
781 }
782
783 // Look up top + 1
784 HeapWord* addr_2 = p + 1;
785 if (addr_2 < the_end) {
786 HeapWord* b_start_2 = block_start_const(addr_2);
787 if (b_start_2 != p) {
788 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " "
789 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
790 p2i(addr_2), p2i(b_start_2), p2i(p));
791 *failures = true;
792 return;
793 }
794 }
795
796 // Look up an address between top and end
797 size_t diff = pointer_delta(the_end, p) / 2;
798 HeapWord* addr_3 = p + diff;
799 if (addr_3 < the_end) {
800 HeapWord* b_start_3 = block_start_const(addr_3);
801 if (b_start_3 != p) {
802 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " "
803 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
804 p2i(addr_3), p2i(b_start_3), p2i(p));
805 *failures = true;
806 return;
807 }
808 }
809
810 // Look up end - 1
811 HeapWord* addr_4 = the_end - 1;
812 HeapWord* b_start_4 = block_start_const(addr_4);
813 if (b_start_4 != p) {
814 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " "
815 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT,
816 p2i(addr_4), p2i(b_start_4), p2i(p));
817 *failures = true;
818 return;
819 }
820 }
821
822 verify_strong_code_roots(vo, failures);
823 }
824
825 void HeapRegion::verify() const {
826 bool dummy = false;
827 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
828 }
829
830 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const {
831 G1CollectedHeap* g1h = G1CollectedHeap::heap();
832 *failures = false;
833 HeapWord* p = bottom();
834 HeapWord* prev_p = NULL;
835 VerifyRemSetClosure vr_cl(g1h, vo);
836 while (p < top()) {
837 oop obj = oop(p);
838 size_t obj_size = block_size(p);
839
840 if (!g1h->is_obj_dead_cond(obj, this, vo)) {
841 if (oopDesc::is_oop(obj)) {
842 vr_cl.set_containing_obj(obj);
843 obj->oop_iterate(&vr_cl);
844
845 if (vr_cl.failures()) {
846 *failures = true;
847 }
848 if (G1MaxVerifyFailures >= 0 &&
849 vr_cl.n_failures() >= G1MaxVerifyFailures) {
850 return;
851 }
852 } else {
853 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj));
854 *failures = true;
855 return;
856 }
857 }
858
859 prev_p = p;
860 p += obj_size;
861 }
862 }
863
864 void HeapRegion::verify_rem_set() const {
865 bool failures = false;
866 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures);
867 guarantee(!failures, "HeapRegion RemSet verification failed");
868 }
869
870 void HeapRegion::clear(bool mangle_space) {
871 set_top(bottom());
872 set_compaction_top(bottom());
873
874 if (ZapUnusedHeapArea && mangle_space) {
875 mangle_unused_area();
876 }
877 reset_bot();
878 }
879
880 #ifndef PRODUCT
881 void HeapRegion::mangle_unused_area() {
882 SpaceMangler::mangle_region(MemRegion(top(), end()));
883 }
884 #endif
885
886 HeapWord* HeapRegion::initialize_threshold() {
887 return _bot_part.initialize_threshold();
888 }
889
890 HeapWord* HeapRegion::cross_threshold(HeapWord* start, HeapWord* end) {
891 _bot_part.alloc_block(start, end);
892 return _bot_part.threshold();
893 }
894
895 void HeapRegion::object_iterate(ObjectClosure* blk) {
896 HeapWord* p = bottom();
897 while (p < top()) {
898 if (block_is_obj(p)) {
899 blk->do_object(oop(p));
900 }
901 p += block_size(p);
902 }
903 }