1/*
2 * Copyright (c) 2016, 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/g1Allocator.inline.hpp"
28#include "gc/g1/g1CollectedHeap.inline.hpp"
29#include "gc/g1/g1ConcurrentMarkThread.hpp"
30#include "gc/g1/g1HeapVerifier.hpp"
31#include "gc/g1/g1Policy.hpp"
32#include "gc/g1/g1RemSet.hpp"
33#include "gc/g1/g1RootProcessor.hpp"
34#include "gc/g1/heapRegion.inline.hpp"
35#include "gc/g1/heapRegionRemSet.hpp"
36#include "gc/g1/g1StringDedup.hpp"
37#include "logging/log.hpp"
38#include "logging/logStream.hpp"
39#include "memory/iterator.inline.hpp"
40#include "memory/resourceArea.hpp"
41#include "memory/universe.hpp"
42#include "oops/access.inline.hpp"
43#include "oops/compressedOops.inline.hpp"
44#include "oops/oop.inline.hpp"
45#include "runtime/handles.inline.hpp"
46
47int G1HeapVerifier::_enabled_verification_types = G1HeapVerifier::G1VerifyAll;
48
49class VerifyRootsClosure: public OopClosure {
50private:
51 G1CollectedHeap* _g1h;
52 VerifyOption _vo;
53 bool _failures;
54public:
55 // _vo == UsePrevMarking -> use "prev" marking information,
56 // _vo == UseNextMarking -> use "next" marking information,
57 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
58 VerifyRootsClosure(VerifyOption vo) :
59 _g1h(G1CollectedHeap::heap()),
60 _vo(vo),
61 _failures(false) { }
62
63 bool failures() { return _failures; }
64
65 template <class T> void do_oop_work(T* p) {
66 T heap_oop = RawAccess<>::oop_load(p);
67 if (!CompressedOops::is_null(heap_oop)) {
68 oop obj = CompressedOops::decode_not_null(heap_oop);
69 if (_g1h->is_obj_dead_cond(obj, _vo)) {
70 Log(gc, verify) log;
71 log.error("Root location " PTR_FORMAT " points to dead obj " PTR_FORMAT, p2i(p), p2i(obj));
72 ResourceMark rm;
73 LogStream ls(log.error());
74 obj->print_on(&ls);
75 _failures = true;
76 }
77 }
78 }
79
80 void do_oop(oop* p) { do_oop_work(p); }
81 void do_oop(narrowOop* p) { do_oop_work(p); }
82};
83
84class G1VerifyCodeRootOopClosure: public OopClosure {
85 G1CollectedHeap* _g1h;
86 OopClosure* _root_cl;
87 nmethod* _nm;
88 VerifyOption _vo;
89 bool _failures;
90
91 template <class T> void do_oop_work(T* p) {
92 // First verify that this root is live
93 _root_cl->do_oop(p);
94
95 if (!G1VerifyHeapRegionCodeRoots) {
96 // We're not verifying the code roots attached to heap region.
97 return;
98 }
99
100 // Don't check the code roots during marking verification in a full GC
101 if (_vo == VerifyOption_G1UseFullMarking) {
102 return;
103 }
104
105 // Now verify that the current nmethod (which contains p) is
106 // in the code root list of the heap region containing the
107 // object referenced by p.
108
109 T heap_oop = RawAccess<>::oop_load(p);
110 if (!CompressedOops::is_null(heap_oop)) {
111 oop obj = CompressedOops::decode_not_null(heap_oop);
112
113 // Now fetch the region containing the object
114 HeapRegion* hr = _g1h->heap_region_containing(obj);
115 HeapRegionRemSet* hrrs = hr->rem_set();
116 // Verify that the strong code root list for this region
117 // contains the nmethod
118 if (!hrrs->strong_code_roots_list_contains(_nm)) {
119 log_error(gc, verify)("Code root location " PTR_FORMAT " "
120 "from nmethod " PTR_FORMAT " not in strong "
121 "code roots for region [" PTR_FORMAT "," PTR_FORMAT ")",
122 p2i(p), p2i(_nm), p2i(hr->bottom()), p2i(hr->end()));
123 _failures = true;
124 }
125 }
126 }
127
128public:
129 G1VerifyCodeRootOopClosure(G1CollectedHeap* g1h, OopClosure* root_cl, VerifyOption vo):
130 _g1h(g1h), _root_cl(root_cl), _nm(NULL), _vo(vo), _failures(false) {}
131
132 void do_oop(oop* p) { do_oop_work(p); }
133 void do_oop(narrowOop* p) { do_oop_work(p); }
134
135 void set_nmethod(nmethod* nm) { _nm = nm; }
136 bool failures() { return _failures; }
137};
138
139class G1VerifyCodeRootBlobClosure: public CodeBlobClosure {
140 G1VerifyCodeRootOopClosure* _oop_cl;
141
142public:
143 G1VerifyCodeRootBlobClosure(G1VerifyCodeRootOopClosure* oop_cl):
144 _oop_cl(oop_cl) {}
145
146 void do_code_blob(CodeBlob* cb) {
147 nmethod* nm = cb->as_nmethod_or_null();
148 if (nm != NULL) {
149 _oop_cl->set_nmethod(nm);
150 nm->oops_do(_oop_cl);
151 }
152 }
153};
154
155class YoungRefCounterClosure : public OopClosure {
156 G1CollectedHeap* _g1h;
157 int _count;
158 public:
159 YoungRefCounterClosure(G1CollectedHeap* g1h) : _g1h(g1h), _count(0) {}
160 void do_oop(oop* p) { if (_g1h->is_in_young(*p)) { _count++; } }
161 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
162
163 int count() { return _count; }
164 void reset_count() { _count = 0; };
165};
166
167class VerifyCLDClosure: public CLDClosure {
168 YoungRefCounterClosure _young_ref_counter_closure;
169 OopClosure *_oop_closure;
170 public:
171 VerifyCLDClosure(G1CollectedHeap* g1h, OopClosure* cl) : _young_ref_counter_closure(g1h), _oop_closure(cl) {}
172 void do_cld(ClassLoaderData* cld) {
173 cld->oops_do(_oop_closure, ClassLoaderData::_claim_none);
174
175 _young_ref_counter_closure.reset_count();
176 cld->oops_do(&_young_ref_counter_closure, ClassLoaderData::_claim_none);
177 if (_young_ref_counter_closure.count() > 0) {
178 guarantee(cld->has_modified_oops(), "CLD " PTR_FORMAT ", has young %d refs but is not dirty.", p2i(cld), _young_ref_counter_closure.count());
179 }
180 }
181};
182
183class VerifyLivenessOopClosure: public BasicOopIterateClosure {
184 G1CollectedHeap* _g1h;
185 VerifyOption _vo;
186public:
187 VerifyLivenessOopClosure(G1CollectedHeap* g1h, VerifyOption vo):
188 _g1h(g1h), _vo(vo)
189 { }
190 void do_oop(narrowOop *p) { do_oop_work(p); }
191 void do_oop( oop *p) { do_oop_work(p); }
192
193 template <class T> void do_oop_work(T *p) {
194 oop obj = RawAccess<>::oop_load(p);
195 guarantee(obj == NULL || !_g1h->is_obj_dead_cond(obj, _vo),
196 "Dead object referenced by a not dead object");
197 }
198};
199
200class VerifyObjsInRegionClosure: public ObjectClosure {
201private:
202 G1CollectedHeap* _g1h;
203 size_t _live_bytes;
204 HeapRegion *_hr;
205 VerifyOption _vo;
206public:
207 // _vo == UsePrevMarking -> use "prev" marking information,
208 // _vo == UseNextMarking -> use "next" marking information,
209 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
210 VerifyObjsInRegionClosure(HeapRegion *hr, VerifyOption vo)
211 : _live_bytes(0), _hr(hr), _vo(vo) {
212 _g1h = G1CollectedHeap::heap();
213 }
214 void do_object(oop o) {
215 VerifyLivenessOopClosure isLive(_g1h, _vo);
216 assert(o != NULL, "Huh?");
217 if (!_g1h->is_obj_dead_cond(o, _vo)) {
218 // If the object is alive according to the full gc mark,
219 // then verify that the marking information agrees.
220 // Note we can't verify the contra-positive of the
221 // above: if the object is dead (according to the mark
222 // word), it may not be marked, or may have been marked
223 // but has since became dead, or may have been allocated
224 // since the last marking.
225 if (_vo == VerifyOption_G1UseFullMarking) {
226 guarantee(!_g1h->is_obj_dead(o), "Full GC marking and concurrent mark mismatch");
227 }
228
229 o->oop_iterate(&isLive);
230 if (!_hr->obj_allocated_since_prev_marking(o)) {
231 size_t obj_size = o->size(); // Make sure we don't overflow
232 _live_bytes += (obj_size * HeapWordSize);
233 }
234 }
235 }
236 size_t live_bytes() { return _live_bytes; }
237};
238
239class VerifyArchiveOopClosure: public BasicOopIterateClosure {
240 HeapRegion* _hr;
241public:
242 VerifyArchiveOopClosure(HeapRegion *hr)
243 : _hr(hr) { }
244 void do_oop(narrowOop *p) { do_oop_work(p); }
245 void do_oop( oop *p) { do_oop_work(p); }
246
247 template <class T> void do_oop_work(T *p) {
248 oop obj = RawAccess<>::oop_load(p);
249
250 if (_hr->is_open_archive()) {
251 guarantee(obj == NULL || G1ArchiveAllocator::is_archived_object(obj),
252 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
253 p2i(p), p2i(obj));
254 } else {
255 assert(_hr->is_closed_archive(), "should be closed archive region");
256 guarantee(obj == NULL || G1ArchiveAllocator::is_closed_archive_object(obj),
257 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
258 p2i(p), p2i(obj));
259 }
260 }
261};
262
263class VerifyObjectInArchiveRegionClosure: public ObjectClosure {
264 HeapRegion* _hr;
265public:
266 VerifyObjectInArchiveRegionClosure(HeapRegion *hr, bool verbose)
267 : _hr(hr) { }
268 // Verify that all object pointers are to archive regions.
269 void do_object(oop o) {
270 VerifyArchiveOopClosure checkOop(_hr);
271 assert(o != NULL, "Should not be here for NULL oops");
272 o->oop_iterate(&checkOop);
273 }
274};
275
276// Should be only used at CDS dump time
277class VerifyReadyForArchivingRegionClosure : public HeapRegionClosure {
278 bool _seen_free;
279 bool _has_holes;
280 bool _has_unexpected_holes;
281 bool _has_humongous;
282public:
283 bool has_holes() {return _has_holes;}
284 bool has_unexpected_holes() {return _has_unexpected_holes;}
285 bool has_humongous() {return _has_humongous;}
286
287 VerifyReadyForArchivingRegionClosure() : HeapRegionClosure() {
288 _seen_free = false;
289 _has_holes = false;
290 _has_unexpected_holes = false;
291 _has_humongous = false;
292 }
293 virtual bool do_heap_region(HeapRegion* hr) {
294 const char* hole = "";
295
296 if (hr->is_free()) {
297 _seen_free = true;
298 } else {
299 if (_seen_free) {
300 _has_holes = true;
301 if (hr->is_humongous()) {
302 hole = " hole";
303 } else {
304 _has_unexpected_holes = true;
305 hole = " hole **** unexpected ****";
306 }
307 }
308 }
309 if (hr->is_humongous()) {
310 _has_humongous = true;
311 }
312 log_info(gc, region, cds)("HeapRegion " INTPTR_FORMAT " %s%s", p2i(hr->bottom()), hr->get_type_str(), hole);
313 return false;
314 }
315};
316
317// We want all used regions to be moved to the bottom-end of the heap, so we have
318// a contiguous range of free regions at the top end of the heap. This way, we can
319// avoid fragmentation while allocating the archive regions.
320//
321// Before calling this, a full GC should have been executed with a single worker thread,
322// so that no old regions would be moved to the middle of the heap.
323void G1HeapVerifier::verify_ready_for_archiving() {
324 VerifyReadyForArchivingRegionClosure cl;
325 G1CollectedHeap::heap()->heap_region_iterate(&cl);
326 if (cl.has_holes()) {
327 log_warning(gc, verify)("All free regions should be at the top end of the heap, but"
328 " we found holes. This is probably caused by (unmovable) humongous"
329 " allocations, and may lead to fragmentation while"
330 " writing archive heap memory regions.");
331 }
332 if (cl.has_humongous()) {
333 log_warning(gc, verify)("(Unmovable) humongous regions have been found and"
334 " may lead to fragmentation while"
335 " writing archive heap memory regions.");
336 }
337 assert(!cl.has_unexpected_holes(), "all holes should have been caused by humongous regions");
338}
339
340class VerifyArchivePointerRegionClosure: public HeapRegionClosure {
341 virtual bool do_heap_region(HeapRegion* r) {
342 if (r->is_archive()) {
343 VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
344 r->object_iterate(&verify_oop_pointers);
345 }
346 return false;
347 }
348};
349
350void G1HeapVerifier::verify_archive_regions() {
351 G1CollectedHeap* g1h = G1CollectedHeap::heap();
352 VerifyArchivePointerRegionClosure cl;
353 g1h->heap_region_iterate(&cl);
354}
355
356class VerifyRegionClosure: public HeapRegionClosure {
357private:
358 bool _par;
359 VerifyOption _vo;
360 bool _failures;
361public:
362 // _vo == UsePrevMarking -> use "prev" marking information,
363 // _vo == UseNextMarking -> use "next" marking information,
364 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
365 VerifyRegionClosure(bool par, VerifyOption vo)
366 : _par(par),
367 _vo(vo),
368 _failures(false) {}
369
370 bool failures() {
371 return _failures;
372 }
373
374 bool do_heap_region(HeapRegion* r) {
375 guarantee(!r->has_index_in_opt_cset(), "Region %u still has opt collection set index %u", r->hrm_index(), r->index_in_opt_cset());
376 guarantee(!r->is_young() || r->rem_set()->is_complete(), "Remembered set for Young region %u must be complete, is %s", r->hrm_index(), r->rem_set()->get_state_str());
377 // Humongous and old regions regions might be of any state, so can't check here.
378 guarantee(!r->is_free() || !r->rem_set()->is_tracked(), "Remembered set for free region %u must be untracked, is %s", r->hrm_index(), r->rem_set()->get_state_str());
379 // Verify that the continues humongous regions' remembered set state matches the
380 // one from the starts humongous region.
381 if (r->is_continues_humongous()) {
382 if (r->rem_set()->get_state_str() != r->humongous_start_region()->rem_set()->get_state_str()) {
383 log_error(gc, verify)("Remset states differ: Region %u (%s) remset %s with starts region %u (%s) remset %s",
384 r->hrm_index(),
385 r->get_short_type_str(),
386 r->rem_set()->get_state_str(),
387 r->humongous_start_region()->hrm_index(),
388 r->humongous_start_region()->get_short_type_str(),
389 r->humongous_start_region()->rem_set()->get_state_str());
390 _failures = true;
391 }
392 }
393 // For archive regions, verify there are no heap pointers to
394 // non-pinned regions. For all others, verify liveness info.
395 if (r->is_closed_archive()) {
396 VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
397 r->object_iterate(&verify_oop_pointers);
398 return true;
399 } else if (r->is_open_archive()) {
400 VerifyObjsInRegionClosure verify_open_archive_oop(r, _vo);
401 r->object_iterate(&verify_open_archive_oop);
402 return true;
403 } else if (!r->is_continues_humongous()) {
404 bool failures = false;
405 r->verify(_vo, &failures);
406 if (failures) {
407 _failures = true;
408 } else if (!r->is_starts_humongous()) {
409 VerifyObjsInRegionClosure not_dead_yet_cl(r, _vo);
410 r->object_iterate(&not_dead_yet_cl);
411 if (_vo != VerifyOption_G1UseNextMarking) {
412 if (r->max_live_bytes() < not_dead_yet_cl.live_bytes()) {
413 log_error(gc, verify)("[" PTR_FORMAT "," PTR_FORMAT "] max_live_bytes " SIZE_FORMAT " < calculated " SIZE_FORMAT,
414 p2i(r->bottom()), p2i(r->end()), r->max_live_bytes(), not_dead_yet_cl.live_bytes());
415 _failures = true;
416 }
417 } else {
418 // When vo == UseNextMarking we cannot currently do a sanity
419 // check on the live bytes as the calculation has not been
420 // finalized yet.
421 }
422 }
423 }
424 return false; // stop the region iteration if we hit a failure
425 }
426};
427
428// This is the task used for parallel verification of the heap regions
429
430class G1ParVerifyTask: public AbstractGangTask {
431private:
432 G1CollectedHeap* _g1h;
433 VerifyOption _vo;
434 bool _failures;
435 HeapRegionClaimer _hrclaimer;
436
437public:
438 // _vo == UsePrevMarking -> use "prev" marking information,
439 // _vo == UseNextMarking -> use "next" marking information,
440 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
441 G1ParVerifyTask(G1CollectedHeap* g1h, VerifyOption vo) :
442 AbstractGangTask("Parallel verify task"),
443 _g1h(g1h),
444 _vo(vo),
445 _failures(false),
446 _hrclaimer(g1h->workers()->active_workers()) {}
447
448 bool failures() {
449 return _failures;
450 }
451
452 void work(uint worker_id) {
453 HandleMark hm;
454 VerifyRegionClosure blk(true, _vo);
455 _g1h->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
456 if (blk.failures()) {
457 _failures = true;
458 }
459 }
460};
461
462void G1HeapVerifier::enable_verification_type(G1VerifyType type) {
463 // First enable will clear _enabled_verification_types.
464 if (_enabled_verification_types == G1VerifyAll) {
465 _enabled_verification_types = type;
466 } else {
467 _enabled_verification_types |= type;
468 }
469}
470
471bool G1HeapVerifier::should_verify(G1VerifyType type) {
472 return (_enabled_verification_types & type) == type;
473}
474
475void G1HeapVerifier::verify(VerifyOption vo) {
476 if (!SafepointSynchronize::is_at_safepoint()) {
477 log_info(gc, verify)("Skipping verification. Not at safepoint.");
478 }
479
480 assert(Thread::current()->is_VM_thread(),
481 "Expected to be executed serially by the VM thread at this point");
482
483 log_debug(gc, verify)("Roots");
484 VerifyRootsClosure rootsCl(vo);
485 VerifyCLDClosure cldCl(_g1h, &rootsCl);
486
487 // We apply the relevant closures to all the oops in the
488 // system dictionary, class loader data graph, the string table
489 // and the nmethods in the code cache.
490 G1VerifyCodeRootOopClosure codeRootsCl(_g1h, &rootsCl, vo);
491 G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
492
493 {
494 G1RootProcessor root_processor(_g1h, 1);
495 root_processor.process_all_roots(&rootsCl, &cldCl, &blobsCl);
496 }
497
498 bool failures = rootsCl.failures() || codeRootsCl.failures();
499
500 if (!_g1h->policy()->collector_state()->in_full_gc()) {
501 // If we're verifying during a full GC then the region sets
502 // will have been torn down at the start of the GC. Therefore
503 // verifying the region sets will fail. So we only verify
504 // the region sets when not in a full GC.
505 log_debug(gc, verify)("HeapRegionSets");
506 verify_region_sets();
507 }
508
509 log_debug(gc, verify)("HeapRegions");
510 if (GCParallelVerificationEnabled && ParallelGCThreads > 1) {
511
512 G1ParVerifyTask task(_g1h, vo);
513 _g1h->workers()->run_task(&task);
514 if (task.failures()) {
515 failures = true;
516 }
517
518 } else {
519 VerifyRegionClosure blk(false, vo);
520 _g1h->heap_region_iterate(&blk);
521 if (blk.failures()) {
522 failures = true;
523 }
524 }
525
526 if (G1StringDedup::is_enabled()) {
527 log_debug(gc, verify)("StrDedup");
528 G1StringDedup::verify();
529 }
530
531 if (failures) {
532 log_error(gc, verify)("Heap after failed verification (kind %d):", vo);
533 // It helps to have the per-region information in the output to
534 // help us track down what went wrong. This is why we call
535 // print_extended_on() instead of print_on().
536 Log(gc, verify) log;
537 ResourceMark rm;
538 LogStream ls(log.error());
539 _g1h->print_extended_on(&ls);
540 }
541 guarantee(!failures, "there should not have been any failures");
542}
543
544// Heap region set verification
545
546class VerifyRegionListsClosure : public HeapRegionClosure {
547private:
548 HeapRegionSet* _old_set;
549 HeapRegionSet* _archive_set;
550 HeapRegionSet* _humongous_set;
551 HeapRegionManager* _hrm;
552
553public:
554 uint _old_count;
555 uint _archive_count;
556 uint _humongous_count;
557 uint _free_count;
558
559 VerifyRegionListsClosure(HeapRegionSet* old_set,
560 HeapRegionSet* archive_set,
561 HeapRegionSet* humongous_set,
562 HeapRegionManager* hrm) :
563 _old_set(old_set), _archive_set(archive_set), _humongous_set(humongous_set), _hrm(hrm),
564 _old_count(), _archive_count(), _humongous_count(), _free_count(){ }
565
566 bool do_heap_region(HeapRegion* hr) {
567 if (hr->is_young()) {
568 // TODO
569 } else if (hr->is_humongous()) {
570 assert(hr->containing_set() == _humongous_set, "Heap region %u is humongous but not in humongous set.", hr->hrm_index());
571 _humongous_count++;
572 } else if (hr->is_empty()) {
573 assert(_hrm->is_free(hr), "Heap region %u is empty but not on the free list.", hr->hrm_index());
574 _free_count++;
575 } else if (hr->is_archive()) {
576 assert(hr->containing_set() == _archive_set, "Heap region %u is archive but not in the archive set.", hr->hrm_index());
577 _archive_count++;
578 } else if (hr->is_old()) {
579 assert(hr->containing_set() == _old_set, "Heap region %u is old but not in the old set.", hr->hrm_index());
580 _old_count++;
581 } else {
582 // There are no other valid region types. Check for one invalid
583 // one we can identify: pinned without old or humongous set.
584 assert(!hr->is_pinned(), "Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index());
585 ShouldNotReachHere();
586 }
587 return false;
588 }
589
590 void verify_counts(HeapRegionSet* old_set, HeapRegionSet* archive_set, HeapRegionSet* humongous_set, HeapRegionManager* free_list) {
591 guarantee(old_set->length() == _old_count, "Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count);
592 guarantee(archive_set->length() == _archive_count, "Archive set count mismatch. Expected %u, actual %u.", archive_set->length(), _archive_count);
593 guarantee(humongous_set->length() == _humongous_count, "Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count);
594 guarantee(free_list->num_free_regions() == _free_count, "Free list count mismatch. Expected %u, actual %u.", free_list->num_free_regions(), _free_count);
595 }
596};
597
598void G1HeapVerifier::verify_region_sets() {
599 assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
600
601 // First, check the explicit lists.
602 _g1h->_hrm->verify();
603
604 // Finally, make sure that the region accounting in the lists is
605 // consistent with what we see in the heap.
606
607 VerifyRegionListsClosure cl(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
608 _g1h->heap_region_iterate(&cl);
609 cl.verify_counts(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
610}
611
612void G1HeapVerifier::prepare_for_verify() {
613 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
614 _g1h->ensure_parsability(false);
615 }
616}
617
618double G1HeapVerifier::verify(G1VerifyType type, VerifyOption vo, const char* msg) {
619 double verify_time_ms = 0.0;
620
621 if (should_verify(type) && _g1h->total_collections() >= VerifyGCStartAt) {
622 double verify_start = os::elapsedTime();
623 HandleMark hm; // Discard invalid handles created during verification
624 prepare_for_verify();
625 Universe::verify(vo, msg);
626 verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
627 }
628
629 return verify_time_ms;
630}
631
632void G1HeapVerifier::verify_before_gc(G1VerifyType type) {
633 if (VerifyBeforeGC) {
634 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "Before GC");
635 _g1h->phase_times()->record_verify_before_time_ms(verify_time_ms);
636 }
637}
638
639void G1HeapVerifier::verify_after_gc(G1VerifyType type) {
640 if (VerifyAfterGC) {
641 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "After GC");
642 _g1h->phase_times()->record_verify_after_time_ms(verify_time_ms);
643 }
644}
645
646
647#ifndef PRODUCT
648class G1VerifyCardTableCleanup: public HeapRegionClosure {
649 G1HeapVerifier* _verifier;
650public:
651 G1VerifyCardTableCleanup(G1HeapVerifier* verifier)
652 : _verifier(verifier) { }
653 virtual bool do_heap_region(HeapRegion* r) {
654 if (r->is_survivor()) {
655 _verifier->verify_dirty_region(r);
656 } else {
657 _verifier->verify_not_dirty_region(r);
658 }
659 return false;
660 }
661};
662
663void G1HeapVerifier::verify_card_table_cleanup() {
664 if (G1VerifyCTCleanup || VerifyAfterGC) {
665 G1VerifyCardTableCleanup cleanup_verifier(this);
666 _g1h->heap_region_iterate(&cleanup_verifier);
667 }
668}
669
670void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
671 // All of the region should be clean.
672 G1CardTable* ct = _g1h->card_table();
673 MemRegion mr(hr->bottom(), hr->end());
674 ct->verify_not_dirty_region(mr);
675}
676
677void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
678 // We cannot guarantee that [bottom(),end()] is dirty. Threads
679 // dirty allocated blocks as they allocate them. The thread that
680 // retires each region and replaces it with a new one will do a
681 // maximal allocation to fill in [pre_dummy_top(),end()] but will
682 // not dirty that area (one less thing to have to do while holding
683 // a lock). So we can only verify that [bottom(),pre_dummy_top()]
684 // is dirty.
685 G1CardTable* ct = _g1h->card_table();
686 MemRegion mr(hr->bottom(), hr->pre_dummy_top());
687 if (hr->is_young()) {
688 ct->verify_g1_young_region(mr);
689 } else {
690 ct->verify_dirty_region(mr);
691 }
692}
693
694class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
695private:
696 G1HeapVerifier* _verifier;
697public:
698 G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
699 virtual bool do_heap_region(HeapRegion* r) {
700 _verifier->verify_dirty_region(r);
701 return false;
702 }
703};
704
705void G1HeapVerifier::verify_dirty_young_regions() {
706 G1VerifyDirtyYoungListClosure cl(this);
707 _g1h->collection_set()->iterate(&cl);
708}
709
710bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
711 HeapWord* tams, HeapWord* end) {
712 guarantee(tams <= end,
713 "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
714 HeapWord* result = bitmap->get_next_marked_addr(tams, end);
715 if (result < end) {
716 log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
717 log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
718 return false;
719 }
720 return true;
721}
722
723bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
724 const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prev_mark_bitmap();
725 const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->next_mark_bitmap();
726
727 HeapWord* ptams = hr->prev_top_at_mark_start();
728 HeapWord* ntams = hr->next_top_at_mark_start();
729 HeapWord* end = hr->end();
730
731 bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
732
733 bool res_n = true;
734 // We cannot verify the next bitmap while we are about to clear it.
735 if (!_g1h->collector_state()->clearing_next_bitmap()) {
736 res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
737 }
738 if (!res_p || !res_n) {
739 log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
740 log_error(gc, verify)("#### Caller: %s", caller);
741 return false;
742 }
743 return true;
744}
745
746void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
747 if (!G1VerifyBitmaps) {
748 return;
749 }
750
751 guarantee(verify_bitmaps(caller, hr), "bitmap verification");
752}
753
754class G1VerifyBitmapClosure : public HeapRegionClosure {
755private:
756 const char* _caller;
757 G1HeapVerifier* _verifier;
758 bool _failures;
759
760public:
761 G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
762 _caller(caller), _verifier(verifier), _failures(false) { }
763
764 bool failures() { return _failures; }
765
766 virtual bool do_heap_region(HeapRegion* hr) {
767 bool result = _verifier->verify_bitmaps(_caller, hr);
768 if (!result) {
769 _failures = true;
770 }
771 return false;
772 }
773};
774
775void G1HeapVerifier::check_bitmaps(const char* caller) {
776 if (!G1VerifyBitmaps) {
777 return;
778 }
779
780 G1VerifyBitmapClosure cl(caller, this);
781 _g1h->heap_region_iterate(&cl);
782 guarantee(!cl.failures(), "bitmap verification");
783}
784
785class G1CheckRegionAttrTableClosure : public HeapRegionClosure {
786private:
787 bool _failures;
788
789public:
790 G1CheckRegionAttrTableClosure() : HeapRegionClosure(), _failures(false) { }
791
792 virtual bool do_heap_region(HeapRegion* hr) {
793 uint i = hr->hrm_index();
794 G1HeapRegionAttr region_attr = (G1HeapRegionAttr) G1CollectedHeap::heap()->_region_attr.get_by_index(i);
795 if (hr->is_humongous()) {
796 if (hr->in_collection_set()) {
797 log_error(gc, verify)("## humongous region %u in CSet", i);
798 _failures = true;
799 return true;
800 }
801 if (region_attr.is_in_cset()) {
802 log_error(gc, verify)("## inconsistent region attr type %s for humongous region %u", region_attr.get_type_str(), i);
803 _failures = true;
804 return true;
805 }
806 if (hr->is_continues_humongous() && region_attr.is_humongous()) {
807 log_error(gc, verify)("## inconsistent region attr type %s for continues humongous region %u", region_attr.get_type_str(), i);
808 _failures = true;
809 return true;
810 }
811 } else {
812 if (region_attr.is_humongous()) {
813 log_error(gc, verify)("## inconsistent region attr type %s for non-humongous region %u", region_attr.get_type_str(), i);
814 _failures = true;
815 return true;
816 }
817 if (hr->in_collection_set() != region_attr.is_in_cset()) {
818 log_error(gc, verify)("## in CSet %d / region attr type %s inconsistency for region %u",
819 hr->in_collection_set(), region_attr.get_type_str(), i);
820 _failures = true;
821 return true;
822 }
823 if (region_attr.is_in_cset()) {
824 if (hr->is_archive()) {
825 log_error(gc, verify)("## is_archive in collection set for region %u", i);
826 _failures = true;
827 return true;
828 }
829 if (hr->is_young() != (region_attr.is_young())) {
830 log_error(gc, verify)("## is_young %d / region attr type %s inconsistency for region %u",
831 hr->is_young(), region_attr.get_type_str(), i);
832 _failures = true;
833 return true;
834 }
835 if (hr->is_old() != (region_attr.is_old())) {
836 log_error(gc, verify)("## is_old %d / region attr type %s inconsistency for region %u",
837 hr->is_old(), region_attr.get_type_str(), i);
838 _failures = true;
839 return true;
840 }
841 }
842 }
843 return false;
844 }
845
846 bool failures() const { return _failures; }
847};
848
849bool G1HeapVerifier::check_region_attr_table() {
850 G1CheckRegionAttrTableClosure cl;
851 _g1h->_hrm->iterate(&cl);
852 return !cl.failures();
853}
854#endif // PRODUCT
855