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 "oops/access.inline.hpp"
42 #include "oops/compressedOops.inline.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "runtime/handles.inline.hpp"
45
46 int G1HeapVerifier::_enabled_verification_types = G1HeapVerifier::G1VerifyAll;
47
48 class VerifyRootsClosure: public OopClosure {
49 private:
50 G1CollectedHeap* _g1h;
51 VerifyOption _vo;
52 bool _failures;
53 public:
54 // _vo == UsePrevMarking -> use "prev" marking information,
55 // _vo == UseNextMarking -> use "next" marking information,
56 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
57 VerifyRootsClosure(VerifyOption vo) :
58 _g1h(G1CollectedHeap::heap()),
59 _vo(vo),
60 _failures(false) { }
61
62 bool failures() { return _failures; }
63
64 template <class T> void do_oop_work(T* p) {
65 T heap_oop = RawAccess<>::oop_load(p);
66 if (!CompressedOops::is_null(heap_oop)) {
67 oop obj = CompressedOops::decode_not_null(heap_oop);
68 if (_g1h->is_obj_dead_cond(obj, _vo)) {
69 Log(gc, verify) log;
70 log.error("Root location " PTR_FORMAT " points to dead obj " PTR_FORMAT, p2i(p), p2i(obj));
71 ResourceMark rm;
72 LogStream ls(log.error());
73 obj->print_on(&ls);
74 _failures = true;
75 }
76 }
77 }
78
79 void do_oop(oop* p) { do_oop_work(p); }
80 void do_oop(narrowOop* p) { do_oop_work(p); }
81 };
82
83 class G1VerifyCodeRootOopClosure: public OopClosure {
84 G1CollectedHeap* _g1h;
85 OopClosure* _root_cl;
86 nmethod* _nm;
87 VerifyOption _vo;
88 bool _failures;
89
90 template <class T> void do_oop_work(T* p) {
91 // First verify that this root is live
92 _root_cl->do_oop(p);
93
94 if (!G1VerifyHeapRegionCodeRoots) {
95 // We're not verifying the code roots attached to heap region.
96 return;
97 }
98
99 // Don't check the code roots during marking verification in a full GC
100 if (_vo == VerifyOption_G1UseFullMarking) {
101 return;
102 }
103
104 // Now verify that the current nmethod (which contains p) is
105 // in the code root list of the heap region containing the
106 // object referenced by p.
107
108 T heap_oop = RawAccess<>::oop_load(p);
109 if (!CompressedOops::is_null(heap_oop)) {
110 oop obj = CompressedOops::decode_not_null(heap_oop);
111
112 // Now fetch the region containing the object
113 HeapRegion* hr = _g1h->heap_region_containing(obj);
114 HeapRegionRemSet* hrrs = hr->rem_set();
115 // Verify that the strong code root list for this region
116 // contains the nmethod
117 if (!hrrs->strong_code_roots_list_contains(_nm)) {
118 log_error(gc, verify)("Code root location " PTR_FORMAT " "
119 "from nmethod " PTR_FORMAT " not in strong "
120 "code roots for region [" PTR_FORMAT "," PTR_FORMAT ")",
121 p2i(p), p2i(_nm), p2i(hr->bottom()), p2i(hr->end()));
122 _failures = true;
123 }
124 }
125 }
126
127 public:
128 G1VerifyCodeRootOopClosure(G1CollectedHeap* g1h, OopClosure* root_cl, VerifyOption vo):
129 _g1h(g1h), _root_cl(root_cl), _nm(NULL), _vo(vo), _failures(false) {}
130
131 void do_oop(oop* p) { do_oop_work(p); }
132 void do_oop(narrowOop* p) { do_oop_work(p); }
133
134 void set_nmethod(nmethod* nm) { _nm = nm; }
135 bool failures() { return _failures; }
136 };
137
138 class G1VerifyCodeRootBlobClosure: public CodeBlobClosure {
139 G1VerifyCodeRootOopClosure* _oop_cl;
140
141 public:
142 G1VerifyCodeRootBlobClosure(G1VerifyCodeRootOopClosure* oop_cl):
143 _oop_cl(oop_cl) {}
144
145 void do_code_blob(CodeBlob* cb) {
146 nmethod* nm = cb->as_nmethod_or_null();
147 if (nm != NULL) {
148 _oop_cl->set_nmethod(nm);
149 nm->oops_do(_oop_cl);
150 }
151 }
152 };
153
154 class YoungRefCounterClosure : public OopClosure {
155 G1CollectedHeap* _g1h;
156 int _count;
157 public:
158 YoungRefCounterClosure(G1CollectedHeap* g1h) : _g1h(g1h), _count(0) {}
159 void do_oop(oop* p) { if (_g1h->is_in_young(*p)) { _count++; } }
160 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
161
162 int count() { return _count; }
163 void reset_count() { _count = 0; };
164 };
165
166 class VerifyCLDClosure: public CLDClosure {
167 YoungRefCounterClosure _young_ref_counter_closure;
168 OopClosure *_oop_closure;
169 public:
170 VerifyCLDClosure(G1CollectedHeap* g1h, OopClosure* cl) : _young_ref_counter_closure(g1h), _oop_closure(cl) {}
171 void do_cld(ClassLoaderData* cld) {
172 cld->oops_do(_oop_closure, ClassLoaderData::_claim_none);
173
174 _young_ref_counter_closure.reset_count();
175 cld->oops_do(&_young_ref_counter_closure, ClassLoaderData::_claim_none);
176 if (_young_ref_counter_closure.count() > 0) {
177 guarantee(cld->has_modified_oops(), "CLD " PTR_FORMAT ", has young %d refs but is not dirty.", p2i(cld), _young_ref_counter_closure.count());
178 }
179 }
180 };
181
182 class VerifyLivenessOopClosure: public BasicOopIterateClosure {
183 G1CollectedHeap* _g1h;
184 VerifyOption _vo;
185 public:
186 VerifyLivenessOopClosure(G1CollectedHeap* g1h, VerifyOption vo):
187 _g1h(g1h), _vo(vo)
188 { }
189 void do_oop(narrowOop *p) { do_oop_work(p); }
190 void do_oop( oop *p) { do_oop_work(p); }
191
192 template <class T> void do_oop_work(T *p) {
193 oop obj = RawAccess<>::oop_load(p);
194 guarantee(obj == NULL || !_g1h->is_obj_dead_cond(obj, _vo),
195 "Dead object referenced by a not dead object");
196 }
197 };
198
199 class VerifyObjsInRegionClosure: public ObjectClosure {
200 private:
201 G1CollectedHeap* _g1h;
202 size_t _live_bytes;
203 HeapRegion *_hr;
204 VerifyOption _vo;
205 public:
206 // _vo == UsePrevMarking -> use "prev" marking information,
207 // _vo == UseNextMarking -> use "next" marking information,
208 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS.
209 VerifyObjsInRegionClosure(HeapRegion *hr, VerifyOption vo)
210 : _live_bytes(0), _hr(hr), _vo(vo) {
211 _g1h = G1CollectedHeap::heap();
212 }
213 void do_object(oop o) {
214 VerifyLivenessOopClosure isLive(_g1h, _vo);
215 assert(o != NULL, "Huh?");
216 if (!_g1h->is_obj_dead_cond(o, _vo)) {
217 // If the object is alive according to the full gc mark,
218 // then verify that the marking information agrees.
219 // Note we can't verify the contra-positive of the
220 // above: if the object is dead (according to the mark
221 // word), it may not be marked, or may have been marked
222 // but has since became dead, or may have been allocated
223 // since the last marking.
224 if (_vo == VerifyOption_G1UseFullMarking) {
225 guarantee(!_g1h->is_obj_dead(o), "Full GC marking and concurrent mark mismatch");
226 }
227
228 o->oop_iterate(&isLive);
229 if (!_hr->obj_allocated_since_prev_marking(o)) {
230 size_t obj_size = o->size(); // Make sure we don't overflow
231 _live_bytes += (obj_size * HeapWordSize);
232 }
233 }
234 }
235 size_t live_bytes() { return _live_bytes; }
236 };
237
238 class VerifyArchiveOopClosure: public BasicOopIterateClosure {
239 HeapRegion* _hr;
240 public:
241 VerifyArchiveOopClosure(HeapRegion *hr)
242 : _hr(hr) { }
243 void do_oop(narrowOop *p) { do_oop_work(p); }
244 void do_oop( oop *p) { do_oop_work(p); }
245
246 template <class T> void do_oop_work(T *p) {
247 oop obj = RawAccess<>::oop_load(p);
248
249 if (_hr->is_open_archive()) {
250 guarantee(obj == NULL || G1ArchiveAllocator::is_archived_object(obj),
251 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
252 p2i(p), p2i(obj));
253 } else {
254 assert(_hr->is_closed_archive(), "should be closed archive region");
255 guarantee(obj == NULL || G1ArchiveAllocator::is_closed_archive_object(obj),
256 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
257 p2i(p), p2i(obj));
258 }
259 }
260 };
261
262 class VerifyObjectInArchiveRegionClosure: public ObjectClosure {
263 HeapRegion* _hr;
264 public:
265 VerifyObjectInArchiveRegionClosure(HeapRegion *hr, bool verbose)
266 : _hr(hr) { }
267 // Verify that all object pointers are to archive regions.
268 void do_object(oop o) {
269 VerifyArchiveOopClosure checkOop(_hr);
270 assert(o != NULL, "Should not be here for NULL oops");
271 o->oop_iterate(&checkOop);
272 }
273 };
274
275 // Should be only used at CDS dump time
276 class VerifyReadyForArchivingRegionClosure : public HeapRegionClosure {
277 bool _seen_free;
278 bool _has_holes;
279 bool _has_unexpected_holes;
280 bool _has_humongous;
281 public:
282 bool has_holes() {return _has_holes;}
283 bool has_unexpected_holes() {return _has_unexpected_holes;}
284 bool has_humongous() {return _has_humongous;}
285
286 VerifyReadyForArchivingRegionClosure() : HeapRegionClosure() {
287 _seen_free = false;
288 _has_holes = false;
289 _has_unexpected_holes = false;
290 _has_humongous = false;
291 }
292 virtual bool do_heap_region(HeapRegion* hr) {
293 const char* hole = "";
294
295 if (hr->is_free()) {
296 _seen_free = true;
297 } else {
298 if (_seen_free) {
299 _has_holes = true;
300 if (hr->is_humongous()) {
301 hole = " hole";
302 } else {
303 _has_unexpected_holes = true;
304 hole = " hole **** unexpected ****";
305 }
306 }
307 }
308 if (hr->is_humongous()) {
309 _has_humongous = true;
310 }
311 log_info(gc, region, cds)("HeapRegion " INTPTR_FORMAT " %s%s", p2i(hr->bottom()), hr->get_type_str(), hole);
312 return false;
313 }
314 };
315
316 // We want all used regions to be moved to the bottom-end of the heap, so we have
317 // a contiguous range of free regions at the top end of the heap. This way, we can
318 // avoid fragmentation while allocating the archive regions.
319 //
320 // Before calling this, a full GC should have been executed with a single worker thread,
321 // so that no old regions would be moved to the middle of the heap.
322 void G1HeapVerifier::verify_ready_for_archiving() {
323 VerifyReadyForArchivingRegionClosure cl;
324 G1CollectedHeap::heap()->heap_region_iterate(&cl);
325 if (cl.has_holes()) {
326 log_warning(gc, verify)("All free regions should be at the top end of the heap, but"
327 " we found holes. This is probably caused by (unmovable) humongous"
328 " allocations, and may lead to fragmentation while"
329 " writing archive heap memory regions.");
330 }
331 if (cl.has_humongous()) {
332 log_warning(gc, verify)("(Unmovable) humongous regions have been found and"
333 " may lead to fragmentation while"
334 " writing archive heap memory regions.");
335 }
336 assert(!cl.has_unexpected_holes(), "all holes should have been caused by humongous regions");
337 }
338
339 class VerifyArchivePointerRegionClosure: public HeapRegionClosure {
340 virtual bool do_heap_region(HeapRegion* r) {
341 if (r->is_archive()) {
342 VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
343 r->object_iterate(&verify_oop_pointers);
344 }
345 return false;
346 }
347 };
348
349 void G1HeapVerifier::verify_archive_regions() {
350 G1CollectedHeap* g1h = G1CollectedHeap::heap();
351 VerifyArchivePointerRegionClosure cl;
352 g1h->heap_region_iterate(&cl);
353 }
354
355 class VerifyRegionClosure: public HeapRegionClosure {
356 private:
357 bool _par;
358 VerifyOption _vo;
359 bool _failures;
360 public:
361 // _vo == UsePrevMarking -> use "prev" marking information,
362 // _vo == UseNextMarking -> use "next" marking information,
363 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
364 VerifyRegionClosure(bool par, VerifyOption vo)
365 : _par(par),
366 _vo(vo),
367 _failures(false) {}
368
369 bool failures() {
370 return _failures;
371 }
372
373 bool do_heap_region(HeapRegion* r) {
374 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());
375 // Humongous and old regions regions might be of any state, so can't check here.
376 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());
377 // Verify that the continues humongous regions' remembered set state matches the
378 // one from the starts humongous region.
379 if (r->is_continues_humongous()) {
380 if (r->rem_set()->get_state_str() != r->humongous_start_region()->rem_set()->get_state_str()) {
381 log_error(gc, verify)("Remset states differ: Region %u (%s) remset %s with starts region %u (%s) remset %s",
382 r->hrm_index(),
383 r->get_short_type_str(),
384 r->rem_set()->get_state_str(),
385 r->humongous_start_region()->hrm_index(),
386 r->humongous_start_region()->get_short_type_str(),
387 r->humongous_start_region()->rem_set()->get_state_str());
388 _failures = true;
389 }
390 }
391 // For archive regions, verify there are no heap pointers to
392 // non-pinned regions. For all others, verify liveness info.
393 if (r->is_closed_archive()) {
394 VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
395 r->object_iterate(&verify_oop_pointers);
396 return true;
397 } else if (r->is_open_archive()) {
398 VerifyObjsInRegionClosure verify_open_archive_oop(r, _vo);
399 r->object_iterate(&verify_open_archive_oop);
400 return true;
401 } else if (!r->is_continues_humongous()) {
402 bool failures = false;
403 r->verify(_vo, &failures);
404 if (failures) {
405 _failures = true;
406 } else if (!r->is_starts_humongous()) {
407 VerifyObjsInRegionClosure not_dead_yet_cl(r, _vo);
408 r->object_iterate(¬_dead_yet_cl);
409 if (_vo != VerifyOption_G1UseNextMarking) {
410 if (r->max_live_bytes() < not_dead_yet_cl.live_bytes()) {
411 log_error(gc, verify)("[" PTR_FORMAT "," PTR_FORMAT "] max_live_bytes " SIZE_FORMAT " < calculated " SIZE_FORMAT,
412 p2i(r->bottom()), p2i(r->end()), r->max_live_bytes(), not_dead_yet_cl.live_bytes());
413 _failures = true;
414 }
415 } else {
416 // When vo == UseNextMarking we cannot currently do a sanity
417 // check on the live bytes as the calculation has not been
418 // finalized yet.
419 }
420 }
421 }
422 return false; // stop the region iteration if we hit a failure
423 }
424 };
425
426 // This is the task used for parallel verification of the heap regions
427
428 class G1ParVerifyTask: public AbstractGangTask {
429 private:
430 G1CollectedHeap* _g1h;
431 VerifyOption _vo;
432 bool _failures;
433 HeapRegionClaimer _hrclaimer;
434
435 public:
436 // _vo == UsePrevMarking -> use "prev" marking information,
437 // _vo == UseNextMarking -> use "next" marking information,
438 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
439 G1ParVerifyTask(G1CollectedHeap* g1h, VerifyOption vo) :
440 AbstractGangTask("Parallel verify task"),
441 _g1h(g1h),
442 _vo(vo),
443 _failures(false),
444 _hrclaimer(g1h->workers()->active_workers()) {}
445
446 bool failures() {
447 return _failures;
448 }
449
450 void work(uint worker_id) {
451 HandleMark hm;
452 VerifyRegionClosure blk(true, _vo);
453 _g1h->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
454 if (blk.failures()) {
455 _failures = true;
456 }
457 }
458 };
459
460 void G1HeapVerifier::enable_verification_type(G1VerifyType type) {
461 // First enable will clear _enabled_verification_types.
462 if (_enabled_verification_types == G1VerifyAll) {
463 _enabled_verification_types = type;
464 } else {
465 _enabled_verification_types |= type;
466 }
467 }
468
469 bool G1HeapVerifier::should_verify(G1VerifyType type) {
470 return (_enabled_verification_types & type) == type;
471 }
472
473 void G1HeapVerifier::verify(VerifyOption vo) {
474 if (!SafepointSynchronize::is_at_safepoint()) {
475 log_info(gc, verify)("Skipping verification. Not at safepoint.");
476 }
477
478 assert(Thread::current()->is_VM_thread(),
479 "Expected to be executed serially by the VM thread at this point");
480
481 log_debug(gc, verify)("Roots");
482 VerifyRootsClosure rootsCl(vo);
483 VerifyCLDClosure cldCl(_g1h, &rootsCl);
484
485 // We apply the relevant closures to all the oops in the
486 // system dictionary, class loader data graph, the string table
487 // and the nmethods in the code cache.
488 G1VerifyCodeRootOopClosure codeRootsCl(_g1h, &rootsCl, vo);
489 G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
490
491 {
492 G1RootProcessor root_processor(_g1h, 1);
493 root_processor.process_all_roots(&rootsCl, &cldCl, &blobsCl);
494 }
495
496 bool failures = rootsCl.failures() || codeRootsCl.failures();
497
498 if (!_g1h->g1_policy()->collector_state()->in_full_gc()) {
499 // If we're verifying during a full GC then the region sets
500 // will have been torn down at the start of the GC. Therefore
501 // verifying the region sets will fail. So we only verify
502 // the region sets when not in a full GC.
503 log_debug(gc, verify)("HeapRegionSets");
504 verify_region_sets();
505 }
506
507 log_debug(gc, verify)("HeapRegions");
508 if (GCParallelVerificationEnabled && ParallelGCThreads > 1) {
509
510 G1ParVerifyTask task(_g1h, vo);
511 _g1h->workers()->run_task(&task);
512 if (task.failures()) {
513 failures = true;
514 }
515
516 } else {
517 VerifyRegionClosure blk(false, vo);
518 _g1h->heap_region_iterate(&blk);
519 if (blk.failures()) {
520 failures = true;
521 }
522 }
523
524 if (G1StringDedup::is_enabled()) {
525 log_debug(gc, verify)("StrDedup");
526 G1StringDedup::verify();
527 }
528
529 if (failures) {
530 log_error(gc, verify)("Heap after failed verification (kind %d):", vo);
531 // It helps to have the per-region information in the output to
532 // help us track down what went wrong. This is why we call
533 // print_extended_on() instead of print_on().
534 Log(gc, verify) log;
535 ResourceMark rm;
536 LogStream ls(log.error());
537 _g1h->print_extended_on(&ls);
538 }
539 guarantee(!failures, "there should not have been any failures");
540 }
541
542 // Heap region set verification
543
544 class VerifyRegionListsClosure : public HeapRegionClosure {
545 private:
546 HeapRegionSet* _old_set;
547 HeapRegionSet* _archive_set;
548 HeapRegionSet* _humongous_set;
549 HeapRegionManager* _hrm;
550
551 public:
552 uint _old_count;
553 uint _archive_count;
554 uint _humongous_count;
555 uint _free_count;
556
557 VerifyRegionListsClosure(HeapRegionSet* old_set,
558 HeapRegionSet* archive_set,
559 HeapRegionSet* humongous_set,
560 HeapRegionManager* hrm) :
561 _old_set(old_set), _archive_set(archive_set), _humongous_set(humongous_set), _hrm(hrm),
562 _old_count(), _archive_count(), _humongous_count(), _free_count(){ }
563
564 bool do_heap_region(HeapRegion* hr) {
565 if (hr->is_young()) {
566 // TODO
567 } else if (hr->is_humongous()) {
568 assert(hr->containing_set() == _humongous_set, "Heap region %u is humongous but not in humongous set.", hr->hrm_index());
569 _humongous_count++;
570 } else if (hr->is_empty()) {
571 assert(_hrm->is_free(hr), "Heap region %u is empty but not on the free list.", hr->hrm_index());
572 _free_count++;
573 } else if (hr->is_archive()) {
574 assert(hr->containing_set() == _archive_set, "Heap region %u is archive but not in the archive set.", hr->hrm_index());
575 _archive_count++;
576 } else if (hr->is_old()) {
577 assert(hr->containing_set() == _old_set, "Heap region %u is old but not in the old set.", hr->hrm_index());
578 _old_count++;
579 } else {
580 // There are no other valid region types. Check for one invalid
581 // one we can identify: pinned without old or humongous set.
582 assert(!hr->is_pinned(), "Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index());
583 ShouldNotReachHere();
584 }
585 return false;
586 }
587
588 void verify_counts(HeapRegionSet* old_set, HeapRegionSet* archive_set, HeapRegionSet* humongous_set, HeapRegionManager* free_list) {
589 guarantee(old_set->length() == _old_count, "Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count);
590 guarantee(archive_set->length() == _archive_count, "Archive set count mismatch. Expected %u, actual %u.", archive_set->length(), _archive_count);
591 guarantee(humongous_set->length() == _humongous_count, "Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count);
592 guarantee(free_list->num_free_regions() == _free_count, "Free list count mismatch. Expected %u, actual %u.", free_list->num_free_regions(), _free_count);
593 }
594 };
595
596 void G1HeapVerifier::verify_region_sets() {
597 assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
598
599 // First, check the explicit lists.
600 _g1h->_hrm->verify();
601
602 // Finally, make sure that the region accounting in the lists is
603 // consistent with what we see in the heap.
604
605 VerifyRegionListsClosure cl(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
606 _g1h->heap_region_iterate(&cl);
607 cl.verify_counts(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
608 }
609
610 void G1HeapVerifier::prepare_for_verify() {
611 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
612 _g1h->ensure_parsability(false);
613 }
614 }
615
616 double G1HeapVerifier::verify(G1VerifyType type, VerifyOption vo, const char* msg) {
617 double verify_time_ms = 0.0;
618
619 if (should_verify(type) && _g1h->total_collections() >= VerifyGCStartAt) {
620 double verify_start = os::elapsedTime();
621 HandleMark hm; // Discard invalid handles created during verification
622 prepare_for_verify();
623 Universe::verify(vo, msg);
624 verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
625 }
626
627 return verify_time_ms;
628 }
629
630 void G1HeapVerifier::verify_before_gc(G1VerifyType type) {
631 if (VerifyBeforeGC) {
632 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "Before GC");
633 _g1h->g1_policy()->phase_times()->record_verify_before_time_ms(verify_time_ms);
634 }
635 }
636
637 void G1HeapVerifier::verify_after_gc(G1VerifyType type) {
638 if (VerifyAfterGC) {
639 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "After GC");
640 _g1h->g1_policy()->phase_times()->record_verify_after_time_ms(verify_time_ms);
641 }
642 }
643
644
645 #ifndef PRODUCT
646 class G1VerifyCardTableCleanup: public HeapRegionClosure {
647 G1HeapVerifier* _verifier;
648 public:
649 G1VerifyCardTableCleanup(G1HeapVerifier* verifier)
650 : _verifier(verifier) { }
651 virtual bool do_heap_region(HeapRegion* r) {
652 if (r->is_survivor()) {
653 _verifier->verify_dirty_region(r);
654 } else {
655 _verifier->verify_not_dirty_region(r);
656 }
657 return false;
658 }
659 };
660
661 void G1HeapVerifier::verify_card_table_cleanup() {
662 if (G1VerifyCTCleanup || VerifyAfterGC) {
663 G1VerifyCardTableCleanup cleanup_verifier(this);
664 _g1h->heap_region_iterate(&cleanup_verifier);
665 }
666 }
667
668 void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
669 // All of the region should be clean.
670 G1CardTable* ct = _g1h->card_table();
671 MemRegion mr(hr->bottom(), hr->end());
672 ct->verify_not_dirty_region(mr);
673 }
674
675 void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
676 // We cannot guarantee that [bottom(),end()] is dirty. Threads
677 // dirty allocated blocks as they allocate them. The thread that
678 // retires each region and replaces it with a new one will do a
679 // maximal allocation to fill in [pre_dummy_top(),end()] but will
680 // not dirty that area (one less thing to have to do while holding
681 // a lock). So we can only verify that [bottom(),pre_dummy_top()]
682 // is dirty.
683 G1CardTable* ct = _g1h->card_table();
684 MemRegion mr(hr->bottom(), hr->pre_dummy_top());
685 if (hr->is_young()) {
686 ct->verify_g1_young_region(mr);
687 } else {
688 ct->verify_dirty_region(mr);
689 }
690 }
691
692 class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
693 private:
694 G1HeapVerifier* _verifier;
695 public:
696 G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
697 virtual bool do_heap_region(HeapRegion* r) {
698 _verifier->verify_dirty_region(r);
699 return false;
700 }
701 };
702
703 void G1HeapVerifier::verify_dirty_young_regions() {
704 G1VerifyDirtyYoungListClosure cl(this);
705 _g1h->collection_set()->iterate(&cl);
706 }
707
708 bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
709 HeapWord* tams, HeapWord* end) {
710 guarantee(tams <= end,
711 "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
712 HeapWord* result = bitmap->get_next_marked_addr(tams, end);
713 if (result < end) {
714 log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
715 log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
716 return false;
717 }
718 return true;
719 }
720
721 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
722 const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prev_mark_bitmap();
723 const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->next_mark_bitmap();
724
725 HeapWord* ptams = hr->prev_top_at_mark_start();
726 HeapWord* ntams = hr->next_top_at_mark_start();
727 HeapWord* end = hr->end();
728
729 bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
730
731 bool res_n = true;
732 // We cannot verify the next bitmap while we are about to clear it.
733 if (!_g1h->collector_state()->clearing_next_bitmap()) {
734 res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
735 }
736 if (!res_p || !res_n) {
737 log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
738 log_error(gc, verify)("#### Caller: %s", caller);
739 return false;
740 }
741 return true;
742 }
743
744 void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
745 if (!G1VerifyBitmaps) {
746 return;
747 }
748
749 guarantee(verify_bitmaps(caller, hr), "bitmap verification");
750 }
751
752 class G1VerifyBitmapClosure : public HeapRegionClosure {
753 private:
754 const char* _caller;
755 G1HeapVerifier* _verifier;
756 bool _failures;
757
758 public:
759 G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
760 _caller(caller), _verifier(verifier), _failures(false) { }
761
762 bool failures() { return _failures; }
763
764 virtual bool do_heap_region(HeapRegion* hr) {
765 bool result = _verifier->verify_bitmaps(_caller, hr);
766 if (!result) {
767 _failures = true;
768 }
769 return false;
770 }
771 };
772
773 void G1HeapVerifier::check_bitmaps(const char* caller) {
774 if (!G1VerifyBitmaps) {
775 return;
776 }
777
778 G1VerifyBitmapClosure cl(caller, this);
779 _g1h->heap_region_iterate(&cl);
780 guarantee(!cl.failures(), "bitmap verification");
781 }
782
783 class G1CheckCSetFastTableClosure : public HeapRegionClosure {
784 private:
785 bool _failures;
786 public:
787 G1CheckCSetFastTableClosure() : HeapRegionClosure(), _failures(false) { }
788
789 virtual bool do_heap_region(HeapRegion* hr) {
790 uint i = hr->hrm_index();
791 InCSetState cset_state = (InCSetState) G1CollectedHeap::heap()->_in_cset_fast_test.get_by_index(i);
792 if (hr->is_humongous()) {
793 if (hr->in_collection_set()) {
794 log_error(gc, verify)("## humongous region %u in CSet", i);
795 _failures = true;
796 return true;
797 }
798 if (cset_state.is_in_cset()) {
799 log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for humongous region %u", cset_state.value(), i);
800 _failures = true;
801 return true;
802 }
803 if (hr->is_continues_humongous() && cset_state.is_humongous()) {
804 log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for continues humongous region %u", cset_state.value(), i);
805 _failures = true;
806 return true;
807 }
808 } else {
809 if (cset_state.is_humongous()) {
810 log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for non-humongous region %u", cset_state.value(), i);
811 _failures = true;
812 return true;
813 }
814 if (hr->in_collection_set() != cset_state.is_in_cset()) {
815 log_error(gc, verify)("## in CSet %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
816 hr->in_collection_set(), cset_state.value(), i);
817 _failures = true;
818 return true;
819 }
820 if (cset_state.is_in_cset()) {
821 if (hr->is_archive()) {
822 log_error(gc, verify)("## is_archive in collection set for region %u", i);
823 _failures = true;
824 return true;
825 }
826 if (hr->is_young() != (cset_state.is_young())) {
827 log_error(gc, verify)("## is_young %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
828 hr->is_young(), cset_state.value(), i);
829 _failures = true;
830 return true;
831 }
832 if (hr->is_old() != (cset_state.is_old())) {
833 log_error(gc, verify)("## is_old %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
834 hr->is_old(), cset_state.value(), i);
835 _failures = true;
836 return true;
837 }
838 }
839 }
840 return false;
841 }
842
843 bool failures() const { return _failures; }
844 };
845
846 bool G1HeapVerifier::check_cset_fast_test() {
847 G1CheckCSetFastTableClosure cl;
848 _g1h->_hrm->iterate(&cl);
849 return !cl.failures();
850 }
851 #endif // PRODUCT