1 /*
2 * Copyright (c) 2016, 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/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
47 int G1HeapVerifier::_enabled_verification_types = G1HeapVerifier::G1VerifyAll;
48
49 class VerifyRootsClosure: public OopClosure {
50 private:
51 G1CollectedHeap* _g1h;
52 VerifyOption _vo;
53 bool _failures;
54 public:
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
84 class 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
128 public:
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
139 class G1VerifyCodeRootBlobClosure: public CodeBlobClosure {
140 G1VerifyCodeRootOopClosure* _oop_cl;
141
142 public:
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
155 class 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
167 class 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
183 class VerifyLivenessOopClosure: public BasicOopIterateClosure {
184 G1CollectedHeap* _g1h;
185 VerifyOption _vo;
186 public:
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
200 class VerifyObjsInRegionClosure: public ObjectClosure {
201 private:
202 G1CollectedHeap* _g1h;
203 size_t _live_bytes;
204 HeapRegion *_hr;
205 VerifyOption _vo;
206 public:
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
239 class VerifyArchiveOopClosure: public BasicOopIterateClosure {
240 HeapRegion* _hr;
241 public:
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
263 class VerifyObjectInArchiveRegionClosure: public ObjectClosure {
264 HeapRegion* _hr;
265 public:
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
277 class VerifyReadyForArchivingRegionClosure : public HeapRegionClosure {
278 bool _seen_free;
279 bool _has_holes;
280 bool _has_unexpected_holes;
281 bool _has_humongous;
282 public:
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.
323 void 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 or active GCLocker, 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 }
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->has_index_in_opt_cset(), "Region %u still has opt collection set index %u", r->hrm_index(), r->index_in_opt_cset());
375 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());
376 // Humongous and old regions regions might be of any state, so can't check here.
377 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());
378 // Verify that the continues humongous regions' remembered set state matches the
379 // one from the starts humongous region.
380 if (r->is_continues_humongous()) {
381 if (r->rem_set()->get_state_str() != r->humongous_start_region()->rem_set()->get_state_str()) {
382 log_error(gc, verify)("Remset states differ: Region %u (%s) remset %s with starts region %u (%s) remset %s",
383 r->hrm_index(),
384 r->get_short_type_str(),
385 r->rem_set()->get_state_str(),
386 r->humongous_start_region()->hrm_index(),
387 r->humongous_start_region()->get_short_type_str(),
388 r->humongous_start_region()->rem_set()->get_state_str());
389 _failures = true;
390 }
391 }
392 // For archive regions, verify there are no heap pointers to
393 // non-pinned regions. For all others, verify liveness info.
394 if (r->is_closed_archive()) {
395 VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
396 r->object_iterate(&verify_oop_pointers);
397 return true;
398 } else if (r->is_open_archive()) {
399 VerifyObjsInRegionClosure verify_open_archive_oop(r, _vo);
400 r->object_iterate(&verify_open_archive_oop);
401 return true;
402 } else if (!r->is_continues_humongous()) {
403 bool failures = false;
404 r->verify(_vo, &failures);
405 if (failures) {
406 _failures = true;
407 } else if (!r->is_starts_humongous()) {
408 VerifyObjsInRegionClosure not_dead_yet_cl(r, _vo);
409 r->object_iterate(¬_dead_yet_cl);
410 if (_vo != VerifyOption_G1UseNextMarking) {
411 if (r->max_live_bytes() < not_dead_yet_cl.live_bytes()) {
412 log_error(gc, verify)("[" PTR_FORMAT "," PTR_FORMAT "] max_live_bytes " SIZE_FORMAT " < calculated " SIZE_FORMAT,
413 p2i(r->bottom()), p2i(r->end()), r->max_live_bytes(), not_dead_yet_cl.live_bytes());
414 _failures = true;
415 }
416 } else {
417 // When vo == UseNextMarking we cannot currently do a sanity
418 // check on the live bytes as the calculation has not been
419 // finalized yet.
420 }
421 }
422 }
423 return false; // stop the region iteration if we hit a failure
424 }
425 };
426
427 // This is the task used for parallel verification of the heap regions
428
429 class G1ParVerifyTask: public AbstractGangTask {
430 private:
431 G1CollectedHeap* _g1h;
432 VerifyOption _vo;
433 bool _failures;
434 HeapRegionClaimer _hrclaimer;
435
436 public:
437 // _vo == UsePrevMarking -> use "prev" marking information,
438 // _vo == UseNextMarking -> use "next" marking information,
439 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
440 G1ParVerifyTask(G1CollectedHeap* g1h, VerifyOption vo) :
441 AbstractGangTask("Parallel verify task"),
442 _g1h(g1h),
443 _vo(vo),
444 _failures(false),
445 _hrclaimer(g1h->workers()->active_workers()) {}
446
447 bool failures() {
448 return _failures;
449 }
450
451 void work(uint worker_id) {
452 HandleMark hm;
453 VerifyRegionClosure blk(true, _vo);
454 _g1h->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
455 if (blk.failures()) {
456 _failures = true;
457 }
458 }
459 };
460
461 void G1HeapVerifier::enable_verification_type(G1VerifyType type) {
462 // First enable will clear _enabled_verification_types.
463 if (_enabled_verification_types == G1VerifyAll) {
464 _enabled_verification_types = type;
465 } else {
466 _enabled_verification_types |= type;
467 }
468 }
469
470 bool G1HeapVerifier::should_verify(G1VerifyType type) {
471 return (_enabled_verification_types & type) == type;
472 }
473
474 void G1HeapVerifier::verify(VerifyOption vo) {
475 if (!SafepointSynchronize::is_at_safepoint()) {
476 log_info(gc, verify)("Skipping verification. Not at safepoint.");
477 }
478
479 assert(Thread::current()->is_VM_thread(),
480 "Expected to be executed serially by the VM thread at this point");
481
482 log_debug(gc, verify)("Roots");
483 VerifyRootsClosure rootsCl(vo);
484 VerifyCLDClosure cldCl(_g1h, &rootsCl);
485
486 // We apply the relevant closures to all the oops in the
487 // system dictionary, class loader data graph, the string table
488 // and the nmethods in the code cache.
489 G1VerifyCodeRootOopClosure codeRootsCl(_g1h, &rootsCl, vo);
490 G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
491
492 {
493 G1RootProcessor root_processor(_g1h, 1);
494 root_processor.process_all_roots(&rootsCl, &cldCl, &blobsCl);
495 }
496
497 bool failures = rootsCl.failures() || codeRootsCl.failures();
498
499 if (!_g1h->policy()->collector_state()->in_full_gc()) {
500 // If we're verifying during a full GC then the region sets
501 // will have been torn down at the start of the GC. Therefore
502 // verifying the region sets will fail. So we only verify
503 // the region sets when not in a full GC.
504 log_debug(gc, verify)("HeapRegionSets");
505 verify_region_sets();
506 }
507
508 log_debug(gc, verify)("HeapRegions");
509 if (GCParallelVerificationEnabled && ParallelGCThreads > 1) {
510
511 G1ParVerifyTask task(_g1h, vo);
512 _g1h->workers()->run_task(&task);
513 if (task.failures()) {
514 failures = true;
515 }
516
517 } else {
518 VerifyRegionClosure blk(false, vo);
519 _g1h->heap_region_iterate(&blk);
520 if (blk.failures()) {
521 failures = true;
522 }
523 }
524
525 if (G1StringDedup::is_enabled()) {
526 log_debug(gc, verify)("StrDedup");
527 G1StringDedup::verify();
528 }
529
530 if (failures) {
531 log_error(gc, verify)("Heap after failed verification (kind %d):", vo);
532 // It helps to have the per-region information in the output to
533 // help us track down what went wrong. This is why we call
534 // print_extended_on() instead of print_on().
535 Log(gc, verify) log;
536 ResourceMark rm;
537 LogStream ls(log.error());
538 _g1h->print_extended_on(&ls);
539 }
540 guarantee(!failures, "there should not have been any failures");
541 }
542
543 // Heap region set verification
544
545 class VerifyRegionListsClosure : public HeapRegionClosure {
546 private:
547 HeapRegionSet* _old_set;
548 HeapRegionSet* _archive_set;
549 HeapRegionSet* _humongous_set;
550 HeapRegionManager* _hrm;
551
552 public:
553 uint _old_count;
554 uint _archive_count;
555 uint _humongous_count;
556 uint _free_count;
557
558 VerifyRegionListsClosure(HeapRegionSet* old_set,
559 HeapRegionSet* archive_set,
560 HeapRegionSet* humongous_set,
561 HeapRegionManager* hrm) :
562 _old_set(old_set), _archive_set(archive_set), _humongous_set(humongous_set), _hrm(hrm),
563 _old_count(), _archive_count(), _humongous_count(), _free_count(){ }
564
565 bool do_heap_region(HeapRegion* hr) {
566 if (hr->is_young()) {
567 // TODO
568 } else if (hr->is_humongous()) {
569 assert(hr->containing_set() == _humongous_set, "Heap region %u is humongous but not in humongous set.", hr->hrm_index());
570 _humongous_count++;
571 } else if (hr->is_empty()) {
572 assert(_hrm->is_free(hr), "Heap region %u is empty but not on the free list.", hr->hrm_index());
573 _free_count++;
574 } else if (hr->is_archive()) {
575 assert(hr->containing_set() == _archive_set, "Heap region %u is archive but not in the archive set.", hr->hrm_index());
576 _archive_count++;
577 } else if (hr->is_old()) {
578 assert(hr->containing_set() == _old_set, "Heap region %u is old but not in the old set.", hr->hrm_index());
579 _old_count++;
580 } else {
581 // There are no other valid region types. Check for one invalid
582 // one we can identify: pinned without old or humongous set.
583 assert(!hr->is_pinned(), "Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index());
584 ShouldNotReachHere();
585 }
586 return false;
587 }
588
589 void verify_counts(HeapRegionSet* old_set, HeapRegionSet* archive_set, HeapRegionSet* humongous_set, HeapRegionManager* free_list) {
590 guarantee(old_set->length() == _old_count, "Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count);
591 guarantee(archive_set->length() == _archive_count, "Archive set count mismatch. Expected %u, actual %u.", archive_set->length(), _archive_count);
592 guarantee(humongous_set->length() == _humongous_count, "Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count);
593 guarantee(free_list->num_free_regions() == _free_count, "Free list count mismatch. Expected %u, actual %u.", free_list->num_free_regions(), _free_count);
594 }
595 };
596
597 void G1HeapVerifier::verify_region_sets() {
598 assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
599
600 // First, check the explicit lists.
601 _g1h->_hrm->verify();
602
603 // Finally, make sure that the region accounting in the lists is
604 // consistent with what we see in the heap.
605
606 VerifyRegionListsClosure cl(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
607 _g1h->heap_region_iterate(&cl);
608 cl.verify_counts(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, _g1h->_hrm);
609 }
610
611 void G1HeapVerifier::prepare_for_verify() {
612 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
613 _g1h->ensure_parsability(false);
614 }
615 }
616
617 double G1HeapVerifier::verify(G1VerifyType type, VerifyOption vo, const char* msg) {
618 double verify_time_ms = 0.0;
619
620 if (should_verify(type) && _g1h->total_collections() >= VerifyGCStartAt) {
621 double verify_start = os::elapsedTime();
622 HandleMark hm; // Discard invalid handles created during verification
623 prepare_for_verify();
624 Universe::verify(vo, msg);
625 verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
626 }
627
628 return verify_time_ms;
629 }
630
631 void G1HeapVerifier::verify_before_gc(G1VerifyType type) {
632 if (VerifyBeforeGC) {
633 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "Before GC");
634 _g1h->phase_times()->record_verify_before_time_ms(verify_time_ms);
635 }
636 }
637
638 void G1HeapVerifier::verify_after_gc(G1VerifyType type) {
639 if (VerifyAfterGC) {
640 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "After GC");
641 _g1h->phase_times()->record_verify_after_time_ms(verify_time_ms);
642 }
643 }
644
645
646 #ifndef PRODUCT
647 class G1VerifyCardTableCleanup: public HeapRegionClosure {
648 G1HeapVerifier* _verifier;
649 public:
650 G1VerifyCardTableCleanup(G1HeapVerifier* verifier)
651 : _verifier(verifier) { }
652 virtual bool do_heap_region(HeapRegion* r) {
653 if (r->is_survivor()) {
654 _verifier->verify_dirty_region(r);
655 } else {
656 _verifier->verify_not_dirty_region(r);
657 }
658 return false;
659 }
660 };
661
662 void G1HeapVerifier::verify_card_table_cleanup() {
663 if (G1VerifyCTCleanup || VerifyAfterGC) {
664 G1VerifyCardTableCleanup cleanup_verifier(this);
665 _g1h->heap_region_iterate(&cleanup_verifier);
666 }
667 }
668
669 void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
670 // All of the region should be clean.
671 G1CardTable* ct = _g1h->card_table();
672 MemRegion mr(hr->bottom(), hr->end());
673 ct->verify_not_dirty_region(mr);
674 }
675
676 void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
677 // We cannot guarantee that [bottom(),end()] is dirty. Threads
678 // dirty allocated blocks as they allocate them. The thread that
679 // retires each region and replaces it with a new one will do a
680 // maximal allocation to fill in [pre_dummy_top(),end()] but will
681 // not dirty that area (one less thing to have to do while holding
682 // a lock). So we can only verify that [bottom(),pre_dummy_top()]
683 // is dirty.
684 G1CardTable* ct = _g1h->card_table();
685 MemRegion mr(hr->bottom(), hr->pre_dummy_top());
686 if (hr->is_young()) {
687 ct->verify_g1_young_region(mr);
688 } else {
689 ct->verify_dirty_region(mr);
690 }
691 }
692
693 class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
694 private:
695 G1HeapVerifier* _verifier;
696 public:
697 G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
698 virtual bool do_heap_region(HeapRegion* r) {
699 _verifier->verify_dirty_region(r);
700 return false;
701 }
702 };
703
704 void G1HeapVerifier::verify_dirty_young_regions() {
705 G1VerifyDirtyYoungListClosure cl(this);
706 _g1h->collection_set()->iterate(&cl);
707 }
708
709 bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
710 HeapWord* tams, HeapWord* end) {
711 guarantee(tams <= end,
712 "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
713 HeapWord* result = bitmap->get_next_marked_addr(tams, end);
714 if (result < end) {
715 log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
716 log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
717 return false;
718 }
719 return true;
720 }
721
722 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
723 const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prev_mark_bitmap();
724 const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->next_mark_bitmap();
725
726 HeapWord* ptams = hr->prev_top_at_mark_start();
727 HeapWord* ntams = hr->next_top_at_mark_start();
728 HeapWord* end = hr->end();
729
730 bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
731
732 bool res_n = true;
733 // We cannot verify the next bitmap while we are about to clear it.
734 if (!_g1h->collector_state()->clearing_next_bitmap()) {
735 res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
736 }
737 if (!res_p || !res_n) {
738 log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
739 log_error(gc, verify)("#### Caller: %s", caller);
740 return false;
741 }
742 return true;
743 }
744
745 void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
746 if (!G1VerifyBitmaps) {
747 return;
748 }
749
750 guarantee(verify_bitmaps(caller, hr), "bitmap verification");
751 }
752
753 class G1VerifyBitmapClosure : public HeapRegionClosure {
754 private:
755 const char* _caller;
756 G1HeapVerifier* _verifier;
757 bool _failures;
758
759 public:
760 G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
761 _caller(caller), _verifier(verifier), _failures(false) { }
762
763 bool failures() { return _failures; }
764
765 virtual bool do_heap_region(HeapRegion* hr) {
766 bool result = _verifier->verify_bitmaps(_caller, hr);
767 if (!result) {
768 _failures = true;
769 }
770 return false;
771 }
772 };
773
774 void G1HeapVerifier::check_bitmaps(const char* caller) {
775 if (!G1VerifyBitmaps) {
776 return;
777 }
778
779 G1VerifyBitmapClosure cl(caller, this);
780 _g1h->heap_region_iterate(&cl);
781 guarantee(!cl.failures(), "bitmap verification");
782 }
783
784 class G1CheckRegionAttrTableClosure : public HeapRegionClosure {
785 private:
786 bool _failures;
787
788 public:
789 G1CheckRegionAttrTableClosure() : HeapRegionClosure(), _failures(false) { }
790
791 virtual bool do_heap_region(HeapRegion* hr) {
792 uint i = hr->hrm_index();
793 G1HeapRegionAttr region_attr = (G1HeapRegionAttr) G1CollectedHeap::heap()->_region_attr.get_by_index(i);
794 if (hr->is_humongous()) {
795 if (hr->in_collection_set()) {
796 log_error(gc, verify)("## humongous region %u in CSet", i);
797 _failures = true;
798 return true;
799 }
800 if (region_attr.is_in_cset()) {
801 log_error(gc, verify)("## inconsistent region attr type %s for humongous region %u", region_attr.get_type_str(), i);
802 _failures = true;
803 return true;
804 }
805 if (hr->is_continues_humongous() && region_attr.is_humongous()) {
806 log_error(gc, verify)("## inconsistent region attr type %s for continues humongous region %u", region_attr.get_type_str(), i);
807 _failures = true;
808 return true;
809 }
810 } else {
811 if (region_attr.is_humongous()) {
812 log_error(gc, verify)("## inconsistent region attr type %s for non-humongous region %u", region_attr.get_type_str(), i);
813 _failures = true;
814 return true;
815 }
816 if (hr->in_collection_set() != region_attr.is_in_cset()) {
817 log_error(gc, verify)("## in CSet %d / region attr type %s inconsistency for region %u",
818 hr->in_collection_set(), region_attr.get_type_str(), i);
819 _failures = true;
820 return true;
821 }
822 if (region_attr.is_in_cset()) {
823 if (hr->is_archive()) {
824 log_error(gc, verify)("## is_archive in collection set for region %u", i);
825 _failures = true;
826 return true;
827 }
828 if (hr->is_young() != (region_attr.is_young())) {
829 log_error(gc, verify)("## is_young %d / region attr type %s inconsistency for region %u",
830 hr->is_young(), region_attr.get_type_str(), i);
831 _failures = true;
832 return true;
833 }
834 if (hr->is_old() != (region_attr.is_old())) {
835 log_error(gc, verify)("## is_old %d / region attr type %s inconsistency for region %u",
836 hr->is_old(), region_attr.get_type_str(), i);
837 _failures = true;
838 return true;
839 }
840 }
841 }
842 return false;
843 }
844
845 bool failures() const { return _failures; }
846 };
847
848 bool G1HeapVerifier::check_region_attr_table() {
849 G1CheckRegionAttrTableClosure cl;
850 _g1h->_hrm->iterate(&cl);
851 return !cl.failures();
852 }
853 #endif // PRODUCT