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 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->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 prepare_for_verify();
622 Universe::verify(vo, msg);
623 verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
624 }
625
626 return verify_time_ms;
627 }
628
629 void G1HeapVerifier::verify_before_gc(G1VerifyType type) {
630 if (VerifyBeforeGC) {
631 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "Before GC");
632 _g1h->phase_times()->record_verify_before_time_ms(verify_time_ms);
633 }
634 }
635
636 void G1HeapVerifier::verify_after_gc(G1VerifyType type) {
637 if (VerifyAfterGC) {
638 double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "After GC");
639 _g1h->phase_times()->record_verify_after_time_ms(verify_time_ms);
640 }
641 }
642
643
644 #ifndef PRODUCT
645 class G1VerifyCardTableCleanup: public HeapRegionClosure {
646 G1HeapVerifier* _verifier;
647 public:
648 G1VerifyCardTableCleanup(G1HeapVerifier* verifier)
649 : _verifier(verifier) { }
650 virtual bool do_heap_region(HeapRegion* r) {
651 if (r->is_survivor()) {
652 _verifier->verify_dirty_region(r);
653 } else {
654 _verifier->verify_not_dirty_region(r);
655 }
656 return false;
657 }
658 };
659
660 void G1HeapVerifier::verify_card_table_cleanup() {
661 if (G1VerifyCTCleanup || VerifyAfterGC) {
662 G1VerifyCardTableCleanup cleanup_verifier(this);
663 _g1h->heap_region_iterate(&cleanup_verifier);
664 }
665 }
666
667 void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
668 // All of the region should be clean.
669 G1CardTable* ct = _g1h->card_table();
670 MemRegion mr(hr->bottom(), hr->end());
671 ct->verify_not_dirty_region(mr);
672 }
673
674 void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
675 // We cannot guarantee that [bottom(),end()] is dirty. Threads
676 // dirty allocated blocks as they allocate them. The thread that
677 // retires each region and replaces it with a new one will do a
678 // maximal allocation to fill in [pre_dummy_top(),end()] but will
679 // not dirty that area (one less thing to have to do while holding
680 // a lock). So we can only verify that [bottom(),pre_dummy_top()]
681 // is dirty.
682 G1CardTable* ct = _g1h->card_table();
683 MemRegion mr(hr->bottom(), hr->pre_dummy_top());
684 if (hr->is_young()) {
685 ct->verify_g1_young_region(mr);
686 } else {
687 ct->verify_dirty_region(mr);
688 }
689 }
690
691 class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
692 private:
693 G1HeapVerifier* _verifier;
694 public:
695 G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
696 virtual bool do_heap_region(HeapRegion* r) {
697 _verifier->verify_dirty_region(r);
698 return false;
699 }
700 };
701
702 void G1HeapVerifier::verify_dirty_young_regions() {
703 G1VerifyDirtyYoungListClosure cl(this);
704 _g1h->collection_set()->iterate(&cl);
705 }
706
707 bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
708 HeapWord* tams, HeapWord* end) {
709 guarantee(tams <= end,
710 "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
711 HeapWord* result = bitmap->get_next_marked_addr(tams, end);
712 if (result < end) {
713 log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
714 log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
715 return false;
716 }
717 return true;
718 }
719
720 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
721 const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prev_mark_bitmap();
722 const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->next_mark_bitmap();
723
724 HeapWord* ptams = hr->prev_top_at_mark_start();
725 HeapWord* ntams = hr->next_top_at_mark_start();
726 HeapWord* end = hr->end();
727
728 bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
729
730 bool res_n = true;
731 // We cannot verify the next bitmap while we are about to clear it.
732 if (!_g1h->collector_state()->clearing_next_bitmap()) {
733 res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
734 }
735 if (!res_p || !res_n) {
736 log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
737 log_error(gc, verify)("#### Caller: %s", caller);
738 return false;
739 }
740 return true;
741 }
742
743 void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
744 if (!G1VerifyBitmaps) {
745 return;
746 }
747
748 guarantee(verify_bitmaps(caller, hr), "bitmap verification");
749 }
750
751 class G1VerifyBitmapClosure : public HeapRegionClosure {
752 private:
753 const char* _caller;
754 G1HeapVerifier* _verifier;
755 bool _failures;
756
757 public:
758 G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
759 _caller(caller), _verifier(verifier), _failures(false) { }
760
761 bool failures() { return _failures; }
762
763 virtual bool do_heap_region(HeapRegion* hr) {
764 bool result = _verifier->verify_bitmaps(_caller, hr);
765 if (!result) {
766 _failures = true;
767 }
768 return false;
769 }
770 };
771
772 void G1HeapVerifier::check_bitmaps(const char* caller) {
773 if (!G1VerifyBitmaps) {
774 return;
775 }
776
777 G1VerifyBitmapClosure cl(caller, this);
778 _g1h->heap_region_iterate(&cl);
779 guarantee(!cl.failures(), "bitmap verification");
780 }
781
782 class G1CheckRegionAttrTableClosure : public HeapRegionClosure {
783 private:
784 bool _failures;
785
786 public:
787 G1CheckRegionAttrTableClosure() : HeapRegionClosure(), _failures(false) { }
788
789 virtual bool do_heap_region(HeapRegion* hr) {
790 uint i = hr->hrm_index();
791 G1HeapRegionAttr region_attr = (G1HeapRegionAttr) G1CollectedHeap::heap()->_region_attr.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 (region_attr.is_in_cset()) {
799 log_error(gc, verify)("## inconsistent region attr type %s for humongous region %u", region_attr.get_type_str(), i);
800 _failures = true;
801 return true;
802 }
803 if (hr->is_continues_humongous() && region_attr.is_humongous()) {
804 log_error(gc, verify)("## inconsistent region attr type %s for continues humongous region %u", region_attr.get_type_str(), i);
805 _failures = true;
806 return true;
807 }
808 } else {
809 if (region_attr.is_humongous()) {
810 log_error(gc, verify)("## inconsistent region attr type %s for non-humongous region %u", region_attr.get_type_str(), i);
811 _failures = true;
812 return true;
813 }
814 if (hr->in_collection_set() != region_attr.is_in_cset()) {
815 log_error(gc, verify)("## in CSet %d / region attr type %s inconsistency for region %u",
816 hr->in_collection_set(), region_attr.get_type_str(), i);
817 _failures = true;
818 return true;
819 }
820 if (region_attr.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() != (region_attr.is_young())) {
827 log_error(gc, verify)("## is_young %d / region attr type %s inconsistency for region %u",
828 hr->is_young(), region_attr.get_type_str(), i);
829 _failures = true;
830 return true;
831 }
832 if (hr->is_old() != (region_attr.is_old())) {
833 log_error(gc, verify)("## is_old %d / region attr type %s inconsistency for region %u",
834 hr->is_old(), region_attr.get_type_str(), 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_region_attr_table() {
847 G1CheckRegionAttrTableClosure cl;
848 _g1h->_hrm->iterate(&cl);
849 return !cl.failures();
850 }
851 #endif // PRODUCT