1 /*
  2  * Copyright (c) 2016, 2018, 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 "gc/g1/g1Allocator.inline.hpp"
 27 #include "gc/g1/g1CollectedHeap.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.hpp"
 35 #include "gc/g1/heapRegion.inline.hpp"
 36 #include "gc/g1/heapRegionRemSet.hpp"
 37 #include "gc/g1/g1StringDedup.hpp"
 38 #include "logging/log.hpp"
 39 #include "logging/logStream.hpp"
 40 #include "memory/iterator.inline.hpp"
 41 #include "memory/resourceArea.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, false);
174 
175     _young_ref_counter_closure.reset_count();
176     cld->oops_do(&_young_ref_counter_closure, false);
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_archive_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 VerifyArchivePointerRegionClosure: public HeapRegionClosure {
278 private:
279   G1CollectedHeap* _g1h;
280 public:
281   VerifyArchivePointerRegionClosure(G1CollectedHeap* g1h) { }
282   virtual bool do_heap_region(HeapRegion* r) {
283    if (r->is_archive()) {
284       VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
285       r->object_iterate(&verify_oop_pointers);
286     }
287     return false;
288   }
289 };
290 
291 void G1HeapVerifier::verify_archive_regions() {
292   G1CollectedHeap*  g1h = G1CollectedHeap::heap();
293   VerifyArchivePointerRegionClosure cl(NULL);
294   g1h->heap_region_iterate(&cl);
295 }
296 
297 class VerifyRegionClosure: public HeapRegionClosure {
298 private:
299   bool             _par;
300   VerifyOption     _vo;
301   bool             _failures;
302 public:
303   // _vo == UsePrevMarking -> use "prev" marking information,
304   // _vo == UseNextMarking -> use "next" marking information,
305   // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
306   VerifyRegionClosure(bool par, VerifyOption vo)
307     : _par(par),
308       _vo(vo),
309       _failures(false) {}
310 
311   bool failures() {
312     return _failures;
313   }
314 
315   bool do_heap_region(HeapRegion* r) {
316     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());
317     // Humongous and old regions regions might be of any state, so can't check here.
318     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());
319     // Verify that the continues humongous regions' remembered set state matches the
320     // one from the starts humongous region.
321     if (r->is_continues_humongous()) {
322       if (r->rem_set()->get_state_str() != r->humongous_start_region()->rem_set()->get_state_str()) {
323          log_error(gc, verify)("Remset states differ: Region %u (%s) remset %s with starts region %u (%s) remset %s",
324                                r->hrm_index(),
325                                r->get_short_type_str(),
326                                r->rem_set()->get_state_str(),
327                                r->humongous_start_region()->hrm_index(),
328                                r->humongous_start_region()->get_short_type_str(),
329                                r->humongous_start_region()->rem_set()->get_state_str());
330          _failures = true;
331       }
332     }
333     // For archive regions, verify there are no heap pointers to
334     // non-pinned regions. For all others, verify liveness info.
335     if (r->is_closed_archive()) {
336       VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
337       r->object_iterate(&verify_oop_pointers);
338       return true;
339     } else if (r->is_open_archive()) {
340       VerifyObjsInRegionClosure verify_open_archive_oop(r, _vo);
341       r->object_iterate(&verify_open_archive_oop);
342       return true;
343     } else if (!r->is_continues_humongous()) {
344       bool failures = false;
345       r->verify(_vo, &failures);
346       if (failures) {
347         _failures = true;
348       } else if (!r->is_starts_humongous()) {
349         VerifyObjsInRegionClosure not_dead_yet_cl(r, _vo);
350         r->object_iterate(&not_dead_yet_cl);
351         if (_vo != VerifyOption_G1UseNextMarking) {
352           if (r->max_live_bytes() < not_dead_yet_cl.live_bytes()) {
353             log_error(gc, verify)("[" PTR_FORMAT "," PTR_FORMAT "] max_live_bytes " SIZE_FORMAT " < calculated " SIZE_FORMAT,
354                                   p2i(r->bottom()), p2i(r->end()), r->max_live_bytes(), not_dead_yet_cl.live_bytes());
355             _failures = true;
356           }
357         } else {
358           // When vo == UseNextMarking we cannot currently do a sanity
359           // check on the live bytes as the calculation has not been
360           // finalized yet.
361         }
362       }
363     }
364     return false; // stop the region iteration if we hit a failure
365   }
366 };
367 
368 // This is the task used for parallel verification of the heap regions
369 
370 class G1ParVerifyTask: public AbstractGangTask {
371 private:
372   G1CollectedHeap*  _g1h;
373   VerifyOption      _vo;
374   bool              _failures;
375   HeapRegionClaimer _hrclaimer;
376 
377 public:
378   // _vo == UsePrevMarking -> use "prev" marking information,
379   // _vo == UseNextMarking -> use "next" marking information,
380   // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS
381   G1ParVerifyTask(G1CollectedHeap* g1h, VerifyOption vo) :
382       AbstractGangTask("Parallel verify task"),
383       _g1h(g1h),
384       _vo(vo),
385       _failures(false),
386       _hrclaimer(g1h->workers()->active_workers()) {}
387 
388   bool failures() {
389     return _failures;
390   }
391 
392   void work(uint worker_id) {
393     HandleMark hm;
394     VerifyRegionClosure blk(true, _vo);
395     _g1h->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
396     if (blk.failures()) {
397       _failures = true;
398     }
399   }
400 };
401 
402 void G1HeapVerifier::enable_verification_type(G1VerifyType type) {
403   // First enable will clear _enabled_verification_types.
404   if (_enabled_verification_types == G1VerifyAll) {
405     _enabled_verification_types = type;
406   } else {
407     _enabled_verification_types |= type;
408   }
409 }
410 
411 bool G1HeapVerifier::should_verify(G1VerifyType type) {
412   return (_enabled_verification_types & type) == type;
413 }
414 
415 void G1HeapVerifier::verify(VerifyOption vo) {
416   if (!SafepointSynchronize::is_at_safepoint()) {
417     log_info(gc, verify)("Skipping verification. Not at safepoint.");
418   }
419 
420   assert(Thread::current()->is_VM_thread(),
421          "Expected to be executed serially by the VM thread at this point");
422 
423   log_debug(gc, verify)("Roots");
424   VerifyRootsClosure rootsCl(vo);
425   VerifyCLDClosure cldCl(_g1h, &rootsCl);
426 
427   // We apply the relevant closures to all the oops in the
428   // system dictionary, class loader data graph, the string table
429   // and the nmethods in the code cache.
430   G1VerifyCodeRootOopClosure codeRootsCl(_g1h, &rootsCl, vo);
431   G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
432 
433   {
434     G1RootProcessor root_processor(_g1h, 1);
435     root_processor.process_all_roots(&rootsCl,
436                                      &cldCl,
437                                      &blobsCl);
438   }
439 
440   bool failures = rootsCl.failures() || codeRootsCl.failures();
441 
442   if (!_g1h->g1_policy()->collector_state()->in_full_gc()) {
443     // If we're verifying during a full GC then the region sets
444     // will have been torn down at the start of the GC. Therefore
445     // verifying the region sets will fail. So we only verify
446     // the region sets when not in a full GC.
447     log_debug(gc, verify)("HeapRegionSets");
448     verify_region_sets();
449   }
450 
451   log_debug(gc, verify)("HeapRegions");
452   if (GCParallelVerificationEnabled && ParallelGCThreads > 1) {
453 
454     G1ParVerifyTask task(_g1h, vo);
455     _g1h->workers()->run_task(&task);
456     if (task.failures()) {
457       failures = true;
458     }
459 
460   } else {
461     VerifyRegionClosure blk(false, vo);
462     _g1h->heap_region_iterate(&blk);
463     if (blk.failures()) {
464       failures = true;
465     }
466   }
467 
468   if (G1StringDedup::is_enabled()) {
469     log_debug(gc, verify)("StrDedup");
470     G1StringDedup::verify();
471   }
472 
473   if (failures) {
474     log_error(gc, verify)("Heap after failed verification (kind %d):", vo);
475     // It helps to have the per-region information in the output to
476     // help us track down what went wrong. This is why we call
477     // print_extended_on() instead of print_on().
478     Log(gc, verify) log;
479     ResourceMark rm;
480     LogStream ls(log.error());
481     _g1h->print_extended_on(&ls);
482   }
483   guarantee(!failures, "there should not have been any failures");
484 }
485 
486 // Heap region set verification
487 
488 class VerifyRegionListsClosure : public HeapRegionClosure {
489 private:
490   HeapRegionSet*   _old_set;
491   HeapRegionSet*   _archive_set;
492   HeapRegionSet*   _humongous_set;
493   HeapRegionManager* _hrm;
494 
495 public:
496   uint _old_count;
497   uint _archive_count;
498   uint _humongous_count;
499   uint _free_count;
500 
501   VerifyRegionListsClosure(HeapRegionSet* old_set,
502                            HeapRegionSet* archive_set,
503                            HeapRegionSet* humongous_set,
504                            HeapRegionManager* hrm) :
505     _old_set(old_set), _archive_set(archive_set), _humongous_set(humongous_set), _hrm(hrm),
506     _old_count(), _archive_count(), _humongous_count(), _free_count(){ }
507 
508   bool do_heap_region(HeapRegion* hr) {
509     if (hr->is_young()) {
510       // TODO
511     } else if (hr->is_humongous()) {
512       assert(hr->containing_set() == _humongous_set, "Heap region %u is humongous but not in humongous set.", hr->hrm_index());
513       _humongous_count++;
514     } else if (hr->is_empty()) {
515       assert(_hrm->is_free(hr), "Heap region %u is empty but not on the free list.", hr->hrm_index());
516       _free_count++;
517     } else if (hr->is_archive()) {
518       assert(hr->containing_set() == _archive_set, "Heap region %u is archive but not in the archive set.", hr->hrm_index());
519       _archive_count++;
520     } else if (hr->is_old()) {
521       assert(hr->containing_set() == _old_set, "Heap region %u is old but not in the old set.", hr->hrm_index());
522       _old_count++;
523     } else {
524       // There are no other valid region types. Check for one invalid
525       // one we can identify: pinned without old or humongous set.
526       assert(!hr->is_pinned(), "Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index());
527       ShouldNotReachHere();
528     }
529     return false;
530   }
531 
532   void verify_counts(HeapRegionSet* old_set, HeapRegionSet* archive_set, HeapRegionSet* humongous_set, HeapRegionManager* free_list) {
533     guarantee(old_set->length() == _old_count, "Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count);
534     guarantee(archive_set->length() == _archive_count, "Archive set count mismatch. Expected %u, actual %u.", archive_set->length(), _archive_count);
535     guarantee(humongous_set->length() == _humongous_count, "Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count);
536     guarantee(free_list->num_free_regions() == _free_count, "Free list count mismatch. Expected %u, actual %u.", free_list->num_free_regions(), _free_count);
537   }
538 };
539 
540 void G1HeapVerifier::verify_region_sets() {
541   assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
542 
543   // First, check the explicit lists.
544   _g1h->_hrm.verify();
545 
546   // Finally, make sure that the region accounting in the lists is
547   // consistent with what we see in the heap.
548 
549   VerifyRegionListsClosure cl(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, &_g1h->_hrm);
550   _g1h->heap_region_iterate(&cl);
551   cl.verify_counts(&_g1h->_old_set, &_g1h->_archive_set, &_g1h->_humongous_set, &_g1h->_hrm);
552 }
553 
554 void G1HeapVerifier::prepare_for_verify() {
555   if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
556     _g1h->ensure_parsability(false);
557   }
558 }
559 
560 double G1HeapVerifier::verify(G1VerifyType type, VerifyOption vo, const char* msg) {
561   double verify_time_ms = 0.0;
562 
563   if (should_verify(type) && _g1h->total_collections() >= VerifyGCStartAt) {
564     double verify_start = os::elapsedTime();
565     HandleMark hm;  // Discard invalid handles created during verification
566     prepare_for_verify();
567     Universe::verify(vo, msg);
568     verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
569   }
570 
571   return verify_time_ms;
572 }
573 
574 void G1HeapVerifier::verify_before_gc(G1VerifyType type) {
575   if (VerifyBeforeGC) {
576     double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "Before GC");
577     _g1h->g1_policy()->phase_times()->record_verify_before_time_ms(verify_time_ms);
578   }
579 }
580 
581 void G1HeapVerifier::verify_after_gc(G1VerifyType type) {
582   if (VerifyAfterGC) {
583     double verify_time_ms = verify(type, VerifyOption_G1UsePrevMarking, "After GC");
584     _g1h->g1_policy()->phase_times()->record_verify_after_time_ms(verify_time_ms);
585   }
586 }
587 
588 
589 #ifndef PRODUCT
590 class G1VerifyCardTableCleanup: public HeapRegionClosure {
591   G1HeapVerifier* _verifier;
592 public:
593   G1VerifyCardTableCleanup(G1HeapVerifier* verifier)
594     : _verifier(verifier) { }
595   virtual bool do_heap_region(HeapRegion* r) {
596     if (r->is_survivor()) {
597       _verifier->verify_dirty_region(r);
598     } else {
599       _verifier->verify_not_dirty_region(r);
600     }
601     return false;
602   }
603 };
604 
605 void G1HeapVerifier::verify_card_table_cleanup() {
606   if (G1VerifyCTCleanup || VerifyAfterGC) {
607     G1VerifyCardTableCleanup cleanup_verifier(this);
608     _g1h->heap_region_iterate(&cleanup_verifier);
609   }
610 }
611 
612 void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
613   // All of the region should be clean.
614   G1CardTable* ct = _g1h->card_table();
615   MemRegion mr(hr->bottom(), hr->end());
616   ct->verify_not_dirty_region(mr);
617 }
618 
619 void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
620   // We cannot guarantee that [bottom(),end()] is dirty.  Threads
621   // dirty allocated blocks as they allocate them. The thread that
622   // retires each region and replaces it with a new one will do a
623   // maximal allocation to fill in [pre_dummy_top(),end()] but will
624   // not dirty that area (one less thing to have to do while holding
625   // a lock). So we can only verify that [bottom(),pre_dummy_top()]
626   // is dirty.
627   G1CardTable* ct = _g1h->card_table();
628   MemRegion mr(hr->bottom(), hr->pre_dummy_top());
629   if (hr->is_young()) {
630     ct->verify_g1_young_region(mr);
631   } else {
632     ct->verify_dirty_region(mr);
633   }
634 }
635 
636 class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
637 private:
638   G1HeapVerifier* _verifier;
639 public:
640   G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
641   virtual bool do_heap_region(HeapRegion* r) {
642     _verifier->verify_dirty_region(r);
643     return false;
644   }
645 };
646 
647 void G1HeapVerifier::verify_dirty_young_regions() {
648   G1VerifyDirtyYoungListClosure cl(this);
649   _g1h->collection_set()->iterate(&cl);
650 }
651 
652 bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, const G1CMBitMap* const bitmap,
653                                                HeapWord* tams, HeapWord* end) {
654   guarantee(tams <= end,
655             "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
656   HeapWord* result = bitmap->get_next_marked_addr(tams, end);
657   if (result < end) {
658     log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
659     log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
660     return false;
661   }
662   return true;
663 }
664 
665 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
666   const G1CMBitMap* const prev_bitmap = _g1h->concurrent_mark()->prev_mark_bitmap();
667   const G1CMBitMap* const next_bitmap = _g1h->concurrent_mark()->next_mark_bitmap();
668 
669   HeapWord* ptams  = hr->prev_top_at_mark_start();
670   HeapWord* ntams  = hr->next_top_at_mark_start();
671   HeapWord* end    = hr->end();
672 
673   bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
674 
675   bool res_n = true;
676   // We cannot verify the next bitmap while we are about to clear it.
677   if (!_g1h->collector_state()->clearing_next_bitmap()) {
678     res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
679   }
680   if (!res_p || !res_n) {
681     log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
682     log_error(gc, verify)("#### Caller: %s", caller);
683     return false;
684   }
685   return true;
686 }
687 
688 void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
689   if (!G1VerifyBitmaps) {
690     return;
691   }
692 
693   guarantee(verify_bitmaps(caller, hr), "bitmap verification");
694 }
695 
696 class G1VerifyBitmapClosure : public HeapRegionClosure {
697 private:
698   const char* _caller;
699   G1HeapVerifier* _verifier;
700   bool _failures;
701 
702 public:
703   G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
704     _caller(caller), _verifier(verifier), _failures(false) { }
705 
706   bool failures() { return _failures; }
707 
708   virtual bool do_heap_region(HeapRegion* hr) {
709     bool result = _verifier->verify_bitmaps(_caller, hr);
710     if (!result) {
711       _failures = true;
712     }
713     return false;
714   }
715 };
716 
717 void G1HeapVerifier::check_bitmaps(const char* caller) {
718   if (!G1VerifyBitmaps) {
719     return;
720   }
721 
722   G1VerifyBitmapClosure cl(caller, this);
723   _g1h->heap_region_iterate(&cl);
724   guarantee(!cl.failures(), "bitmap verification");
725 }
726 
727 class G1CheckCSetFastTableClosure : public HeapRegionClosure {
728  private:
729   bool _failures;
730  public:
731   G1CheckCSetFastTableClosure() : HeapRegionClosure(), _failures(false) { }
732 
733   virtual bool do_heap_region(HeapRegion* hr) {
734     uint i = hr->hrm_index();
735     InCSetState cset_state = (InCSetState) G1CollectedHeap::heap()->_in_cset_fast_test.get_by_index(i);
736     if (hr->is_humongous()) {
737       if (hr->in_collection_set()) {
738         log_error(gc, verify)("## humongous region %u in CSet", i);
739         _failures = true;
740         return true;
741       }
742       if (cset_state.is_in_cset()) {
743         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for humongous region %u", cset_state.value(), i);
744         _failures = true;
745         return true;
746       }
747       if (hr->is_continues_humongous() && cset_state.is_humongous()) {
748         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for continues humongous region %u", cset_state.value(), i);
749         _failures = true;
750         return true;
751       }
752     } else {
753       if (cset_state.is_humongous()) {
754         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for non-humongous region %u", cset_state.value(), i);
755         _failures = true;
756         return true;
757       }
758       if (hr->in_collection_set() != cset_state.is_in_cset()) {
759         log_error(gc, verify)("## in CSet %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
760                              hr->in_collection_set(), cset_state.value(), i);
761         _failures = true;
762         return true;
763       }
764       if (cset_state.is_in_cset()) {
765         if (hr->is_archive()) {
766           log_error(gc, verify)("## is_archive in collection set for region %u", i);
767           _failures = true;
768           return true;
769         }
770         if (hr->is_young() != (cset_state.is_young())) {
771           log_error(gc, verify)("## is_young %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
772                                hr->is_young(), cset_state.value(), i);
773           _failures = true;
774           return true;
775         }
776         if (hr->is_old() != (cset_state.is_old())) {
777           log_error(gc, verify)("## is_old %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
778                                hr->is_old(), cset_state.value(), i);
779           _failures = true;
780           return true;
781         }
782       }
783     }
784     return false;
785   }
786 
787   bool failures() const { return _failures; }
788 };
789 
790 bool G1HeapVerifier::check_cset_fast_test() {
791   G1CheckCSetFastTableClosure cl;
792   _g1h->_hrm.iterate(&cl);
793   return !cl.failures();
794 }
795 #endif // PRODUCT