1 /*
   2  * Copyright (c) 2016, 2017, 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/concurrentMarkThread.hpp"
  27 #include "gc/g1/g1Allocator.inline.hpp"
  28 #include "gc/g1/g1CollectedHeap.hpp"
  29 #include "gc/g1/g1CollectedHeap.inline.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/resourceArea.hpp"
  41 #include "oops/oop.inline.hpp"
  42 
  43 class VerifyRootsClosure: public OopClosure {
  44 private:
  45   G1CollectedHeap* _g1h;
  46   VerifyOption     _vo;
  47   bool             _failures;
  48 public:
  49   // _vo == UsePrevMarking -> use "prev" marking information,
  50   // _vo == UseNextMarking -> use "next" marking information,
  51   // _vo == UseMarkWord    -> use mark word from object header.
  52   VerifyRootsClosure(VerifyOption vo) :
  53     _g1h(G1CollectedHeap::heap()),
  54     _vo(vo),
  55     _failures(false) { }
  56 
  57   bool failures() { return _failures; }
  58 
  59   template <class T> void do_oop_nv(T* p) {
  60     T heap_oop = oopDesc::load_heap_oop(p);
  61     if (!oopDesc::is_null(heap_oop)) {
  62       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  63       if (_g1h->is_obj_dead_cond(obj, _vo)) {
  64         Log(gc, verify) log;
  65         log.info("Root location " PTR_FORMAT " points to dead obj " PTR_FORMAT, p2i(p), p2i(obj));
  66         if (_vo == VerifyOption_G1UseMarkWord) {
  67           log.error("  Mark word: " PTR_FORMAT, p2i(obj->mark()));
  68         }
  69         ResourceMark rm;
  70         LogStream ls(log.error());
  71         obj->print_on(&ls);
  72         _failures = true;
  73       }
  74     }
  75   }
  76 
  77   void do_oop(oop* p)       { do_oop_nv(p); }
  78   void do_oop(narrowOop* p) { do_oop_nv(p); }
  79 };
  80 
  81 class G1VerifyCodeRootOopClosure: public OopClosure {
  82   G1CollectedHeap* _g1h;
  83   OopClosure* _root_cl;
  84   nmethod* _nm;
  85   VerifyOption _vo;
  86   bool _failures;
  87 
  88   template <class T> void do_oop_work(T* p) {
  89     // First verify that this root is live
  90     _root_cl->do_oop(p);
  91 
  92     if (!G1VerifyHeapRegionCodeRoots) {
  93       // We're not verifying the code roots attached to heap region.
  94       return;
  95     }
  96 
  97     // Don't check the code roots during marking verification in a full GC
  98     if (_vo == VerifyOption_G1UseMarkWord) {
  99       return;
 100     }
 101 
 102     // Now verify that the current nmethod (which contains p) is
 103     // in the code root list of the heap region containing the
 104     // object referenced by p.
 105 
 106     T heap_oop = oopDesc::load_heap_oop(p);
 107     if (!oopDesc::is_null(heap_oop)) {
 108       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 109 
 110       // Now fetch the region containing the object
 111       HeapRegion* hr = _g1h->heap_region_containing(obj);
 112       HeapRegionRemSet* hrrs = hr->rem_set();
 113       // Verify that the strong code root list for this region
 114       // contains the nmethod
 115       if (!hrrs->strong_code_roots_list_contains(_nm)) {
 116         log_error(gc, verify)("Code root location " PTR_FORMAT " "
 117                               "from nmethod " PTR_FORMAT " not in strong "
 118                               "code roots for region [" PTR_FORMAT "," PTR_FORMAT ")",
 119                               p2i(p), p2i(_nm), p2i(hr->bottom()), p2i(hr->end()));
 120         _failures = true;
 121       }
 122     }
 123   }
 124 
 125 public:
 126   G1VerifyCodeRootOopClosure(G1CollectedHeap* g1h, OopClosure* root_cl, VerifyOption vo):
 127     _g1h(g1h), _root_cl(root_cl), _vo(vo), _nm(NULL), _failures(false) {}
 128 
 129   void do_oop(oop* p) { do_oop_work(p); }
 130   void do_oop(narrowOop* p) { do_oop_work(p); }
 131 
 132   void set_nmethod(nmethod* nm) { _nm = nm; }
 133   bool failures() { return _failures; }
 134 };
 135 
 136 class G1VerifyCodeRootBlobClosure: public CodeBlobClosure {
 137   G1VerifyCodeRootOopClosure* _oop_cl;
 138 
 139 public:
 140   G1VerifyCodeRootBlobClosure(G1VerifyCodeRootOopClosure* oop_cl):
 141     _oop_cl(oop_cl) {}
 142 
 143   void do_code_blob(CodeBlob* cb) {
 144     nmethod* nm = cb->as_nmethod_or_null();
 145     if (nm != NULL) {
 146       _oop_cl->set_nmethod(nm);
 147       nm->oops_do(_oop_cl);
 148     }
 149   }
 150 };
 151 
 152 class YoungRefCounterClosure : public OopClosure {
 153   G1CollectedHeap* _g1h;
 154   int              _count;
 155  public:
 156   YoungRefCounterClosure(G1CollectedHeap* g1h) : _g1h(g1h), _count(0) {}
 157   void do_oop(oop* p)       { if (_g1h->is_in_young(*p)) { _count++; } }
 158   void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 159 
 160   int count() { return _count; }
 161   void reset_count() { _count = 0; };
 162 };
 163 
 164 class VerifyKlassClosure: public KlassClosure {
 165   YoungRefCounterClosure _young_ref_counter_closure;
 166   OopClosure *_oop_closure;
 167  public:
 168   VerifyKlassClosure(G1CollectedHeap* g1h, OopClosure* cl) : _young_ref_counter_closure(g1h), _oop_closure(cl) {}
 169   void do_klass(Klass* k) {
 170     k->oops_do(_oop_closure);
 171 
 172     _young_ref_counter_closure.reset_count();
 173     k->oops_do(&_young_ref_counter_closure);
 174     if (_young_ref_counter_closure.count() > 0) {
 175       guarantee(k->has_modified_oops(), "Klass " PTR_FORMAT ", has young refs but is not dirty.", p2i(k));
 176     }
 177   }
 178 };
 179 
 180 class VerifyLivenessOopClosure: public OopClosure {
 181   G1CollectedHeap* _g1h;
 182   VerifyOption _vo;
 183 public:
 184   VerifyLivenessOopClosure(G1CollectedHeap* g1h, VerifyOption vo):
 185     _g1h(g1h), _vo(vo)
 186   { }
 187   void do_oop(narrowOop *p) { do_oop_work(p); }
 188   void do_oop(      oop *p) { do_oop_work(p); }
 189 
 190   template <class T> void do_oop_work(T *p) {
 191     oop obj = oopDesc::load_decode_heap_oop(p);
 192     guarantee(obj == NULL || !_g1h->is_obj_dead_cond(obj, _vo),
 193               "Dead object referenced by a not dead object");
 194   }
 195 };
 196 
 197 class VerifyObjsInRegionClosure: public ObjectClosure {
 198 private:
 199   G1CollectedHeap* _g1h;
 200   size_t _live_bytes;
 201   HeapRegion *_hr;
 202   VerifyOption _vo;
 203 public:
 204   // _vo == UsePrevMarking -> use "prev" marking information,
 205   // _vo == UseNextMarking -> use "next" marking information,
 206   // _vo == UseMarkWord    -> use mark word from object header.
 207   VerifyObjsInRegionClosure(HeapRegion *hr, VerifyOption vo)
 208     : _live_bytes(0), _hr(hr), _vo(vo) {
 209     _g1h = G1CollectedHeap::heap();
 210   }
 211   void do_object(oop o) {
 212     VerifyLivenessOopClosure isLive(_g1h, _vo);
 213     assert(o != NULL, "Huh?");
 214     if (!_g1h->is_obj_dead_cond(o, _vo)) {
 215       // If the object is alive according to the mark word,
 216       // then verify that the marking information agrees.
 217       // Note we can't verify the contra-positive of the
 218       // above: if the object is dead (according to the mark
 219       // word), it may not be marked, or may have been marked
 220       // but has since became dead, or may have been allocated
 221       // since the last marking.
 222       if (_vo == VerifyOption_G1UseMarkWord) {
 223         guarantee(!_g1h->is_obj_dead(o), "mark word and concurrent mark mismatch");
 224       }
 225 
 226       o->oop_iterate_no_header(&isLive);
 227       if (!_hr->obj_allocated_since_prev_marking(o)) {
 228         size_t obj_size = o->size();    // Make sure we don't overflow
 229         _live_bytes += (obj_size * HeapWordSize);
 230       }
 231     }
 232   }
 233   size_t live_bytes() { return _live_bytes; }
 234 };
 235 
 236 class VerifyArchiveOopClosure: public OopClosure {
 237   HeapRegion* _hr;
 238 public:
 239   VerifyArchiveOopClosure(HeapRegion *hr)
 240     : _hr(hr) { }
 241   void do_oop(narrowOop *p) { do_oop_work(p); }
 242   void do_oop(      oop *p) { do_oop_work(p); }
 243 
 244   template <class T> void do_oop_work(T *p) {
 245     oop obj = oopDesc::load_decode_heap_oop(p);
 246 
 247     if (_hr->is_open_archive()) {
 248       guarantee(obj == NULL || G1ArchiveAllocator::is_archive_object(obj),
 249                 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
 250                 p2i(p), p2i(obj));
 251     } else {
 252       assert(_hr->is_closed_archive(), "should be archive region");
 253       guarantee(obj == NULL || G1ArchiveAllocator::is_closed_archive_object(obj),
 254                 "Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
 255                 p2i(p), p2i(obj));
 256     }
 257   }
 258 };
 259 
 260 class VerifyObjectInArchiveRegionClosure: public ObjectClosure {
 261   HeapRegion* _hr;
 262 public:
 263   VerifyObjectInArchiveRegionClosure(HeapRegion *hr, bool verbose)
 264     : _hr(hr) { }
 265   // Verify that all object pointers are to archive regions.
 266   void do_object(oop o) {
 267     VerifyArchiveOopClosure checkOop(_hr);
 268     assert(o != NULL, "Should not be here for NULL oops");
 269     o->oop_iterate_no_header(&checkOop);
 270   }
 271 };
 272 
 273 // Should be only used at CDS dump time
 274 class VerifyArchivePointerRegionClosure: public HeapRegionClosure {
 275 private:
 276   G1CollectedHeap* _g1h;
 277 public:
 278   VerifyArchivePointerRegionClosure(G1CollectedHeap* g1h) { }
 279   virtual bool doHeapRegion(HeapRegion* r) {
 280    if (r->is_archive()) {
 281       VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
 282       r->object_iterate(&verify_oop_pointers);
 283     }
 284     return false;
 285   }
 286 };
 287 
 288 void G1HeapVerifier::verify_archive_regions() {
 289   G1CollectedHeap*  g1h = G1CollectedHeap::heap();
 290   VerifyArchivePointerRegionClosure cl(NULL);
 291   g1h->heap_region_iterate(&cl);
 292 }
 293 
 294 class VerifyRegionClosure: public HeapRegionClosure {
 295 private:
 296   bool             _par;
 297   VerifyOption     _vo;
 298   bool             _failures;
 299 public:
 300   // _vo == UsePrevMarking -> use "prev" marking information,
 301   // _vo == UseNextMarking -> use "next" marking information,
 302   // _vo == UseMarkWord    -> use mark word from object header.
 303   VerifyRegionClosure(bool par, VerifyOption vo)
 304     : _par(par),
 305       _vo(vo),
 306       _failures(false) {}
 307 
 308   bool failures() {
 309     return _failures;
 310   }
 311 
 312   bool doHeapRegion(HeapRegion* r) {
 313     // For archive regions, verify there are no heap pointers to
 314     // non-pinned regions. For all others, verify liveness info.
 315     if (r->is_closed_archive()) {
 316       VerifyObjectInArchiveRegionClosure verify_oop_pointers(r, false);
 317       r->object_iterate(&verify_oop_pointers);
 318       return true;
 319     } else if (r->is_open_archive()) {
 320       VerifyObjsInRegionClosure verify_open_archive_oop(r, _vo);
 321       r->object_iterate(&verify_open_archive_oop);
 322       return true;
 323     } else if (!r->is_continues_humongous()) {
 324       bool failures = false;
 325       r->verify(_vo, &failures);
 326       if (failures) {
 327         _failures = true;
 328       } else if (!r->is_starts_humongous()) {
 329         VerifyObjsInRegionClosure not_dead_yet_cl(r, _vo);
 330         r->object_iterate(&not_dead_yet_cl);
 331         if (_vo != VerifyOption_G1UseNextMarking) {
 332           if (r->max_live_bytes() < not_dead_yet_cl.live_bytes()) {
 333             log_error(gc, verify)("[" PTR_FORMAT "," PTR_FORMAT "] max_live_bytes " SIZE_FORMAT " < calculated " SIZE_FORMAT,
 334                                   p2i(r->bottom()), p2i(r->end()), r->max_live_bytes(), not_dead_yet_cl.live_bytes());
 335             _failures = true;
 336           }
 337         } else {
 338           // When vo == UseNextMarking we cannot currently do a sanity
 339           // check on the live bytes as the calculation has not been
 340           // finalized yet.
 341         }
 342       }
 343     }
 344     return false; // stop the region iteration if we hit a failure
 345   }
 346 };
 347 
 348 // This is the task used for parallel verification of the heap regions
 349 
 350 class G1ParVerifyTask: public AbstractGangTask {
 351 private:
 352   G1CollectedHeap*  _g1h;
 353   VerifyOption      _vo;
 354   bool              _failures;
 355   HeapRegionClaimer _hrclaimer;
 356 
 357 public:
 358   // _vo == UsePrevMarking -> use "prev" marking information,
 359   // _vo == UseNextMarking -> use "next" marking information,
 360   // _vo == UseMarkWord    -> use mark word from object header.
 361   G1ParVerifyTask(G1CollectedHeap* g1h, VerifyOption vo) :
 362       AbstractGangTask("Parallel verify task"),
 363       _g1h(g1h),
 364       _vo(vo),
 365       _failures(false),
 366       _hrclaimer(g1h->workers()->active_workers()) {}
 367 
 368   bool failures() {
 369     return _failures;
 370   }
 371 
 372   void work(uint worker_id) {
 373     HandleMark hm;
 374     VerifyRegionClosure blk(true, _vo);
 375     _g1h->heap_region_par_iterate(&blk, worker_id, &_hrclaimer);
 376     if (blk.failures()) {
 377       _failures = true;
 378     }
 379   }
 380 };
 381 
 382 
 383 void G1HeapVerifier::verify(VerifyOption vo) {
 384   if (!SafepointSynchronize::is_at_safepoint()) {
 385     log_info(gc, verify)("Skipping verification. Not at safepoint.");
 386   }
 387 
 388   assert(Thread::current()->is_VM_thread(),
 389          "Expected to be executed serially by the VM thread at this point");
 390 
 391   log_debug(gc, verify)("Roots");
 392   VerifyRootsClosure rootsCl(vo);
 393   VerifyKlassClosure klassCl(_g1h, &rootsCl);
 394   CLDToKlassAndOopClosure cldCl(&klassCl, &rootsCl, false);
 395 
 396   // We apply the relevant closures to all the oops in the
 397   // system dictionary, class loader data graph, the string table
 398   // and the nmethods in the code cache.
 399   G1VerifyCodeRootOopClosure codeRootsCl(_g1h, &rootsCl, vo);
 400   G1VerifyCodeRootBlobClosure blobsCl(&codeRootsCl);
 401 
 402   {
 403     G1RootProcessor root_processor(_g1h, 1);
 404     root_processor.process_all_roots(&rootsCl,
 405                                      &cldCl,
 406                                      &blobsCl);
 407   }
 408 
 409   bool failures = rootsCl.failures() || codeRootsCl.failures();
 410 
 411   if (vo != VerifyOption_G1UseMarkWord) {
 412     // If we're verifying during a full GC then the region sets
 413     // will have been torn down at the start of the GC. Therefore
 414     // verifying the region sets will fail. So we only verify
 415     // the region sets when not in a full GC.
 416     log_debug(gc, verify)("HeapRegionSets");
 417     verify_region_sets();
 418   }
 419 
 420   log_debug(gc, verify)("HeapRegions");
 421   if (GCParallelVerificationEnabled && ParallelGCThreads > 1) {
 422 
 423     G1ParVerifyTask task(_g1h, vo);
 424     _g1h->workers()->run_task(&task);
 425     if (task.failures()) {
 426       failures = true;
 427     }
 428 
 429   } else {
 430     VerifyRegionClosure blk(false, vo);
 431     _g1h->heap_region_iterate(&blk);
 432     if (blk.failures()) {
 433       failures = true;
 434     }
 435   }
 436 
 437   if (G1StringDedup::is_enabled()) {
 438     log_debug(gc, verify)("StrDedup");
 439     G1StringDedup::verify();
 440   }
 441 
 442   if (failures) {
 443     log_error(gc, verify)("Heap after failed verification:");
 444     // It helps to have the per-region information in the output to
 445     // help us track down what went wrong. This is why we call
 446     // print_extended_on() instead of print_on().
 447     Log(gc, verify) log;
 448     ResourceMark rm;
 449     LogStream ls(log.error());
 450     _g1h->print_extended_on(&ls);
 451   }
 452   guarantee(!failures, "there should not have been any failures");
 453 }
 454 
 455 // Heap region set verification
 456 
 457 class VerifyRegionListsClosure : public HeapRegionClosure {
 458 private:
 459   HeapRegionSet*   _old_set;
 460   HeapRegionSet*   _humongous_set;
 461   HeapRegionManager*   _hrm;
 462 
 463 public:
 464   uint _old_count;
 465   uint _humongous_count;
 466   uint _free_count;
 467 
 468   VerifyRegionListsClosure(HeapRegionSet* old_set,
 469                            HeapRegionSet* humongous_set,
 470                            HeapRegionManager* hrm) :
 471     _old_set(old_set), _humongous_set(humongous_set), _hrm(hrm),
 472     _old_count(), _humongous_count(), _free_count(){ }
 473 
 474   bool doHeapRegion(HeapRegion* hr) {
 475     if (hr->is_young()) {
 476       // TODO
 477     } else if (hr->is_humongous()) {
 478       assert(hr->containing_set() == _humongous_set, "Heap region %u is humongous but not in humongous set.", hr->hrm_index());
 479       _humongous_count++;
 480     } else if (hr->is_empty()) {
 481       assert(_hrm->is_free(hr), "Heap region %u is empty but not on the free list.", hr->hrm_index());
 482       _free_count++;
 483     } else if (hr->is_old()) {
 484       assert(hr->containing_set() == _old_set, "Heap region %u is old but not in the old set.", hr->hrm_index());
 485       _old_count++;
 486     } else {
 487       // There are no other valid region types. Check for one invalid
 488       // one we can identify: pinned without old or humongous set.
 489       assert(!hr->is_pinned(), "Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index());
 490       ShouldNotReachHere();
 491     }
 492     return false;
 493   }
 494 
 495   void verify_counts(HeapRegionSet* old_set, HeapRegionSet* humongous_set, HeapRegionManager* free_list) {
 496     guarantee(old_set->length() == _old_count, "Old set count mismatch. Expected %u, actual %u.", old_set->length(), _old_count);
 497     guarantee(humongous_set->length() == _humongous_count, "Hum set count mismatch. Expected %u, actual %u.", humongous_set->length(), _humongous_count);
 498     guarantee(free_list->num_free_regions() == _free_count, "Free list count mismatch. Expected %u, actual %u.", free_list->num_free_regions(), _free_count);
 499   }
 500 };
 501 
 502 void G1HeapVerifier::verify_region_sets() {
 503   assert_heap_locked_or_at_safepoint(true /* should_be_vm_thread */);
 504 
 505   // First, check the explicit lists.
 506   _g1h->_hrm.verify();
 507   {
 508     // Given that a concurrent operation might be adding regions to
 509     // the secondary free list we have to take the lock before
 510     // verifying it.
 511     MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag);
 512     _g1h->_secondary_free_list.verify_list();
 513   }
 514 
 515   // If a concurrent region freeing operation is in progress it will
 516   // be difficult to correctly attributed any free regions we come
 517   // across to the correct free list given that they might belong to
 518   // one of several (free_list, secondary_free_list, any local lists,
 519   // etc.). So, if that's the case we will skip the rest of the
 520   // verification operation. Alternatively, waiting for the concurrent
 521   // operation to complete will have a non-trivial effect on the GC's
 522   // operation (no concurrent operation will last longer than the
 523   // interval between two calls to verification) and it might hide
 524   // any issues that we would like to catch during testing.
 525   if (_g1h->free_regions_coming()) {
 526     return;
 527   }
 528 
 529   // Make sure we append the secondary_free_list on the free_list so
 530   // that all free regions we will come across can be safely
 531   // attributed to the free_list.
 532   _g1h->append_secondary_free_list_if_not_empty_with_lock();
 533 
 534   // Finally, make sure that the region accounting in the lists is
 535   // consistent with what we see in the heap.
 536 
 537   VerifyRegionListsClosure cl(&_g1h->_old_set, &_g1h->_humongous_set, &_g1h->_hrm);
 538   _g1h->heap_region_iterate(&cl);
 539   cl.verify_counts(&_g1h->_old_set, &_g1h->_humongous_set, &_g1h->_hrm);
 540 }
 541 
 542 void G1HeapVerifier::prepare_for_verify() {
 543   if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
 544     _g1h->ensure_parsability(false);
 545   }
 546 }
 547 
 548 double G1HeapVerifier::verify(bool guard, const char* msg) {
 549   double verify_time_ms = 0.0;
 550 
 551   if (guard && _g1h->total_collections() >= VerifyGCStartAt) {
 552     double verify_start = os::elapsedTime();
 553     HandleMark hm;  // Discard invalid handles created during verification
 554     prepare_for_verify();
 555     Universe::verify(VerifyOption_G1UsePrevMarking, msg);
 556     verify_time_ms = (os::elapsedTime() - verify_start) * 1000;
 557   }
 558 
 559   return verify_time_ms;
 560 }
 561 
 562 void G1HeapVerifier::verify_before_gc() {
 563   double verify_time_ms = verify(VerifyBeforeGC, "Before GC");
 564   _g1h->g1_policy()->phase_times()->record_verify_before_time_ms(verify_time_ms);
 565 }
 566 
 567 void G1HeapVerifier::verify_after_gc() {
 568   double verify_time_ms = verify(VerifyAfterGC, "After GC");
 569   _g1h->g1_policy()->phase_times()->record_verify_after_time_ms(verify_time_ms);
 570 }
 571 
 572 
 573 #ifndef PRODUCT
 574 class G1VerifyCardTableCleanup: public HeapRegionClosure {
 575   G1HeapVerifier* _verifier;
 576   G1SATBCardTableModRefBS* _ct_bs;
 577 public:
 578   G1VerifyCardTableCleanup(G1HeapVerifier* verifier, G1SATBCardTableModRefBS* ct_bs)
 579     : _verifier(verifier), _ct_bs(ct_bs) { }
 580   virtual bool doHeapRegion(HeapRegion* r) {
 581     if (r->is_survivor()) {
 582       _verifier->verify_dirty_region(r);
 583     } else {
 584       _verifier->verify_not_dirty_region(r);
 585     }
 586     return false;
 587   }
 588 };
 589 
 590 void G1HeapVerifier::verify_card_table_cleanup() {
 591   if (G1VerifyCTCleanup || VerifyAfterGC) {
 592     G1VerifyCardTableCleanup cleanup_verifier(this, _g1h->g1_barrier_set());
 593     _g1h->heap_region_iterate(&cleanup_verifier);
 594   }
 595 }
 596 
 597 void G1HeapVerifier::verify_not_dirty_region(HeapRegion* hr) {
 598   // All of the region should be clean.
 599   G1SATBCardTableModRefBS* ct_bs = _g1h->g1_barrier_set();
 600   MemRegion mr(hr->bottom(), hr->end());
 601   ct_bs->verify_not_dirty_region(mr);
 602 }
 603 
 604 void G1HeapVerifier::verify_dirty_region(HeapRegion* hr) {
 605   // We cannot guarantee that [bottom(),end()] is dirty.  Threads
 606   // dirty allocated blocks as they allocate them. The thread that
 607   // retires each region and replaces it with a new one will do a
 608   // maximal allocation to fill in [pre_dummy_top(),end()] but will
 609   // not dirty that area (one less thing to have to do while holding
 610   // a lock). So we can only verify that [bottom(),pre_dummy_top()]
 611   // is dirty.
 612   G1SATBCardTableModRefBS* ct_bs = _g1h->g1_barrier_set();
 613   MemRegion mr(hr->bottom(), hr->pre_dummy_top());
 614   if (hr->is_young()) {
 615     ct_bs->verify_g1_young_region(mr);
 616   } else {
 617     ct_bs->verify_dirty_region(mr);
 618   }
 619 }
 620 
 621 class G1VerifyDirtyYoungListClosure : public HeapRegionClosure {
 622 private:
 623   G1HeapVerifier* _verifier;
 624 public:
 625   G1VerifyDirtyYoungListClosure(G1HeapVerifier* verifier) : HeapRegionClosure(), _verifier(verifier) { }
 626   virtual bool doHeapRegion(HeapRegion* r) {
 627     _verifier->verify_dirty_region(r);
 628     return false;
 629   }
 630 };
 631 
 632 void G1HeapVerifier::verify_dirty_young_regions() {
 633   G1VerifyDirtyYoungListClosure cl(this);
 634   _g1h->collection_set()->iterate(&cl);
 635 }
 636 
 637 bool G1HeapVerifier::verify_no_bits_over_tams(const char* bitmap_name, G1CMBitMapRO* bitmap,
 638                                                HeapWord* tams, HeapWord* end) {
 639   guarantee(tams <= end,
 640             "tams: " PTR_FORMAT " end: " PTR_FORMAT, p2i(tams), p2i(end));
 641   HeapWord* result = bitmap->getNextMarkedWordAddress(tams, end);
 642   if (result < end) {
 643     log_error(gc, verify)("## wrong marked address on %s bitmap: " PTR_FORMAT, bitmap_name, p2i(result));
 644     log_error(gc, verify)("## %s tams: " PTR_FORMAT " end: " PTR_FORMAT, bitmap_name, p2i(tams), p2i(end));
 645     return false;
 646   }
 647   return true;
 648 }
 649 
 650 bool G1HeapVerifier::verify_bitmaps(const char* caller, HeapRegion* hr) {
 651   G1CMBitMapRO* prev_bitmap = _g1h->concurrent_mark()->prevMarkBitMap();
 652   G1CMBitMapRO* next_bitmap = (G1CMBitMapRO*) _g1h->concurrent_mark()->nextMarkBitMap();
 653 
 654   HeapWord* bottom = hr->bottom();
 655   HeapWord* ptams  = hr->prev_top_at_mark_start();
 656   HeapWord* ntams  = hr->next_top_at_mark_start();
 657   HeapWord* end    = hr->end();
 658 
 659   bool res_p = verify_no_bits_over_tams("prev", prev_bitmap, ptams, end);
 660 
 661   bool res_n = true;
 662   // We reset mark_in_progress() before we reset _cmThread->in_progress() and in this window
 663   // we do the clearing of the next bitmap concurrently. Thus, we can not verify the bitmap
 664   // if we happen to be in that state.
 665   if (_g1h->collector_state()->mark_in_progress() || !_g1h->_cmThread->in_progress()) {
 666     res_n = verify_no_bits_over_tams("next", next_bitmap, ntams, end);
 667   }
 668   if (!res_p || !res_n) {
 669     log_error(gc, verify)("#### Bitmap verification failed for " HR_FORMAT, HR_FORMAT_PARAMS(hr));
 670     log_error(gc, verify)("#### Caller: %s", caller);
 671     return false;
 672   }
 673   return true;
 674 }
 675 
 676 void G1HeapVerifier::check_bitmaps(const char* caller, HeapRegion* hr) {
 677   if (!G1VerifyBitmaps) return;
 678 
 679   guarantee(verify_bitmaps(caller, hr), "bitmap verification");
 680 }
 681 
 682 class G1VerifyBitmapClosure : public HeapRegionClosure {
 683 private:
 684   const char* _caller;
 685   G1HeapVerifier* _verifier;
 686   bool _failures;
 687 
 688 public:
 689   G1VerifyBitmapClosure(const char* caller, G1HeapVerifier* verifier) :
 690     _caller(caller), _verifier(verifier), _failures(false) { }
 691 
 692   bool failures() { return _failures; }
 693 
 694   virtual bool doHeapRegion(HeapRegion* hr) {
 695     bool result = _verifier->verify_bitmaps(_caller, hr);
 696     if (!result) {
 697       _failures = true;
 698     }
 699     return false;
 700   }
 701 };
 702 
 703 void G1HeapVerifier::check_bitmaps(const char* caller) {
 704   if (!G1VerifyBitmaps) return;
 705 
 706   G1VerifyBitmapClosure cl(caller, this);
 707   _g1h->heap_region_iterate(&cl);
 708   guarantee(!cl.failures(), "bitmap verification");
 709 }
 710 
 711 class G1CheckCSetFastTableClosure : public HeapRegionClosure {
 712  private:
 713   bool _failures;
 714  public:
 715   G1CheckCSetFastTableClosure() : HeapRegionClosure(), _failures(false) { }
 716 
 717   virtual bool doHeapRegion(HeapRegion* hr) {
 718     uint i = hr->hrm_index();
 719     InCSetState cset_state = (InCSetState) G1CollectedHeap::heap()->_in_cset_fast_test.get_by_index(i);
 720     if (hr->is_humongous()) {
 721       if (hr->in_collection_set()) {
 722         log_error(gc, verify)("## humongous region %u in CSet", i);
 723         _failures = true;
 724         return true;
 725       }
 726       if (cset_state.is_in_cset()) {
 727         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for humongous region %u", cset_state.value(), i);
 728         _failures = true;
 729         return true;
 730       }
 731       if (hr->is_continues_humongous() && cset_state.is_humongous()) {
 732         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for continues humongous region %u", cset_state.value(), i);
 733         _failures = true;
 734         return true;
 735       }
 736     } else {
 737       if (cset_state.is_humongous()) {
 738         log_error(gc, verify)("## inconsistent cset state " CSETSTATE_FORMAT " for non-humongous region %u", cset_state.value(), i);
 739         _failures = true;
 740         return true;
 741       }
 742       if (hr->in_collection_set() != cset_state.is_in_cset()) {
 743         log_error(gc, verify)("## in CSet %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
 744                              hr->in_collection_set(), cset_state.value(), i);
 745         _failures = true;
 746         return true;
 747       }
 748       if (cset_state.is_in_cset()) {
 749         if (hr->is_young() != (cset_state.is_young())) {
 750           log_error(gc, verify)("## is_young %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
 751                                hr->is_young(), cset_state.value(), i);
 752           _failures = true;
 753           return true;
 754         }
 755         if (hr->is_old() != (cset_state.is_old())) {
 756           log_error(gc, verify)("## is_old %d / cset state " CSETSTATE_FORMAT " inconsistency for region %u",
 757                                hr->is_old(), cset_state.value(), i);
 758           _failures = true;
 759           return true;
 760         }
 761       }
 762     }
 763     return false;
 764   }
 765 
 766   bool failures() const { return _failures; }
 767 };
 768 
 769 bool G1HeapVerifier::check_cset_fast_test() {
 770   G1CheckCSetFastTableClosure cl;
 771   _g1h->_hrm.iterate(&cl);
 772   return !cl.failures();
 773 }
 774 #endif // PRODUCT