src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp

Thu, 28 Aug 2014 17:05:41 +0200

author
tschatzl
date
Thu, 28 Aug 2014 17:05:41 +0200
changeset 7100
edb5f3b38aab
parent 7091
a8ea2f110d87
child 7118
227a9e5e4b4a
permissions
-rw-r--r--

8054808: Bitmap verification sometimes fails after Full GC aborts concurrent mark.
Summary: The verification code that checked whether no bitmap mark had been found re-read HeapRegion::end() after the check on the bitmap. Concurrent humongous object allocation could have changed HeapRegion::end() in the meantime. Fix this by using the actual end of the region instead of HeapRegion::end() for comparison.
Reviewed-by: brutisso, jmasa

     1 /*
     2  * Copyright (c) 2001, 2014, 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.
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     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
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    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
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    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
    28 #include "gc_implementation/g1/concurrentMark.hpp"
    29 #include "gc_implementation/g1/g1CollectedHeap.hpp"
    30 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
    31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
    32 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
    33 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
    34 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
    35 #include "runtime/orderAccess.inline.hpp"
    36 #include "utilities/taskqueue.hpp"
    38 // Inline functions for G1CollectedHeap
    40 // Return the region with the given index. It assumes the index is valid.
    41 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
    43 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
    44   assert(is_in_reserved(addr),
    45          err_msg("Cannot calculate region index for address "PTR_FORMAT" that is outside of the heap ["PTR_FORMAT", "PTR_FORMAT")",
    46                  p2i(addr), p2i(_reserved.start()), p2i(_reserved.end())));
    47   return (uint)(pointer_delta(addr, _reserved.start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
    48 }
    50 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
    51   return _hrm.reserved().start() + index * HeapRegion::GrainWords;
    52 }
    54 template <class T>
    55 inline HeapRegion* G1CollectedHeap::heap_region_containing_raw(const T addr) const {
    56   assert(addr != NULL, "invariant");
    57   assert(is_in_g1_reserved((const void*) addr),
    58       err_msg("Address "PTR_FORMAT" is outside of the heap ranging from ["PTR_FORMAT" to "PTR_FORMAT")",
    59           p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end())));
    60   return _hrm.addr_to_region((HeapWord*) addr);
    61 }
    63 template <class T>
    64 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
    65   HeapRegion* hr = heap_region_containing_raw(addr);
    66   if (hr->continuesHumongous()) {
    67     return hr->humongous_start_region();
    68   }
    69   return hr;
    70 }
    72 inline void G1CollectedHeap::reset_gc_time_stamp() {
    73   _gc_time_stamp = 0;
    74   OrderAccess::fence();
    75   // Clear the cached CSet starting regions and time stamps.
    76   // Their validity is dependent on the GC timestamp.
    77   clear_cset_start_regions();
    78 }
    80 inline void G1CollectedHeap::increment_gc_time_stamp() {
    81   ++_gc_time_stamp;
    82   OrderAccess::fence();
    83 }
    85 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
    86   _old_set.remove(hr);
    87 }
    89 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
    90   HeapRegion* r = _hrm.addr_to_region((HeapWord*) obj);
    91   return r != NULL && r->in_collection_set();
    92 }
    94 inline HeapWord* G1CollectedHeap::attempt_allocation(size_t word_size,
    95                                                      unsigned int* gc_count_before_ret,
    96                                                      int* gclocker_retry_count_ret) {
    97   assert_heap_not_locked_and_not_at_safepoint();
    98   assert(!isHumongous(word_size), "attempt_allocation() should not "
    99          "be called for humongous allocation requests");
   101   HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
   102                                                       false /* bot_updates */);
   103   if (result == NULL) {
   104     result = attempt_allocation_slow(word_size,
   105                                      gc_count_before_ret,
   106                                      gclocker_retry_count_ret);
   107   }
   108   assert_heap_not_locked();
   109   if (result != NULL) {
   110     dirty_young_block(result, word_size);
   111   }
   112   return result;
   113 }
   115 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
   116                                                               word_size) {
   117   assert(!isHumongous(word_size),
   118          "we should not be seeing humongous-size allocations in this path");
   120   HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
   121                                                       false /* bot_updates */);
   122   if (result == NULL) {
   123     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
   124     result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
   125                                                       false /* bot_updates */);
   126   }
   127   if (result != NULL) {
   128     dirty_young_block(result, word_size);
   129   }
   130   return result;
   131 }
   133 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
   134   assert(!isHumongous(word_size),
   135          "we should not be seeing humongous-size allocations in this path");
   137   HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
   138                                                        true /* bot_updates */);
   139   if (result == NULL) {
   140     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
   141     result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
   142                                                        true /* bot_updates */);
   143   }
   144   return result;
   145 }
   147 // It dirties the cards that cover the block so that so that the post
   148 // write barrier never queues anything when updating objects on this
   149 // block. It is assumed (and in fact we assert) that the block
   150 // belongs to a young region.
   151 inline void
   152 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
   153   assert_heap_not_locked();
   155   // Assign the containing region to containing_hr so that we don't
   156   // have to keep calling heap_region_containing_raw() in the
   157   // asserts below.
   158   DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
   159   assert(word_size > 0, "pre-condition");
   160   assert(containing_hr->is_in(start), "it should contain start");
   161   assert(containing_hr->is_young(), "it should be young");
   162   assert(!containing_hr->isHumongous(), "it should not be humongous");
   164   HeapWord* end = start + word_size;
   165   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
   167   MemRegion mr(start, end);
   168   g1_barrier_set()->g1_mark_as_young(mr);
   169 }
   171 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
   172   return _task_queues->queue(i);
   173 }
   175 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
   176   return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
   177 }
   179 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
   180   return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
   181 }
   183 // This is a fast test on whether a reference points into the
   184 // collection set or not. Assume that the reference
   185 // points into the heap.
   186 inline bool G1CollectedHeap::is_in_cset(oop obj) {
   187   bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
   188   // let's make sure the result is consistent with what the slower
   189   // test returns
   190   assert( ret || !obj_in_cs(obj), "sanity");
   191   assert(!ret ||  obj_in_cs(obj), "sanity");
   192   return ret;
   193 }
   195 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
   196   return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
   197 }
   199 G1CollectedHeap::in_cset_state_t G1CollectedHeap::in_cset_state(const oop obj) {
   200   return _in_cset_fast_test.at((HeapWord*)obj);
   201 }
   203 void G1CollectedHeap::register_humongous_region_with_in_cset_fast_test(uint index) {
   204   _in_cset_fast_test.set_humongous(index);
   205 }
   207 #ifndef PRODUCT
   208 // Support for G1EvacuationFailureALot
   210 inline bool
   211 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
   212                                                      bool during_initial_mark,
   213                                                      bool during_marking) {
   214   bool res = false;
   215   if (during_marking) {
   216     res |= G1EvacuationFailureALotDuringConcMark;
   217   }
   218   if (during_initial_mark) {
   219     res |= G1EvacuationFailureALotDuringInitialMark;
   220   }
   221   if (gcs_are_young) {
   222     res |= G1EvacuationFailureALotDuringYoungGC;
   223   } else {
   224     // GCs are mixed
   225     res |= G1EvacuationFailureALotDuringMixedGC;
   226   }
   227   return res;
   228 }
   230 inline void
   231 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
   232   if (G1EvacuationFailureALot) {
   233     // Note we can't assert that _evacuation_failure_alot_for_current_gc
   234     // is clear here. It may have been set during a previous GC but that GC
   235     // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
   236     // trigger an evacuation failure and clear the flags and and counts.
   238     // Check if we have gone over the interval.
   239     const size_t gc_num = total_collections();
   240     const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
   242     _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
   244     // Now check if G1EvacuationFailureALot is enabled for the current GC type.
   245     const bool gcs_are_young = g1_policy()->gcs_are_young();
   246     const bool during_im = g1_policy()->during_initial_mark_pause();
   247     const bool during_marking = mark_in_progress();
   249     _evacuation_failure_alot_for_current_gc &=
   250       evacuation_failure_alot_for_gc_type(gcs_are_young,
   251                                           during_im,
   252                                           during_marking);
   253   }
   254 }
   256 inline bool G1CollectedHeap::evacuation_should_fail() {
   257   if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
   258     return false;
   259   }
   260   // G1EvacuationFailureALot is in effect for current GC
   261   // Access to _evacuation_failure_alot_count is not atomic;
   262   // the value does not have to be exact.
   263   if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
   264     return false;
   265   }
   266   _evacuation_failure_alot_count = 0;
   267   return true;
   268 }
   270 inline void G1CollectedHeap::reset_evacuation_should_fail() {
   271   if (G1EvacuationFailureALot) {
   272     _evacuation_failure_alot_gc_number = total_collections();
   273     _evacuation_failure_alot_count = 0;
   274     _evacuation_failure_alot_for_current_gc = false;
   275   }
   276 }
   277 #endif  // #ifndef PRODUCT
   279 inline bool G1CollectedHeap::is_in_young(const oop obj) {
   280   if (obj == NULL) {
   281     return false;
   282   }
   283   return heap_region_containing(obj)->is_young();
   284 }
   286 // We don't need barriers for initializing stores to objects
   287 // in the young gen: for the SATB pre-barrier, there is no
   288 // pre-value that needs to be remembered; for the remembered-set
   289 // update logging post-barrier, we don't maintain remembered set
   290 // information for young gen objects.
   291 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
   292   return is_in_young(new_obj);
   293 }
   295 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
   296   if (obj == NULL) {
   297     return false;
   298   }
   299   return is_obj_dead(obj, heap_region_containing(obj));
   300 }
   302 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
   303   if (obj == NULL) {
   304     return false;
   305   }
   306   return is_obj_ill(obj, heap_region_containing(obj));
   307 }
   309 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
   310   uint region = addr_to_region((HeapWord*)obj);
   311   // We not only set the "live" flag in the humongous_is_live table, but also
   312   // reset the entry in the _in_cset_fast_test table so that subsequent references
   313   // to the same humongous object do not go into the slow path again.
   314   // This is racy, as multiple threads may at the same time enter here, but this
   315   // is benign.
   316   // During collection we only ever set the "live" flag, and only ever clear the
   317   // entry in the in_cset_fast_table.
   318   // We only ever evaluate the contents of these tables (in the VM thread) after
   319   // having synchronized the worker threads with the VM thread, or in the same
   320   // thread (i.e. within the VM thread).
   321   if (!_humongous_is_live.is_live(region)) {
   322     _humongous_is_live.set_live(region);
   323     _in_cset_fast_test.clear_humongous(region);
   324   }
   325 }
   327 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP

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