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src/hotspot/share/gc/g1/g1EvacFailure.cpp

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rev 60059 : imported patch 8210462-fix-remaining-mentions-of-im


  62       return;
  63     }
  64 
  65     if (HeapRegion::is_in_same_region(p, CompressedOops::decode(o))) {
  66       return;
  67     }
  68     size_t card_index = _ct->index_for(p);
  69     if (card_index != _last_enqueued_card) {
  70       _rdcq->enqueue(_ct->byte_for_index(card_index));
  71       _last_enqueued_card = card_index;
  72     }
  73   }
  74 };
  75 
  76 class RemoveSelfForwardPtrObjClosure: public ObjectClosure {
  77   G1CollectedHeap* _g1h;
  78   G1ConcurrentMark* _cm;
  79   HeapRegion* _hr;
  80   size_t _marked_bytes;
  81   UpdateLogBuffersDeferred* _log_buffer_cl;
  82   bool _during_initial_mark;
  83   uint _worker_id;
  84   HeapWord* _last_forwarded_object_end;
  85 
  86 public:
  87   RemoveSelfForwardPtrObjClosure(HeapRegion* hr,
  88                                  UpdateLogBuffersDeferred* log_buffer_cl,
  89                                  bool during_initial_mark,
  90                                  uint worker_id) :
  91     _g1h(G1CollectedHeap::heap()),
  92     _cm(_g1h->concurrent_mark()),
  93     _hr(hr),
  94     _marked_bytes(0),
  95     _log_buffer_cl(log_buffer_cl),
  96     _during_initial_mark(during_initial_mark),
  97     _worker_id(worker_id),
  98     _last_forwarded_object_end(hr->bottom()) { }
  99 
 100   size_t marked_bytes() { return _marked_bytes; }
 101 
 102   // Iterate over the live objects in the region to find self-forwarded objects
 103   // that need to be kept live. We need to update the remembered sets of these
 104   // objects. Further update the BOT and marks.
 105   // We can coalesce and overwrite the remaining heap contents with dummy objects
 106   // as they have either been dead or evacuated (which are unreferenced now, i.e.
 107   // dead too) already.
 108   void do_object(oop obj) {
 109     HeapWord* obj_addr = cast_from_oop<HeapWord*>(obj);
 110     assert(_hr->is_in(obj_addr), "sanity");
 111 
 112     if (obj->is_forwarded() && obj->forwardee() == obj) {
 113       // The object failed to move.
 114 
 115       zap_dead_objects(_last_forwarded_object_end, obj_addr);
 116       // We consider all objects that we find self-forwarded to be
 117       // live. What we'll do is that we'll update the prev marking
 118       // info so that they are all under PTAMS and explicitly marked.
 119       if (!_cm->is_marked_in_prev_bitmap(obj)) {
 120         _cm->mark_in_prev_bitmap(obj);
 121       }
 122       if (_during_initial_mark) {
 123         // For the next marking info we'll only mark the
 124         // self-forwarded objects explicitly if we are during
 125         // initial-mark (since, normally, we only mark objects pointed
 126         // to by roots if we succeed in copying them). By marking all
 127         // self-forwarded objects we ensure that we mark any that are
 128         // still pointed to be roots. During concurrent marking, and
 129         // after initial-mark, we don't need to mark any objects
 130         // explicitly and all objects in the CSet are considered
 131         // (implicitly) live. So, we won't mark them explicitly and
 132         // we'll leave them over NTAMS.
 133         _cm->mark_in_next_bitmap(_worker_id, _hr, obj);
 134       }
 135       size_t obj_size = obj->size();
 136 
 137       _marked_bytes += (obj_size * HeapWordSize);
 138       PreservedMarks::init_forwarded_mark(obj);
 139 
 140       // While we were processing RSet buffers during the collection,
 141       // we actually didn't scan any cards on the collection set,
 142       // since we didn't want to update remembered sets with entries
 143       // that point into the collection set, given that live objects
 144       // from the collection set are about to move and such entries
 145       // will be stale very soon.
 146       // This change also dealt with a reliability issue which
 147       // involved scanning a card in the collection set and coming
 148       // across an array that was being chunked and looking malformed.
 149       // The problem is that, if evacuation fails, we might have


 194     zap_dead_objects(_last_forwarded_object_end, _hr->top());
 195   }
 196 };
 197 
 198 class RemoveSelfForwardPtrHRClosure: public HeapRegionClosure {
 199   G1CollectedHeap* _g1h;
 200   uint _worker_id;
 201 
 202   G1RedirtyCardsQueue _rdcq;
 203   UpdateLogBuffersDeferred _log_buffer_cl;
 204 
 205 public:
 206   RemoveSelfForwardPtrHRClosure(G1RedirtyCardsQueueSet* rdcqs, uint worker_id) :
 207     _g1h(G1CollectedHeap::heap()),
 208     _worker_id(worker_id),
 209     _rdcq(rdcqs),
 210     _log_buffer_cl(&_rdcq) {
 211   }
 212 
 213   size_t remove_self_forward_ptr_by_walking_hr(HeapRegion* hr,
 214                                                bool during_initial_mark) {
 215     RemoveSelfForwardPtrObjClosure rspc(hr,
 216                                         &_log_buffer_cl,
 217                                         during_initial_mark,
 218                                         _worker_id);
 219     hr->object_iterate(&rspc);
 220     // Need to zap the remainder area of the processed region.
 221     rspc.zap_remainder();
 222 
 223     return rspc.marked_bytes();
 224   }
 225 
 226   bool do_heap_region(HeapRegion *hr) {
 227     assert(!hr->is_pinned(), "Unexpected pinned region at index %u", hr->hrm_index());
 228     assert(hr->in_collection_set(), "bad CS");
 229 
 230     if (hr->evacuation_failed()) {
 231       hr->clear_index_in_opt_cset();
 232 
 233       bool during_initial_mark = _g1h->collector_state()->in_initial_mark_gc();
 234       bool during_conc_mark = _g1h->collector_state()->mark_or_rebuild_in_progress();
 235 
 236       hr->note_self_forwarding_removal_start(during_initial_mark,
 237                                                during_conc_mark);
 238       _g1h->verifier()->check_bitmaps("Self-Forwarding Ptr Removal", hr);
 239 
 240       hr->reset_bot();
 241 
 242       size_t live_bytes = remove_self_forward_ptr_by_walking_hr(hr, during_initial_mark);
 243 
 244       hr->rem_set()->clean_strong_code_roots(hr);
 245       hr->rem_set()->clear_locked(true);
 246 
 247       hr->note_self_forwarding_removal_end(live_bytes);
 248     }
 249     return false;
 250   }
 251 };
 252 
 253 G1ParRemoveSelfForwardPtrsTask::G1ParRemoveSelfForwardPtrsTask(G1RedirtyCardsQueueSet* rdcqs) :
 254   AbstractGangTask("G1 Remove Self-forwarding Pointers"),
 255   _g1h(G1CollectedHeap::heap()),
 256   _rdcqs(rdcqs),
 257   _hrclaimer(_g1h->workers()->active_workers()) { }
 258 
 259 void G1ParRemoveSelfForwardPtrsTask::work(uint worker_id) {
 260   RemoveSelfForwardPtrHRClosure rsfp_cl(_rdcqs, worker_id);
 261 
 262   _g1h->collection_set_iterate_increment_from(&rsfp_cl, &_hrclaimer, worker_id);


  62       return;
  63     }
  64 
  65     if (HeapRegion::is_in_same_region(p, CompressedOops::decode(o))) {
  66       return;
  67     }
  68     size_t card_index = _ct->index_for(p);
  69     if (card_index != _last_enqueued_card) {
  70       _rdcq->enqueue(_ct->byte_for_index(card_index));
  71       _last_enqueued_card = card_index;
  72     }
  73   }
  74 };
  75 
  76 class RemoveSelfForwardPtrObjClosure: public ObjectClosure {
  77   G1CollectedHeap* _g1h;
  78   G1ConcurrentMark* _cm;
  79   HeapRegion* _hr;
  80   size_t _marked_bytes;
  81   UpdateLogBuffersDeferred* _log_buffer_cl;
  82   bool _during_concurrent_start;
  83   uint _worker_id;
  84   HeapWord* _last_forwarded_object_end;
  85 
  86 public:
  87   RemoveSelfForwardPtrObjClosure(HeapRegion* hr,
  88                                  UpdateLogBuffersDeferred* log_buffer_cl,
  89                                  bool during_concurrent_start,
  90                                  uint worker_id) :
  91     _g1h(G1CollectedHeap::heap()),
  92     _cm(_g1h->concurrent_mark()),
  93     _hr(hr),
  94     _marked_bytes(0),
  95     _log_buffer_cl(log_buffer_cl),
  96     _during_concurrent_start(during_concurrent_start),
  97     _worker_id(worker_id),
  98     _last_forwarded_object_end(hr->bottom()) { }
  99 
 100   size_t marked_bytes() { return _marked_bytes; }
 101 
 102   // Iterate over the live objects in the region to find self-forwarded objects
 103   // that need to be kept live. We need to update the remembered sets of these
 104   // objects. Further update the BOT and marks.
 105   // We can coalesce and overwrite the remaining heap contents with dummy objects
 106   // as they have either been dead or evacuated (which are unreferenced now, i.e.
 107   // dead too) already.
 108   void do_object(oop obj) {
 109     HeapWord* obj_addr = cast_from_oop<HeapWord*>(obj);
 110     assert(_hr->is_in(obj_addr), "sanity");
 111 
 112     if (obj->is_forwarded() && obj->forwardee() == obj) {
 113       // The object failed to move.
 114 
 115       zap_dead_objects(_last_forwarded_object_end, obj_addr);
 116       // We consider all objects that we find self-forwarded to be
 117       // live. What we'll do is that we'll update the prev marking
 118       // info so that they are all under PTAMS and explicitly marked.
 119       if (!_cm->is_marked_in_prev_bitmap(obj)) {
 120         _cm->mark_in_prev_bitmap(obj);
 121       }
 122       if (_during_concurrent_start) {
 123         // For the next marking info we'll only mark the
 124         // self-forwarded objects explicitly if we are during
 125         // concurrent start (since, normally, we only mark objects pointed
 126         // to by roots if we succeed in copying them). By marking all
 127         // self-forwarded objects we ensure that we mark any that are
 128         // still pointed to be roots. During concurrent marking, and
 129         // after concurrent start, we don't need to mark any objects
 130         // explicitly and all objects in the CSet are considered
 131         // (implicitly) live. So, we won't mark them explicitly and
 132         // we'll leave them over NTAMS.
 133         _cm->mark_in_next_bitmap(_worker_id, _hr, obj);
 134       }
 135       size_t obj_size = obj->size();
 136 
 137       _marked_bytes += (obj_size * HeapWordSize);
 138       PreservedMarks::init_forwarded_mark(obj);
 139 
 140       // While we were processing RSet buffers during the collection,
 141       // we actually didn't scan any cards on the collection set,
 142       // since we didn't want to update remembered sets with entries
 143       // that point into the collection set, given that live objects
 144       // from the collection set are about to move and such entries
 145       // will be stale very soon.
 146       // This change also dealt with a reliability issue which
 147       // involved scanning a card in the collection set and coming
 148       // across an array that was being chunked and looking malformed.
 149       // The problem is that, if evacuation fails, we might have


 194     zap_dead_objects(_last_forwarded_object_end, _hr->top());
 195   }
 196 };
 197 
 198 class RemoveSelfForwardPtrHRClosure: public HeapRegionClosure {
 199   G1CollectedHeap* _g1h;
 200   uint _worker_id;
 201 
 202   G1RedirtyCardsQueue _rdcq;
 203   UpdateLogBuffersDeferred _log_buffer_cl;
 204 
 205 public:
 206   RemoveSelfForwardPtrHRClosure(G1RedirtyCardsQueueSet* rdcqs, uint worker_id) :
 207     _g1h(G1CollectedHeap::heap()),
 208     _worker_id(worker_id),
 209     _rdcq(rdcqs),
 210     _log_buffer_cl(&_rdcq) {
 211   }
 212 
 213   size_t remove_self_forward_ptr_by_walking_hr(HeapRegion* hr,
 214                                                bool during_concurrent_start) {
 215     RemoveSelfForwardPtrObjClosure rspc(hr,
 216                                         &_log_buffer_cl,
 217                                         during_concurrent_start,
 218                                         _worker_id);
 219     hr->object_iterate(&rspc);
 220     // Need to zap the remainder area of the processed region.
 221     rspc.zap_remainder();
 222 
 223     return rspc.marked_bytes();
 224   }
 225 
 226   bool do_heap_region(HeapRegion *hr) {
 227     assert(!hr->is_pinned(), "Unexpected pinned region at index %u", hr->hrm_index());
 228     assert(hr->in_collection_set(), "bad CS");
 229 
 230     if (hr->evacuation_failed()) {
 231       hr->clear_index_in_opt_cset();
 232 
 233       bool during_concurrent_start = _g1h->collector_state()->in_concurrent_start_gc();
 234       bool during_concurrent_mark = _g1h->collector_state()->mark_or_rebuild_in_progress();
 235 
 236       hr->note_self_forwarding_removal_start(during_concurrent_start,
 237                                              during_concurrent_mark);
 238       _g1h->verifier()->check_bitmaps("Self-Forwarding Ptr Removal", hr);
 239 
 240       hr->reset_bot();
 241 
 242       size_t live_bytes = remove_self_forward_ptr_by_walking_hr(hr, during_concurrent_start);
 243 
 244       hr->rem_set()->clean_strong_code_roots(hr);
 245       hr->rem_set()->clear_locked(true);
 246 
 247       hr->note_self_forwarding_removal_end(live_bytes);
 248     }
 249     return false;
 250   }
 251 };
 252 
 253 G1ParRemoveSelfForwardPtrsTask::G1ParRemoveSelfForwardPtrsTask(G1RedirtyCardsQueueSet* rdcqs) :
 254   AbstractGangTask("G1 Remove Self-forwarding Pointers"),
 255   _g1h(G1CollectedHeap::heap()),
 256   _rdcqs(rdcqs),
 257   _hrclaimer(_g1h->workers()->active_workers()) { }
 258 
 259 void G1ParRemoveSelfForwardPtrsTask::work(uint worker_id) {
 260   RemoveSelfForwardPtrHRClosure rsfp_cl(_rdcqs, worker_id);
 261 
 262   _g1h->collection_set_iterate_increment_from(&rsfp_cl, &_hrclaimer, worker_id);
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