src/share/vm/gc/g1/g1CollectedHeap.cpp

rev 10808 : imported patch eager-reclaim-alive-check

*** 2938,2954 ****
      return G1EagerReclaimHumongousObjectsWithStaleRefs
        ? rset->occupancy_less_or_equal_than(G1RSetSparseRegionEntries)
        : rset->is_empty();
    }
  
-   bool is_typeArray_region(HeapRegion* region) const {
-     return oop(region->bottom())->is_typeArray();
-   }
- 
    bool humongous_region_is_candidate(G1CollectedHeap* heap, HeapRegion* region) const {
      assert(region->is_starts_humongous(), "Must start a humongous object");
  
      // Candidate selection must satisfy the following constraints
      // while concurrent marking is in progress:
      //
      // * In order to maintain SATB invariants, an object must not be
      // reclaimed if it was allocated before the start of marking and
--- 2938,2958 ----
      return G1EagerReclaimHumongousObjectsWithStaleRefs
        ? rset->occupancy_less_or_equal_than(G1RSetSparseRegionEntries)
        : rset->is_empty();
    }
  
    bool humongous_region_is_candidate(G1CollectedHeap* heap, HeapRegion* region) const {
      assert(region->is_starts_humongous(), "Must start a humongous object");
  
+     oop obj = oop(region->bottom());
+ 
+     // Dead objects cannot be eager reclaim candidates. Due to class
+     // unloading it is unsafe to query their classes so we return early.
+     if (heap->is_obj_dead(obj, region)) {
+       return false;
+     }
+ 
      // Candidate selection must satisfy the following constraints
      // while concurrent marking is in progress:
      //
      // * In order to maintain SATB invariants, an object must not be
      // reclaimed if it was allocated before the start of marking and
*** 2981,2991 ****
      // such objects to be built-in and so ensured to be kept live.
      // Frequent allocation and drop of large binary blobs is an
      // important use case for eager reclaim, and this special handling
      // may reduce needed headroom.
  
!     return is_typeArray_region(region) && is_remset_small(region);
    }
  
   public:
    RegisterHumongousWithInCSetFastTestClosure()
    : _total_humongous(0),
--- 2985,2995 ----
      // such objects to be built-in and so ensured to be kept live.
      // Frequent allocation and drop of large binary blobs is an
      // important use case for eager reclaim, and this special handling
      // may reduce needed headroom.
  
!     return obj->is_typeArray() && is_remset_small(region);
    }
  
   public:
    RegisterHumongousWithInCSetFastTestClosure()
    : _total_humongous(0),