src/share/vm/oops/cpCacheKlass.hpp

Thu, 07 Apr 2011 09:53:20 -0700

author
johnc
date
Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781
e1162778c1c8
parent 2533
c5a923563727
child 2708
1d1603768966
permissions
-rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

     1 /*
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     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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     5  * This code is free software; you can redistribute it and/or modify it
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    12  * version 2 for more details (a copy is included in the LICENSE file that
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    25 #ifndef SHARE_VM_OOPS_CPCACHEKLASS_HPP
    26 #define SHARE_VM_OOPS_CPCACHEKLASS_HPP
    28 #include "oops/arrayKlass.hpp"
    29 #include "oops/cpCacheOop.hpp"
    30 #include "oops/instanceKlass.hpp"
    32 class constantPoolCacheKlass: public Klass {
    33   juint    _alloc_size;        // allocation profiling support
    34  public:
    35   // Dispatched klass operations
    36   bool oop_is_constantPoolCache() const          { return true; }
    37   int  oop_size(oop obj) const;
    38   int  klass_oop_size() const                    { return object_size(); }
    40   // Allocation
    41   DEFINE_ALLOCATE_PERMANENT(constantPoolCacheKlass);
    42   constantPoolCacheOop allocate(int length, TRAPS);
    43   static klassOop create_klass(TRAPS);
    45   // Casting from klassOop
    46   static constantPoolCacheKlass* cast(klassOop k) {
    47     assert(k->klass_part()->oop_is_constantPoolCache(), "cast to constantPoolCacheKlass");
    48     return (constantPoolCacheKlass*)k->klass_part();
    49   }
    51   // Sizing
    52   static int header_size()       { return oopDesc::header_size() + sizeof(constantPoolCacheKlass)/HeapWordSize; }
    53   int object_size() const        { return align_object_size(header_size()); }
    55   // Garbage collection
    56   void oop_follow_contents(oop obj);
    57   int oop_adjust_pointers(oop obj);
    59   // Parallel Scavenge and Parallel Old
    60   PARALLEL_GC_DECLS
    62   // Iterators
    63   int oop_oop_iterate(oop obj, OopClosure* blk);
    64   int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr);
    66   // Allocation profiling support
    67   juint alloc_size() const              { return _alloc_size; }
    68   void set_alloc_size(juint n)          { _alloc_size = n; }
    70   // Printing
    71   void oop_print_value_on(oop obj, outputStream* st);
    72   void oop_print_on(oop obj, outputStream* st);
    74   // Verification
    75   const char* internal_name() const;
    76   void oop_verify_on(oop obj, outputStream* st);
    77 };
    79 #endif // SHARE_VM_OOPS_CPCACHEKLASS_HPP

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