src/share/vm/oops/arrayKlassKlass.hpp

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

author
johnc
date
Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781
e1162778c1c8
parent 2314
f95d63e2154a
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 /*
     2  * Copyright (c) 1997, 2010, 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_OOPS_ARRAYKLASSKLASS_HPP
    26 #define SHARE_VM_OOPS_ARRAYKLASSKLASS_HPP
    28 #include "oops/arrayKlass.hpp"
    29 #include "oops/klassKlass.hpp"
    31 // arrayKlassKlass is the abstract baseclass for all array class classes
    33 class arrayKlassKlass : public klassKlass {
    34  public:
    35    // Testing
    36   bool oop_is_arrayKlass() const { return true; }
    38   // Allocation
    39   DEFINE_ALLOCATE_PERMANENT(arrayKlassKlass);
    40   static klassOop create_klass(TRAPS);
    42   // Casting from klassOop
    43   static arrayKlassKlass* cast(klassOop k) {
    44     assert(k->klass_part()->oop_is_klass(), "cast to arrayKlassKlass");
    45     return (arrayKlassKlass*) k->klass_part();
    46   }
    48   // Sizing
    49   static int header_size()      { return oopDesc::header_size() + sizeof(arrayKlassKlass)/HeapWordSize; }
    50   int object_size() const       { return align_object_size(header_size()); }
    52   // Garbage collection
    53   void oop_follow_contents(oop obj);
    54   int oop_adjust_pointers(oop obj);
    55   bool oop_is_parsable(oop obj) const;
    57   // Parallel Scavenge and Parallel Old
    58   PARALLEL_GC_DECLS
    60   // Iterators
    61   int oop_oop_iterate(oop obj, OopClosure* blk);
    62   int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr);
    64   // Printing
    65   void oop_print_value_on(oop obj, outputStream* st);
    66   void oop_print_on(oop obj, outputStream* st);
    68   // Verification
    69   const char* internal_name() const;
    70   void oop_verify_on(oop obj, outputStream* st);
    71 };
    73 #endif // SHARE_VM_OOPS_ARRAYKLASSKLASS_HPP

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