jdk8-mips64-public/hotspot: src/share/vm/oops/klassKlass.hpp@e1162778c1c8

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.

     8  *

     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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    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

    20  * or visit www.oracle.com if you need additional information or have any

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    23  */

    25 #ifndef SHARE_VM_OOPS_KLASSKLASS_HPP

    26 #define SHARE_VM_OOPS_KLASSKLASS_HPP

    28 #include "memory/oopFactory.hpp"

    29 #include "oops/klass.hpp"

    30 #include "oops/klassOop.hpp"

    32 // A klassKlass serves as the fix point of the klass chain.

    33 // The klass of klassKlass is itself.

    35 class klassKlass: public Klass {

    36   friend class VMStructs;

    37  private:

    38   juint    _alloc_size;        // allocation profiling support

    39  public:

    40   // Testing

    41   bool oop_is_klass()  const { return true; }

    42   bool is_leaf_class() const { return true; }

    44   // Sizing

    45   int oop_size(oop obj) const;

    46   int klass_oop_size() const { return object_size(); }

    48   // Allocation

    49   DEFINE_ALLOCATE_PERMANENT(klassKlass);

    50   static klassOop create_klass(TRAPS );

    52   // Casting from klassOop

    53   static klassKlass* cast(klassOop k) {

    54     assert(k->klass_part()->oop_is_klass(), "cast to klassKlass");

    55     return (klassKlass*) k->klass_part();

    56   }

    58   // Sizing

    59   static int header_size()  { return oopDesc::header_size() + sizeof(klassKlass)/HeapWordSize; }

    60   int object_size() const   { return align_object_size(header_size()); }

    62   // Garbage collection

    63   void oop_follow_contents(oop obj);

    64   int  oop_adjust_pointers(oop obj);

    66   // Parallel Scavenge and Parallel Old

    67   PARALLEL_GC_DECLS

    69   // Iterators

    70   int  oop_oop_iterate(oop obj, OopClosure* blk);

    71   int  oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr);

    73   // Allocation profiling support

    74   juint alloc_size() const              { return _alloc_size; }

    75   void set_alloc_size(juint n)          { _alloc_size = n; }

    77   // Printing

    78   void oop_print_value_on(oop obj, outputStream* st);

    79   void oop_print_on      (oop obj, outputStream* st);

    81   // Verification

    82   const char* internal_name() const;

    83   void oop_verify_on(oop obj, outputStream* st);

    84 };

    86 #endif // SHARE_VM_OOPS_KLASSKLASS_HPP

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/oops/klassKlass.hpp@e1162778c1c8

src/share/vm/oops/klassKlass.hpp