jdk8-mips64-public/hotspot: src/share/vm/oops/instanceOop.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_INSTANCEOOP_HPP

    26 #define SHARE_VM_OOPS_INSTANCEOOP_HPP

    28 #include "oops/oop.hpp"

    30 // An instanceOop is an instance of a Java Class

    31 // Evaluating "new HashTable()" will create an instanceOop.

    33 class instanceOopDesc : public oopDesc {

    34  public:

    35   // aligned header size.

    36   static int header_size() { return sizeof(instanceOopDesc)/HeapWordSize; }

    38   // If compressed, the offset of the fields of the instance may not be aligned.

    39   static int base_offset_in_bytes() {

    40     return UseCompressedOops ?

    41              klass_gap_offset_in_bytes() :

    42              sizeof(instanceOopDesc);

    43   }

    45   static bool contains_field_offset(int offset, int nonstatic_field_size) {

    46     int base_in_bytes = base_offset_in_bytes();

    47     return (offset >= base_in_bytes &&

    48             (offset-base_in_bytes) < nonstatic_field_size * heapOopSize);

    49   }

    50 };

    52 #endif // SHARE_VM_OOPS_INSTANCEOOP_HPP

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

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

src/share/vm/oops/instanceOop.hpp