jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1MarkSweep.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) 2001, 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

    21  * questions.

    22  *

    23  */

    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1MARKSWEEP_HPP

    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1MARKSWEEP_HPP

    28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"

    29 #include "gc_implementation/g1/heapRegion.hpp"

    30 #include "memory/genMarkSweep.hpp"

    31 #include "memory/generation.hpp"

    32 #include "memory/universe.hpp"

    33 #include "oops/markOop.hpp"

    34 #include "oops/oop.hpp"

    35 #include "runtime/timer.hpp"

    36 #include "utilities/growableArray.hpp"

    38 class ReferenceProcessor;

    40 // G1MarkSweep takes care of global mark-compact garbage collection for a

    41 // G1CollectedHeap using a four-phase pointer forwarding algorithm.  All

    42 // generations are assumed to support marking; those that can also support

    43 // compaction.

    44 //

    45 // Class unloading will only occur when a full gc is invoked.

    48 class G1MarkSweep : AllStatic {

    49   friend class VM_G1MarkSweep;

    50   friend class Scavenge;

    52  public:

    54   static void invoke_at_safepoint(ReferenceProcessor* rp,

    55                                   bool clear_all_softrefs);

    57  private:

    59   // Mark live objects

    60   static void mark_sweep_phase1(bool& marked_for_deopt,

    61                                 bool clear_all_softrefs);

    62   // Calculate new addresses

    63   static void mark_sweep_phase2();

    64   // Update pointers

    65   static void mark_sweep_phase3();

    66   // Move objects to new positions

    67   static void mark_sweep_phase4();

    69   static void allocate_stacks();

    70 };

    72 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1MARKSWEEP_HPP

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

src/share/vm/gc_implementation/g1/g1MarkSweep.hpp@e1162778c1c8

src/share/vm/gc_implementation/g1/g1MarkSweep.hpp