1 /*

     2  * Copyright (c) 2017, 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  */

    24 

    25 #ifndef SHARE_VM_GC_SHARED_WEAKPROCESSOR_HPP

    26 #define SHARE_VM_GC_SHARED_WEAKPROCESSOR_HPP

    27 

    28 #include "memory/allocation.hpp"

    29 #include "memory/iterator.hpp"

    30 

    31 // Helper class to aid in root scanning and cleaning of weak oops in the VM.

    32 //

    33 // New containers of weak oops added to this class will automatically

    34 // be cleaned by all GCs, including the young generation GCs.

    35 class WeakProcessor : AllStatic {

    36 public:

    37   // Visit all oop*s and apply the keep_alive closure if the referenced

    38   // object is considered alive by the is_alive closure, otherwise do some

    39   // container specific cleanup of element holding the oop.

    40   //

    41   // The complete closure is used as a post-processing step,

    42   // called after all container have been processed.

    43   static void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, VoidClosure* complete = NULL);

    44 

    45   // Visit all oop*s and apply the given closure.

    46   static void oops_do(OopClosure* closure);

    47 };

    48 

    49 #endif // SHARE_VM_GC_SHARED_WEAKPROCESSOR_HPP