1 /*

     2  * Copyright (c) 2013, 2015, 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_CLASSFILE_METADATAONSTACKMARK_HPP

    26 #define SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP

    27 

    28 #include "memory/allocation.hpp"

    29 #include "utilities/chunkedList.hpp"

    30 

    31 class Metadata;

    32 

    33 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;

    34 

    35 // Helper class to mark and unmark metadata used on the stack as either handles

    36 // or executing methods, so that it can't be deleted during class redefinition

    37 // and class unloading.

    38 // This is also used for other things that can be deallocated, like class

    39 // metadata during parsing if errors occur, relocated methods, and temporary

    40 // constant pools.

    41 class MetadataOnStackMark : public StackObj {

    42   NOT_PRODUCT(static bool _is_active;)

    43   static MetadataOnStackBuffer* _used_buffers;

    44   static MetadataOnStackBuffer* _free_buffers;

    45   static MetadataOnStackBuffer* _current_buffer;

    46 

    47   static MetadataOnStackBuffer* allocate_buffer();

    48   static void retire_buffer(MetadataOnStackBuffer* buffer);

    49 

    50  public:

    51   MetadataOnStackMark(bool redefinition_walk);

    52    ~MetadataOnStackMark();

    53 

    54   static void record(Metadata* m);

    55   static void retire_current_buffer();

    56 };

    57 

    58 #endif // SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP