1 /*

     2  * Copyright (c) 2001, 2009, 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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

    23  * questions.

    24  */

    25 

    26 package sun.nio.ch;

    27 

    28 import java.io.IOException;

    29 import java.nio.channels.*;

    30 

    31 public class FileLockImpl

    32     extends FileLock

    33 {

    34     private volatile boolean invalid;

    35 

    36     FileLockImpl(FileChannel channel, long position, long size, boolean shared)

    37     {

    38         super(channel, position, size, shared);

    39     }

    40 

    41     FileLockImpl(AsynchronousFileChannel channel, long position, long size, boolean shared)

    42     {

    43         super(channel, position, size, shared);

    44     }

    45 

    46     public boolean isValid() {

    47         return !invalid;

    48     }

    49 

    50     void invalidate() {

    51         assert Thread.holdsLock(this);

    52         invalid = true;

    53     }

    54 

    55     public synchronized void release() throws IOException {

    56         Channel ch = acquiredBy();

    57         if (!ch.isOpen())

    58             throw new ClosedChannelException();

    59         if (isValid()) {

    60             if (ch instanceof FileChannelImpl)

    61                 ((FileChannelImpl)ch).release(this);

    62             else if (ch instanceof AsynchronousFileChannelImpl)

    63                 ((AsynchronousFileChannelImpl)ch).release(this);

    64             else throw new AssertionError();

    65             invalidate();

    66         }

    67     }

    68 }