/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

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

 *

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

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

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

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

 * accompanied this code).

 *

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

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

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

 *

 */

package sun.nio.ch;

import java.io.IOException;

import java.nio.channels.*;

public class FileLockImpl

    extends FileLock

{

    private volatile boolean valid = true;

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

    {

        super(channel, position, size, shared);

    }

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

    {

        super(channel, position, size, shared);

    }

    public boolean isValid() {

        return valid;

    }

    void invalidate() {

        assert Thread.holdsLock(this);

        valid = false;

    }

    public synchronized void release() throws IOException {

        Channel ch = acquiredBy();

        if (!ch.isOpen())

            throw new ClosedChannelException();

        if (valid) {

            if (ch instanceof FileChannelImpl)

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

            else if (ch instanceof AsynchronousFileChannelImpl)

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

            else throw new AssertionError();

            valid = false;

        }

    }

}