--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/nio/ch/FileLockImpl.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2001-2003 Sun Microsystems, Inc.  All Rights Reserved.
+ * 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
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.nio.ch;
+
+import java.io.IOException;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.FileLock;
+import java.nio.channels.FileChannel;
+
+public class FileLockImpl
+    extends FileLock
+{
+    boolean valid;
+
+    FileLockImpl(FileChannel channel, long position, long size, boolean shared)
+    {
+        super(channel, position, size, shared);
+        this.valid = true;
+    }
+
+    public synchronized boolean isValid() {
+        return valid;
+    }
+
+    synchronized void invalidate() {
+        valid = false;
+    }
+
+    public synchronized void release() throws IOException {
+        if (!channel().isOpen())
+            throw new ClosedChannelException();
+        if (valid) {
+            ((FileChannelImpl)channel()).release(this);
+            valid = false;
+        }
+    }
+
+}