--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/awt/Mutex.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,62 @@
+/*
+ * Copyright 1999-2000 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.awt;
+
+public class Mutex {
+    private boolean locked;
+    private Thread owner;
+
+    public synchronized void lock() {
+        if (locked && Thread.currentThread() == owner) {
+            throw new IllegalMonitorStateException();
+        }
+        do {
+            if (!locked) {
+                locked = true;
+                owner = Thread.currentThread();
+            } else {
+                try {
+                    wait();
+                } catch (InterruptedException e) {
+                    // try again
+                }
+            }
+        } while (owner != Thread.currentThread());
+    }
+
+    public synchronized void unlock() {
+        if (Thread.currentThread() != owner) {
+            throw new IllegalMonitorStateException();
+        }
+        owner = null;
+        locked = false;
+        notify();
+    }
+
+    protected boolean isOwned() {
+        return (locked && Thread.currentThread() == owner);
+    }
+}