--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/misc/ConditionLock.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,82 @@
+/*
+ * Copyright 1994-2005 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.misc;
+
+/**
+ * ConditionLock is a Lock with a built in state variable.  This class
+ * provides the ability to wait for the state variable to be set to a
+ * desired value and then acquire the lock.<p>
+ *
+ * The lockWhen() and unlockWith() methods can be safely intermixed
+ * with the lock() and unlock() methods. However if there is a thread
+ * waiting for the state variable to become a particular value and you
+ * simply call Unlock(), that thread will not be able to acquire the
+ * lock until the state variable equals its desired value. <p>
+ *
+ * @author      Peter King
+ */
+public final
+class ConditionLock extends Lock {
+    private int state = 0;
+
+    /**
+     * Creates a ConditionLock.
+     */
+    public ConditionLock () {
+    }
+
+    /**
+     * Creates a ConditionLock in an initialState.
+     */
+    public ConditionLock (int initialState) {
+        state = initialState;
+    }
+
+    /**
+     * Acquires the lock when the state variable equals the desired state.
+     *
+     * @param desiredState the desired state
+     * @exception  java.lang.InterruptedException if any thread has
+     *               interrupted this thread.
+     */
+    public synchronized void lockWhen(int desiredState)
+        throws InterruptedException
+    {
+        while (state != desiredState) {
+            wait();
+        }
+        lock();
+    }
+
+    /**
+     * Releases the lock, and sets the state to a new value.
+     * @param newState the new state
+     */
+    public synchronized void unlockWith(int newState) {
+        state = newState;
+        unlock();
+    }
+}