| /* |
| * Copyright (c) 1994, 2005, Oracle and/or its affiliates. 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.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(); |
| } |
| } |