001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.internal;
018
019import java.util.concurrent.locks.*;
020
021/**
022 * A simple auto-closeable wrapper around a lock.
023 */
024public class SimpleLock implements AutoCloseable {
025
026   /**
027    * A simple no-op lock.
028    */
029   public static final SimpleLock NO_OP = new SimpleLock(null);
030
031   private final Lock lock;
032
033   /**
034    * Constructor.
035    *
036    * @param lock The lock being wrapped.
037    */
038   public SimpleLock(Lock lock) {
039      this.lock = lock;
040      if (lock != null)
041         lock.lock();
042   }
043
044   @Override
045   public void close() {
046      if (lock != null)
047         lock.unlock();
048   }
049}