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 * An extension of {@link ReentrantReadWriteLock} with convenience methods for creating
023 * auto-closeable locks.
024 */
025public class SimpleReadWriteLock extends ReentrantReadWriteLock {
026   private static final long serialVersionUID = 1L;
027
028   //-----------------------------------------------------------------------------------------------------------------
029   // Static
030   //-----------------------------------------------------------------------------------------------------------------
031
032   /**
033    * A no-op lock.
034    */
035   public static SimpleReadWriteLock NO_OP = new SimpleReadWriteLock() {
036      private static final long serialVersionUID = 1L;
037
038      @Override
039      public SimpleLock write() {
040         return SimpleLock.NO_OP;
041      }
042      @Override
043      public SimpleLock read(){
044         return SimpleLock.NO_OP;
045      }
046   };
047
048   //-----------------------------------------------------------------------------------------------------------------
049   // Instance
050   //-----------------------------------------------------------------------------------------------------------------
051
052   /**
053    * Constructor.
054    */
055   public SimpleReadWriteLock() {
056   }
057
058   /**
059    * Constructor
060    *
061    * @param fair <jk>true</jk> if this lock should use a fair ordering policy.
062    */
063   public SimpleReadWriteLock(boolean fair) {
064      super(fair);
065   }
066
067   /**
068    * Construct a write lock.
069    *
070    * @return A new closeable write lock.
071    */
072   public SimpleLock write(){
073      return new SimpleLock(writeLock());
074   }
075
076   /**
077    * Construct a read lock.
078    *
079    * @return A new closeable read lock.
080    */
081   public SimpleLock read(){
082      return new SimpleLock(readLock());
083   }
084}