001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.internal;
014
015import java.util.concurrent.locks.ReentrantReadWriteLock;
016
017/**
018 * An extension of {@link ReentrantReadWriteLock} with convenience methods for creating
019 * auto-closeable locks.
020 */
021public class SimpleReadWriteLock extends ReentrantReadWriteLock {
022   private static final long serialVersionUID = 1L;
023
024   //-----------------------------------------------------------------------------------------------------------------
025   // Static
026   //-----------------------------------------------------------------------------------------------------------------
027
028   /**
029    * A no-op lock.
030    */
031   public static SimpleReadWriteLock NO_OP = new SimpleReadWriteLock() {
032      private static final long serialVersionUID = 1L;
033
034      @Override
035      public SimpleLock write() {
036         return SimpleLock.NO_OP;
037      }
038      @Override
039      public SimpleLock read(){
040         return SimpleLock.NO_OP;
041      }
042   };
043
044   //-----------------------------------------------------------------------------------------------------------------
045   // Instance
046   //-----------------------------------------------------------------------------------------------------------------
047
048   /**
049    * Constructor.
050    */
051   public SimpleReadWriteLock() {
052   }
053
054   /**
055    * Constructor
056    *
057    * @param fair <jk>true</jk> if this lock should use a fair ordering policy.
058    */
059   public SimpleReadWriteLock(boolean fair) {
060      super(fair);
061   }
062
063   /**
064    * Construct a write lock.
065    *
066    * @return A new closeable write lock.
067    */
068   public SimpleLock write(){
069      return new SimpleLock(writeLock());
070   }
071
072   /**
073    * Construct a read lock.
074    *
075    * @return A new closeable read lock.
076    */
077   public SimpleLock read(){
078      return new SimpleLock(readLock());
079   }
080}