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.commons.configuration2.sync; 018 019/** 020 * <p> 021 * An enumeration used by {@link SynchronizerSupport} to specify how an object 022 * is locked. 023 * </p> 024 * <p> 025 * The {@code SynchronizerSupport} interface allows locking an object. This can 026 * be done in different ways controlling the level of concurrency still possible 027 * with the object. One of the constants defined here can be passed in when 028 * calling the {@code lock()} method of a {@code SynchronizerSupport} object. 029 * (Note that at the end of the day it is up to a concrete implementation of 030 * {@link Synchronizer} how these lock modes are interpreted.) 031 * </p> 032 * 033 * @since 2.0 034 */ 035public enum LockMode 036{ 037 /** 038 * Lock mode <em>READ</em>. The object is accessed in a read-only manner. 039 * Typically, this means that other read locks can be granted while 040 * concurrent writes are not permitted. 041 */ 042 READ, 043 044 /** 045 * Lock mode <em>WRITE</em>. The object is updated. This usually means that 046 * this object is exclusively locked. Attempts of other readers or writers 047 * will block until the current update operation is complete. 048 */ 049 WRITE 050}