001package org.apache.commons.jcs.engine.behavior;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022/**
023 * ShutdownObservers can observe ShutdownObservable objects.
024 * The CacheManager is the primary observable that this is intended for.
025 * <p>
026 * Most shutdown operations will occur outside this framework for now.  The initial
027 * goal is to allow background threads that are not reachable through any reference
028 * that the cache manager maintains to be killed on shutdown.
029 * <p>
030 * Perhaps the composite cache itself should be the observable object.
031 * It doesn't make much of a difference.  There are some problems with
032 * region by region shutdown.  Some auxiliaries are local.  They will
033 * need to track when every region has shutdown before doing things like
034 * closing the socket with a lateral.
035 * <p>
036 * @author Aaron Smuts
037 *
038 */
039public interface IShutdownObservable
040{
041
042    /**
043     * Registers an observer with the observable object.
044     * @param observer
045     */
046    void registerShutdownObserver( IShutdownObserver observer );
047
048    /**
049     * Deregisters the observer with the observable.
050     *
051     * @param observer
052     */
053    void deregisterShutdownObserver( IShutdownObserver observer );
054
055}