001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // 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
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.hivemind;
016    
017    /**
018     * Implemented by a core service implementationsthat require notification when they are
019     * discarded. This interface is only used by the 
020     * {@link org.apache.hivemind.impl.servicemodel.ThreadedServiceModel threaded service model},
021     * which creates a service for a short period, then discards it when notified
022     * by the {@link org.apache.hivemind.service.ThreadEventNotifier}.
023     * 
024     * <p>
025     * The service instance will be discarded regardless; this interface allows
026     * the core service implementation to know immediately when this happens,
027     * so that it can release any acquired resources.
028     *
029     * @author Howard Lewis Ship
030     */
031    public interface Discardable
032    {
033        /**
034         * Invoked when a service is being discarded.
035         */
036        public void threadDidDiscardService();
037    }