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     */
017    
018    package org.apache.commons.daemon;
019    
020    /**
021     * This interface tags a Daemon as supporting some kind of
022     * signaling method that allows the java application to
023     * perform a custom action.
024     * <p>
025     * User must implement a signal method that will be called from
026     * native upon receiving {@code SIGUSR2} signal from the operating system.
027     * </p>
028     * @author Nick Griffiths <nicobrevin@gmail.com>
029     * @author Mladen Turk <mturk@apache.org>
030     */
031    public interface DaemonUserSignal
032    {
033    
034        /**
035         * Perform a custom action on received user signal.
036         */
037        void signal();
038    
039    }