1 /**************************************************************** 2 * Licensed to the Apache Software Foundation (ASF) under one * 3 * or more contributor license agreements. See the NOTICE file * 4 * distributed with this work for additional information * 5 * regarding copyright ownership. The ASF licenses this file * 6 * to you under the Apache License, Version 2.0 (the * 7 * "License"); you may not use this file except in compliance * 8 * with the License. You may obtain a copy of the License at * 9 * * 10 * http://www.apache.org/licenses/LICENSE-2.0 * 11 * * 12 * Unless required by applicable law or agreed to in writing, * 13 * software distributed under the License is distributed on an * 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * 15 * KIND, either express or implied. See the License for the * 16 * specific language governing permissions and limitations * 17 * under the License. * 18 ****************************************************************/ 19 20 21 package org.apache.james.util.watchdog; 22 23 /** 24 * This interface represents an abstract watchdog process that serves to 25 * monitor a situation and triggers an action under an implementation-specific 26 * trigger condition. 27 * 28 */ 29 public interface Watchdog { 30 31 /** 32 * Start this Watchdog, causing it to begin monitoring. The Watchdog can 33 * be stopped and restarted. 34 */ 35 void start(); 36 37 /** 38 * Reset this Watchdog. Resets any conditions in the implementations 39 * (time to expiration, etc.) to their original values 40 */ 41 void reset(); 42 43 /** 44 * Stop this Watchdog, terminating the monitoring condition. The monitor 45 * can be restarted with a call to startWatchdog. 46 */ 47 void stop(); 48 }