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 }