1 /************************************************************************
2 * Copyright (c) 2000-2006 The Apache Software Foundation. *
3 * All rights reserved. *
4 * ------------------------------------------------------------------- *
5 * Licensed under the Apache License, Version 2.0 (the "License"); you *
6 * may not use this file except in compliance with the License. You *
7 * may obtain a copy of the License at: *
8 * *
9 * http://www.apache.org/licenses/LICENSE-2.0 *
10 * *
11 * Unless required by applicable law or agreed to in writing, software *
12 * distributed under the License is distributed on an "AS IS" BASIS, *
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or *
14 * implied. See the License for the specific language governing *
15 * permissions and limitations under the License. *
16 ***********************************************************************/
17
18 package org.apache.james.util.watchdog;
19
20 /***
21 * This interface represents an abstract watchdog process that serves to
22 * monitor a situation and triggers an action under an implementation-specific
23 * trigger condition.
24 *
25 */
26 public interface Watchdog {
27
28 /***
29 * Start this Watchdog, causing it to begin monitoring. The Watchdog can
30 * be stopped and restarted.
31 */
32 void start();
33
34 /***
35 * Reset this Watchdog. Resets any conditions in the implementations
36 * (time to expiration, etc.) to their original values
37 */
38 void reset();
39
40 /***
41 * Stop this Watchdog, terminating the monitoring condition. The monitor
42 * can be restarted with a call to startWatchdog.
43 */
44 void stop();
45 }