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 package org.apache.mina.filter.executor;
21
22 import java.util.EventListener;
23
24 import org.apache.mina.core.session.IoEvent;
25
26 /**
27 * Listens and filters all event queue operations occurring in
28 * {@link OrderedThreadPoolExecutor} and {@link UnorderedThreadPoolExecutor}.
29 *
30 * @author The Apache MINA Project (dev@mina.apache.org)
31 * @version $Rev: 671827 $, $Date: 2008-06-26 10:49:48 +0200 (jeu, 26 jun 2008) $
32 */
33 public interface IoEventQueueHandler extends EventListener {
34
35 /**
36 * A dummy handler which always accepts event doing nothing particular.
37 */
38 static IoEventQueueHandler NOOP = new IoEventQueueHandler() {
39 public boolean accept(Object source, IoEvent event) {
40 return true;
41 }
42 public void offered(Object source, IoEvent event) {
43 // NOOP
44 }
45 public void polled(Object source, IoEvent event) {
46 // NOOP
47 }
48 };
49
50 /**
51 * Returns <tt>true</tt> if and only if the specified <tt>event</tt> is
52 * allowed to be offered to the event queue. The <tt>event</tt> is dropped
53 * if <tt>false</tt> is returned.
54 */
55 boolean accept(Object source, IoEvent event);
56
57 /**
58 * Invoked after the specified <tt>event</tt> has been offered to the
59 * event queue.
60 */
61 void offered(Object source, IoEvent event);
62
63 /**
64 * Invoked after the specified <tt>event</tt> has been polled from the
65 * event queue.
66 */
67 void polled(Object source, IoEvent event);
68 }