1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.nio.reactor;
29
30 import java.io.IOException;
31
32 /**
33 * HttpCore NIO is based on the Reactor pattern as described by Doug Lea.
34 * The purpose of I/O reactors is to react to I/O events and to dispatch event
35 * notifications to individual I/O sessions. The main idea of I/O reactor
36 * pattern is to break away from the one thread per connection model imposed
37 * by the classic blocking I/O model.
38 * <p>
39 * The IOReactor interface represents an abstract object implementing
40 * the Reactor pattern.
41 * <p>
42 * I/O reactors usually employ a small number of dispatch threads (often as
43 * few as one) to dispatch I/O event notifications to a much greater number
44 * (often as many as several thousands) of I/O sessions or connections. It is
45 * generally recommended to have one dispatch thread per CPU core.
46 *
47 * @since 4.0
48 */
49 public interface IOReactor {
50
51 /**
52 * Returns the current status of the reactor.
53 *
54 * @return reactor status.
55 */
56 IOReactorStatus getStatus();
57
58 /**
59 * Starts the reactor and initiates the dispatch of I/O event notifications
60 * to the given {@link IOEventDispatch}.
61 *
62 * @param eventDispatch the I/O event dispatch.
63 * @throws IOException in case of an I/O error.
64 */
65 void execute(IOEventDispatch eventDispatch)
66 throws IOException;
67
68 /**
69 * Initiates shutdown of the reactor and blocks approximately for the given
70 * period of time in milliseconds waiting for the reactor to terminate all
71 * active connections, to shut down itself and to release system resources
72 * it currently holds.
73 *
74 * @param waitMs wait time in milliseconds.
75 * @throws IOException in case of an I/O error.
76 */
77 void shutdown(long waitMs)
78 throws IOException;
79
80 /**
81 * Initiates shutdown of the reactor and blocks for a default period of
82 * time waiting for the reactor to terminate all active connections, to shut
83 * down itself and to release system resources it currently holds. It is
84 * up to individual implementations to decide for how long this method can
85 * remain blocked.
86 *
87 * @throws IOException in case of an I/O error.
88 */
89 void shutdown()
90 throws IOException;
91
92 }