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.hc.core5.reactor;
29
30 import org.apache.hc.core5.io.CloseMode;
31 import org.apache.hc.core5.io.ModalCloseable;
32 import org.apache.hc.core5.util.TimeValue;
33
34 /**
35 * HttpCore NIO is based on the Reactor pattern as described by Doug Lea.
36 * The purpose of I/O reactors is to react to I/O events and to dispatch event
37 * notifications to individual I/O sessions. The main idea of I/O reactor
38 * pattern is to break away from the one thread per connection model imposed
39 * by the classic blocking I/O model.
40 * <p>
41 * The IOReactor interface represents an abstract object implementing
42 * the Reactor pattern.
43 * <p>
44 * I/O reactors usually employ a small number of dispatch threads (often as
45 * few as one) to dispatch I/O event notifications to a much greater number
46 * (often as many as several thousands) of I/O sessions or connections. It is
47 * generally recommended to have one dispatch thread per CPU core.
48 *
49 * @since 4.0
50 */
51 public interface IOReactor extends ModalCloseable {
52
53 /**
54 * Shuts down the I/O reactor either gracefully or immediately.
55 * During graceful shutdown individual I/O sessions should be
56 * informed about imminent termination and be given a grace period
57 * to complete the ongoing I/O sessions. During immediate shutdown
58 * all ongoing I/O sessions get aborted immediately.
59 *
60 * @param closeMode How to close the I/O reactor.
61 */
62 @Override
63 void close(CloseMode closeMode);
64
65 /**
66 * Returns the current status of the reactor.
67 *
68 * @return reactor status.
69 */
70 IOReactorStatus getStatus();
71
72 /**
73 * Initiates shutdown of the reactor without blocking. The reactor is expected
74 * to terminate all active connections, to shut down itself and to release
75 * system resources it currently holds
76 *
77 * @since 5.0
78 */
79 void initiateShutdown();
80
81 /**
82 * Blocks for the given period of time in milliseconds awaiting
83 * the completion of the reactor shutdown.
84 *
85 * @param waitTime wait time.
86 *
87 * @since 5.0
88 */
89 void awaitShutdown(TimeValue waitTime) throws InterruptedException;
90
91 }