001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.net.server;
015
016import java.io.Closeable;
017import java.io.IOException;
018
019/**
020 * A client of a {@link ServerRunner}.
021 * <p>
022 * This interface exists primarily to abstract away the details of the client's
023 * underlying {@code Socket} and the concurrency associated with handling
024 * multiple clients. Such realities make it difficult to create effective unit
025 * tests for the {@link ServerRunner} that are easy to understand and maintain.
026 * <p>
027 * This interface captures the only those details about a client that the
028 * {@code ServerRunner} cares about; namely, that it is something that
029 * <ol>
030 * <li>is Runnable &mdash; i.e. it can be executed concurrently</li>
031 * <li>holds resources that need to be closed before the client is
032 * discarded</li>
033 * </ol>
034 * 
035 * @author Carl Harris
036 */
037public interface Client extends Runnable, Closeable {
038
039    /**
040     * Closes any resources that are held by the client.
041     * <p>
042     * Note that (as described in Doug Lea's discussion about interrupting I/O
043     * operations in "Concurrent Programming in Java" - Addison-Wesley Professional,
044     * 2nd edition, 1999) this method is used to interrupt any blocked I/O operation
045     * in the client when the server is shutting down. The client implementation
046     * must anticipate this potential, and gracefully exit when the blocked I/O
047     * operation throws the relevant {@link IOException} subclass.
048     * <p>
049     * Note also, that unlike {@link Closeable#close()} this method is not permitted
050     * to propagate any {@link IOException} that occurs when closing the underlying
051     * resource(s).
052     */
053    void close();
054
055}