ThreadFactory.java revision 29957558cf0db700bfaae360a80c42dc3871d0e5 
1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25/*
26 * This file is available under and governed by the GNU General Public
27 * License version 2 only, as published by the Free Software Foundation.
28 * However, the following notice accompanied the original version of this
29 * file:
30 *
31 * Written by Doug Lea with assistance from members of JCP JSR-166
32 * Expert Group and released to the public domain, as explained at
33 * http://creativecommons.org/publicdomain/zero/1.0/
34 */
35
36package java.util.concurrent;
37
38/**
39 * An object that creates new threads on demand.  Using thread factories
40 * removes hardwiring of calls to {@link Thread#Thread(Runnable) new Thread},
41 * enabling applications to use special thread subclasses, priorities, etc.
42 *
43 * <p>
44 * The simplest implementation of this interface is just:
45 * <pre> {@code
46 * class SimpleThreadFactory implements ThreadFactory {
47 *   public Thread newThread(Runnable r) {
48 *     return new Thread(r);
49 *   }
50 * }}</pre>
51 *
52 * The {@link Executors#defaultThreadFactory} method provides a more
53 * useful simple implementation, that sets the created thread context
54 * to known values before returning it.
55 * @since 1.5
56 * @author Doug Lea
57 */
58public interface ThreadFactory {
59
60    /**
61     * Constructs a new {@code Thread}.  Implementations may also initialize
62     * priority, name, daemon status, {@code ThreadGroup}, etc.
63     *
64     * @param r a runnable to be executed by new thread instance
65     * @return constructed thread, or {@code null} if the request to
66     *         create a thread is rejected
67     */
68    Thread newThread(Runnable r);
69}
70