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
22  * questions.
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 
36 package 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  */
58 public 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      */
newThread(Runnable r)68     Thread newThread(Runnable r);
69 }
70