1 //
2 // ========================================================================
3 // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.util.thread;
20
21 /**
22 * Marker that wraps a Runnable, indicating that it is running in a thread that must not be blocked.
23 * <p />
24 * Client code can use the thread-local {@link #isNonBlockingThread()} to detect whether they are
25 * in the context of a non-blocking thread, and perform different actions if that's the case.
26 */
27 public class NonBlockingThread implements Runnable
28 {
29 private final static ThreadLocal<Boolean> __nonBlockingThread = new ThreadLocal<>();
30
31 /**
32 * @return whether the current thread is a thread that must not block.
33 */
34 public static boolean isNonBlockingThread()
35 {
36 return Boolean.TRUE.equals(__nonBlockingThread.get());
37 }
38
39 private final Runnable delegate;
40
41 public NonBlockingThread(Runnable delegate)
42 {
43 this.delegate = delegate;
44 }
45
46 @Override
47 public void run()
48 {
49 try
50 {
51 __nonBlockingThread.set(Boolean.TRUE);
52 delegate.run();
53 }
54 finally
55 {
56 __nonBlockingThread.remove();
57 }
58 }
59 }