1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package org.jboss.netty.util.internal;
17
18 import org.jboss.netty.channel.ChannelFuture;
19
20 /**
21 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
22 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
23 */
24 public class IoWorkerRunnable implements Runnable {
25
26 /**
27 * An <em>internal use only</em> thread-local variable that determines if
28 * the caller is running on an I/O worker thread, which is the case where
29 * the caller enters a dead lock if the caller calls
30 * {@link ChannelFuture#await()} or {@link ChannelFuture#awaitUninterruptibly()}.
31 */
32 public static final ThreadLocal<Boolean> IN_IO_THREAD = new ThreadLocalBoolean();
33
34 private final Runnable runnable;
35
36 public IoWorkerRunnable(Runnable runnable) {
37 if (runnable == null) {
38 throw new NullPointerException("runnable");
39 }
40 this.runnable = runnable;
41 }
42
43 public void run() {
44 IN_IO_THREAD.set(Boolean.TRUE);
45 try {
46 runnable.run();
47 } finally {
48 IN_IO_THREAD.remove();
49 }
50 }
51 }