View Javadoc

    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  }