View Javadoc
1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the 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 io.netty.channel.nio;
17  
18  import java.nio.channels.SelectableChannel;
19  import java.nio.channels.SelectionKey;
20  import java.nio.channels.Selector;
21  
22  /**
23   * An arbitrary task that can be executed by {@link NioEventLoop} when a {@link SelectableChannel} becomes ready.
24   *
25   * @see NioEventLoop#register(SelectableChannel, int, NioTask)
26   */
27  public interface NioTask<C extends SelectableChannel> {
28      /**
29       * Invoked when the {@link SelectableChannel} has been selected by the {@link Selector}.
30       */
31      void channelReady(C ch, SelectionKey key) throws Exception;
32  
33      /**
34       * Invoked when the {@link SelectionKey} of the specified {@link SelectableChannel} has been cancelled and thus
35       * this {@link NioTask} will not be notified anymore.
36       *
37       * @param cause the cause of the unregistration. {@code null} if a user called {@link SelectionKey#cancel()} or
38       *              the event loop has been shut down.
39       */
40      void channelUnregistered(C ch, Throwable cause) throws Exception;
41  }