View Javadoc

1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.core.future;
21  
22  import java.util.concurrent.atomic.AtomicInteger;
23  
24  import org.apache.mina.core.IoUtil;
25  
26  /**
27   * An {@link IoFuture} of {@link IoFuture}s.  It is useful when you want to
28   * get notified when all {@link IoFuture}s are complete.  It is not recommended
29   * to use {@link CompositeIoFuture} if you just want to wait for all futures.
30   * In that case, please use {@link IoUtil#await(Iterable)} instead
31   * for better performance.
32   * 
33   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
34   *
35   * @param <E> the type of the child futures.
36   */
37  public class CompositeIoFuture<E extends IoFuture> extends DefaultIoFuture {
38  
39      private final NotifyingListener listener = new NotifyingListener();
40  
41      private final AtomicInteger unnotified = new AtomicInteger();
42  
43      private volatile boolean constructionFinished;
44  
45      public CompositeIoFuture(Iterable<E> children) {
46          super(null);
47  
48          for (E f : children) {
49              f.addListener(listener);
50              unnotified.incrementAndGet();
51          }
52  
53          constructionFinished = true;
54          if (unnotified.get() == 0) {
55              setValue(true);
56          }
57      }
58  
59      private class NotifyingListener implements IoFutureListener<IoFuture> {
60          public void operationComplete(IoFuture future) {
61              if (unnotified.decrementAndGet() == 0 && constructionFinished) {
62                  setValue(true);
63              }
64          }
65      }
66  }