1 | /* |
2 | * @(#) $Id: BlockingSet.java 332218 2005-11-10 03:52:42Z trustin $ |
3 | * |
4 | * Copyright 2004 The Apache Software Foundation |
5 | * |
6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
7 | * you may not use this file except in compliance with the License. |
8 | * 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, software |
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
15 | * See the License for the specific language governing permissions and |
16 | * limitations under the License. |
17 | * |
18 | */ |
19 | package org.apache.mina.util; |
20 | |
21 | import java.util.HashSet; |
22 | import java.util.Iterator; |
23 | |
24 | /** |
25 | * A {@link HashSet} that can wait until it is not empty. |
26 | * |
27 | * @author The Apache Directory Project (dev@directory.apache.org) |
28 | * @version $Rev: 332218 $, $Date: 2005-11-10 12:52:42 +0900 $ |
29 | */ |
30 | public class BlockingSet extends HashSet |
31 | { |
32 | private static final long serialVersionUID = 3258134669538309941L; |
33 | |
34 | private int waiters = 0; |
35 | |
36 | public synchronized boolean add( Object o ) |
37 | { |
38 | boolean ret = super.add( o ); |
39 | if( ret && waiters > 0 ) |
40 | notify(); |
41 | return ret; |
42 | } |
43 | |
44 | public Iterator iterator() |
45 | { |
46 | return super.iterator(); |
47 | } |
48 | |
49 | public synchronized boolean remove( Object o ) |
50 | { |
51 | return super.remove( o ); |
52 | } |
53 | |
54 | public synchronized void waitForNewItem() throws InterruptedException |
55 | { |
56 | waiters++; |
57 | try |
58 | { |
59 | while( isEmpty() ) |
60 | { |
61 | wait(); |
62 | } |
63 | } |
64 | finally |
65 | { |
66 | waiters--; |
67 | } |
68 | } |
69 | } |