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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  package org.apache.maven.surefire.extensions.util;
20  
21  import javax.annotation.Nonnegative;
22  import javax.annotation.Nonnull;
23  
24  import java.io.Closeable;
25  import java.io.IOException;
26  
27  /**
28   * Decrements {@code countdown} and calls {@code closeable} if reached zero.
29   */
30  public final class CountdownCloseable implements Closeable {
31      private final Closeable closeable;
32      private volatile int countdown;
33  
34      public CountdownCloseable(@Nonnull Closeable closeable, @Nonnegative int countdown) {
35          this.closeable = closeable;
36          this.countdown = countdown;
37      }
38  
39      @Override
40      public synchronized void close() throws IOException {
41          if (--countdown == 0) {
42              try {
43                  closeable.close();
44              } finally {
45                  notifyAll();
46              }
47          }
48      }
49  
50      /**
51       * Waiting for one Thread in {@link CommandlineExecutor#awaitExit()}.
52       *
53       * @throws InterruptedException see {@link Object#wait()}
54       */
55      public synchronized void awaitClosed() throws InterruptedException {
56          if (countdown > 0) {
57              wait();
58          }
59      }
60  }