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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, 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  package org.apache.hadoop.hbase;
19  
20  import java.util.concurrent.ThreadFactory;
21  import java.util.concurrent.atomic.AtomicInteger;
22  
23  /**
24   * Thread factory that creates daemon threads
25   */
26  public class DaemonThreadFactory implements ThreadFactory {
27    private static final AtomicInteger poolNumber = new AtomicInteger(1);
28    private final ThreadGroup group;
29    private final AtomicInteger threadNumber = new AtomicInteger(1);
30    private final String namePrefix;
31  
32    public DaemonThreadFactory(String name) {
33      SecurityManager s = System.getSecurityManager();
34      group = (s != null) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
35      namePrefix = name + poolNumber.getAndIncrement() + "-thread-";
36    }
37  
38    @Override
39    public Thread newThread(Runnable r) {
40      Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement(), 0);
41      if (!t.isDaemon()) {
42        t.setDaemon(true);
43      }
44      if (t.getPriority() != Thread.NORM_PRIORITY) {
45        t.setPriority(Thread.NORM_PRIORITY);
46      }
47      return t;
48    }
49  }