1 package org.eclipse.aether.util.concurrency;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.concurrent.Executors;
23 import java.util.concurrent.ThreadFactory;
24 import java.util.concurrent.atomic.AtomicInteger;
25
26 /**
27 * A factory to create worker threads with a given name prefix.
28 */
29 public final class WorkerThreadFactory
30 implements ThreadFactory
31 {
32
33 private final ThreadFactory factory;
34
35 private final String namePrefix;
36
37 private final AtomicInteger threadIndex;
38
39 private static final AtomicInteger POOL_INDEX = new AtomicInteger();
40
41 /**
42 * Creates a new thread factory whose threads will have names using the specified prefix.
43 *
44 * @param namePrefix The prefix for the thread names, may be {@code null} or empty to derive the prefix from the
45 * caller's simple class name.
46 */
47 public WorkerThreadFactory( String namePrefix )
48 {
49 this.factory = Executors.defaultThreadFactory();
50 this.namePrefix =
51 ( ( namePrefix != null && namePrefix.length() > 0 ) ? namePrefix : getCallerSimpleClassName() + '-' )
52 + POOL_INDEX.getAndIncrement() + '-';
53 threadIndex = new AtomicInteger();
54 }
55
56 private static String getCallerSimpleClassName()
57 {
58 StackTraceElement[] stack = new Exception().getStackTrace();
59 if ( stack == null || stack.length <= 2 )
60 {
61 return "Worker-";
62 }
63 String name = stack[2].getClassName();
64 name = name.substring( name.lastIndexOf( '.' ) + 1 );
65 return name;
66 }
67
68 public Thread newThread( Runnable r )
69 {
70 Thread thread = factory.newThread( r );
71 thread.setName( namePrefix + threadIndex.getAndIncrement() );
72 thread.setDaemon( true );
73 return thread;
74 }
75
76 }