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.eclipse.aether.util.concurrency;
20
21 import java.util.concurrent.Executors;
22 import java.util.concurrent.ThreadFactory;
23 import java.util.concurrent.atomic.AtomicInteger;
24
25 /**
26 * A factory to create worker threads with a given name prefix.
27 */
28 public final class WorkerThreadFactory implements ThreadFactory {
29
30 private final ThreadFactory factory;
31
32 private final String namePrefix;
33
34 private final AtomicInteger threadIndex;
35
36 private static final AtomicInteger POOL_INDEX = new AtomicInteger();
37
38 /**
39 * Creates a new thread factory whose threads will have names using the specified prefix.
40 *
41 * @param namePrefix The prefix for the thread names, may be {@code null} or empty to derive the prefix from the
42 * caller's simple class name.
43 */
44 public WorkerThreadFactory(String namePrefix) {
45 this.factory = Executors.defaultThreadFactory();
46 this.namePrefix =
47 ((namePrefix != null && namePrefix.length() > 0) ? namePrefix : getCallerSimpleClassName() + '-')
48 + POOL_INDEX.getAndIncrement()
49 + '-';
50 threadIndex = new AtomicInteger();
51 }
52
53 private static String getCallerSimpleClassName() {
54 StackTraceElement[] stack = new Exception().getStackTrace();
55 if (stack == null || stack.length <= 2) {
56 return "Worker-";
57 }
58 String name = stack[2].getClassName();
59 name = name.substring(name.lastIndexOf('.') + 1);
60 return name;
61 }
62
63 public Thread newThread(Runnable r) {
64 Thread thread = factory.newThread(r);
65 thread.setName(namePrefix + threadIndex.getAndIncrement());
66 thread.setDaemon(true);
67 return thread;
68 }
69 }