Thomas Vachuska | 9c17a6d | 2015-02-17 23:36:43 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onlab.util; |
| 17 | |
| 18 | import org.apache.commons.lang3.concurrent.ConcurrentUtils; |
| 19 | |
| 20 | import java.util.concurrent.ConcurrentHashMap; |
| 21 | import java.util.concurrent.ThreadFactory; |
| 22 | |
| 23 | import static com.google.common.base.MoreObjects.toStringHelper; |
| 24 | |
| 25 | /** |
| 26 | * Thread factory for creating threads that belong to the specified thread group. |
| 27 | */ |
| 28 | public final class GroupedThreadFactory implements ThreadFactory { |
| 29 | |
| 30 | public static final String DELIMITER = "/"; |
| 31 | |
| 32 | private final ThreadGroup group; |
| 33 | |
| 34 | // Cache of created thread factories. |
| 35 | private static final ConcurrentHashMap<String, GroupedThreadFactory> FACTORIES = |
| 36 | new ConcurrentHashMap<>(); |
| 37 | |
| 38 | /** |
| 39 | * Returns thread factory for producing threads associated with the specified |
| 40 | * group name. The group name-space is hierarchical, based on slash-delimited |
| 41 | * name segments, e.g. {@code onos/intent}. |
| 42 | * |
| 43 | * @param groupName group name |
| 44 | * @return thread factory |
| 45 | */ |
| 46 | public static GroupedThreadFactory groupedThreadFactory(String groupName) { |
| 47 | GroupedThreadFactory factory = FACTORIES.get(groupName); |
| 48 | if (factory != null) { |
| 49 | return factory; |
| 50 | } |
| 51 | |
| 52 | // Find the parent group or root the group hierarchy under default group. |
| 53 | int i = groupName.lastIndexOf(DELIMITER); |
| 54 | if (i > 0) { |
| 55 | String name = groupName.substring(0, i); |
| 56 | ThreadGroup parentGroup = groupedThreadFactory(name).threadGroup(); |
| 57 | factory = new GroupedThreadFactory(new ThreadGroup(parentGroup, groupName)); |
| 58 | } else { |
| 59 | factory = new GroupedThreadFactory(new ThreadGroup(groupName)); |
| 60 | } |
| 61 | |
| 62 | return ConcurrentUtils.putIfAbsent(FACTORIES, groupName, factory); |
| 63 | } |
| 64 | |
| 65 | // Creates a new thread group |
| 66 | private GroupedThreadFactory(ThreadGroup group) { |
| 67 | this.group = group; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Returns the thread group associated with the factory. |
| 72 | * |
| 73 | * @return thread group |
| 74 | */ |
| 75 | public ThreadGroup threadGroup() { |
| 76 | return group; |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public Thread newThread(Runnable r) { |
| 81 | return new Thread(group, r); |
| 82 | } |
| 83 | |
| 84 | @Override |
| 85 | public String toString() { |
| 86 | return toStringHelper(this).add("group", group).toString(); |
| 87 | } |
| 88 | } |