| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.catalina.tribes.util; |
| |
| import java.util.Collection; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.LinkedBlockingQueue; |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.ThreadPoolExecutor; |
| import java.util.concurrent.TimeUnit; |
| |
| public class ExecutorFactory { |
| |
| public static ExecutorService newThreadPool(int minThreads, int maxThreads, long maxIdleTime, TimeUnit unit) { |
| TaskQueue taskqueue = new TaskQueue(); |
| ThreadPoolExecutor service = new ThreadPoolExecutor(minThreads, maxThreads, maxIdleTime, unit,taskqueue); |
| taskqueue.setParent(service); |
| return service; |
| } |
| |
| public static ExecutorService newThreadPool(int minThreads, int maxThreads, long maxIdleTime, TimeUnit unit, ThreadFactory threadFactory) { |
| TaskQueue taskqueue = new TaskQueue(); |
| ThreadPoolExecutor service = new ThreadPoolExecutor(minThreads, maxThreads, maxIdleTime, unit,taskqueue, threadFactory); |
| taskqueue.setParent(service); |
| return service; |
| } |
| |
| // ---------------------------------------------- TaskQueue Inner Class |
| private static class TaskQueue extends LinkedBlockingQueue<Runnable> { |
| private static final long serialVersionUID = 1L; |
| |
| ThreadPoolExecutor parent = null; |
| |
| public TaskQueue() { |
| super(); |
| } |
| |
| public TaskQueue(int initialCapacity) { |
| super(initialCapacity); |
| } |
| |
| public TaskQueue(Collection<? extends Runnable> c) { |
| super(c); |
| } |
| |
| public void setParent(ThreadPoolExecutor tp) { |
| parent = tp; |
| } |
| |
| public boolean force(Runnable o) { |
| if ( parent.isShutdown() ) throw new RejectedExecutionException("Executor not running, can't force a command into the queue"); |
| return super.offer(o); //forces the item onto the queue, to be used if the task is rejected |
| } |
| |
| @Override |
| public boolean offer(Runnable o) { |
| //we can't do any checks |
| if (parent==null) return super.offer(o); |
| //we are maxed out on threads, simply queue the object |
| if (parent.getPoolSize() == parent.getMaximumPoolSize()) return super.offer(o); |
| //we have idle threads, just add it to the queue |
| //this is an approximation, so it could use some tuning |
| if (parent.getActiveCount()<(parent.getPoolSize())) return super.offer(o); |
| //if we have less threads than maximum force creation of a new thread |
| if (parent.getPoolSize()<parent.getMaximumPoolSize()) return false; |
| //if we reached here, we need to add it to the queue |
| return super.offer(o); |
| } |
| } |
| } |