001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.activemq.thread; 018 019 import org.apache.activemq.util.MDCHelper; 020 import org.slf4j.MDC; 021 022 import java.util.Map; 023 import java.util.concurrent.Executor; 024 025 /** 026 * 027 */ 028 public class DeterministicTaskRunner implements TaskRunner { 029 030 private final Executor executor; 031 private final Task task; 032 private final Runnable runable; 033 private boolean shutdown; 034 035 /**Constructor 036 * @param executor 037 * @param task 038 */ 039 public DeterministicTaskRunner(Executor executor, Task task) { 040 this.executor = executor; 041 this.task = task; 042 final Map context = MDCHelper.getCopyOfContextMap(); 043 this.runable = new Runnable() { 044 public void run() { 045 Thread.currentThread(); 046 if (context != null) { 047 MDCHelper.setContextMap(context); 048 } 049 runTask(); 050 } 051 }; 052 } 053 054 /** 055 * We Expect MANY wakeup calls on the same TaskRunner - but each 056 * needs to run 057 */ 058 public void wakeup() throws InterruptedException { 059 synchronized (runable) { 060 061 if (shutdown) { 062 return; 063 } 064 executor.execute(runable); 065 066 } 067 } 068 069 /** 070 * shut down the task 071 * 072 * @throws InterruptedException 073 */ 074 public void shutdown(long timeout) throws InterruptedException { 075 synchronized (runable) { 076 shutdown = true; 077 } 078 } 079 080 public void shutdown() throws InterruptedException { 081 shutdown(0); 082 } 083 084 final void runTask() { 085 086 synchronized (runable) { 087 if (shutdown) { 088 runable.notifyAll(); 089 return; 090 } 091 } 092 task.iterate(); 093 } 094 }