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 */ 017package org.apache.activemq.transport.nio; 018 019import java.io.IOException; 020import java.nio.channels.spi.AbstractSelectableChannel; 021import java.util.LinkedList; 022import java.util.concurrent.*; 023 024/** 025 * The SelectorManager will manage one Selector and the thread that checks the 026 * selector. 027 * 028 * We may need to consider running more than one thread to check the selector if 029 * servicing the selector takes too long. 030 */ 031public final class SelectorManager { 032 033 public static final SelectorManager SINGLETON = new SelectorManager(); 034 035 private Executor selectorExecutor = createDefaultExecutor(); 036 private Executor channelExecutor = selectorExecutor; 037 private final LinkedList<SelectorWorker> freeWorkers = new LinkedList<SelectorWorker>(); 038 private int maxChannelsPerWorker = 1024; 039 040 protected ExecutorService createDefaultExecutor() { 041 ThreadPoolExecutor rc = new ThreadPoolExecutor(getDefaultCorePoolSize(), getDefaultMaximumPoolSize(), getDefaultKeepAliveTime(), TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(), 042 new ThreadFactory() { 043 044 private long i = 0; 045 046 @Override 047 public Thread newThread(Runnable runnable) { 048 this.i++; 049 final Thread t = new Thread(runnable, "ActiveMQ NIO Worker " + this.i); 050 return t; 051 } 052 }); 053 054 return rc; 055 } 056 057 private static int getDefaultCorePoolSize() { 058 return Integer.getInteger("org.apache.activemq.transport.nio.SelectorManager.corePoolSize", 10); 059 } 060 061 private static int getDefaultMaximumPoolSize() { 062 return Integer.getInteger("org.apache.activemq.transport.nio.SelectorManager.maximumPoolSize", 1024); 063 } 064 065 private static int getDefaultKeepAliveTime() { 066 return Integer.getInteger("org.apache.activemq.transport.nio.SelectorManager.keepAliveTime", 30); 067 } 068 069 public static SelectorManager getInstance() { 070 return SINGLETON; 071 } 072 073 public interface Listener { 074 void onSelect(SelectorSelection selector); 075 076 void onError(SelectorSelection selection, Throwable error); 077 } 078 079 public synchronized SelectorSelection register(AbstractSelectableChannel selectableChannel, Listener listener) throws IOException { 080 SelectorSelection selection = null; 081 while (selection == null) { 082 if (freeWorkers.size() > 0) { 083 SelectorWorker worker = freeWorkers.getFirst(); 084 if (worker.isReleased()) { 085 freeWorkers.remove(worker); 086 } else { 087 worker.retain(); 088 selection = new SelectorSelection(worker, selectableChannel, listener); 089 } 090 } else { 091 // Worker starts /w retain count of 1 092 SelectorWorker worker = new SelectorWorker(this); 093 freeWorkers.addFirst(worker); 094 selection = new SelectorSelection(worker, selectableChannel, listener); 095 } 096 } 097 098 return selection; 099 } 100 101 synchronized void onWorkerFullEvent(SelectorWorker worker) { 102 freeWorkers.remove(worker); 103 } 104 105 public synchronized void onWorkerEmptyEvent(SelectorWorker worker) { 106 freeWorkers.remove(worker); 107 } 108 109 public synchronized void onWorkerNotFullEvent(SelectorWorker worker) { 110 freeWorkers.addFirst(worker); 111 } 112 113 public Executor getChannelExecutor() { 114 return channelExecutor; 115 } 116 117 public void setChannelExecutor(Executor channelExecutor) { 118 this.channelExecutor = channelExecutor; 119 } 120 121 public int getMaxChannelsPerWorker() { 122 return maxChannelsPerWorker; 123 } 124 125 public void setMaxChannelsPerWorker(int maxChannelsPerWorker) { 126 this.maxChannelsPerWorker = maxChannelsPerWorker; 127 } 128 129 public Executor getSelectorExecutor() { 130 return selectorExecutor; 131 } 132 133 public void setSelectorExecutor(Executor selectorExecutor) { 134 this.selectorExecutor = selectorExecutor; 135 } 136}