1.1 Disruptor并发框架简介
Martin Fowler在自己网站上写了一篇LMAX架构的文章，在文章中他介绍了LMAX是一种新型零售金融交易平台，它能够以很低的延迟产生大量交易。这个系统是建立在JVM平台上，其核心是一个业务逻辑处理器，它能够在一个线程里每秒处理6百万订单。业务逻辑处理器完全是运行在内存中，使用事件源驱动方式。业务逻辑处理器的核心是Disruptor。
Disruptor它是一个开源的并发框架，并获得2011 Duke’s 程序框架创新奖，能够在无锁的情况下实现网络的Queue并发操作。
Disruptor是一个高性能的异步处理框架，或者可以认为是最快的消息框架（轻量的JMS），也可以认为是一个观察者模式的实现，或者事件监听模式的实现。
1.2 Disruptor并发框架使用
目前我们使用disruptor已经更新到了3.x版本，比之前的2.x版本性能更加的优秀，提供更多的API使用方式。
下载disruptor-3.3.2.jar引入我们的项目既可以开始disruptor之旅。
在使用之前，首先说明disruptor主要功能加以说明，你可以理解为他是一种高效的"生产者-消费者"模型。也就性能远远高于传统的BlockingQueue容器。
官方学习网站：http://ifeve.com/disruptor-getting-started/
在Disruptor中，我们想实现hello world 需要如下几步骤：
第一：建立一个Event类 //一个具体的数据
第二：建立一个工厂Event类，用于创建Event类实例对象 //数据类型规定死
第三：需要有一个监听事件类，用于处理数据（Event类）
第四：我们需要进行测试代码编写。实例化Disruptor实例，配置一系列参数。然后我们对Disruptor实例绑定监听事件类，接受并处理数据。
第五：在Disruptor中，真正存储数据的核心叫做RingBuffer，我们通过Disruptor实例拿到它，然后把数据生产出来，把数据加入到RingBuffer的实例对象中即可。
我们一起来看下这个HelloWorld程序：com.bjsxt.base
HelloWorld1:
package bhz.base;
//http://ifeve.com/disruptor-getting-started/
public class LongEvent {
private long value;
public long getValue() {
return value;
}
public void setValue(long value) {
this.value = value;
}
}
package bhz.base;
import com.lmax.disruptor.EventFactory;
// 需要让disruptor为我们创建事件，我们同时还声明了一个EventFactory来实例化Event对象。
public class LongEventFactory implements EventFactory {
@Override
public Object newInstance() {
return new LongEvent();
}
}
package bhz.base;
import com.lmax.disruptor.EventHandler;
//我们还需要一个事件消费者，也就是一个事件处理器。这个事件处理器简单地把事件中存储的数据打印到终端：
public class LongEventHandler implements EventHandler<LongEvent> {
@Override
public void onEvent(LongEvent longEvent, long l, boolean b) throws Exception {
System.out.println(longEvent.getValue());
}
}
package bhz.base;
import java.nio.ByteBuffer;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.YieldingWaitStrategy;
import com.lmax.disruptor.dsl.Disruptor;
import com.lmax.disruptor.dsl.ProducerType;
public class LongEventMain {
public static void main(String[] args) throws Exception {
//创建缓冲池
ExecutorService executor = Executors.newCachedThreadPool();
//创建工厂
LongEventFactory factory = new LongEventFactory();
//创建bufferSize ,也就是RingBuffer大小，必须是2的N次方
int ringBufferSize = 1024 * 1024; //
/**
//BlockingWaitStrategy 是最低效的策略，但其对CPU的消耗最小并且在各种不同部署环境中能提供更加一致的性能表现
WaitStrategy BLOCKING_WAIT = new BlockingWaitStrategy();
//SleepingWaitStrategy 的性能表现跟BlockingWaitStrategy差不多，对CPU的消耗也类似，但其对生产者线程的影响最小，适合用于异步日志类似的场景
WaitStrategy SLEEPING_WAIT = new SleepingWaitStrategy();
//YieldingWaitStrategy 的性能是最好的，适合用于低延迟的系统。在要求极高性能且事件处理线数小于CPU逻辑核心数的场景中，推荐使用此策略；例如，CPU开启超线程的特性
WaitStrategy YIELDING_WAIT = new YieldingWaitStrategy();
*/
//创建disruptor
Disruptor<LongEvent> disruptor =
new Disruptor<LongEvent>(factory, ringBufferSize, executor, ProducerType.SINGLE, new YieldingWaitStrategy());
// 连接消费事件方法
disruptor.handleEventsWith(new LongEventHandler());
// 启动
disruptor.start();
//Disruptor 的事件发布过程是一个两阶段提交的过程：
//发布事件
RingBuffer<LongEvent> ringBuffer = disruptor.getRingBuffer();
LongEventProducer producer = new LongEventProducer(ringBuffer);
//LongEventProducerWithTranslator producer = new LongEventProducerWithTranslator(ringBuffer);
ByteBuffer byteBuffer = ByteBuffer.allocate(8);
for(long l = 0; l<100; l++){
byteBuffer.putLong(0, l);
producer.onData(byteBuffer);
//Thread.sleep(1000);
}
disruptor.shutdown();//关闭 disruptor，方法会堵塞，直至所有的事件都得到处理；
executor.shutdown();//关闭 disruptor 使用的线程池；如果需要的话，必须手动关闭， disruptor 在 shutdown 时不会自动关闭；
}
}
package bhz.base;
import java.nio.ByteBuffer;
import com.lmax.disruptor.RingBuffer;
/**
* 很明显的是：当用一个简单队列来发布事件的时候会牵涉更多的细节，这是因为事件对象还需要预先创建。
* 发布事件最少需要两步：获取下一个事件槽并发布事件（发布事件的时候要使用try/finnally保证事件一定会被发布）。
* 如果我们使用RingBuffer.next()获取一个事件槽，那么一定要发布对应的事件。
* 如果不能发布事件，那么就会引起Disruptor状态的混乱。
* 尤其是在多个事件生产者的情况下会导致事件消费者失速，从而不得不重启应用才能会恢复。
*/
public class LongEventProducer {
private final RingBuffer<LongEvent> ringBuffer;
public LongEventProducer(RingBuffer<LongEvent> ringBuffer){
this.ringBuffer = ringBuffer;
}
/**
* onData用来发布事件，每调用一次就发布一次事件
* 它的参数会用过事件传递给消费者
*/
public void onData(ByteBuffer bb){
//1.可以把ringBuffer看做一个事件队列，那么next就是得到下面一个事件槽
long sequence = ringBuffer.next();
try {
//2.用上面的索引取出一个空的事件用于填充（获取该序号对应的事件对象）
LongEvent event = ringBuffer.get(sequence);
//3.获取要通过事件传递的业务数据
event.setValue(bb.getLong(0));
} finally {
//4.发布事件
//注意，最后的 ringBuffer.publish 方法必须包含在 finally 中以确保必须得到调用；如果某个请求的 sequence 未被提交，将会堵塞后续的发布操作或者其它的 producer。
ringBuffer.publish(sequence);
}
}
}
package bhz.base;
import java.nio.ByteBuffer;
import com.lmax.disruptor.EventTranslatorOneArg;
import com.lmax.disruptor.RingBuffer;
/**
* Disruptor 3.0提供了lambda式的API。这样可以把一些复杂的操作放在Ring Buffer，
* 所以在Disruptor3.0以后的版本最好使用Event Publisher或者Event Translator来发布事件
* <B>系统名称：</B><BR>
* <B>模块名称：</B><BR>
* <B>中文类名：</B><BR>
* <B>概要说明：</B><BR>
* @author 北京尚学堂（alienware）
* @since 2015年11月23日
*/
public class LongEventProducerWithTranslator {
//一个translator可以看做一个事件初始化器，publicEvent方法会调用它
//填充Event
private static final EventTranslatorOneArg<LongEvent, ByteBuffer> TRANSLATOR =
new EventTranslatorOneArg<LongEvent, ByteBuffer>() {
@Override
public void translateTo(LongEvent event, long sequeue, ByteBuffer buffer) {
event.setValue(buffer.getLong(0));
}
};
private final RingBuffer<LongEvent> ringBuffer;
public LongEventProducerWithTranslator(RingBuffer<LongEvent> ringBuffer) {
this.ringBuffer = ringBuffer;
}
public void onData(ByteBuffer buffer){
ringBuffer.publishEvent(TRANSLATOR, buffer);
}
}
HelloWorld2:
package bhz.multi;
import java.util.concurrent.atomic.AtomicInteger;
import com.lmax.disruptor.WorkHandler;
public class Consumer implements WorkHandler<Order>{
private String consumerId;
private static AtomicInteger count = new AtomicInteger(0);
public Consumer(String consumerId){
this.consumerId = consumerId;
}
@Override
public void onEvent(Order order) throws Exception {
System.out.println("当前消费者: " + this.consumerId + "，消费信息：" + order.getId());
count.incrementAndGet();
}
public int getCount(){
return count.get();
}
}
package bhz.multi;
import java.nio.ByteBuffer;
import java.util.UUID;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executors;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.ExceptionHandler;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.SequenceBarrier;
import com.lmax.disruptor.WorkHandler;
import com.lmax.disruptor.WorkerPool;
import com.lmax.disruptor.YieldingWaitStrategy;
import com.lmax.disruptor.dsl.ProducerType;
public class Main {
public static void main(String[] args) throws Exception {
//创建ringBuffer
RingBuffer<Order> ringBuffer =
RingBuffer.create(ProducerType.MULTI,
new EventFactory<Order>() {
@Override
public Order newInstance() {
return new Order();
}
},
1024 * 1024,
new YieldingWaitStrategy());
SequenceBarrier barriers = ringBuffer.newBarrier();
Consumer[] consumers = new Consumer[3];
for(int i = 0; i < consumers.length; i++){
consumers[i] = new Consumer("c" + i);
}
WorkerPool<Order> workerPool =
new WorkerPool<Order>(ringBuffer,
barriers,
new IntEventExceptionHandler(),
consumers);
ringBuffer.addGatingSequences(workerPool.getWorkerSequences());
workerPool.start(Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()));
final CountDownLatch latch = new CountDownLatch(1);
for (int i = 0; i < 100; i++) {
final Producer p = new Producer(ringBuffer);
new Thread(new Runnable() {
@Override
public void run() {
try {
latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
for(int j = 0; j < 100; j ++){
p.onData(UUID.randomUUID().toString());
}
}
}).start();
}
Thread.sleep(2000);
System.out.println("---------------开始生产-----------------");
latch.countDown();
Thread.sleep(5000);
System.out.println("总数:" + consumers[0].getCount() );
}
static class IntEventExceptionHandler implements ExceptionHandler {
public void handleEventException(Throwable ex, long sequence, Object event) {}
public void handleOnStartException(Throwable ex) {}
public void handleOnShutdownException(Throwable ex) {}
}
}
package bhz.multi;
public class Order {
private String id;//ID
private String name;
private double price;//金额
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}
package bhz.multi;
import java.nio.ByteBuffer;
import java.util.UUID;
import bhz.base.LongEvent;
import com.lmax.disruptor.EventTranslatorOneArg;
import com.lmax.disruptor.RingBuffer;
/**
* <B>系统名称：</B><BR>
* <B>模块名称：</B><BR>
* <B>中文类名：</B><BR>
* <B>概要说明：</B><BR>
* @author 北京尚学堂（alienware）
* @since 2015年11月23日
*/
public class Producer {
private final RingBuffer<Order> ringBuffer;
public Producer(RingBuffer<Order> ringBuffer){
this.ringBuffer = ringBuffer;
}
/**
* onData用来发布事件，每调用一次就发布一次事件
* 它的参数会用过事件传递给消费者
*/
public void onData(String data){
//可以把ringBuffer看做一个事件队列，那么next就是得到下面一个事件槽
long sequence = ringBuffer.next();
try {
//用上面的索引取出一个空的事件用于填充（获取该序号对应的事件对象）
Order order = ringBuffer.get(sequence);
//获取要通过事件传递的业务数据
order.setId(data);
} finally {
//发布事件
//注意，最后的 ringBuffer.publish 方法必须包含在 finally 中以确保必须得到调用；如果某个请求的 sequence 未被提交，将会堵塞后续的发布操作或者其它的 producer。
ringBuffer.publish(sequence);
}
}
}
helloWorld3:
package bhz.generate1;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import com.lmax.disruptor.BatchEventProcessor;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.EventProcessor;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.SequenceBarrier;
import com.lmax.disruptor.YieldingWaitStrategy;
public class Main1 {
public static void main(String[] args) throws Exception {
int BUFFER_SIZE=1024;
int THREAD_NUMBERS=4;
/*
* createSingleProducer创建一个单生产者的RingBuffer，
* 第一个参数叫EventFactory，从名字上理解就是"事件工厂"，其实它的职责就是产生数据填充RingBuffer的区块。
* 第二个参数是RingBuffer的大小，它必须是2的指数倍 目的是为了将求模运算转为&运算提高效率
* 第三个参数是RingBuffer的生产都在没有可用区块的时候(可能是消费者（或者说是事件处理器） 太慢了)的等待策略
*/
final RingBuffer<Trade> ringBuffer = RingBuffer.createSingleProducer(new EventFactory<Trade>() {
@Override
public Trade newInstance() {
return new Trade();
}
}, BUFFER_SIZE, new YieldingWaitStrategy());
//创建线程池
ExecutorService executors = Executors.newFixedThreadPool(THREAD_NUMBERS);
//创建SequenceBarrier
SequenceBarrier sequenceBarrier = ringBuffer.newBarrier();
//创建消息处理器
BatchEventProcessor<Trade> transProcessor = new BatchEventProcessor<Trade>(
ringBuffer, sequenceBarrier, new TradeHandler());
//这一步的目的就是把消费者的位置信息引用注入到生产者 如果只有一个消费者的情况可以省略
ringBuffer.addGatingSequences(transProcessor.getSequence());
//把消息处理器提交到线程池
executors.submit(transProcessor);
//如果存在多个消费者 那重复执行上面3行代码 把TradeHandler换成其它消费者类
Future<?> future= executors.submit(new Callable<Void>() {
@Override
public Void call() throws Exception {
long seq;
for(int i=0;i<10;i++){
seq = ringBuffer.next();//占个坑 --ringBuffer一个可用区块
ringBuffer.get(seq).setPrice(Math.random()*9999);//给这个区块放入 数据
ringBuffer.publish(seq);//发布这个区块的数据使handler(consumer)可见
}
return null;
}
});
future.get();//等待生产者结束
Thread.sleep(1000);//等上1秒，等消费都处理完成
transProcessor.halt();//通知事件(或者说消息)处理器 可以结束了（并不是马上结束!!!）
executors.shutdown();//终止线程
}
}
package bhz.generate1;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.IgnoreExceptionHandler;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.SequenceBarrier;
import com.lmax.disruptor.WorkHandler;
import com.lmax.disruptor.WorkerPool;
public class Main2 {
public static void main(String[] args) throws InterruptedException {
int BUFFER_SIZE=1024;
int THREAD_NUMBERS=4;
EventFactory<Trade> eventFactory = new EventFactory<Trade>() {
public Trade newInstance() {
return new Trade();
}
};
RingBuffer<Trade> ringBuffer = RingBuffer.createSingleProducer(eventFactory, BUFFER_SIZE);
SequenceBarrier sequenceBarrier = ringBuffer.newBarrier();
ExecutorService executor = Executors.newFixedThreadPool(THREAD_NUMBERS);
WorkHandler<Trade> handler = new TradeHandler();
WorkerPool<Trade> workerPool = new WorkerPool<Trade>(ringBuffer, sequenceBarrier, new IgnoreExceptionHandler(), handler);
workerPool.start(executor);
//下面这个生产8个数据
for(int i=0;i<8;i++){
long seq=ringBuffer.next();
ringBuffer.get(seq).setPrice(Math.random()*9999);
ringBuffer.publish(seq);
}
Thread.sleep(1000);
workerPool.halt();
executor.shutdown();
}
}
package bhz.generate1;
import java.util.concurrent.atomic.AtomicInteger;
public class Trade {
private String id;//ID
private String name;
private double price;//金额
private AtomicInteger count = new AtomicInteger(0);
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public AtomicInteger getCount() {
return count;
}
public void setCount(AtomicInteger count) {
this.count = count;
}
}
package bhz.generate1;
import java.util.UUID;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.WorkHandler;
public class TradeHandler implements EventHandler<Trade>, WorkHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
this.onEvent(event);
}
@Override
public void onEvent(Trade event) throws Exception {
//这里做具体的消费逻辑
event.setId(UUID.randomUUID().toString());//简单生成下ID
System.out.println(event.getId());
}
}
helloWorld4:
package bhz.generate2;
import java.util.UUID;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.WorkHandler;
public class Handler1 implements EventHandler<Trade>,WorkHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
this.onEvent(event);
}
@Override
public void onEvent(Trade event) throws Exception {
System.out.println("handler1: set name");
event.setName("h1");
Thread.sleep(1000);
}
}
package bhz.generate2;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventHandler;
public class Handler2 implements EventHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
System.out.println("handler2: set price");
event.setPrice(17.0);
Thread.sleep(1000);
}
}
package bhz.generate2;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventHandler;
public class Handler3 implements EventHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
System.out.println("handler3: name: " + event.getName() + " , price: " + event.getPrice() + "; instance: " + event.toString());
}
}
package bhz.generate2;
import java.util.UUID;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.WorkHandler;
public class Handler4 implements EventHandler<Trade>,WorkHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
this.onEvent(event);
}
@Override
public void onEvent(Trade event) throws Exception {
System.out.println("handler4: get name : " + event.getName());
event.setName(event.getName() + "h4");
}
}
package bhz.generate2;
import java.util.UUID;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.WorkHandler;
public class Handler5 implements EventHandler<Trade>,WorkHandler<Trade> {
@Override
public void onEvent(Trade event, long sequence, boolean endOfBatch) throws Exception {
this.onEvent(event);
}
@Override
public void onEvent(Trade event) throws Exception {
System.out.println("handler5: get price : " + event.getPrice());
event.setPrice(event.getPrice() + 3.0);
}
}
package bhz.generate2;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import bhz.generate1.Trade;
import bhz.generate1.TradeHandler;
import com.lmax.disruptor.BusySpinWaitStrategy;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.dsl.Disruptor;
import com.lmax.disruptor.dsl.EventHandlerGroup;
import com.lmax.disruptor.dsl.ProducerType;
public class Main {
public static void main(String[] args) throws InterruptedException {
long beginTime=System.currentTimeMillis();
int bufferSize=1024;
ExecutorService executor=Executors.newFixedThreadPool(8);
Disruptor<Trade> disruptor = new Disruptor<Trade>(new EventFactory<Trade>() {
@Override
public Trade newInstance() {
return new Trade();
}
}, bufferSize, executor, ProducerType.SINGLE, new BusySpinWaitStrategy());
//菱形操作
/**
//使用disruptor创建消费者组C1,C2
EventHandlerGroup<Trade> handlerGroup =
disruptor.handleEventsWith(new Handler1(), new Handler2());
//声明在C1,C2完事之后执行JMS消息发送操作 也就是流程走到C3
handlerGroup.then(new Handler3());
*/
//顺序操作
/**
disruptor.handleEventsWith(new Handler1()).
handleEventsWith(new Handler2()).
handleEventsWith(new Handler3());
*/
//六边形操作.
/**
Handler1 h1 = new Handler1();
Handler2 h2 = new Handler2();
Handler3 h3 = new Handler3();
Handler4 h4 = new Handler4();
Handler5 h5 = new Handler5();
disruptor.handleEventsWith(h1, h2);
disruptor.after(h1).handleEventsWith(h4);
disruptor.after(h2).handleEventsWith(h5);
disruptor.after(h4, h5).handleEventsWith(h3);
*/
disruptor.start();//启动
CountDownLatch latch=new CountDownLatch(1);
//生产者准备
executor.submit(new TradePublisher(latch, disruptor));
latch.await();//等待生产者完事.
disruptor.shutdown();
executor.shutdown();
System.out.println("总耗时:"+(System.currentTimeMillis()-beginTime));
}
}
package bhz.generate2;
import java.util.Random;
import java.util.concurrent.CountDownLatch;
import bhz.generate1.Trade;
import com.lmax.disruptor.EventTranslator;
import com.lmax.disruptor.dsl.Disruptor;
public class TradePublisher implements Runnable {
Disruptor<Trade> disruptor;
private CountDownLatch latch;
private static int LOOP=10;//模拟百万次交易的发生
public TradePublisher(CountDownLatch latch,Disruptor<Trade> disruptor) {
this.disruptor=disruptor;
this.latch=latch;
}
@Override
public void run() {
TradeEventTranslator tradeTransloator = new TradeEventTranslator();
for(int i=0;i<LOOP;i++){
disruptor.publishEvent(tradeTransloator);
}
latch.countDown();
}
}
class TradeEventTranslator implements EventTranslator<Trade>{
private Random random=new Random();
@Override
public void translateTo(Trade event, long sequence) {
this.generateTrade(event);
}
private Trade generateTrade(Trade trade){
trade.setPrice(random.nextDouble()*9999);
return trade;
}
}
来源：CSDN
作者：qq_53294028
链接：https://blog.csdn.net/qq_43277087/article/details/104047537