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Disruptor 是一款高性能的 Java 框架,主要用于解决生产者-消费者模式(producer-consumer problem,简称 PCP)中的性能瓶颈问题。其核心设计理念在于通过无锁算法和环形缓冲区实现高吞吐量和低延迟,尤其适用于高频交易等场景。
Disruptor 的核心组件包括:
环形缓冲区(Ring Buffer):负责存储和交换通过 Disruptor 进行的数据事件(events)。从 3.0 版本开始,其职责简化为仅负责数据存储与更新,高级场景下可通过自定义实现替代。
序列号管理(Sequence):通过递增的序号来唯一标识和管理数据事件的处理流程。Sequence 不仅用于跟踪进度,还能避免 CPU 缓存的伪共享问题,这是 Disruptor 性能优越的关键之一。
序列器(Sequencer):定义了生产者与消费者之间快速、安全传递数据的并发算法。其有两个实现类:SingleProducerSequencer 和 MultiProducerSequencer,分别适用于单线程和多线程场景。
序列屏障(Sequence Barrier):维护了 RingBuffer 的 main published Sequence 和其他 Consumer 的 Sequence 引用,同时定义了决定 Consumer 是否还有可处理事件的逻辑。
消费者策略(Consumer Strategy):定义了消费者等待下一个事件的策略。Disruptor 提供多种策略选项,以适应不同的性能需求。
事件(Event):Disruptor 中的数据交换对象,不是特定类型,而是由使用者自定义。事件处理接口(EventHandler)是 Consumer 的真正实现。
事件处理器(EventProcessor):持有特定 Consumer 的 Sequence,并提供事件处理的执行环境(Event Loop)。
com.lmax disruptor 3.3.4
@Datapublic class MessageModel { private String message;} public class HelloEventFactory implements EventFactory{ @Override public MessageModel newInstance() { return new MessageModel(); }}
@Slf4jpublic class HelloEventHandler implements EventHandler{ @Override public void onEvent(MessageModel event, long sequence, boolean endOfBatch) { try { Thread.sleep(1000); log.info("消费者处理消息开始"); if (event != null) { log.info("消费者消费的信息是:{}", event); } log.info("消费者处理消息结束"); } catch (Exception e) { log.error("消费者处理消息失败"); } }}
@Componentpublic class BeanManager implements ApplicationContextAware { private static ApplicationContext applicationContext = null; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; } public static ApplicationContext getApplicationContext() { return applicationContext; } public static Object getBean(String name) { return applicationContext.getBean(name); } public static T getBean(Class clazz) { return applicationContext.getBean(clazz); }} @Configurationpublic class MQManager { @Bean("messageModel") public RingBuffer messageModelRingBuffer() { ExecutorService executor = Executors.newFixedThreadPool(2); HelloEventFactory factory = new HelloEventFactory(); int bufferSize = 1024 * 256; Disruptor disruptor = new Disruptor<>(factory, bufferSize, executor, ProducerType.SINGLE, new BlockingWaitStrategy()); disruptor.handleEventsWith(new HelloEventHandler()); disruptor.start(); return disruptor.getRingBuffer(); }} public interface DisruptorMqService { void sayHelloMq(String message);}@Slf4j@Componentpublic class DisruptorMqServiceImpl implements DisruptorMqService { @Autowired private RingBuffer messageModelRingBuffer; @Override public void sayHelloMq(String message) { log.info("record the message: {}", message); long sequence = messageModelRingBuffer.next(); try { MessageModel event = messageModelRingBuffer.get(sequence); event.setMessage(message); log.info("往消息队列中添加消息:{}", event); } catch (Exception e) { log.error("failed to add event to messageModelRingBuffer for: {}, {}", e, e.getMessage()); } finally { messageModelRingBuffer.publish(sequence); } }} @Slf4j@RunWith(SpringRunner.class)@SpringBootTest(classes = DemoApplication.class)public class DemoApplicationTests { @Autowired private DisruptorMqService disruptorMqService; @Test public void sayHelloMqTest() throws Exception { disruptorMqService.sayHelloMq("消息到了,Hello world!"); log.info("消息队列已发送完毕"); Thread.sleep(2000); }} 2020-04-05 14:31:18.543 INFO 7274 --- [main] c.e.u.d.d.s.Impl.DisruptorMqServiceImpl : record the message: 消息到了,Hello world!2020-04-05 14:31:18.545 INFO 7274 --- [main] c.e.u.d.d.s.Impl.DisruptorMqServiceImpl : 往消息队列中添加消息:MessageModel(message=消息到了,Hello world!)2020-04-05 14:31:19.547 INFO 7274 --- [pool-1-thread-1] c.e.u.d.disrupMq.mq.HelloEventHandler : 消费者处理消息开始2020-04-05 14:31:19.547 INFO 7274 --- [pool-1-thread-1] c.e.u.d.disrupMq.mq.HelloEventHandler : 消费者消费的信息是:MessageModel(message=消息到了,Hello world!)2020-04-05 14:31:19.547 INFO 7274 --- [pool-1-thread-1] c.e.u.d.disrupMq.mq.HelloEventHandler : 消费者处理消息结束
通过上述步骤,可以成功将 Disruptor 集成到项目中,实现高效的消息队列功能。
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