com.lmax.disruptor.SequenceBarrier Java Examples

@Override
public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence,
                    final SequenceBarrier barrier) throws AlertException {
    long availableSequence;
    int counter = retries;

    // dependentSequence 该项目组织架构中，其实只是生产者的sequence，也就是cursor
    while ((availableSequence = dependentSequence.get()) < sequence) {
        counter = applyWaitMethod(barrier, counter);

        // 每睡眠一次，执行一次循环
        if (counter <= 0) {
            eventLoop.safeLoopOnce();
        }
    }
    return availableSequence;
}
 

private int applyWaitMethod(final SequenceBarrier barrier, int counter)
        throws AlertException {
    // 检查中断/终止信号
    barrier.checkAlert();

    if (counter > 100) {
        // 大于100时自旋
        --counter;
    } else if (counter > 0) {
        // 大于0时尝试让出Cpu
        --counter;
        Thread.yield();
    } else {
        // 等到最大次数了，睡眠等待
        LockSupport.parkNanos(sleepTimeNs);
    }
    return counter;
}
 

@Override
public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence,
                    final SequenceBarrier barrier) throws AlertException, InterruptedException {

    long availableSequence;
    int spinTries = 0;

    // dependentSequence 该项目组织架构中，其实只是生产者的sequence，也就是cursor
    while ((availableSequence = dependentSequence.get()) < sequence) {
        barrier.checkAlert();
        Thread.onSpinWait();

        if (++spinTries == loopOnceSpinTries) {
            spinTries = 0;
            eventLoop.safeLoopOnce();
        }
    }

    return availableSequence;
}
 

public long waitFor(long sequence, Sequence cursorSequence, Sequence dependentSequence, SequenceBarrier barrier)
        throws AlertException, InterruptedException {
    if (cursorSequence.get() < sequence) {
        this.lock.lock();

        try {
            while (cursorSequence.get() < sequence) {
                barrier.checkAlert();
                this.processorNotifyCondition.await();
            }
        } finally {
            this.lock.unlock();
        }
    }

    long availableSequence;
    while ((availableSequence = dependentSequence.get()) < sequence) {
        barrier.checkAlert();
        LockSupport.parkNanos(1L);
    }

    return availableSequence;
}
 

/**
 *
 * @param consumerNum
 * @param threadNum
 * @param ringBufferSize RingBuffer 大小，必须是 2 的 N 次方
 */
public DisruptorQueue(int consumerNum,int threadNum,int ringBufferSize) {

    Consumer[] consumers = new Consumer[consumerNum];

    //创建ringBuffer
    ringBuffer = RingBuffer.create(ProducerType.MULTI,
            new EventFactory<RequestEvent>() {
                @Override
                public RequestEvent newInstance() {
                    return new RequestEvent();
                }
            },
            ringBufferSize ,
            new YieldingWaitStrategy());

    SequenceBarrier barriers = ringBuffer.newBarrier();

    for (int i = 0; i < consumers.length; i++) {
        consumers[i] = new Consumer();
    }

    WorkerPool<RequestEvent> workerPool = new WorkerPool<RequestEvent>(ringBuffer,
                    barriers,
                    new EventExceptionHandler(),
                    consumers);

    ringBuffer.addGatingSequences(workerPool.getWorkerSequences());
    workerPool.start(Executors.newFixedThreadPool(threadNum));

    producer = new Producer(ringBuffer);
}
 

@Override
public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence, final SequenceBarrier barrier)
        throws AlertException, InterruptedException
{
    long availableSequence;

    while ((availableSequence = dependentSequence.get()) < sequence)
    {
        SpinHint.spinLoopHint();
        barrier.checkAlert();
    }

    return availableSequence;
}
 

@Override
public long waitFor(long sequence,
                    Sequence cursor,
                    Sequence dependentSequence,
                    SequenceBarrier barrier) throws AlertException,
  InterruptedException,
  TimeoutException {
  long availableSequence;
  while ((availableSequence = dependentSequence.get()) < sequence) {
    barrier.checkAlert();
    LockSupport.parkNanos(parkFor);
  }
  return availableSequence;
}
 

public long waitFor(
	long sequence,
	Sequence cursor,
	Sequence dependentSequence,
	SequenceBarrier barrier
) throws AlertException, InterruptedException, TimeoutException {
	long availableSequence;
	if ((availableSequence = cursor.get()) < sequence) {
		flush();
		synchronized (lock) {
			++numWaiters;
			while ((availableSequence = cursor.get()) < sequence) {
				if (state == State.STOPPED) {
					disruptor.halt();
					throw AlertException.INSTANCE;
				}
				barrier.checkAlert();
				//*/
				lock.wait();
				/*/
				Thread.sleep(1);
				//*/
			}
			--numWaiters;
		}
	}
	while ((availableSequence = dependentSequence.get()) < sequence) {
		barrier.checkAlert();
	}

	return availableSequence;
}
 

private int applyWaitMethod(final SequenceBarrier barrier, int counter)
        throws AlertException {
    // 检查中断、停止信号
    barrier.checkAlert();

    if (counter > 0) {
        --counter;
    } else {
        Thread.yield();
    }
    return counter;
}
 

private int applyWaitMethod(final SequenceBarrier barrier, int currentSleep) throws AlertException {
    barrier.checkAlert();

    if (currentSleep < sleepTimeNsMax) {
        LockSupport.parkNanos(currentSleep);
        return currentSleep * 2;
    } else {
        LockSupport.parkNanos(sleepTimeNsMax);
        return currentSleep;
    }
}
 

@Override
public long waitFor(final long sequence, Sequence cursor, final Sequence dependentSequence, final SequenceBarrier barrier) throws AlertException {
    long availableSequence;
    int currentSleep = sleepTimeNsStart;

    while ((availableSequence = dependentSequence.get()) < sequence) {
        currentSleep = applyWaitMethod(barrier, currentSleep);
    }

    return availableSequence;
}
 

@Override
public long waitFor(long sequence, Sequence cursor, Sequence dependentSequence, SequenceBarrier barrier) {
    return dependentSequence.get();
}
 

public static <T> boolean waitRequestOrTerminalEvent(
  Sequence pendingRequest,
  RingBuffer<MutableSignal<T>> ringBuffer,
  SequenceBarrier barrier,
  Subscriber<? super T> subscriber,
  AtomicBoolean isRunning
) {
  final long waitedSequence = ringBuffer.getCursor() + 1L;
  try {
    MutableSignal<T> event = null;
    while (pendingRequest.get() < 0l) {
      //pause until first request
      if (event == null) {
        barrier.waitFor(waitedSequence);
        event = ringBuffer.get(waitedSequence);

        if (event.type == MutableSignal.Type.COMPLETE) {
          try {
            subscriber.onComplete();
            return false;
          } catch (Throwable t) {
            Exceptions.throwIfFatal(t);
            subscriber.onError(t);
            return false;
          }
        } else if (event.type == MutableSignal.Type.ERROR) {
          subscriber.onError(event.error);
          return false;
        }
      } else {
        barrier.checkAlert();
      }
      LockSupport.parkNanos(1l);
    }
  } catch (TimeoutException te) {
    //ignore
  } catch (AlertException ae) {
    if (!isRunning.get()) {
      return false;
    }
  } catch (InterruptedException ie) {
    Thread.currentThread().interrupt();
  }

  return true;
}
 

@Override
public long waitFor(long sequence, Sequence cursor, Sequence dependentSequence, SequenceBarrier barrier)
  throws AlertException, InterruptedException, TimeoutException {
  return currentStrategy.waitFor(sequence, cursor, dependentSequence, barrier);
}
 

@Override
public void start() {
    super.start();
    this.exception = null;
    this.disruptorMsgBuffer = RingBuffer.createSingleProducer(new MessageEventFactory(),
        ringBufferSize,
        new BlockingWaitStrategy());
    int tc = parserThreadCount > 0 ? parserThreadCount : 1;
    this.parserExecutor = Executors.newFixedThreadPool(tc, new NamedThreadFactory("MultiStageCoprocessor-Parser-"
                                                                                  + destination));

    this.stageExecutor = Executors.newFixedThreadPool(2, new NamedThreadFactory("MultiStageCoprocessor-other-"
                                                                                + destination));
    SequenceBarrier sequenceBarrier = disruptorMsgBuffer.newBarrier();
    ExceptionHandler exceptionHandler = new SimpleFatalExceptionHandler();
    // stage 2
    this.logContext = new LogContext();
    simpleParserStage = new BatchEventProcessor<MessageEvent>(disruptorMsgBuffer,
        sequenceBarrier,
        new SimpleParserStage(logContext));
    simpleParserStage.setExceptionHandler(exceptionHandler);
    disruptorMsgBuffer.addGatingSequences(simpleParserStage.getSequence());

    // stage 3
    SequenceBarrier dmlParserSequenceBarrier = disruptorMsgBuffer.newBarrier(simpleParserStage.getSequence());
    WorkHandler<MessageEvent>[] workHandlers = new DmlParserStage[tc];
    for (int i = 0; i < tc; i++) {
        workHandlers[i] = new DmlParserStage();
    }
    workerPool = new WorkerPool<MessageEvent>(disruptorMsgBuffer,
        dmlParserSequenceBarrier,
        exceptionHandler,
        workHandlers);
    Sequence[] sequence = workerPool.getWorkerSequences();
    disruptorMsgBuffer.addGatingSequences(sequence);

    // stage 4
    SequenceBarrier sinkSequenceBarrier = disruptorMsgBuffer.newBarrier(sequence);
    sinkStoreStage = new BatchEventProcessor<MessageEvent>(disruptorMsgBuffer,
        sinkSequenceBarrier,
        new SinkStoreStage());
    sinkStoreStage.setExceptionHandler(exceptionHandler);
    disruptorMsgBuffer.addGatingSequences(sinkStoreStage.getSequence());

    // start work
    stageExecutor.submit(simpleParserStage);
    stageExecutor.submit(sinkStoreStage);
    workerPool.start(parserExecutor);
}
 

public SequenceBarrier get_barrier() {
    return _barrier;
}
 

/**
 * Create a new SequenceBarrier to be used by an EventProcessor to track which messages are available to be read from the ring buffer given a list of
 * sequences to track.
 * 
 * @see SequenceBarrier
 * @param sequencesToTrack the additional sequences to track
 * @return A sequence barrier that will track the specified sequences.
 */
public SequenceBarrier newBarrier(Sequence... sequencesToTrack) {
    return sequencer.newBarrier(sequencesToTrack);
}