com.lmax.disruptor

Interface WaitStrategy

All Known Implementing Classes:

BlockingWaitStrategy, BusySpinWaitStrategy, LiteBlockingWaitStrategy, LiteTimeoutBlockingWaitStrategy, PhasedBackoffWaitStrategy, SleepingWaitStrategy, TimeoutBlockingWaitStrategy, YieldingWaitStrategy

public interface WaitStrategy

Strategy employed for making EventProcessors wait on a cursor Sequence.

Method Summary

Modifier and Type	Method and Description
void	signalAllWhenBlocking() Implementations should signal the waiting EventProcessors that the cursor has advanced.
long	waitFor(long sequence, Sequence cursor, Sequence dependentSequence, SequenceBarrier barrier) Wait for the given sequence to be available.

Method Detail

waitFor

long waitFor(long sequence,
             Sequence cursor,
             Sequence dependentSequence,
             SequenceBarrier barrier)
      throws AlertException,
             java.lang.InterruptedException,
             TimeoutException

Wait for the given sequence to be available. It is possible for this method to return a value less than the sequence number supplied depending on the implementation of the WaitStrategy. A common use for this is to signal a timeout. Any EventProcessor that is using a WaitStrategy to get notifications about message becoming available should remember to handle this case. The BatchEventProcessor explicitly handles this case and will signal a timeout if required.

Parameters:

sequence - to be waited on.

cursor - the main sequence from ringbuffer. Wait/notify strategies will need this as it's the only sequence that is also notified upon update.

dependentSequence - on which to wait.

barrier - the processor is waiting on.

Returns:

the sequence that is available which may be greater than the requested sequence.

Throws:

AlertException - if the status of the Disruptor has changed.

java.lang.InterruptedException - if the thread is interrupted.

TimeoutException - if a timeout occurs before waiting completes (not used by some strategies)

signalAllWhenBlocking

void signalAllWhenBlocking()

Implementations should signal the waiting EventProcessors that the cursor has advanced.