com.lmax.disruptor

Class BusySpinWaitStrategy

java.lang.Object

com.lmax.disruptor.BusySpinWaitStrategy

All Implemented Interfaces:

WaitStrategy

public final class BusySpinWaitStrategy
extends java.lang.Object
implements WaitStrategy

Busy Spin strategy that uses a busy spin loop for EventProcessors waiting on a barrier.

This strategy will use CPU resource to avoid syscalls which can introduce latency jitter. It is best used when threads can be bound to specific CPU cores.

Constructor Summary

Constructors

Constructor and Description
BusySpinWaitStrategy()

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.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BusySpinWaitStrategy

public BusySpinWaitStrategy()

Method Detail

waitFor

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

Description copied from interface: WaitStrategy

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.

Specified by:

waitFor in interface WaitStrategy

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.

signalAllWhenBlocking

public void signalAllWhenBlocking()

Description copied from interface: WaitStrategy

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

Specified by:

signalAllWhenBlocking in interface WaitStrategy