Module com.lmax.disruptor

Package com.lmax.disruptor

Class TimeoutBlockingWaitStrategy

java.lang.Object

com.lmax.disruptor.TimeoutBlockingWaitStrategy

All Implemented Interfaces:

WaitStrategy

public class TimeoutBlockingWaitStrategy
extends java.lang.Object
implements WaitStrategy

Blocking strategy that uses a lock and condition variable for EventProcessors waiting on a barrier. However it will periodically wake up if it has been idle for specified period by throwing a TimeoutException. To make use of this, the event handler class should override EventHandlerBase.onTimeout(long), which the BatchEventProcessor will call if the timeout occurs.

This strategy can be used when throughput and low-latency are not as important as CPU resource.

Constructor Summary

Constructors

Constructor	Description
TimeoutBlockingWaitStrategy(long timeout, java.util.concurrent.TimeUnit units)

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

TimeoutBlockingWaitStrategy

public TimeoutBlockingWaitStrategy(long timeout,
                                   java.util.concurrent.TimeUnit units)

Parameters:

timeout - how long to wait before waking up

units - the unit in which timeout is specified

Method Detail

waitFor

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

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.

cursorSequence - 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

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

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object