com.lmax.disruptor

Class PhasedBackoffWaitStrategy

java.lang.Object

com.lmax.disruptor.PhasedBackoffWaitStrategy

All Implemented Interfaces:

WaitStrategy

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

Phased wait strategy for waiting EventProcessors on a barrier.

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

Spins, then yields, then blocks on the configured BlockingStrategy.

Constructor Summary

Constructors

Constructor and Description
PhasedBackoffWaitStrategy(long spinTimeoutMillis, long yieldTimeoutMillis, java.util.concurrent.TimeUnit units, com.lmax.disruptor.PhasedBackoffWaitStrategy.BlockingStrategy lockingStrategy)

Method Summary

Methods

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.
static PhasedBackoffWaitStrategy	withLock(long spinTimeoutMillis, long yieldTimeoutMillis, java.util.concurrent.TimeUnit units) Block with wait/notifyAll semantics
static PhasedBackoffWaitStrategy	withSleep(long spinTimeoutMillis, long yieldTimeoutMillis, java.util.concurrent.TimeUnit units) Block by sleeping in a loop

Methods inherited from class java.lang.Object

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

Constructor Detail

PhasedBackoffWaitStrategy

public PhasedBackoffWaitStrategy(long spinTimeoutMillis,
                         long yieldTimeoutMillis,
                         java.util.concurrent.TimeUnit units,
                         com.lmax.disruptor.PhasedBackoffWaitStrategy.BlockingStrategy lockingStrategy)

Method Detail

withLock

public static PhasedBackoffWaitStrategy withLock(long spinTimeoutMillis,
                                 long yieldTimeoutMillis,
                                 java.util.concurrent.TimeUnit units)

Block with wait/notifyAll semantics

withSleep

public static PhasedBackoffWaitStrategy withSleep(long spinTimeoutMillis,
                                  long yieldTimeoutMillis,
                                  java.util.concurrent.TimeUnit units)

Block by sleeping in a loop

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 WaitStragegy 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