org.apache.flink.streaming.runtime.io

Class BarrierBuffer

java.lang.Object

org.apache.flink.streaming.runtime.io.BarrierBuffer

public class BarrierBuffer
extends Object

Class encapsulating the functionality that is necessary to sync inputs on superstep barriers. Once a barrier is received from an input channel, whe should not process further buffers from that channel until we received the barrier from all other channels as well. To avoid back-pressuring the readers, we buffer up the new data received from the blocked channels until the blocks are released.

Constructor Summary

Constructors

Constructor and Description
BarrierBuffer(org.apache.flink.runtime.io.network.partition.consumer.InputGate inputGate, org.apache.flink.runtime.io.network.api.reader.AbstractReader reader)

Method Summary

Modifier and Type	Method and Description
protected void	actOnAllBlocked() Method that is executed once the barrier has been received from all channels.
protected void	blockChannel(int channelIndex) Blocks the given channel index, from which a barrier has been received.
void	cleanup()
org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent	getNextNonBlocked() Returns the next non-blocked BufferOrEvent.
protected org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent	getNonProcessed() Get then next non-blocked non-processed BufferOrEvent.
protected boolean	isAllBlocked() Checks whether all channels are blocked meaning that barriers are received from all channels
protected boolean	isBlocked(int channelIndex) Checks whether a given channel index is blocked for this inputgate
boolean	isEmpty()
void	processSuperstep(org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent bufferOrEvent) Processes a streaming superstep event
protected void	releaseBlocks() Releases the blocks on all channels.
protected void	startSuperstep(StreamingSuperstep superstep) Starts the next superstep in the buffer
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

BarrierBuffer

public BarrierBuffer(org.apache.flink.runtime.io.network.partition.consumer.InputGate inputGate,
                     org.apache.flink.runtime.io.network.api.reader.AbstractReader reader)

Method Detail

startSuperstep

protected void startSuperstep(StreamingSuperstep superstep)

Starts the next superstep in the buffer

Parameters:

superstep - The next superstep

getNonProcessed

protected org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent getNonProcessed()
                                                                                        throws IOException

Get then next non-blocked non-processed BufferOrEvent. Returns null if not available.

Throws:

IOException

isBlocked

protected boolean isBlocked(int channelIndex)

Checks whether a given channel index is blocked for this inputgate

Parameters:

channelIndex - The channel index to check

isAllBlocked

protected boolean isAllBlocked()

Checks whether all channels are blocked meaning that barriers are received from all channels

getNextNonBlocked

public org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent getNextNonBlocked()
                                                                                       throws IOException,
                                                                                              InterruptedException

Returns the next non-blocked BufferOrEvent. This is a blocking operator.

Throws:

IOException

InterruptedException

blockChannel

protected void blockChannel(int channelIndex)

Blocks the given channel index, from which a barrier has been received.

Parameters:

channelIndex - The channel index to block.

releaseBlocks

protected void releaseBlocks()

Releases the blocks on all channels.

Throws:

IOException

actOnAllBlocked

protected void actOnAllBlocked()

Method that is executed once the barrier has been received from all channels.

processSuperstep

public void processSuperstep(org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent bufferOrEvent)

Processes a streaming superstep event

Parameters:

bufferOrEvent - The BufferOrEvent containing the event

cleanup

public void cleanup()
             throws IOException

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

isEmpty

public boolean isEmpty()