Package org.apache.flink.runtime.io.network

Class TaskEventDispatcher

java.lang.Object

org.apache.flink.runtime.io.network.TaskEventDispatcher

All Implemented Interfaces:

TaskEventPublisher

public class TaskEventDispatcher
extends Object
implements TaskEventPublisher

The task event dispatcher dispatches events flowing backwards from a consuming task to the task producing the consumed result.

Backwards events only work for tasks, which produce pipelined results, where both the producing and consuming task are running at the same time.

Constructor Summary

Constructors

Constructor	Description
TaskEventDispatcher()

Method Summary

Modifier and Type	Method	Description
void	clearAll()	Removes all registered event handlers.
boolean	publish(ResultPartitionID partitionId, TaskEvent event)	Publishes the event to the registered EventListener instances.
void	registerPartition(ResultPartitionID partitionId)	Registers the given partition for incoming task events allowing calls to subscribeToEvent(ResultPartitionID, EventListener, Class).
void	subscribeToEvent(ResultPartitionID partitionId, EventListener<TaskEvent> eventListener, Class<? extends TaskEvent> eventType)	Subscribes a listener to this dispatcher for events on a partition.
void	unregisterPartition(ResultPartitionID partitionId)	Removes the given partition from listening to incoming task events, thus forbidding calls to subscribeToEvent(ResultPartitionID, EventListener, Class).

Methods inherited from class java.lang.Object

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

Constructor Detail

TaskEventDispatcher

public TaskEventDispatcher()

Method Detail

registerPartition

public void registerPartition(ResultPartitionID partitionId)

Registers the given partition for incoming task events allowing calls to subscribeToEvent(ResultPartitionID, EventListener, Class).

Parameters:

partitionId - the partition ID

unregisterPartition

public void unregisterPartition(ResultPartitionID partitionId)

Removes the given partition from listening to incoming task events, thus forbidding calls to subscribeToEvent(ResultPartitionID, EventListener, Class).

Parameters:

partitionId - the partition ID

subscribeToEvent

public void subscribeToEvent(ResultPartitionID partitionId,
                             EventListener<TaskEvent> eventListener,
                             Class<? extends TaskEvent> eventType)

Subscribes a listener to this dispatcher for events on a partition.

Parameters:

partitionId - ID of the partition to subscribe for (must be registered via registerPartition(ResultPartitionID) first!)

eventListener - the event listener to subscribe

eventType - event type to subscribe to

publish

public boolean publish(ResultPartitionID partitionId,
                       TaskEvent event)

Publishes the event to the registered EventListener instances.

This method is either called directly from a LocalInputChannel or the network I/O thread on behalf of a RemoteInputChannel.

Specified by:

publish in interface TaskEventPublisher

Parameters:

partitionId - the partition ID to get registered handlers

event - the task event to be published to the handlers

Returns:

whether the event was published to a registered event handler (initiated via registerPartition(ResultPartitionID)) or not

clearAll

public void clearAll()

Removes all registered event handlers.