groovyx.gpars.dataflow.operator.component
Class ProcessorPauseResume

java.lang.Object
  groovyx.gpars.dataflow.operator.DataflowEventAdapter
      groovyx.gpars.dataflow.operator.component.ProcessorPauseResume

All Implemented Interfaces:

DataflowEventListener

public final class ProcessorPauseResume
extends DataflowEventAdapter

A listener to dataflow operators and selectors allowing them to be paused and resumed.

Author:

Vaclav Pech

Field Summary

private boolean

paused

Constructor Summary

ProcessorPauseResume()

Method Summary

java.util.List<java.lang.Object>	beforeRun(DataflowProcessor processor, java.util.List<java.lang.Object> messages) Invoked when all messages required to trigger the operator become available in the input channels.
void	pause() Pauses the operator so that it blocks the next time it attempts to process a message.
void	resume() Resumes the operator so that it can start processing messages again.

Methods inherited from class groovyx.gpars.dataflow.operator.DataflowEventAdapter

afterRun, afterStart, afterStop, controlMessageArrived, customEvent, messageArrived, messageSentOut, onException, registered

Methods inherited from class java.lang.Object

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

Field Detail

paused

private boolean paused

Constructor Detail

ProcessorPauseResume

public ProcessorPauseResume()

Method Detail

beforeRun

public java.util.List<java.lang.Object> beforeRun(DataflowProcessor processor,
                                                  java.util.List<java.lang.Object> messages)

Description copied from class: DataflowEventAdapter

Invoked when all messages required to trigger the operator become available in the input channels.

Specified by:

beforeRun in interface DataflowEventListener

Overrides:

beforeRun in class DataflowEventAdapter

Parameters:

processor - The reporting dataflow operator/selector

messages - The incoming messages

Returns:

The original list of messages or a modified/new list of messages that should be used instead

pause

public void pause()

Pauses the operator so that it blocks the next time it attempts to process a message. The operator's thread will be blocked, so care should be taken in order not to exhaust all available operator threads when pausing multiple operators.

resume

public void resume()

Resumes the operator so that it can start processing messages again.