Package org.apache.wayang.core.util

Class OneTimeExecutable

java.lang.Object

org.apache.wayang.core.util.OneTimeExecutable

Direct Known Subclasses:

Job, LoopEnumerator, LoopIsolator, PushExecutorTemplate.StageExecution, StageAssignmentTraversal

public abstract class OneTimeExecutable
extends Object

Method wrapper that ensures that it is called only once.

Constructor Summary

Constructors

Constructor	Description
OneTimeExecutable()

Method Summary

Modifier and Type	Method	Description
protected abstract void	doExecute()	Performs the actual work of this instance.
protected void	execute()	Invoke doExecute().
protected boolean	tryExecute()	Invoke doExecute() unless it has been executed already.

Methods inherited from class java.lang.Object

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

Constructor Details

OneTimeExecutable

public OneTimeExecutable()

Method Details

tryExecute

protected boolean tryExecute()

Invoke doExecute() unless it has been executed already. Also, ensure that it will not be invoked a second time.

Returns:

whether the method invocation resulted in invoking doExecute()

execute

protected void execute()
                throws IllegalStateException

Invoke doExecute(). Also, ensure that it will not be invoked a second time.

Throws:

IllegalStateException - if doExecute() has been already invoked

doExecute

protected abstract void doExecute()

Performs the actual work of this instance. Should only be invoked via execute() and tryExecute().