net.sf.asyncobjects.util
Class Seq<R>

java.lang.Object
  net.sf.asyncobjects.util.RunDispatcher
      net.sf.asyncobjects.util.Seq<R>

Type Parameters:

R - A result type

All Implemented Interfaces:

ExplicitSharing

public abstract class Seq<R>
extends RunDispatcher

A sequence control construct. This construct ensures that next actions is executed only if previous finished one way or another. If one of actions fails, next are not executed. Seq is sequeduled to be executed on some later turn because it reuses when construct. This also means that constructor completes before construct is executed. The control construct attempts to execute as much as possible in the single turn.

Author:

const

Field Summary

Fields inherited from class net.sf.asyncobjects.util.RunDispatcher

NO_FURTHER_ACTIONS

Constructor Summary

protected

Seq() A constructor.

Method Summary

protected Promise<?>	finallyDo() This method is executed when all actions are finished.
Promise<R>	promise()
protected Promise<R>	smashed(int action, Throwable problem) Handle fault on one of actions.

Methods inherited from class net.sf.asyncobjects.util.RunDispatcher

run1, run10, run11, run12, run13, run14, run15, run16, run2, run3, run4, run5, run6, run7, run8, run9, runNext

Methods inherited from class java.lang.Object

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

Constructor Detail

Seq

protected Seq()

A constructor. Constructors schedule execution of this seq construct.

Method Detail

smashed

protected Promise<R> smashed(int action,
                             Throwable problem)
                      throws Throwable

Handle fault on one of actions. By default just fail.

Parameters:

action - action number

problem - a problem

Returns:

a result to be returned

Throws:

Throwable - a problem that is used to smash result promise.

finallyDo

protected Promise<?> finallyDo()
                        throws Throwable

This method is executed when all actions are finished. The method does not affect return value, however it can generate a fault that will be reflected in execution result.

Returns:

a promise or null which means that there is no finally action

Throws:

Throwable - that will be result of Seq

promise

public Promise<R> promise()

Returns:

a promise for this sequence of actions