org.oddjob.jobs.structural

Class ParallelJob

java.lang.Object

org.oddjob.framework.extend.BaseComponent

org.oddjob.framework.extend.BasePrimary

org.oddjob.framework.extend.StructuralJob<java.lang.Object>

org.oddjob.framework.extend.SimultaneousStructural

org.oddjob.jobs.structural.ParallelJob

All Implemented Interfaces:

java.io.Serializable, java.lang.Runnable, ArooaContextAware, ArooaSessionAware, Forceable, OptionallyTransient, PropertyChangeNotifier, Iconic, LogEnabled, Resettable, Stateful, Stoppable, Structural

public class ParallelJob
extends SimultaneousStructural
implements OptionallyTransient

Description

A job which executes it's child jobs in parallel.

Once the child jobs are submitted, Oddjob's thread of execution continues on out of this job. The state is set to ACTIVE and will continue to change depending on the state of the child Jobs. The join property can be used to hold the thread of execution until the submitted jobs have finished executing - but it's use is discouraged. See the property documentation below for more information. The state of job, including its modification by the stateOperator property is identical to SequentialJob and is well documented there. Likewise with the transient property.

Example

Two jobs running in parallel. Note that the order of execution of the two child jobs is not predictable.

<oddjob>
    <job>
        <parallel>
            <jobs>
                <echo>This runs in parallel</echo>
                <echo>With this which could be displayed first!</echo>
            </jobs>
        </parallel>
    </job>
</oddjob>

Example

Two services started in parallel. This might be quite useful if the services took a long time to start - maybe because they loaded a lot of data into a cache for instance.

<oddjob>
    <job>
        <cascade cascadeOn="COMPLETE">
            <jobs>
                <parallel>
                    <jobs>
                        <bean class="org.oddjob.jobs.structural.ServiceManagerTest$Lights" id="lights"/>
                        <bean class="org.oddjob.jobs.structural.ServiceManagerTest$MachineThatGoes" goes="ping" id="machine"/>
                    </jobs>
                </parallel>
                <echo>The lights are ${lights.are} and the machine goes ${machine.goes}.</echo>
            </jobs>
        </cascade>
    </job>
</oddjob>

The CascadeJob will execute the final job only once both services have started, and it will continue be in a STARTED after execution has completed.

Adding a SERVICES stateOperator property will mean that parallel is COMPLETE once the services have started and so the whole cascade shows as complete.

<oddjob>
    <job>
        <cascade>
            <jobs>
                <parallel stateOperator="SERVICES">
                    <jobs>
                        <bean class="org.oddjob.jobs.structural.ServiceManagerTest$Lights" id="lights"/>
                        <bean class="org.oddjob.jobs.structural.ServiceManagerTest$MachineThatGoes" goes="ping" id="machine"/>
                    </jobs>
                </parallel>
                <echo>The lights are ${lights.are} and the machine goes ${machine.goes}.</echo>
            </jobs>
        </cascade>
    </job>
</oddjob>

Example

Examples elsewhere.

• ExecutorThrottleType has an example of limiting the number of concurrently executing jobs.

See Also:

Serialized Form

Author:

Rob Gordon

Field Summary

Fields inherited from class org.oddjob.framework.extend.StructuralJob

childHelper, destroy, stop, structuralState

Constructor Summary

Constructors

Constructor and Description
ParallelJob()

Method Summary

Modifier and Type	Method and Description
protected StateOperator	getInitialStateOp() Subclasses must provide the StateOperator that will decide how to evaluate the children's state.
StateOperator	getStateOperator() Getter for State Operator.
boolean	isJoin() Should execution wait for all jobs to be executed before returning to calling code.
boolean	isTransient() Is the component transient.
void	setJoin(boolean join)
void	setStateOperator(StateOperator stateOperator)
void	setTransient(boolean _transient)

Methods inherited from class org.oddjob.framework.extend.SimultaneousStructural

execute, getExecutorService, onStop, setExecutorService, setJobs, startChildStateReflector

Methods inherited from class org.oddjob.framework.extend.StructuralJob

addStructuralListener, fireDestroyedState, force, getStateChanger, hardReset, iconHelper, isStop, onDestroy, onHardReset, onReset, onSoftReset, postStop, removeStructuralListener, run, softReset, stateHandler, stop, stopChildStateReflector, waitForChildrenOnStop

Methods inherited from class org.oddjob.framework.extend.BasePrimary

configure, getName, logger, logger, loggerName, save, setName, toString

Methods inherited from class org.oddjob.framework.extend.BaseComponent

addIconListener, addPropertyChangeListener, addStateListener, configure, destroy, firePropertyChange, getArooaSession, iconForId, initialise, lastStateEvent, onConfigured, onInitialised, removeIconListener, removePropertyChangeListener, removeStateListener, save, setArooaContext, setArooaSession

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.oddjob.Stoppable

stop

Methods inherited from interface org.oddjob.Stateful

addStateListener, lastStateEvent, removeStateListener

Constructor Detail

ParallelJob

public ParallelJob()

Method Detail

setStateOperator

public void setStateOperator(StateOperator stateOperator)

Property: stateOperator

Description: Set the way the children's state is evaluated and reflected by the parent. Values can be WORST, ACTIVE, or SERVICES.

Required: No, default is ACTIVE.

Parameters:

stateOperator - The state operator to be applied to children's states to derive our state.

getStateOperator

public StateOperator getStateOperator()

Getter for State Operator.

Returns:

getInitialStateOp

protected StateOperator getInitialStateOp()

Description copied from class: StructuralJob

Subclasses must provide the StateOperator that will decide how to evaluate the children's state.

Specified by:

getInitialStateOp in class StructuralJob<java.lang.Object>

Returns:

A State Operator. Must not be null.

isJoin

public boolean isJoin()

Description copied from class: SimultaneousStructural

Should execution wait for all jobs to be executed before returning to calling code.

This property is intended to be overridden by sub classes that wish to give that choice to users.

Overrides:

isJoin in class SimultaneousStructural

Returns:

true for execution to wait for children. False for completion to be asynchronous.

setJoin

public void setJoin(boolean join)

isTransient

public boolean isTransient()

Description copied from interface: OptionallyTransient

Is the component transient.

Specified by:

isTransient in interface OptionallyTransient

Returns:

true if transient, false otherwise.

setTransient

public void setTransient(boolean _transient)