Package nz.org.riskscape.engine.task

Class ChainTask

java.lang.Object

nz.org.riskscape.engine.task.WorkerTask

nz.org.riskscape.engine.task.ChainTask

All Implemented Interfaces:

AutoCloseable

public class ChainTask
extends WorkerTask

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ChainTask.NamedOp
static class	ChainTask.StackElement

Field Summary

Fields inherited from class nz.org.riskscape.engine.task.WorkerTask

contextSwitches, id, in, out, pageReader, pageWriter, processingResult, runtime, runtimeAverage, spec

Constructor Summary

Constructors

Constructor	Description
ChainTask(TaskSpec spec)

Method Summary

Modifier and Type	Method	Description
void	close()	Override this method to clean up any resources that were allocated/created by this task for use during execution.
ChainTask.NamedOp	getLastOperation()
List<ChainTask.NamedOp>	getOperations()
String	getSpecNameBrief()
boolean	hasPageInProgress()	Returns true if the task currently has a page of either input or output that it hasn't finished with yet.
boolean	isReadyToRun()	Returns true if the task has work it can do.
boolean	producesResult()
ReturnState	run()	Processes the work that the task has to do.

Methods inherited from class nz.org.riskscape.engine.task.WorkerTask

consumeProcessingResult, getContext, getFirstStep, getFirstStepRealizedResult, getLastStep, getName, getPageReader, getPageWriter, getSpec, hasInputPage, hasOutputPage, isComplete, isCreated, isInputReady, isOutputReady, isStarted, markComplete, markStarted, runPublic, taskComplete, toString

Methods inherited from class java.lang.Object

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

Constructor Details

ChainTask

public ChainTask(TaskSpec spec)
          throws nz.org.riskscape.problem.ProblemException

Throws:

nz.org.riskscape.problem.ProblemException

Method Details

hasPageInProgress

public boolean hasPageInProgress()

Description copied from class: WorkerTask

Returns true if the task currently has a page of either input or output that it hasn't finished with yet.

Overrides:

hasPageInProgress in class WorkerTask

isReadyToRun

public boolean isReadyToRun()

Description copied from class: WorkerTask

Returns true if the task has work it can do. Returns false if the task is blocked waiting on either more input, more output buffers to free up, or it's dependent on other tasks that haven't completed yet.

Overrides:

isReadyToRun in class WorkerTask

run

public ReturnState run()

Description copied from class: WorkerTask

Processes the work that the task has to do. The task doesn't necessarily run to completion in one go - it's likely that the task will run out of input or output first, so it'll need to keep coming back and chipping away at the work.

Specified by:

run in class WorkerTask

close

public void close()

Description copied from class: WorkerTask

Override this method to clean up any resources that were allocated/created by this task for use during execution. Will be called from the scheduler once the task has signaled it is complete, but it may also get called if a job that this task was part of has failed.

Thread safety should be ensured by requiring the scheduler to only call close on a task that is not currently being run.

Implementations shouldn't need to do any buffer management in this method, it's meant for closing things like TupleIterators or other sorts of resources that follow the Closeable pattern.

Specified by:

close in interface AutoCloseable

Overrides:

close in class WorkerTask

producesResult

public boolean producesResult()

Specified by:

producesResult in class WorkerTask

getLastOperation

public ChainTask.NamedOp getLastOperation()

getSpecNameBrief

public String getSpecNameBrief()

Overrides:

getSpecNameBrief in class WorkerTask

Returns:

a unique name for the worker's TaskSpec that is brief and user-friendly. This can be used as a simple way to represent the work that this task is doing to the user.

getOperations

public List<ChainTask.NamedOp> getOperations()