org.globus.cog.abstraction.interfaces
Interface Task

All Superinterfaces:

ExecutableObject

All Known Implementing Classes:

TaskImpl

public interface Task

extends ExecutableObject

A Task is the atomic unit of execution in the Java CoG Kit abstractions framework. It represents a generic Grid functionality such as remote job execution, file transfer request, file access operation, or information query.

It is a container object encapsulating the task identity, task execution status, task specification, remote service(s), task output, task submission-, and completion-times.

Field Summary

static int	FILE_OPERATION Represents a file operation task
static int	FILE_TRANSFER Represents a file transfer task between two file servers
static int	INFORMATION_QUERY Represents an information query task.
static int	JOB_SUBMISSION Represents a remote job submission task

Fields inherited from interface org.globus.cog.abstraction.interfaces.ExecutableObject

TASK, TASKGRAPH

Method Summary

void	addOutputListener(OutputListener listener) Adds a listener to recieve the output events associated with this Task.
void	addService(Service service) Adds the Serviceto the tail of the ordered list of services.
Enumeration	getAllAttributes() Returns all the attribute names associated with this Task.
Collection	getAllServices() Returns all the services associated with this task.
Object	getAttribute(String name) Returns the value associated with the given attribute name.
Calendar	getCompletedTime() Returns the time when this Task was completed.
String	getProvider() Deprecated. Use Service.setProvider(String)instead.
int	getRequiredServices() Returns the maximum number of services required for this task.
Service	getService(int index) Returns the Serviceat the given index of the ordered list of services
Specification	getSpecification() Returns the Specificationassociated with this Task.
String	getStdError() Returns the standard error of the remote task execution.
String	getStdOutput() Returns the standard output of the remote task execution.
Calendar	getSubmittedTime() Returns the time when this Task was submitted to the remote service.
int	getType() Retruns the type of this Task.
boolean	isActive() Returns a boolean indicating if the task is active.
boolean	isCanceled() Returns a boolean indicating if the task is canceled.
boolean	isCompleted() Returns a boolean indicating if the task is completed.
boolean	isFailed() Returns a boolean indicating if the task is failed.
boolean	isSuspended() Returns a boolean indicating if the task is suspended.
boolean	isUnsubmitted() Returns a boolean indicating if the task is unsubmitted.
Collection	removeAllServices() Removes all the services associated with this task.
void	removeOutputListener(OutputListener listener) Removes the output listener.
void	removeService(Collection collection) Removes all the services associated with this task that also belongs to the given Collection of services.
Service	removeService(int index) Removes the Servicefrom the given position in the ordered list of Grid services.
void	setAttribute(String name, Object value) Sets an attribute for this Task.
void	setProvider(String provider) Deprecated. Use Service.setProvider(String)instead.
void	setRequiredService(int value) Sets the maximum number of services required for this task.
void	setService(int index, Service service) Sets one of the Servicerequired to execute this task.
void	setSpecification(Specification specification) Sets the Specificationdescribing the execution parameters of this Task.
void	setStdError(String error) Sets the standard error produced by this Task.
void	setStdOutput(String output) Sets the standard output produced by this Task.
void	setType(int type) Sets the type of this Task.
String	toString()
void	toXML(File file) Checkpoints the current state of this Task in XML format.

Methods inherited from interface org.globus.cog.abstraction.interfaces.ExecutableObject

addStatusListener, getIdentity, getName, getObjectType, getStatus, removeStatusListener, setIdentity, setName, setStatus, setStatus

Field Detail

JOB_SUBMISSION

public static final int JOB_SUBMISSION

Represents a remote job submission task

See Also:

Constant Field Values

FILE_TRANSFER

public static final int FILE_TRANSFER

Represents a file transfer task between two file servers

See Also:

Constant Field Values

INFORMATION_QUERY

public static final int INFORMATION_QUERY

Represents an information query task. Not implemented at this time

See Also:

Constant Field Values

FILE_OPERATION

public static final int FILE_OPERATION

Represents a file operation task

See Also:

Constant Field Values

Method Detail

setType

public void setType(int type)

Sets the type of this Task. Supported task types include: JOB_SUBMISSION,FILE_TRANSFER, and FILE_OPERATION.

Parameters:

type - the type of this Task.

getType

public int getType()

Retruns the type of this Task.

setProvider

public void setProvider(String provider)

Deprecated. Use Service.setProvider(String)instead.

getProvider

public String getProvider()

Deprecated. Use Service.setProvider(String)instead.

setService

public void setService(int index,
                       Service service)

Sets one of the Servicerequired to execute this task. The index at which this service is inserted determines its semantic role in the execution of the task. A task can require more than one service for execution. Thus, services are an ordered list.

Parameters:

index - the index representing the position of the service in the ordered list.

service - the remote Grid service.

addService

public void addService(Service service)

Adds the Serviceto the tail of the ordered list of services.

Parameters:

service - the remote Grid service

removeService

public Service removeService(int index)

Removes the Servicefrom the given position in the ordered list of Grid services.

Parameters:

index - the index representing the position of the service in the ordered list.

Returns:

the remote Grid service.

removeAllServices

public Collection removeAllServices()

Removes all the services associated with this task.

Returns:

a Collection of services

removeService

public void removeService(Collection collection)

Removes all the services associated with this task that also belongs to the given Collection of services.

Returns:

a Collection of services

getService

public Service getService(int index)

Returns the Serviceat the given index of the ordered list of services

Parameters:

index - the index representing the position of the service in the ordered list.

Returns:

the remote Grid service.

getAllServices

public Collection getAllServices()

Returns all the services associated with this task.

Returns:

a Collection of services

setRequiredService

public void setRequiredService(int value)

Sets the maximum number of services required for this task. For example, the JOB_SUBMISSION task requires a maximum of 1 service by default, where as the FILE_TRANSFER task requires a maximum of 2 services by default.

Parameters:

value - the maximum number of services required

getRequiredServices

public int getRequiredServices()

Returns the maximum number of services required for this task.

Returns:

number of services

setSpecification

public void setSpecification(Specification specification)

Sets the Specificationdescribing the execution parameters of this Task.

Parameters:

specification - the execution specification associated with this Task.

getSpecification

public Specification getSpecification()

Returns the Specificationassociated with this Task.

setStdOutput

public void setStdOutput(String output)

Sets the standard output produced by this Task. This method is used by the TaskHandlerto store the stdout of the remote task execution if it is redirected to the local machine.

getStdOutput

public String getStdOutput()

Returns the standard output of the remote task execution.

Returns:

the standard out of the remote task execution. null if no output was produced on the remote stdOut.

setStdError

public void setStdError(String error)

Sets the standard error produced by this Task. This method is used by the TaskHandlerto store the stderr of the remote task execution if it is redirected to the local machine.

getStdError

public String getStdError()

Returns the standard error of the remote task execution.

Returns:

the standard error of the remote task execution. null if no error was produced on the remote stderr.

setAttribute

public void setAttribute(String name,
                         Object value)

Sets an attribute for this Task. The interpretation of these attributes are TaskHandlerspecific and may not be utilized at all by some handlers.

Parameters:

name - a string representing the name of the attribute value an object representing the value of this attribute

getAttribute

public Object getAttribute(String name)

Returns the value associated with the given attribute name.

Parameters:

name - the name of the desired attribute

Returns:

the value of the given attribute name. null if attribute not available

getAllAttributes

public Enumeration getAllAttributes()

Returns all the attribute names associated with this Task.

Returns:

an enumeration of all the attribute names. null if no attribute available

addOutputListener

public void addOutputListener(OutputListener listener)

Adds a listener to recieve the output events associated with this Task. The listener reveives events related to the changes in the stdout of this Task.

Parameters:

listener - the output listener for this Task.

removeOutputListener

public void removeOutputListener(OutputListener listener)

Removes the output listener.

toXML

public void toXML(File file)
           throws MarshalException

Checkpoints the current state of this Task in XML format. Using the TaskUnmarshaller, the checkpointed Task can once again be re-instantiated.

Parameters:

file - the file to store the checkpointed task.

Throws:

MarshalException - during an error in XML translation.

toString

public String toString()

isUnsubmitted

public boolean isUnsubmitted()

Returns a boolean indicating if the task is unsubmitted.

isActive

public boolean isActive()

Returns a boolean indicating if the task is active.

isCompleted

public boolean isCompleted()

Returns a boolean indicating if the task is completed.

isSuspended

public boolean isSuspended()

Returns a boolean indicating if the task is suspended.

isFailed

public boolean isFailed()

Returns a boolean indicating if the task is failed.

isCanceled

public boolean isCanceled()

Returns a boolean indicating if the task is canceled.

getSubmittedTime

public Calendar getSubmittedTime()

Returns the time when this Task was submitted to the remote service.

Returns:

the Task submission time. null, if this Task is not yet submitted

getCompletedTime

public Calendar getCompletedTime()

Returns the time when this Task was completed.

Returns:

the Task completion time. null, if this Task is not yet complete.