uws.job.manager

Class QueuedExecutionManager

java.lang.Object

uws.job.manager.AbstractQueuedExecutionManager

uws.job.manager.QueuedExecutionManager

All Implemented Interfaces:

ExecutionManager

public class QueuedExecutionManager
extends AbstractQueuedExecutionManager

Implementation of the interface ExecutionManager which lets managing an execution queue in function of a maximum number of running jobs: if there are more running jobs than a given number, the jobs to execute are put in the queue until a running job stops. The order of queued jobs are preserved: it is implemented by a FIFO queue.

Version:

4.1 (08/2014)

Author:

Grégory Mantelet (CDS;ARI)

Field Summary

Fields

Modifier and Type	Field and Description
protected int	nbMaxRunningJobs The maximum number of running jobs.
static int	NO_QUEUE The value of nbMaxRunningJobs which indicates that there is no queue.

Fields inherited from class uws.job.manager.AbstractQueuedExecutionManager

logger, queuedJobs, runningJobs

Constructor Summary

Constructors

Constructor and Description
QueuedExecutionManager(UWSLog logger) Builds an execution manager without queue.
QueuedExecutionManager(UWSLog logger, int maxRunningJobs) Builds an execution manager with a queue.

Method Summary

Modifier and Type	Method and Description
int	getMaxRunningJobs() Gets the maximum number of running jobs.
boolean	isReadyForExecution(UWSJob jobToExecute) Tells whether the given job can be executed NOW.
void	setMaxRunningJobs(int maxRunningJobs) Sets the maximum number of running jobs.
void	setNoQueue()

Methods inherited from class uws.job.manager.AbstractQueuedExecutionManager

execute, getNbQueuedJobs, getNbRunningJobs, getQueuedJobs, getRunningJobs, hasQueue, refresh, remove, startJob, stopAll

Methods inherited from class java.lang.Object

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

Field Detail

nbMaxRunningJobs

protected int nbMaxRunningJobs

The maximum number of running jobs.

NO_QUEUE

public static final int NO_QUEUE

The value of nbMaxRunningJobs which indicates that there is no queue.

See Also:

Constant Field Values

Constructor Detail

QueuedExecutionManager

public QueuedExecutionManager(UWSLog logger)

Builds an execution manager without queue.

Parameters:

logger - The object to user to log some messages (error, info, debug).

QueuedExecutionManager

public QueuedExecutionManager(UWSLog logger,
                              int maxRunningJobs)

Builds an execution manager with a queue. The number of executing jobs is limited by the given value (if positive and different from 0).

Parameters:

logger - The object to user to log some messages (error, info, debug).

maxRunningJobs - The maximum number of running jobs (must be > 0 to have a queue).

Method Detail

setNoQueue

public final void setNoQueue()

getMaxRunningJobs

public final int getMaxRunningJobs()

Gets the maximum number of running jobs.

Returns:

The maximum number of running jobs.

setMaxRunningJobs

public void setMaxRunningJobs(int maxRunningJobs)
                       throws UWSException

Sets the maximum number of running jobs.

Note: If the new maximum number of running jobs is increasing the list of running jobs is immediately updated BUT NOT IF it is decreasing (that is to say, running jobs will not be interrupted to be put in the queue, they continue to run) !

Parameters:

maxRunningJobs - The new maximum number of running jobs (NO_QUEUE or a negative value means no maximum number of running jobs: there will be no queue any more).

Throws:

UWSException - If there is an error while updating the list of running jobs (in other words if some queued jobs can not be executed).

See Also:

AbstractQueuedExecutionManager.refresh()

isReadyForExecution

public final boolean isReadyForExecution(UWSJob jobToExecute)

Description copied from class: AbstractQueuedExecutionManager

Tells whether the given job can be executed NOW. In other words, in function of the result of this function, the given job will be put in the queue or it will be executed.

Specified by:

isReadyForExecution in class AbstractQueuedExecutionManager

Returns:

true if the given job can be executed NOW (=> it will be executed), false otherwise (=> it will be put in the queue).