uws.job.manager

Class AbstractQueuedExecutionManager

java.lang.Object

uws.job.manager.AbstractQueuedExecutionManager

All Implemented Interfaces:

ExecutionManager

Direct Known Subclasses:

QueuedExecutionManager

public abstract class AbstractQueuedExecutionManager
extends java.lang.Object
implements ExecutionManager

Abstract implementation of the interface ExecutionManager which lets managing an execution queue.

When calling execute(UWSJob), ALL jobs are put into the list of queued jobs (so their phase is changed to ExecutionPhase.QUEUED). A call to refresh(), reads this list and tries to execute the first job of the list. The function isReadyForExecution(UWSJob) decides whether the first job of the queue can be executed NOW or not.

Note: The order of queued jobs is preserved: it is implemented by a FIFO queue.

Note: After a call to stopAll(), this manager is still able to execute new jobs. Except if it was not possible to stop them properly, stopped jobs could be executed again by calling afterwards execute(UWSJob) with these jobs in parameter.

Version:

4.3 (09/2017)

Author:

Grégory Mantelet (CDS;ARI)

Field Summary

Fields

Modifier and Type	Field and Description
protected UWSLog	logger
protected java.util.Vector<UWSJob>	queuedJobs List of queued jobs.
protected java.util.Map<java.lang.String,UWSJob>	runningJobs List of running jobs.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractQueuedExecutionManager(UWSLog logger) Builds an execution manager without queue.

Method Summary

Modifier and Type	Method and Description
ExecutionPhase	execute(UWSJob jobToExecute) Refreshes this manager and then put the given job into the queue (if it is not already into it).
int	getNbQueuedJobs() Gets the total number of queued jobs.
int	getNbRunningJobs() Gets the total number of running jobs.
java.util.Iterator<UWSJob>	getQueuedJobs() Gets the list of queued jobs.
java.util.Iterator<UWSJob>	getRunningJobs() Gets the list of running jobs.
boolean	hasQueue() Tells whether there is a waiting queue.
abstract boolean	isReadyForExecution(UWSJob jobToExecute) Tells whether the given job can be executed NOW.
void	refresh() Removes the first queued job(s) from the queue and executes it (them) ONLY IF it (they) can be executed (see isReadyForExecution(UWSJob)).
void	remove(UWSJob jobToRemove) Removes the given job from the lists of queued and running jobs and then refreshes the manager.
protected void	startJob(UWSJob jobToStartNow) Starts immediately the given job.
void	stopAll() Stop all running jobs.

Methods inherited from class java.lang.Object

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

Field Detail

runningJobs

protected java.util.Map<java.lang.String,UWSJob> runningJobs

List of running jobs.

queuedJobs

protected java.util.Vector<UWSJob> queuedJobs

List of queued jobs.

logger

protected final UWSLog logger

Constructor Detail

AbstractQueuedExecutionManager

protected AbstractQueuedExecutionManager(UWSLog logger)

Builds an execution manager without queue.

Method Detail

getRunningJobs

public final java.util.Iterator<UWSJob> getRunningJobs()

Description copied from interface: ExecutionManager

Gets the list of running jobs.

Specified by:

getRunningJobs in interface ExecutionManager

Returns:

An iterator on the running jobs.

getNbRunningJobs

public final int getNbRunningJobs()

Description copied from interface: ExecutionManager

Gets the total number of running jobs.

Specified by:

getNbRunningJobs in interface ExecutionManager

Returns:

The number of running jobs.

getQueuedJobs

public final java.util.Iterator<UWSJob> getQueuedJobs()

Description copied from interface: ExecutionManager

Gets the list of queued jobs.

Specified by:

getQueuedJobs in interface ExecutionManager

Returns:

An iterator on the queued jobs.

getNbQueuedJobs

public final int getNbQueuedJobs()

Description copied from interface: ExecutionManager

Gets the total number of queued jobs.

Specified by:

getNbQueuedJobs in interface ExecutionManager

Returns:

The number of queued jobs.

hasQueue

public boolean hasQueue()

Tells whether there is a waiting queue.

Returns:

true if at least one job is into the queue, false otherwise.

isReadyForExecution

public abstract boolean isReadyForExecution(UWSJob jobToExecute)

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.

Parameters:

jobToExecute -

Returns:

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

refresh

public final void refresh()

Removes the first queued job(s) from the queue and executes it (them) ONLY IF it (they) can be executed (see isReadyForExecution(UWSJob)).

Note: Nothing is done if there is no queue.

Note: If any error occurs while refreshing this manager, it SHOULD be logged using the service logger.

Specified by:

refresh in interface ExecutionManager

See Also:

hasQueue(), isReadyForExecution(UWSJob), startJob(UWSJob), ExecutionManager.refresh()

startJob

protected void startJob(UWSJob jobToStartNow)
                 throws UWSException

Starts immediately the given job. This job is removed from the list of queued jobs and added into the list of running jobs.

Parameters:

jobToStartNow - The job to start.

Throws:

UWSException - If there is an error while starting the job.

See Also:

UWSJob.start(boolean)

execute

public final ExecutionPhase execute(UWSJob jobToExecute)

Refreshes this manager and then put the given job into the queue (if it is not already into it).

Note: If any error occurs while executing the given job, it SHOULD be logged using the service logger.

Specified by:

execute in interface ExecutionManager

Parameters:

jobToExecute - The job to execute.

Returns:

The resulting execution phase of the given job (EXECUTING or QUEUED or null if the given job is null).

See Also:

refresh(), UWSJob.isRunning(), isReadyForExecution(UWSJob), UWSJob.setPhase(ExecutionPhase), ExecutionManager.execute(UWSJob)

remove

public final void remove(UWSJob jobToRemove)

Removes the given job from the lists of queued and running jobs and then refreshes the manager.

Note: If any error occurs while removing a job from this manager, it SHOULD be logged using the service logger.

Specified by:

remove in interface ExecutionManager

Parameters:

jobToRemove - The job to remove.

See Also:

ExecutionManager.remove(uws.job.UWSJob)

stopAll

public final void stopAll()

Description copied from interface: ExecutionManager

Stop all running jobs. No more job, even the queued ones, must be executed after a call to this function. All stopped or aborted queued jobs should be set forcedly back to the PENDING status.

Note: A call to ExecutionManager.execute(UWSJob) would re-activate this manager. However jobs stopped or aborted using this function might not be starting again. These behaviors at implementation-dependent.

Specified by:

stopAll in interface ExecutionManager