org.lsst.ccs.services

Class AgentPeriodicTaskService

java.lang.Object

org.lsst.ccs.services.AgentPeriodicTaskService

All Implemented Interfaces:

HasLifecycle, ServiceLifecycle

public final class AgentPeriodicTaskService
extends Object
implements ServiceLifecycle

A service to schedule periodic tasks. This service is responsible to manage the Agent's periodic tasks: - allow components to schedule periodic tasks - starts all the scheduled tasks once the Agent has started - stops the tasks upon shutdown It also provides utility methods to set/get the period of a task.

Author:

The LSST CCS Team

Constructor Summary

Constructors

Constructor and Description
AgentPeriodicTaskService(Agent a) Create an instance of the AgentPeriodicTaskService for a given Agent.

Method Summary

Modifier and Type	Method and Description
List<String>	getAgentPeriodicTaskNames() Get the list of names of the scheduled tasks.
Duration	getPeriodicTaskPeriod(String taskName) Get the period of a PeriodicTaks.
List<PeriodicTask>	getPeriodicTasks()
String	getSchedulerState() Get a string representing the state of the scheduler.
void	postStop() Called from the enclosing Subsystem when org.lsst.ccs.Subsystem#shutdown() has been called after shtudownNow has been invoked on all the children.
void	preInit()
void	scheduleAgentPeriodicTask(AgentPeriodicTask task) Schedule a PeriodicTask.
void	setPeriodicTaskPeriod(String taskName, Duration period) Change the period of a PeriodicTask.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.lsst.ccs.ServiceLifecycle

preBuild, preShutdown, preStart

Methods inherited from interface org.lsst.ccs.framework.HasLifecycle

build, init, postBuild, postInit, postShutdown, postStart, start, stop

Constructor Detail

AgentPeriodicTaskService

public AgentPeriodicTaskService(Agent a)

Create an instance of the AgentPeriodicTaskService for a given Agent.

Parameters:

a - The Agent this Service belongs to.

Method Detail

preInit

public void preInit()

Specified by:

preInit in interface ServiceLifecycle

postStop

public void postStop()

Description copied from interface: HasLifecycle

Called from the enclosing Subsystem when org.lsst.ccs.Subsystem#shutdown() has been called after shtudownNow has been invoked on all the children. At the time it is called :

• PhaseState is CLOSING.
• HardwareController.checkStopped() has been called

It should be overridden to free non hardware related resources.

Specified by:

postStop in interface HasLifecycle

scheduleAgentPeriodicTask

public void scheduleAgentPeriodicTask(AgentPeriodicTask task)

Schedule a PeriodicTask. Any CCS component can schedule an AgentPeriodicTask for execution. This method is available only using the init period of . Any invocation of this method at a later stage will result in a RuntimeException.

Parameters:

task - The PeriodicTask to schedule

getPeriodicTaskPeriod

public Duration getPeriodicTaskPeriod(String taskName)

Get the period of a PeriodicTaks.

Parameters:

taskName - The name of the task

Returns:

The periodic task period in milliseconds.

setPeriodicTaskPeriod

public void setPeriodicTaskPeriod(String taskName,
                                  Duration period)

Change the period of a PeriodicTask. If the Subsystem configuration Environment has been initialized and the Subsystem is not in INITAIL_SAFE configuration we use the configuration environment to change the period. Otherwise we simply change the AgentPeriodicTask directly.

Parameters:

taskName - The name of the task

period - The period Duration

getAgentPeriodicTaskNames

@Command(name="getAgentPeriodicTaskNames",
         description="Get the list of the names of the scheduled tasks",
         type=QUERY,
         category=SYSTEM)
public List<String> getAgentPeriodicTaskNames()

Get the list of names of the scheduled tasks.

Returns:

the Enumeration of task names.

getPeriodicTasks

public List<PeriodicTask> getPeriodicTasks()

getSchedulerState

public String getSchedulerState()

Get a string representing the state of the scheduler.

Returns:

the Scheduler's state.