jrun.jms.core.messagemgr
Class Scheduler

jrunx.kernel.ServiceAdapter
  |
  +--jrun.jms.core.util.JMSServiceAdapter
        |
        +--jrun.jms.core.messagemgr.Scheduler

All Implemented Interfaces:

JMSService, JMSServiceAdapterMBean, javax.naming.Referenceable, java.lang.Runnable, java.io.Serializable, Service, ServiceMBean

public class Scheduler

extends JMSServiceAdapter

implements java.lang.Runnable

A scheduler for Runnable objects. Clients add Runnable objects to this scheduler, and when a thread becomes available, they will be executed.

Version:

$Revision: 1.6 $ $Date: 2001/06/11 15:49:36 $

Author:

Jim Mourikis, Tim Anderson

See Also:

Runnable, org.exolab.core.service.BasicService, org.exolab.core.threadPool.ThreadPool, Serialized Form

Field Summary

static java.lang.String

OBJECT_NAME

Fields inherited from class jrunx.kernel.ServiceAdapter

DEFAULT_DEACTIVATED, DEFAULT_DOMAIN, DOMAIN_NAME_SEPARATOR, DOMAIN_NAME_SUFFIX, domainName, jndiBindable, LOGGER_CACHE_TIME, SCHEDULER_SERVICE, SECURITY_MANAGER, server, status, TRANSACTION_MANAGER

Fields inherited from interface jrunx.kernel.Service

INITIALIZED, STARTED, STARTING, STOPPED, STOPPING, UNINITIALIZED

Constructor Summary

	Scheduler(int maxThreads) Constructor that constructs a scheduler with the default service name.
protected	Scheduler(int maxThreads, java.lang.String name) Constructor that constructs a scheduler with a specified service name.

Method Summary

void	add(java.lang.Runnable runner) Add a Runnable object to the scheduler queue.
boolean	contains(java.lang.Runnable runner) Returns if a Runnable object exists in the scheduler queue.
static Scheduler	instance()
boolean	isEmpty() Returns true if the scheduler queue is empty
protected java.lang.Runnable	next() Return the next object in the queue to execute This method blocks until an object becomes available.
boolean	remove(java.lang.Runnable runner) Remove a Runnable object from the scheduler queue.
void	run() Start the scheduler This can only be terminated by invoking BasicService.stop()
void	start() Starts the scheduler.
void	stop() Stop the scheduler.

Methods inherited from class jrun.jms.core.util.JMSServiceAdapter

getMetaData, restart, resume, setMetaData, suspend

Methods inherited from class jrunx.kernel.ServiceAdapter

bind, destroy, findObjectInstance, findObjectInstance, findObjectInstance, getBindToJNDI, getDeactivated, getDomainName, getDomainSearchPath, getJRunService, getLogger, getName, getParentService, getReference, getResourceManager, getServerName, getServerProperties, getStatus, init, invokeMethod, isInPartition, isPartition, lookup, postDeregister, postRegister, preDeregister, preRegister, requestServer, scheduleRunnable, setBindToJNDI, setDeactivated, setDomainName, setName, setParentService, toString, unbind, unscheduleRunnable, updateStatus

Methods inherited from interface jrunx.kernel.ServiceMBean

bind, getBindToJNDI, getDeactivated, getDomainName, getJRunService, getLogger, getName, getParentService, getServerName, requestServer, setBindToJNDI, setDeactivated, setDomainName, setName, setParentService, unbind

Methods inherited from interface jrunx.kernel.Service

destroy, getStatus, init, updateStatus

Field Detail

OBJECT_NAME

public static final java.lang.String OBJECT_NAME

Constructor Detail

Scheduler

public Scheduler(int maxThreads)

Constructor that constructs a scheduler with the default service name.

Parameters:

maxThreads - the number of threads to use

Scheduler

protected Scheduler(int maxThreads,
                    java.lang.String name)

Constructor that constructs a scheduler with a specified service name.

Parameters:

maxThreads - the number of threads to use

name - the name of this service

Method Detail

instance

public static Scheduler instance()

add

public void add(java.lang.Runnable runner)

Add a Runnable object to the scheduler queue. When a thread becomes available, it will be executed.

Parameters:

runner - the object to execute

remove

public boolean remove(java.lang.Runnable runner)

Remove a Runnable object from the scheduler queue.

Parameters:

runner - the object to remove

Returns:

boolean true if the object was removed, false if it is already running or doesn't exist

contains

public boolean contains(java.lang.Runnable runner)

Returns if a Runnable object exists in the scheduler queue.

Parameters:

runner - the object to remove

Returns:

boolean true if the object exists, false if it is already running or doesn't exist

isEmpty

public boolean isEmpty()

Returns true if the scheduler queue is empty

Returns:

true if the scheduler queue is empty

run

public void run()

Start the scheduler This can only be terminated by invoking BasicService.stop()

Specified by:

run in interface java.lang.Runnable

start

public void start()
           throws java.lang.Exception

Starts the scheduler.

Overrides:

start in class ServiceAdapter

stop

public void stop()
          throws java.lang.Exception

Stop the scheduler. Any threads will be terminated.

Overrides:

stop in class ServiceAdapter

Throws:

ServiceException -

next

protected java.lang.Runnable next()

Return the next object in the queue to execute This method blocks until an object becomes available.

Returns:

Runnable the next object to execute