Package overit.geocall.da

Class TimeSlot

java.lang.Object

overit.geocall.da.TimeSlot

public class TimeSlot
extends Object

The class defines the TimeSlot object, the one used to manage jobs on multiple nodes with shared resources. The concept of TimeSlot is to allocate a certain amount of time for a given activity. To take advantage of the TimeSots, you need to write concurrent and collaborative tasks to make sure that the workload is divided.

Field Summary

Fields

Modifier and Type	Field	Description
protected String	_name	TimeSlot name
protected String	_uid	Instance identifier

Method Summary

Modifier and Type	Method	Description
void	free()	Frees the TimeSlot that can be obtained by other tasks
String	getName()	Retrieves the name of the TimeSlot
String	getUID()	Retrieves the instance identifier
void	hold(long secs)	Allows to prolong or reduce the duration of the TimeSlot that we have in charge.
static TimeSlot	lockTimeSlot(String name, long secs)	Requests an instance of the TimeSlot.
static TimeSlot	lockTimeSlot(String name, long secs, boolean autoHold)	Requests an instance of the TimeSlot.
String	toString()	Returns a String representation of the TimeSlot

Methods inherited from class java.lang.Object

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

Field Details

_name

protected String _name

TimeSlot name

_uid

protected String _uid

Instance identifier

Method Details

getUID

public String getUID()

Retrieves the instance identifier

Returns:

The string that represent the instance identifier

getName

public String getName()

Retrieves the name of the TimeSlot

Returns:

The string that represent the name of the TimeSlot

lockTimeSlot

public static TimeSlot lockTimeSlot(String name,
 long secs)
                             throws DAException

Requests an instance of the TimeSlot. The instance remain valid from the moment it is obtained for the duration specified in the second parameter.

Parameters:

name - The name of the TimeSlot. Tasks that uses the same TimeSlot name must implement a collision management technique

secs - The length, in seconds, of the validity of the requested timeslot

Returns:

The requested TimeSlot, or null if the specific TimeSlot is already occupied

Throws:

DAException - The exception is raised if there is a database access error

lockTimeSlot

public static TimeSlot lockTimeSlot(String name,
 long secs,
 boolean autoHold)
                             throws DAException

Requests an instance of the TimeSlot. The instance remain valid from the moment it is obtained for the duration specified in the second parameter.

Parameters:

name - The name of the TimeSlot. Tasks that uses the same TimeSlot name must implement a collision management technique

secs - The length, in seconds, of the validity of the requested timeslot

autoHold - true to set the renew value (equals to the validity value), false to set it to 0

Returns:

The requested TimeSlot, or null if the specific TimeSlot is already occupied

Throws:

DAException - The exception is raised if there is a database access error

hold

public void hold(long secs)
          throws DAException

Allows to prolong or reduce the duration of the TimeSlot that we have in charge. If the TimeSlot is not loaded (for example because another parallel task has taken over it), it will be raised an exception that interrupts the task.

Parameters:

secs - The new duration of the TimeSlot, in second, from the current moment

Throws:

DAException - The exception is raised if there is a database access error or in case that another Task has the possession of the TimeSlot

free

public void free()

Frees the TimeSlot that can be obtained by other tasks

toString

public String toString()

Returns a String representation of the TimeSlot

Overrides:

toString in class Object

Returns:

A string representation of the TimeSlot formatted as 'TimeSlot[name / id]';