com.nt.udc.util.state

Class StateFreezer

java.lang.Object

com.nt.udc.util.state.StateFreezer

All Implemented Interfaces:

IntegerCallback

public class StateFreezer
extends java.lang.Object
implements IntegerCallback

This class is responsible for freezing the state of the appropriately registered StateFreezable Objects. Once the Objects have been frozen, other routines may be run with the guarantee that all data processing has been halted. Typically, there will be at least one Object per running thread that drives the processing, and needs to be frozen. As an example, if the state of a node needs saving, then all running threads must be frozen so that the relavent can be written to disk.

Constructor Summary

Constructors

Constructor and Description
StateFreezer(LoggerIfc logger) Creates a StateFreezer Object.

Method Summary

Modifier and Type	Method and Description
void	callback(int id) The callback method for the "freezeObjects()" method.
void	freezeObjects() This method freezes all the registered "active" objects.
void	manageActiveObject(StateFreezable activeObject) Manages a single active Object.
void	unfreezeObjects() This method unfreezes all the registered "active" objects.

Methods inherited from class java.lang.Object

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

Constructor Detail

StateFreezer

public StateFreezer(LoggerIfc logger)

Creates a StateFreezer Object.

Parameters:

logger - Logger for errors and warnings.

Method Detail

manageActiveObject

public void manageActiveObject(StateFreezable activeObject)

Manages a single active Object. This Object will be told to freeze before all state saving routines occur. Note that using this method implies that there are **NO** order dependencies related to the given Object.

Parameters:

activeObject - Object to be frozen during state save

freezeObjects

public void freezeObjects()
                   throws StateException

This method freezes all the registered "active" objects.

Throws:

StateException

callback

public void callback(int id)

The callback method for the "freezeObjects()" method.

Specified by:

callback in interface IntegerCallback

Parameters:

id - The id of the element calling back.

unfreezeObjects

public void unfreezeObjects()
                     throws StateException

This method unfreezes all the registered "active" objects.

Throws:

StateException