edu.utah.janosvm.sys
Class ExportManager

java.lang.Object
  |
  +--edu.utah.janosvm.sys.ExportManager

public final class ExportManager

extends java.lang.Object

Tracks the {@linkplain Importable importables} associated with a single {@linkplain Exportable exportable}. Each ExportManager is associated with exactly one Exportable. An exportable may have multiple managers (if it is exported under mutliple names, for example).

An ExportManager tracks the links between an exported object and its imports. This is required so that we can revoke any references when a team dies or the export is no longer available to other teams.

Author:

Tim Stack, Utah Janos Team

See Also:

Importable, Exportable

Inner Class Summary

class

ExportManager.ImportEnumerator The ImportEnumerator is used to traverse the list of importers of an export.

Field Summary

private Exportable	export The object being exported.
private List	importers List of objects importing our managed object.
private TeamBackEnd	owner The team that owns the objects managed by this ExportManager.

Constructor Summary

(package private)	ExportManager() Construct an empty manager.
(package private)	ExportManager(Exportable export) Construct a manager that is exporting the given object.

Method Summary

void	addImporter(Importable im) Add an Importable to the list of objects importing our export.
(package private) void	cancelImports() Disconnect all of the importers of our export.
ExportManager.ImportEnumerator	getEnumerator()
Exportable	getExport() Get the object that this manager manages.
(package private) TeamBackEnd	getOwner()
ExportManager.ImportEnumerator	imports() Similar to the above except that it constructs a new ImportEnumerator and adds that to the list.
boolean	imports(ExportManager.ImportEnumerator ie) Setup the given ImportEnumerator to traverse the importers list.
(package private) boolean	remImporter(Importable im) Remove an importer from the list of objects importing our export.
void	setExport(Exportable ex) If this manager is empty you can fill in its export with this function.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait, wait0

Field Detail

owner

private final TeamBackEnd owner

The team that owns the objects managed by this ExportManager.

export

private Exportable export

The object being exported.

importers

private final List importers

List of objects importing our managed object.

Constructor Detail

ExportManager

ExportManager(Exportable export)

Construct a manager that is exporting the given object.

Parameters:

export - The exported object this object should manage.

ExportManager

ExportManager()

Construct an empty manager.

Method Detail

getOwner

TeamBackEnd getOwner()

Returns:

The owner of the exported object.

setExport

public void setExport(Exportable ex)

If this manager is empty you can fill in its export with this function. Silently ignores you if this manager already has an exported object.

Parameters:

ex - The exported object to be managed.

Throws:

Throws - a NullPointerException if ex is null.

getExport

public Exportable getExport()

Get the object that this manager manages.

Returns:

The object that is being exported.

addImporter

public void addImporter(Importable im)

Add an Importable to the list of objects importing our export.

Parameters:

im - The Importable that wants a reference to our export.

remImporter

boolean remImporter(Importable im)

Remove an importer from the list of objects importing our export.

Parameters:

im - The Importable to remove.

Returns:

True if this was the last importer of a TemporaryExport, false otherwise.

cancelImports

void cancelImports()

Disconnect all of the importers of our export.

getEnumerator

public ExportManager.ImportEnumerator getEnumerator()

Returns:

An ImportEnumerator for this ExportManager.

imports

public boolean imports(ExportManager.ImportEnumerator ie)

Setup the given ImportEnumerator to traverse the importers list.

Parameters:

ie - The ImportEnumerator that will be inserted into the importers list.

Returns:

True if this manager is still valid and its importers can be traversed, false otherwise.

imports

public ExportManager.ImportEnumerator imports()

Similar to the above except that it constructs a new ImportEnumerator and adds that to the list.

Returns:

A new ImportEnumerator ready to traverse the list or NULL if this manager is invalid.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object