Using the Lime Console

When the Lime console is generated, the following window is displayed on the screen:

A major portion of the console is occupied by the message area, where brief notifications of the operations performed are displayed. The lower area mirrors most of the operations available on the Lime tuple space associated with the console, namely:

Access operations

out inserts a tuple in the Lime tuple space.
outg inserts a set of tuples into the Lime tuple space.
in withdraws a tuple from the Lime tuple space, and blocks if no tuple is found.
rd reads a tuple from the Lime tuple space, and blocks if no tuple is found.
inp withdraws a tuple from the Lime tuple space, returning null if the tuple is not found.
rdp reads a tuple from the Lime tuple space, returning null if the tuple is not found.
ing Removes all tuples matching a specific pattern from the Lime tuple space, returning null if the tuple is not found.
rdg reads all matching tuples from the Lime tuple space, returning null if none are found.
go sends a mobile agent to a specified destination, if the agent is a mobileagent (as opposed to a stationary agent).
out(Hello) writes a tuple containing the string "Hello" to the tuple space. (useful for debugging)
inp(Hello) removes a tuple with the pattern "Hello" from the tuple space, returning null if none is found. (useful for debugging)
rdp(Hello) reads a tuple with the pattern "Hello" from the tuple space, returning null if none is found. (useful for debugging)

Engagement operations

Engage Tuple Space engages the Lime tuple space, i.e., allows sharing with other agents. Note: this, and the next three buttons only work if the engagement mode is set to explicit.
Disengage Tuple Space disengages the Lime tuple space, i.e., makes it private and prohibits sharing with other agents.
Engage Host engages the host. All misplaced tuples contained in shared tuple spaces will be transferred.
Disengage Host disengages the host. All the tuple spaces belonging to agents on this host will be no longer visible to the rest of the system.
Shutdown Lime Server stops the LimeServer runtime environment.

Reactive operations

Add Strong Reactions registers a set of strong reactions with the Lime tuple space.
Add Weak Reactions registers a set of weak reactions with the Lime tuple space.
Remove Weak Reactions deregisters a set of weak reactions from the Lime tuple space.
Remove Strong Reactions deregisters a set of strong reactions from the Lime tuple space.

When pressing one of the buttons for an access operation, a dialog similar to the following is displayed:

The dialog above is for an out operation. The first portion of the dialog is concerned with specifying the tuple to be written (or read/removed). The buttons Dummy Actual and Dummy Formal are provided as a convenience for testing, and insert the tuples ["Hello"] and [<java.lang.String>] respectively, where the latter is a template that matches any String.

The Clear button simply clears the contents of the textfield, while the Edit button allows for editing an arbitrary tuple and displays the following dialog:

Tuples are created field by field. Only String and Integer objects are presently supported by the console, and they can be selected using the first pull-down listbox. The second pull-down listbox determines whether the field is an actual or a formal, and the textfield allows for entering the value of the field. Additional fields can be entered by pressing the More Fields button. Tuple editing is completed by pressing the OK button, which closes the dialog and displays the content of the edited tuple in the access operation textfield.

The second portion of the dialog for the out operation above, is occupied by the specification of the destination locations for the tuple. The default choice is UNSPECIFIED, which corresponds to invoking the out(lights.interfaces.ITuple) method without specifying a location parameter. To accept this choice just press the Select button and the UNSPECIFIED value will be displayed as the value of the destination location. However, it is possible to specify an agent identifier as the destination location in two different ways:

If the desired agent is currently part of the Lime system, i.e., its tuple space is shared and its host is engaged, then choose the item Agent from the pull-down listbox and press the Select button. If there is currently only one agent in the system, the identifier of that agent will be automatically displayed in the destination location field. Otherwise, a dialog will be displayed, such as
allowing selection of an agent identifier from the list.
If the desired agent is not currently present in the Lime system, you can still output a tuple for it by pressing the Fake it! button. Given the semantics of Lime, this tuple will be a misplaced one. The Fake it! button will display the following dialog
that allows to enter an arbitrary agent identifier. Currently, the format for agent identifiers is the symbolic name of the host where the agent has been created, followed by a colon to indicate the port on which the LimeServer was launched, followed by a slash and the number of the agent (defined as an increasing number for each new additional agent starting with 0) (e.g., swarm:1973/0).

After the operation has been performed, a brief message is displayed in the message area of the console.

Similar dialogs are displayed for the other access operations. The buttons and choices available are automatically configured according to the semantics of the operations. Thus, for instance, the in operation has a richer interface

which allows the specification of a destination location where insertion of an UNSPECIFIED value is automatically prevented. On the other hand, it is possible to specify a host as the value of the current location, with steps similar to the selection of an agent described before. Thus, pressing Select will either automatically insert the field of a host, if it is the only one present in the system, or display a list of hosts present in the system. The Fake it! button allows the an agent or host not present to server as either the current or destination field of the tuple pattern, based on the value of the drop down box to the left of the Fake it! button.

The Lime console also has a go button. This button has no effect if the agent extends StationaryAgent, however if the agent is a mobile agent extending MobileAgent, go will send the interactve agent to the specified LimeServer loacation. The dialog box accepts a hostname:port specification in the following interface (note: the default port for a µCode server is 1968):

Engagement operations do not display any additional dialog boxes. They simply cause the corresponding operation to be invoked and then display a brief message in the console.

Reactive operations, on the other hand, display a dialog that is richer than the one used for access operations. The Add Strong Reactions button, for instance, displays a dialog that is similar to the following:

This dialog contains the set of reactions that will be registered with the Lime tuple space. The figure shows one. Of course, initially the list is empty. Pressing the More button generates the following additional dialog that allows the specification of one reaction at a time:

The look and feel of this dialog is similar to the one used for access operations. However, there is an additional field that allows the specifiation of the reaction listener that is associated with the reaction. The lime.util.console package provides a default listener, lime.util.console.LimeConsoleListener, whose behavior is simply to display in the message area the message Reacted to followed by the tuple the listener reacted to. This is the listener that gets selected by pressing the Default button on the dialog box. However, as explained in the documentation for LimeConsoleListener, the programmer can define subclasses of this listener that provide alternative behavior. A specific user listener can be selected using the file dialog that is displayed when the Select button is pressed. The .class containing the bytecode for the listener must be selected.

Similar dialog boxes exist for the installation of weak reactions from the Add Weak Reaction button. The most notable difference is that the UNSPECIFIED option is available as a current location for the pattern.

The Remove Weak/Strong Reaction buttons allow the user to select from the previously installed reactions the set to be disabled. From the dialog box on or more reactions can be selected:

LIME

Intro

Getting Started

Docs

Lime Community

Using the Lime Console

Access operations

Engagement operations

Reactive operations

LIME: Linda in a Mobile Environment