export-remote-symbol

Arguments: home-location symbol export-string &optional propagate

This function was changed incompatibly in release 6.2. It now has three rather than 2 required arguments (and two new optional arguments).

This function defines a mapping from symbols that name a class to a string. It returns export-string. home-location must be an instance of rpc-port or of rpc-port-server (its presence allows the generic function to behave differently on the two classes).

A local reference to a class is identified in an outgoing remote reference by a string. The default string is the "~A" representation of the class name. If an export-string is defined for the class, then the export-string is sent instead.

To avoid ambiguities or conflicts caused by package and case differences between remote images, an application can use export-remote-symbol in the sender to define unique class identifier strings and import-remote-class in the receiver to interpret these unique strings.

Method for: (rpc-port-server t t)

This method updates the table stored in the rpc-port-server instance. The table is copied to any new rpc-port instances created from the server. If the propagate argument is non-nil, then all active ports created from this server are updated as well.

Method: (rpc-port t t)

This method updates the table in the specified rpc-port instance. The propagate argument is ignored.

Example

Suppose the string "bar" is not sufficient or appropriate to identify the correct class when arriving from Image A to Image B. For example, there may be symbols pkg1::bar and pkg2::bar in image A, and an unrelated symbol pkg3::bar in image B. Image A can define a unique string that identifies the desired class bar uniquely to image B, for example "bar-from-a".

Then image A would say:

(export-remote-symbol port-to-b 'bar "bar-from-a")
(rcall 'foo (make-instance 'bar))

Image B would say:

(import-remote-class port-to-a 'far-bar "bar-from-a")

and the function foo gets the correct class instance.

See also the example in the description of import-remote-class.

See also rpc.htm for general information on the Remote Procedure Call utility in Allegro CL.

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Created 2010.1.21.