Synchronous External Entity Operation - modelint/shlaer-mellor-metamodel GitHub Wiki

A synchronous external entity operation corresponds to the bridge operation defined in [MB] .

In [EE] A Synchronous interaction blocks further execution of the invoking activity until the interaction is completed.

In the Elevator Case Study, for example, there is a need to determine immediately whether a moving Cabin can stop at a given floor. The Synchronous Stop here Operation makes it possible to obtain an immediate yes-no answer.

It looks like this in Scrall:

stop possible = CABIN.Stop here( destination : requested floor )

In this example, the assignment action blocks until a boolean value is returned with the destination recomputed in the Transport domain in the case of a returned true value.

Also pointed out in [EE]: The time nature of an interaction, i.e. whether itโ€™s synchronous or asynchronous, is strictly from the viewpoint of the invoking domain. The implementation is free to use any technique to implement the interaction as long as the viewpoint of the invoking domain is maintained. So, synchronous interactions may be implemented by asynchronous implementation mechanisms as long as the expected perception by the invoking domain is maintained.

Identifier

  1. ID + Domain
  2. Name + EE + Domain

Attributes

No non-referential attributes