FUML 1.5 RTF Avatar
  1. OMG Issue

FUML15 — The fUML threading model should be made explicit

  • Key: FUML15-11
  • Status: open  
  • Source: Model Driven Solutions ( Ed Seidewitz)
  • Summary:

    Subclause 8.9.1 of the fUML 1.4 speification describes the "threading model" for concurrent execution of actions within an activity. Currently, this is an "implicit" threading model, in the sense that a "thread" is simply a sequence of operation calls between action activation objects. There is no explicit class in the execution model that represents such a "thread" (as opposed to, for example, the explicit model for the execution of a behavior).

    While this is sufficient for the purposes of defining the semantics of activities as currently defined in fUML, it can be problematic in some cases for building additional semantics on this foundation. For example, in order to define the semantics of timing of execution within an activity (as required to respond to the currently open Precise Semantics of Time RFP), it would be very helpful to have a reified model of threads to which time semantics could be attached. This would also simply the current modeling of suspension and resumption of threads due to accept event actions.

    So, while a refactoring of the fUML execution model to introduce an explicit threading model would not introduce any functional change to fUML itself, it would allow fUML to be a better foundation on which to build other precise semantics standards.

  • Reported: FUML 1.4b1 — Sat, 1 Dec 2018 21:08 GMT
  • Updated: Sun, 2 Dec 2018 12:46 GMT