SysML 1.7 RTF Avatar
  1. OMG Issue

SYSML17 — The NoBuffer specification makes a wrong statement about the UML semantics

  • Key: SYSML17-492
  • Status: closed  
  • Source: Airbus Group ( Mr. Yves Bernard)
  • Summary:

    The sentence that says: “When the stereotype is not applied, the semantics are as in UML, specifically, tokens arriving at an object node that are refused by outgoing edges, or action for input pins, are held until they can leave the object node” is false. This is not the semantics UML specifies. Buffering is provided only for token satisfying the guard but that are not numerous enough to satisfy the “weight” condition.

  • Reported: SysML 1.6 — Wed, 6 Oct 2021 15:25 GMT
  • Disposition: Resolved — SysML 1.7
  • Disposition Summary:

    The sentence is correct, but restates UML semantics.

    The sentence is correct. Buffering of tokens in Pins is possible in UML. The weight is not the only reason, why the outgoing ObjectFlow might refuse to accept tokens. If the guard is not satisfied, tokens are not discarded but buffered.

    However, the second part of the sentence restates UML semantics. In terms of a clean separation of the specifications UML and SysML, the second part is removed and the sentence is changed to "When the stereotype is not applied, the semantics are as in UML."

  • Updated: Thu, 22 Dec 2022 13:45 GMT