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  1. OMG Issue

UML14 — UML RTF 1.4 Issue: Deferred event ambiguity

  • Key: UML14-989
  • Legacy Issue Number: 3277
  • Status: closed  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    What happens when a event is defered in one region, but not another? Is
    it left on the queue accessible to both regions, even if it has already
    been consumed by one of the regions? Semantics says deferred events are
    kept if not used in one of the regions. So if one region uses it, it is
    lost, even if it is deferred in the other region. User cannot use event
    in both regions.

    Reference manual says:

    At the time that an object processes an event, it may be in one or more
    concurrent states. Each state receives a separate copy of the event and
    acts on it independently. Transitions in concurrent states fire
    independently. One substate can change without affecting the others,
    except on a fork or join caused by a complex transition (described
    later).[p 443, Reference Manual]

    and refers to an internal queue of events:

    Deferred events. A list of events whose occurrence in the state
    is postponed until a state in which they are not deferred becomes
    active, at which time they occur and may trigger transitions in
    that state as if they had just occurred. The implementation of
    such deferred events would involve an internal queue of
    events. [p 438]

  • Reported: UML 1.2 — Sat, 5 Feb 2000 05:00 GMT
  • Disposition: Resolved — UML 1.3
  • Disposition Summary:


  • Updated: Fri, 6 Mar 2015 21:37 GMT