1. OMG Issue

UML14 — Events, signals, stimuli, etc.

  • Key: UML14-56
  • Legacy Issue Number: 4263
  • Status: closed  
  • Source: Ecole Polytechnique Federale de Lausanne ( Shane Sendall)
  • Summary:

    Here is my understanding of communication between instances on an
    example (all quotes are from UML 1.4 draft (Feb 2001) of the spec).
    An instance i1 performs a SendAction, according to the spec: "A send
    action is an action that results in the (asynchronous) sending of a
    signal". Then, the signal is delivered to say instance i2, and as a
    consequence of the receipt, a SignalEvent is generated (according to the
    spec, "A signal event represents the RECEPTION of a particular
    (asynchronous) signal")
    Now the problems:
    1) the spec goes on further to say about the signal event that "A signal
    instance should not be confused with the action (e.g., send action) that
    generated it". The problem I have with my above understanding is that
    the send action should not be the one generating the send event but
    rather the reception of the signal should be the one generating it.
    2)According to the spec: "A signal is a specification of an asynchronous
    stimulus communicated between instances" where a stimulus is more
    general "In the metamodel Stimulus is a communication, i.e. a Signal
    sent to an Instance, or an invocation of an Operation". Thus, I conclude
    that the things sent between instances are stimuli.
    However, I'm a little confused of the relationship between events and
    stimuli with the following sentence taken from the spec "Event instances
    are generated as a result of some action either within the system or in
    the environment surrounding the system. An event is then conveyed to one
    or more targets. The means by which event instances are transported to
    their destination depend on the type of action, the target,..."
    Furthermore, how are stimuli and signals related in the metamodel?

  • Reported: UML 1.3 — Tue, 10 Apr 2001 04:00 GMT
  • Disposition: Resolved — UML 1.4.2
  • Disposition Summary:

    No Data Available

  • Updated: Fri, 6 Mar 2015 20:58 GMT