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  1. OMG Issue

UML24 — DecisionNode at all guards evaluated to false

  • Key: UML24-109
  • Legacy Issue Number: 15708
  • Status: closed  
  • Source: ( Stephan Grund)
  • Summary:

    DecisionNode's behaviour when a token cannot pass any edge at the moment it arrives and the guards are evaluated is not specified.
    When will the guards be evaluated next time?

  • Reported: UML 2.3 — Thu, 7 Oct 2010 04:00 GMT
  • Disposition: Resolved — UML 2.4
  • Disposition Summary:

    This is covered in the UML 2.5 beta specification in Subclause 15.3.3 under “Decision Nodes”. The specification
    states: “If any of the outgoing edges of a DecisionNode have guards, then these are evaluated for each incoming
    token.” and “A token offered on the primary incoming edge of a DecisionNode shall not traverse any outgoing edge
    for which the guard evaluates to false.” So, if no guards evaluate to true, the token will not traverse any of the outgoing
    edges. The next time the guards are evaluated is when the next token is offered to the DecisionNode.
    Disposition: Closed - No Change

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