UML24 — DecisionNode at all guards evaluated to false

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?

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