Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content SysML Activity extension stereotypes - REFERENCE CARD Source OMG Systems Modeling Language (SysML) 1.6 Copyright information About Object Management Group copyright in text extracts quoted from OMG specifications for educational purposes Snippet kind INFO UML keywords ObjectNode MultiplicityElement::/upper SysML keywords Overwrite «overwrite» Previous snippet Full quote When the «overwrite» stereotype is applied to object nodes, a token arriving at a full object node removes one that is already there before being added (a full object node has as many tokens as allowed by its upper bound). Next snippet This is typically used on an input pin with an upper bound of 1 to ensure that stale data is overridden at an input pin. Related snippets When the «nobuffer» stereotype is applied to object nodes, tokens arriving at the node are discarded if they are refused by outgoing edges, or refused by actions for object nodes that are input pins. For object nodes that are the target of continuous flows, «nobuffer» and «overwrite» have the same effect. Related snippets (backlinks) This is typically used on an input pin with an upper bound of 1 to ensure that stale data is overridden at an input pin. For upper bounds greater than one, the token removed is the one that has been in the object node the longest. For FIFO ordering, this is the token that is next to be selected, for LIFO it is the token that would be last to be selected. Tokens arriving at a full object node with the Overwrite stereotype applied take up their positions in the ordering as normal, if any. The arriving tokens do not take the positions of the removed tokens. A null token removes all the tokens already there. The number of tokens replaced is equal to the weight of the incoming edge, which defaults to 1. For object nodes that are the target of continuous flows, «overwrite» and «nobuffer» have the same effect. The stereotype does not override UML token offering semantics, just indicates what happens to the token when it is accepted. When the stereotype is not applied, the semantics is as in UML, specifically, tokens arriving at object nodes do not replace ... Visit also Visit also (backlinks) Flags
