Four issues concerning the semantics of Message Flow Graphs

We discuss four issues concerning the semantics of Message Flow Graphs (MFGs). MFGs are extensively used as pictures of message-passing behavior. One type of MFG, Message Sequence Chart (MSC) is ITU Standard Z.120. We require that a system described by an MFG has global states with respect to its message-passing behavior, with transitions betweenthese states e ectedby atomicmessage-passing actions. Underthis assumption, weargue (a) that the collectionof global messagestates de ned by an MFG is nite (whether for synchronous, asynchronous, or partially-asynchronous message-passing); (b) that the unrestricted use of `conditions' requires processes to keep control history variables of potentially unbounded size; (c) that allowing `crossing' messages of the same type implies certain properties of the environment that are neither explicit nor desirable, and (d) that liveness properties of MFGs are more easily expressed by temporal logic formulas over the control states than by Buc...

• Type: Conference
• Year: 1994
• Where: FORTE
• Authors: Peter B. Ladkin, Stefan Leue
• Keywords: FORTE 1994, FORTE 2007, Message Flow Graphs, Message-passing Behavior, Transitions Betweenthese States