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11.3.7 BroadcastSignalAction




    InvocationAction (from BasicActions ) on page 267


   BroadcastSignalAction is an action that transmits a signal instance to all the potential target objects in the system, which may cause the firing of a state machine transitions or the execution of associated activities of a target object. The argument values are available to the execution of associated behaviors. The requestor continues execution immediately after the signals are sent out. It does not wait for receipt. Any reply messages are ignored and are not transmitted to the requestor.


   No additional attributes


   • signal: Signal [1] The specification of signal object transmitted to the target objects.


   [1] The number and order of argument pins must be the same as the number and order of attributes in the signal.

   [2] The type, ordering, and multiplicity of an argument pin must be the same as the corresponding attribute of the signal.


   When all the prerequisites of the action execution are satisfied, a signal object is generated from the argument values according to signal and this signal object is transmitted concurrently to each of the implicit broadcast target objects in the system. The manner of identifying the set of objects that are broadcast targets is a semantic variation point and may be limited to some subset of all the objects that exist. There is no restriction on the location of target objects. The manner of transmitting the signal object, the amount of time required to transmit it, the order in which the transmissions reach the various target objects, and the path for reaching the target objects are undefined.

   [1] When a transmission arrives at a target object, it may invoke a behavior in the target object. The effect of receiving such transmission is specified in Chapter 13, Common Behaviors. Such effects include executing activities and firing state machine transitions.

   [2] A broadcast signal action receives no reply from the invoked behavior; any attempted reply is simply ignored, and no transmission is performed to the requestor.

*Semantic Variation Points

   The determination of the set of broadcast target objects is a semantic variation point.


   No specific notation

   Sends a signal to a set of system defined target objects.

*Changes from previous UML

   Same as UML 1.5.