Sequence diagrams can add execution occurrence to lifelines to control the start and finish behavior or flow of interactions to develop interactions for C/C++ applications..
You can nest execution occurrences to indicate nested behavior in a call sequence. A nested execution occurrence overlaps an existing execution occurrence, and enables you to distinguish exactly where the activity associated with each message starts and finishes.
Creating execution occurrences
In Unified Modeling Language (UML) sequence diagrams, an execution occurrence is created automatically when you create a synchronous or an asynchronous message on a lifeline. You can also manually create an execution occurrence to show the start and finish behavior in an interaction.Resizing and reordering execution occurrences
In Unified Modeling Language (UML) sequence diagrams, an execution occurrence automatically resizes vertically to indicate the time during which a participant is active. The top of the execution occurrence aligns at the point where the message is received and initiates the behavior; the bottom aligns with the finish of the behavior during an interaction. If you resize the execution occurrence across any messages and fragments, the execution occurrence reorders in the interaction.
Parent topic: Developing behavioral features of C/C++ applications with UML sequence diagrams
Related concepts
Execution occurrences