The event model provides the classes to describe the BTF-Events that can be used for the tracing configuration, for the modeling of event chains and for some timing constraints.
There are different event classes for the different entity types that can be traced:
| Entity | Event Class |
|---|---|
| Process (Task, ISR) | ProcessEvent |
| Stimulus | StimulusEvent |
| Runnable | RunnableEvent |
| Label | LabelEvent |
| Semaphore | SemaphoreEvent |
In a running system, each entity can have different states. An event trace consists of the events that are visualizing the state-transitions of the traced entities. To define such an event in the model, each kind of event class contains an event-type-enumeration that provides the event-types for the state-transitions of its entity. The following picture shows the possible states of a process:
So for example the event-type-enumeration for a process event contains the events activate, start, resume, ...
If it is required to define an event like "start-event of some process" then it is enough to create a object of type ProcessEvent and set the event-type start.
It is also possible to restrict the definition of an event to a special entity. So it can be defined like “start-event of task T_1”. Therefore it is possible to reference a process from ProcessEvent. In general, each event class can reference an entity of the corresponding type. In addition to that, each event class provides individual restrictions. So it is possible for ProcessEvent that the event is not only restricted to a special process, it can be also restricted to a core. So that would be like “start-event of task T_1 on core C_2”. Another example is the class RunnableEvent, it allows to restrict the event to a runnable, the process that executes the runnable and the core that executes the process.