All the flowchart modules in ARENALib have been developed as coupled Parallel DEVS models, and implemented using the SIMANLib library.
The data modules correspond to SIMANLib elements, including the Resource module that has been composed using the Resource element and a Counter block.
The documentation of each module describes its characteristics and implementation details.
As Parallel DEVS models, the ARENALib modules communicate using a message passing mechanism. Like in the SIMANLib library, a message represents a transmitted entity.
ARENALib uses the standard message structure defined in DEVSLib. The message contains two variables: a Type and a Value.
The Type represents the type of the entity that is being transmitted.
The Value represents the reference to the dynamic memory space where the entity is stored.
Due to the necessity of knowing the references of the transmitted entities to set up some module parameters (i.e. the parameters that depend on the value of an entity attribute),
each flowchart module includes a variable called e (or ein and eout, in some modules).
That variable stores the reference to the last entity that left the module. In the case of ein variables, it corresponds to the last entity that entered the module.
This variables can be used as parameters of the aget, and eget functions, in order to know the value of an attribute or field of an entity.