VisualUL - Modeling

Modeling

Extending classes
The first thing to do is to define classes. This is done by extending primitive classes or your own classes. When the user clicks on a class in the class hierarchy (fig. 1), he will have the the corresponding class in the main panel and the possibility to extend this class by using the popup menu (fig. 2) of the class or the extend button in of the tool bar (fig. 3).

figure 1 : class hierarchy panel figure 2 : class popup

figure 3 : concurrent process toolbar with the extend button

The classes Process and SuperState have different enabled buttons, but the principle is the same.

Composing your system
Inside your composite object, you may add states and transitions (SuperState and Process objects), and other classes with respect to the composition rules given in the introduction to UL⁺⁺ . This is done with the compose button, to the left of the extend button. If you try a forbidden composition, then you will get an error message. The composition may be forbidden for two reasons:

you have violated the basic composition rules
you have created a cycle in the composition (you put for example a superstate of type A inside a superstate of type B, which has already a superstate of type A).

When you click on the classes, the buttons are updated, so that you know what you are allowed to do. If you activate the tooltip option in the Options menu, you will get the function of each button.

The virtual state concept
A virtual state is a state, a superstate or an entry, exit on a superstate. This abstraction allows us to simplify the transition and connection definitions : a transition is defined between two virtual states and a connective is defined on a virtual state. When you are editing a superstate class, then you may define entry and exits on such virtual states. In a process you may define one initial state (requested for the instanciation) to a virtual state. You have to be carefull when dealing with connectives (entries and exits) because something is always to an entry and from an exit.

Instanciating your system
This is done by pressing the instanciate button in the popup menu of your system definition, in our example, called fischer. You have to put one component there, it is like the system has one composite object as a member. The instanciation may fail if you do not have an initial state in every process, or a connective is missing... appropriate message will warn you.
Once you have your instance, you may navigate through your system by two means :

you may double click with the left button of your mouse on a composite object to open it in a separate window. You will seen in the separate window the local data variables.
you may double click with the middle button of your mouse on a composite object to open itself in a nested panel.

Then you may visualize the instance representation by clicking on Show which will open a window with the ULi (UL instance) textual representation. You may also flatten the model, which breaks the hierarchy, resolves the connections with entries/exits and transforms value passing with channels to a simple channel synchronization with a shared variable as a buffer. You flatten your system by pressing the Flatten button in the file menu of the instance window (fig. 4). Then, you may save your system in different formats, as shown in fig. 5.


figure 4 : file menu before flattening	figure 5 : file menu after flattening

These options are only available in the first (root) instance window, since it contains the system definition. The other windows, when opening a sub component are the same but do not have these functionalities.
The different functions available are :

ta : translation to UPPAAL ta format. This concerns the last version of UPPAAL with local variables.
gta : translation to a graphical/textual format used in some prototypes of a new gui for UPPAAL.
xta : translation to extended UPPAAL language, which will be released in November of December with the editor and the simulator. This new GUI is the target of xta format.

We conclude this short introduction by two overviews : the class editor window and the instance window.

class editor window overview

instance window overview

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