8.2.2 State Properties

Most of the state properties are statically coded in multiple parts of the Java classes. For example, the property of default states are implemented in these functions:

• The initModel function changes the state of the model to its default leaf states. Those default leaf states are computed statically. For example, if states number 4 and 6 are the default leaf states, the following statements are statically coded in function initModel: addInState(4); addInState(6). Method private boolean addInState(int s) simply adds a state to the current state list of the model. If the model is already in state s, the function returns false. Since the current state list of the model is empty when it is being initialized, this function always returns true when invoked by initModel.

• The default states are statically coded in function changeState, which changes the model from one state to another. If the new state is not a leaf state or it is orthogonal to other states in the path from the $Common(SRC,DES)$ to the $DES$ of the transition, default leaf states are generated according to the model structure. SCC invokes the SVM simulator to decide those default leaf states as if the model were being simulated. The default leaf states which need to be added for each transition do not vary in different simulations or executions.

State properties concerning transition priorities ([ITF], OTF and RTO) are statically interpreted. The transitions are sorted according to the algorithm in section 2.2.5. Those transitions are coded in the Java classes in the same order with a switch-case structure. The first enabled transition at run-time is always the one with the highest total priority. This sorting of a submodel's transitions does not vary, because the importing model is not allowed to modify its global option InnerTransitionFirst (which is default to 0).

Orthogonal components are also statically coded in the classes. For a transition going out of an orthogonal component, code is generated to eliminate all other orthogonal components of the same parent. For a transition going into an orthogonal component, the default leaf states of other orthogonal components of the same parent are added to the current state list. SCC hard-codes this information in the Java code to improve performance.