4.3.3 Global Options

Global options of a model are specified under the OPTIONS descriptor. Currently, three global options are supported:

• The ModelName global option specifies the name of the model. By default, the model name is the file name that contains the model description with the .des postfix removed. Designers are allowed to explicitly define model names with this option. Other models use the model name as an ID to locate the model and establish connections to it.

• Harel global option specifies whether the simulator should strictly obey David Harel's statecharts semantics and DCharts 1.0, or use alternate algorithms in the simulation (refer to section 2.3.2). By default Harel is equal to 1, which means SVM strictly follows David Harel's statecharts algorithm, and hence it can also be used as a statecharts simulator. When Harel = 1, the following different points are made:
  1. The alternate algorithm is used to fire all the transitions, which is different from David Harel's algorithm.

  2. Self-loops are not considered as state changes. For example, a transition with $SRC=DES$ does not cause the exit actions or the enter actions of the state to be executed. This is because the algorithm uses $CCS_{alt}(SRC,DES)$ rather than $CCS(SRC,DES)$ to compute the closest common state.

  3. Because self-loops are not state changes, timed transitions are by default once time transitions, unless the model design explicitly assigns the [RTT] (Repeated Timed Transition) property to them.

• InnerTransitionFirst global option specifies whether the model follows the inner-transition-first convention or the outer-transition-first convention. This option affects all the top-level states so that their default behavior conforms to this setting. For example, having InnerTransitionFirst = 1, all the top-level states get the [ITF] property by default, and their substates inherit this behavior by default. However, this default behavior can always be modified with an explicit [ITF], [OTF] or [RTO] property for a state. InnerTransitionFirst = 1 is just a short-hand notation for specifying [ITF] for every top-level state.

  The default value of InnerTransitionFirst is set to 0, which means all the top-level states are outer-transition-first (according to the STATEMATE semantics [5] of David Harel).

The above options are global in the scope of the whole model. They cannot be imported with submodels. When a submodel is imported, its global options are ignored.