Database Reference
In-Depth Information
Figure 6: Constraint violation
However, its function is very important to meta-modeling; the user does not want to wait
to catch syntax errors in her constraints until a constraint is checked in the target environ-
ment. Therefore, we provide an add-on to the meta-modeling environment that checks the
OCL syntax of the constraint that is currently being edited. The OCL expression is a textual
attribute of the constraint object. The OCL syntax checker add-on is registered to catch
attribute change events. Whenever it is fi red it parses the OCL expression and provides
immediate feedback to the user.
As do most meaningful modeling paradigms, the meta-modeling environment has its
own interpreter. It parses all the class diagrams (in the HFSM case there is only a single
one) and generates an XML representation of the modeling language. GME can read this
fi le and confi gure itself to support the new language. Figure 5 shows an example model
captured in the resulting HFSM modeling environment.
The name of the modeling language is shown in the lower right corner again. Notice
that the only part shown in the part browser is State and the only aspect is Main. The attribute
window shows the GuardCondition attribute of one of the transitions. Our simple HFSM
environment uses the standard, built-in decorator that is able to display boxes, icons, names,
etc. Notice that the state Second has two substates with the same name “A”. When trying to
close the model or explicitly requesting constraint checking, the violation is caught by the
constraint manager. The error message displayed is shown in Figure 6.
PRACTICAL APPLICATIONS
Three practical applications of GME are presented below:
MILAN
, the Model-based Integrated simuLAtioN framework, is a GME-based
extensible environment that facilitates rapid evaluation of different performance metrics,
such as power, latency and throughput, at multiple levels of granularity, of a large class of
embedded systems by seamlessly integrating different widely-used simulators into a uni-
fi ed environment (Ledeczi, Davis, Neema & Agrawal, 2003). The MILAN framework is
aimed at the design of embedded high-performance computing platforms, of System-on-
Chip (SoC) architectures for embedded systems, and for the hardware/software co-design
of heterogeneous systems.
MILAN provides an integrated environment where existing development and analysis
tools, primarily simulators, can work seamlessly together. MILAN defi nes an integrated
