The model execution kernel of a real-time software prototyping environment: Master's thesis

Execution techniques for Ward and Mellor's Structured Analysis for Real-Time Systems (SA/RT) software models are studied in the framework of the IPTES prototyping environment. IPTES is an acronym for "Incremental Prototyping Technology for Embedded real-time Systems". SA/RT model execution in the IPTES environment is based on the High-Level Timed Petri Net Kernel (HLTPNK). The kernel has no direct visibility to the user but rather provides an internal framework to be used for model execution. The kernel is built upon a mathematically well-defined formalism, High-Level Timed Petri Nets (HLTPN). The overall function of the HLTPNK is to provide facilities for the configuration, manipulation, and execution of system models expressed with High-Level Timed Petri Nets. An experimental High-Level Timed Petri Net Kernel is designed using object-oriented design techniques. The design is validated by graphical animation. For visual prototyping of the kernel, a dynamic object instantiation technique is developed for Wassemmann's Object-Oriented Structured Design (OOSD). The developed technique provides a basis for graphical animation not only for the HLTPNK model but for other large object-oriented models as well. A prototype implementation of the HLTPNK is developed using the C++ language. The prototype is used in evaluating the performance and timing aspects of the kernel. On the basis of the performance measurements and analysis, the implementation is tuned to support high-speed execution of HLTPN mapped from the SA/RT model. For the kernel execution, a user interface is developed enabling the progress of the execution of models to be monitored. Both the executable design model and the implementation of the HLTPNK provide a platform for further development of the IPTES prototyping environment. The kernel provides an open platform for further research of scheduling algorithms, distribution protocols, and code generation.