Modules
Overview
System Models for Free (SMFF) is a tool for pseudo-random generation of models of realtime systems. Such models include a description of a platform as a platform graph and a description of the software running on this platform. The model may furthermore include a mapping of the application to the platform to denote which software module is executed on which part of the platform. Additionally SMFF provides means to model timing properties. The standard way of modelling timing in SMFF is with period and jitter (P,J) and best-case and worst-case execution times (BCET, WCET). Constraints on timing can be expressed e.g. in the form of end-to-end path latency constraints. Each software module may be associated with scheduling parameters. This description specifies the realtime behavior of the system.
Many algorithms for scheduling, allocation or optimization of realtime systems rely on heuristics, as the underlying problems are NP-hard. When evaluating the performance of such heuristics usually a large number of testcases, that cover a variety of topologies and load scenarios are required. Especially in the academic domain testcase systems are usually not available in large numbers.
As a result researchers perform smaller case studies or use custom simulation environments. In either case the results may be hard to verify and to reproduce. SMFF aims to fill this gap and to provide a publicly available testcase generation platform. As requirements to the generated test systems may differ between different application domains, SMFF allows to extend the system model and the process of testcase generation.
Task Graphs for free (TGFF) is a tool for generation of task graphs that are to be used as testcases. TGFF was developed by the University of York in 1998. It covers only one aspect of testcase generation - the application generation. Other steps of the generation process (platform generation, mapping, assignment of scheduling parameters) are not covered. Thus it provides a subset of the functionality of SMFF. In fact the standard application factory shipped with SMFF builds upon TGFF.
Note, that SMFF and TGFF are two different projects developed by different teams.