A concurrent reactive Esterel processor based on multi-threading

The synchronous language Esterel is well-suited for programming control-dominated reac-tive systems at the system level. It provides non-traditional control structures, in particular concurrency and various forms of preemption, which allow to concisely express reactive behav-ior. As these control structures cannot be mapped easily onto traditional, sequential processors, an alternative approach that has emerged recently makes use of special-purpose reactive pro-cessors. However, the designs proposed so far have limitations regarding completeness of the language support, and did not really take advantage of compile-time knowledge to optimize resource usage. This paper presents a reactive processor, the Kiel Esterel Processor 3a (KEP3a), and its compiler. The KEP3a improves on earlier designs in several areas; most notable are the support for exception handling and the provision of context-dependent preemption handling instruc-tions. The KEP3a compiler presented here is to our knowledge the first for multi-threaded reactive processors. The translation of Esterel’s preemption constructs onto KEP3a assembler is straightforward; however, a challenge is the correct and efficient representation of Esterel’