Section: New Results

Optimized Distribution of Synchronous Programs via a Polychronous Model

Participants : Ke Sun, Jean-Pierre Talpin, Thierry Gautier, Loïc Besnard.

We propose a distribution methodology for synchronous programs [18] , applied in particular on programs written in the Quartz language (The Synchronous Programming Language Quartz. K. Schneider, Technical Report n. 375. University of Kaiserslautern, 2009). The given program is first transformed into an intermediate model of guarded actions. After user-specified partitioning, the generated sub-models are transformed into equivalent Signal processes [7] . Then, the unnecessary constraints are eliminated from the processes to avoid unnecessary synchronization. Finally, within the Signal framework, the minimal frequencies of communication and computation are computed via multi-clock calculation. This operation can efficiently reduce the communication quantity and the computation load, with no change to the interface behaviors. Along this way, an optimized data-flow network over desynchronized processing locations can be constructed.

The presented methodology has been implemented within the integrated framework Quartz/Averest + Signal/Polychrony. To illustrate and validate this methodology, a series of examples served as case studies. Each of them has been written in the Quartz language and distributed over different processing locations using the presented optimization methodology. These case studies confirm that the optimization can bring in significant communication reduction. In the sequel, the efficient utilization of distributed systems is substantially updated.