Section: New Results

Structure-Preserved Distribution of Synchronous Programs

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

We propose an automatically structure-preserved distribution method, which is based on synchronous guarded actions [50] and component calls in an intermediate representation [36] . The guarded actions describe the local behavior. The component calls preserve the modular structure information of synchronous programs. Using this method, the designer can naturally blend the distribution design into the whole system design procedure: following the modular structure, a globally asynchronous locally synchronous (GALS) network over distributed nodes can be automatically constructed. Each node corresponds to a component and contains:

• a computing element, computing (as sender) or reacting to (as receiver) scheduling commands;

• a controlling element, called adaptor, adjusting the asynchronous communication between nodes.

The computing element focuses on the functional behaviors (i.e., value computation) in synchronous runs, which can be perfectly described by synchronous guarded actions. On the other hand, the controlling element mainly considers the temporal constraints (i.e., clock relation) under asynchronous communications. Guarded actions are not suitable for specifying clock relations, then we use polychronous specifications [8] to define the inter-node communications.

A perspective for future work would be the structure-preserved distribution of synchronous programs with multi-interaction. Multiple interactions in one logical instant are desynchronized and projected onto finer grained instants. Owing to this extension, it would provide more convenience for the designer to express the parallelism among components.