Safe System-level Concurrency on Resource-Constrained Nodes Accepted paper in SenSys’13 (preprint version) Francisco Sant’Anna Noemi Rodriguez Roberto Ierusalimschy
[email protected] [email protected] [email protected] Departamento de Informatica´ – PUC-Rio, Brazil Olaf Landsiedel Philippas Tsigas olafl@chalmers.se
[email protected] Computer Science and Engineering – Chalmers University of Technology, Sweden Abstract as an alternative, providing traditional structured program- Despite the continuous research in facilitating program- ming for WSNs [12, 7]. However, the development pro- ming WSNs, most safety analysis and mitigation efforts in cess still requires manual synchronization and bookkeeping concurrency are still left to developers, who must manage of threads [24]. Synchronous languages [2] have also been synchronization and shared memory explicitly. In this paper, adapted to WSNs and offer higher-level compositions of ac- we present a system language that ensures safe concurrency tivities, considerably reducing programming efforts [21, 22]. by handling threats at compile time, rather than at runtime. Despite the increase in development productivity, WSN The synchronous and static foundation of our design allows system languages still fail to ensure static safety properties for a simple reasoning about concurrency enabling compile- for concurrent programs. However, given the difficulty in time analysis to ensure deterministic and memory-safe pro- debugging WSN applications, it is paramount to push as grams. As a trade-off, our design imposes limitations on many safety guarantees to compile time as possible [25]. As the language expressiveness, such as doing computationally- an example, shared memory is widely used as a low-level intensive operations and meeting hard real-time responsive- communication mechanism, but current languages do not ness.