A type system to avoid runtime errors for Multi-ML

Programming parallel architectures using a hierarchical point of view is becoming today’s standard as machines are structured by multiple layers of memories. To handle such architectures, we focus on the MULTI-BSP bridging model. This model extends BSP and proposes a structured way of programming multi-level architectures. In the context of parallel programming we, now need to manage new concerns such as memory coherency, deadlocks and safe data communications. To do so, we propose a typing system for MULTI-ML, a ML-like programming language based on the MULTI-BSP model. This type system introduces data locality using type annotations and effects to be able to detected wrong uses of multi-level architectures. We thus ensure that "Well-typed programs cannot go wrong" on hierarchical architectures.