Vers une programmation fonctionnelle en appel par valeur sur systèmes multi-coeurs : évaluation asynchrone et ramasse-miettes parallèle

Modern multi-core machines are conceived to efficiently execute explicitly parallel assembly programs. Current technology is moving away from instruction-level parallelism, exploitable without changes in the software, toward task-level parallelism requiring modifications in programs. In this context exploiting parallelism entails either exploiting new parallelizing toolchains, or programming in new (higher-level) languages supporting explicit parallelism. In other words exploiting multi-core machines may follow two different routes: changing the programming model or hiding from the user the complexity of this task by delegating to a compiler the parallelization of a higher-level program, preferably in a declarative style. In either case compiled programs must be efficient on such architectures, hence the efficiency of the language runtime support is also central. In particular, when the language is high-level and provides automatic memory management, the garbage collector risks to be the bottleneck limiting the overall performance gain. This paper is an experience report on the association of two softwares which we have implemented, an interpreter for a functional language augmented by a construct for asynchrone computations and a garbage collector for parallel machines. The two tools combined provide the user (be it a human or a compiler), a way to exploit the hardware parallelism of a shared-memory multi-processor machine with a declarative and essentially functional programming style. MOTS-CLÉS : multi-coeur, future, ramasse-miettes, programmation fonctionnelle