Sharing Mutable Objects and Controlling Groups of Tasks in a Concurrent and Distributed Language

. This paper presents: (i) an operational semantics, based on a functional framework, for a concurrent and distributed extension of the Scheme programming language, (ii ) a coherency protocol taking care of shared mutable objects, (iii ) a new coherency protocol to imperatively control hierarchical groups of cooperating tasks. These two protocols do not require broadcast, nor FIFO communications, nor a centralized machine; they allow to manage an unbound number of shared mutable values and groups of tasks. This paper also advocates for the use of a functional continuationbased presentation for these protocols. The omnipresence of interconnected networks exacerbates the need for high level languages allowing to express and control widely distributed computations. Much network services such as news, finger, archie, netfind etc. [ODL93] basically manage a set of informations which is accessed and enriched on a world-distributed basis. We think that it will become more and more necessary f..