DLisp: A Distributed Lisp System Design Criteria and Preliminary Results

In this paper we describe the approach that we pursued on coping with parallelism problem for symbolic applications. Our purpose is to build a parallel symbolic system suited to homogeneous and heterogeneous Distributed Memory Parallel Systems. In particular we describe the design criteria and the implementation strategy for a Distributed Lisp System (DLisp) that relies on a client/server model, such as described in [4], and uses a functional level mechanism to synchronize and control the processes. The intraprocess and interprocess management are obtained using the notion of continuation of a computation for process context switching and resuming. In this way this system does not rely on any control feature outside the Lisp language. The DLisp system is structured in three main layers. The hardware heterogenity is encapsulated using the Parallel Virtual Machine software package [12] to implement the system communication layer. The PVM package allows concurrent computations to run on a loosely coupled networks of heterogeneous processing elements.