Ariadne: Architecture of a Portable Threads System Supporting Thread Migration

Abstract

SUMMARY Threads exhibit a simply expressed and powerful form of concurrency, easily exploitable in applications that run on both uni- and multi-processors, shared- and distributed-memory systems. This paper presents the design and implementation of Ariadne: a layered, C-based software architecture for multi-threaded distributed computing on a variety of platforms. Ariadne is a portable user-spacethreads system that runs on shared- and distributed-memory multiprocessors. Thread-migration is supported at the application level in homogeneous environments (e.g., networks of SPARCs and Sequent Symmetrys, Intel hypercubes). Threads may migrate between processes to access remote data, preserving locality of reference for computations with a dynamic data space. Ariadne can be tuned to specific applications through a customization layer. Support is provided for scheduling via a built-in or application-specific scheduler, and interfacing with any communications library. Ariadne currently runs on the SPARC (SunOS 4.x and SunOS 5.x), Sequent Symmetry, Intel i860, Silicon Graphics workstation (IRIX), and IBM RS/6000 environments. We present simple performance benchmarks comparing Ariadne to threads libraries in the SunOS 4.x and SunOS 5.x systems.