Chant: Lightweight Threads in a Distributed Memory Environment

Lightweight threads are becoming increasingly useful in supporting parallelism and asynchronous events in applications and language implementations. Traditionally, lightweight threads are supported only within the single address space of a process, or in shared memory environments with multiple processes. We introduce and describe the design of Chant, a runtime system supporting lightweight threads in a distributed memory environment. In addition to communication between any two threads in the system, Chant provides support for remote service requests, remote thread operations, and collective communication between thread groups called ropes. Chant provides the rst implementation of lightweight threads for a distributed memory platform whose design incorporates existing standards for lightweight threads and interprocess communication. This paper details the issues that arise in extending a standard threads package to support distributed memory execution, and the solutions that are provided by the Chant system.