Portable Implementation of Continuation Operators in Imperative Languages by Exception Handling

Abstract

This paper describes a scheme of manipulating (partial) continuations in imperative languages such as Java and C++ in a portable manner, where the portability means that this scheme does not depend on structure of the native stack frame nor implementation of virtual machines and runtime systems. Exception handling plays a significant role in this scheme to reduce overheads. The scheme is based on program transformation, but in contrast to CPS transformation, our scheme preserves the call graph of the original program. This scheme has two important applications: transparent migration in mobile computation and checkpointing in a highly reliable system. The former technology enables running computations to move to a remote computer, while the latter one enables running computations to be saved into storages.