TR-128: Efficient Support for Object Mutation and Transparent Forwarding

Abstract

Distributed object oriented applications such as CAD/CIM require efficient support for object mutation and message forwarding. Many research prototypes have been implemented in Smalltalk using doesNotUnderstand to implement forwarders and become: to perform object mutation. The recent development of large object space smalltalks has pointed out the cost of the Smalltalk object mutation facility become:. Performance concerns have caused some implementers to recommend removing become: from the language, arguing that the construct is not really needed. In this paper we argue the need for a become: construct to support object mutation and describe simple techniques for efficiently implementing both object mutation and transparent forwarding.