Two-way coloring approaches for method dispatching in object-oriented programming systems

Abstract

In object-oriented systems, heavy message sending has slowed down the execution efficiency. Most of the current solutions are based on message tables according to a class-hierarchy to develop more efficient method searching algorithms. An approach with little space overhead and constant dispatch time is proposed. The general strategy is called the two-way coloring technique. The algorithm can be applied in both typed and untyped object-oriented languages. For typed languages, the space overhead is not greater than the conventional approaches, but it can dispatch methods in the same situations as untyped languages. For untyped languages, the constraint for dispatch is not decreased and the space overhead is not much higher, but it can dispatch methods in constant time. Based on the comparison with conventional approaches, the proposed approach demonstrates its advantages on space overhead, dispatching speed, and applicability. Several case studies are presented as a comparison with existing run time dispatch mechanisms.<>