- Authors:
- Karel Driesen,
- Urs Holzle
Row displacement dispatch tables implement message dispatching for dynamically-typed languages with a run time overhead of one memory indirection plus an equality test. The technique is similar to virtual function table lookup, which is, however, restricted to statically typed languages like C++. We show how to reduce the space requirements of dispatch tables to approximately the same size as virtual function tables. The scheme is then generalized for multiple inheritance. Experiments on a number of class libraries from five different languages demonstrate that the technique is effective for a broad range of programs. Finally, we discuss optimizations of the row displacement algorithm that allow dispatch table construction of these large samples to take place in a few seconds.
Recommendations
Minimizing row displacement dispatch tables
OOPSLA '95: Proceedings of the tenth annual conference on Object-oriented programming systems, languages, and applicationsRow displacement dispatch tables implement message dispatching for dynamically-typed languages with a run time overhead of one memory indirection plus an equality test. The technique is similar to virtual function table lookup, which is, however, ...
Minimizing row displacement dispatch tables
Row displacement dispatch tables implement message dispatching for dynamically-typed languages with a run time overhead of one memory indirection plus an equality test. The technique is similar to virtual function table lookup, which is, however, ...
Optimizing multi-method dispatch using compressed dispatch tables
Optimizing method dispatch is a central issue in object-oriented language implementation. The dispatch table scheme, used for example by C++, is the only implementation of method dispatch that offers constant time performance. This property is the main ...