Efficient virtual machine support of runtime structural reflection

Increasing trends towards adaptive, distributed, generative and pervasive software have made object-oriented dynamically typed languages become increasingly popular. These languages offer dynamic software evolution by means of reflection, facilitating the development of dynamic systems. Unfortunately, this dynamism commonly imposes a runtime performance penalty. In this paper, we describe how to extend a production JIT-compiler virtual machine to support runtime object-oriented structural reflection offered by many dynamic languages. Our approach improves runtime performance of dynamic languages running on statically-typed virtual machines. At the same time, existing statically-typed languages are still supported by the virtual machine. We have extended the .Net platform with runtime structural reflection adding prototype-based object-oriented semantics to the statically typed class-based model of .Net, supporting both kinds of programming languages. The assessment of runtime performance and memory consumption has revealed that a direct support of structural reflection in a production JIT-based virtual machine designed for statically typed languages provides a significant performance improvement for dynamically typed languages.