Dr. Christian Wimmer

Fine-Grained Modularity and Reuse of Virtual Machine Components

Christian Wimmer, Stefan Brunthaler, Per Larsen, Michael Franz: Fine-Grained Modularity and Reuse of Virtual Machine Components. In Proceedings of the International Conference on Aspect-oriented Software Development, pages 203–213. ACM Press, 2012. doi:10.1145/2162049.2162073

Download as PDF
© ACM, 2012.


Modularity is a key concept for large and complex applications and an important enabler for collaborative research. In comparison, virtual machines (VMs) are still mostly monolithic pieces of software. Our goal is to significantly reduce to the cost of extending VMs to efficiently host and execute multiple, dynamic languages. We are designing and implementing a VM following the "everything is extensible" paradigm. Among the novel use cases that will be enabled by our research are: VM extensions by third parties, support for multiple languages inside one VM, and a universal VM for mobile devices.

Our research will be based on the existing state of the art. We will reuse an existing metacircular Java VM and an existing dynamic language VM implemented in Java. We will split the VMs into fine-grained modules, define explicit interfaces and extension points for the modules, and finally re-connect them.

Performance is one of the most important concerns for VMs. Modularity improves flexibility but can introduce an unacceptable performance overhead at the module boundaries, e.g., for inter-module method calls. We will identify this overhead and address it with novel feedback-directed compiler optimizations. These optimizations will also improve the performance of modular applications running on top of our VM.

The expected results of our research will be not only new insights and a new design approach for VMs, but also a complete reference implementation of a modular VM where everything is extensible by third parties and that supports multiple languages.