Title: Untie the twisted: VM/application isolation in metacircular VMs

Yi Lin (yi.lin@anu.edu.au), with Steve Blackburn, Daniel Frampton

Abstract:

Metacircular virtual machines are an obvious overlap between managed
runtimes that have been evolving for decades of years and the newly
sprouting idea of high-level low-level programming. Implemented in
high-level language to provide runtime for the same language,
metacircular VMs is self-sustained and flexable. However, born with
metacircularity where applications will be written in the same
language as the VM, the blurred boundary between the application, the
VM and the language library leads to poor VM/applicatoin isolation,
which not only tampers the beauty of metacircularity itself, but also
results in problems that have been hanging up for years, such as
VM/application contest over the same object heap, and security issues.

In our work, by taking a software engineering path into a Java-in-Java
VM, Jikes RVM, we clarified a boundary between the VM and
applications, both dynamicly (by dynamic switching instrument) and
statically (by identifying and seperating VM/application shared codes
from VM core components). In the context of metacircular VM, our work
1)tackled VM/application isolation in a lightweight approach,
2)benefit software engineering design to reflect VM/application
isolation in code structure, 3)discovered different run-time
behaviours and characteristics between VM and application. Our work
firmly follows the proof-of-performance concept of Jikes RVM, which
not only brought barely zero overhead to its current release, but also
provided new possibilities of performance improvement in the future.