Program analysis for safety guarantees in a Java virtual machine written in Java

摘要

In this paper, we report on our experiences with guaranteeing GC-pointer safety when using unsafe low-level language extensions to implement a JVM in Java. We give an overview of the original unsafe language extensions that were defined for use by Jalapeno implementers, and introduce sanitized replacements that capture common idioms while also guaranteeing GC-pointer safety. We also outline some simple static and dynamic checks for correct usage of low-level operations, and examine how code containing low-level operations can be optimized correctly and effectively.