SableVM: A Research Framework for the Efficient Execution of Java Bytecode

SableVM is an open-source virtual machine for Java intended as a research framework for efficient execution of Java bytecode. The framework is essentially composed of an extensible bytecode interpreter using state-of-the-art and innovative techniques. Written in the C programming language, and assuming minimal system dependencies, the interpreter emphasizes high-level techniques to support efficient execution. In particular, we introduce a biderectional layout for object instances that groups reference fields sequentially to allow efficient garbage collection. We also introduce a sparse interface virtual table layout that reduces the cost of interface method calls to that of normal virtual calls. Finally, we present a technique to improve thin locks[13] by eliminating busy-wait in presence of contention.