Magic with Dynamo – Flexible Cross-Component Linking for Java with Invokedynamic (Artifact)

Modern software systems are not built from scratch. They use functionality provided by libraries. These libraries evolve and often upgrades are deployed without the systems being recompiled. In Java, this process is particularly error-prone due to the mismatch between source and binary compatibility, and the lack of API stability in many popular libraries. We propose a novel approach to mitigate this problem based on the use of invokedynamic instructions for cross-component method invocations. The dispatch mechanism of invokedynamic is used to provide on-the-fly signature adaptation. We show how this idea can be used to construct a Java compiler that produces more resilient bytecode. We present the dynamo compiler, a proof-of-concept implemented as javac post compiler, and evaluate our approach using several benchmark examples and two case studies showing how the use of the dynamo compiler can prevent certain types of linkage and stack overflow errors that have been observed in real-world systems.