Today I’m going to talk about a recent journey as a HotSpot Java Virtual Machine developer working on the OpenJDK project. While running tests for a new feature, I realized my Java objects and classes were arbitrarily disappearing! What followed was probably the most interesting debugging and fixing experience of my life (so far), which I wanted to share with the world.

What are GC barriers and how do they relate to ahead-of-time compilation? This blog post explores the intersection of HotSpot’s GCs and compilers through the lense of implementing GC-agnostic load barriers at the assembly level, and gives key insights on performance and overall takeaways.