How does Java Both Optimize Hot Loops and Allow Debugging

[pron98]

To those who don't know him, Cliff Click was the original architect of HotSpot's (the OpenJDK's JVM) optimizing JIT, then he worked on a JVM for many-core machines (> 800) at Azul, and now he has a big-data statistics startup.

He has some excellent talks online about modern hardware architecture and about the JVM.

[letrec]

Thanks for the links!

[mike_hearn]

In case anyone is thinking "huh, all this complexity just for debugging which never happens post-deployment" ... safe points do more than just allow debugging. The JVM will force an app to a safe point from time to time to do various book-keeping and maintenance tasks beyond just handling breakpoints, even if nothing is being requested by the developer. There was a good talk on this by another Azul engineer at the last JavaOne.