Squawks of the Parrot

VEE workshop, day 3

A short day, and one I talk at, so less than meets the eye.

I got to talk with Doug Lea at breakfast (which was really cool) about lightweight threading primitives. The more heavyweight stuff's fine, but there's a lot you can do with lightweight stuff. We'd need a way to make a thread wait until woken (with queued wakeups), wake up a thread, and do an atomic compare-and-set. It's interesting, and I think we can do it cheaply enough to make it better than pthreads synchronization.

The morning talks were interesting, if a bit specialized (the Metronome project for guaranteed collector behavior for hard realtime systems was cool, even if I think using Java in a hard realtime environment's a bit... odd). Still, neat. The 3500 byte Java JAR file that triggers degenerate behavior in Java's bytecode verifier (15 minute verify times on a 3GHz machine) was something I really wish I'd copied the URL to. Hopefully the slides to the talk'll make it online.

I was up last (other than the wrapup) and it went... well, it went as well as expected, given the room was filled almost entirely with JVM guys, and I wasn't sure what exactly I was going to talk on anyway. I more or less went through a laundry list of things that VM implementors could (and, indeed, I argue would have to) provide to languages running on top of them. The raw presentation'll probably be on the workshop website in the next few days, and I'll try to get an annotated version together.

I'd have to say, on the whole, the workshop was interesting, and well worth doing. There's a bunch of stuff that came up -- mistakes made by the JVM, or things people really want but don't have -- that we should address in Parrot. I took some paper notes, which I'll have to throw together and get addressed. It was also interesting to see the spots people were talking past one another, and I'm sure I did it but didn't notice, but that's the nature of that sort of thing.