> An example of such an issue is in Netty, where they allocate very large native buffers and cache them in ThreadLocals, which assumes that the number of threads is low, and that they're reused by lots of tasks.

Fixing Netty is very high yield. Every modern Java server application I'm aware of uses Netty. Quarkus, Vertx, Micronaut, Java-GRPC, ...

Then Graal? Virtual threads in Graal with a Netty that isn't 60MB would be superb.

What about just shimming Netty? Is that in Oracle's scope? There are already selectable backends for Netty. Why not have "virtualthread-graalcompatible" that uses your already fixed Java IO? It would reduce so much pain, and make Java competitive with golang for the first time ever.

GraalVM native images have recently gained support for virtual threads. So you can have AOT compiled fast starting binaries that use virtual threads, if you want (or very soon at least, I can't recall if it's out yet or not).

The main gap vs Go would then be the speed of the AOT compile. But you normally develop on HotSpot anyway.

Netty already works with Loom. There are people doing experiments with it where it shows some small performance gains even. They are incrementally improving it so it works better when Loomified, but it does work.

Graal also has a “fast build” mode, likely way slower still than go’s compilation, but there is that. It is meant for development though, you will likely want an optimized build for prod. But yeah, one should probably just develop in the traditional way, and then test it out in native after a few iterations.

It is surely not out yet, latest stable GraalVM is still based on Java 17.

I expect Netty to make the appropriate changes, but Helidon have a new server called Nima (https://medium.com/helidon/please-welcome-helidon-n%C3%ADma-...) that's been built from the ground up to be virtual-thread-friendly.

Do you need Netty in a virtual thread world? Imo Netty made non blocking IO in Java tractable.. but virtual threads does it better and more broadly, so what role does netty play now? What other than thread efficiency does it bring that can’t be achieved more easily now?