Java 19

In the previous post we were testing if Java’s Virtual Threads aren’t used in a way that makes them pinned. It’s because we want our Platform Threads (especially those in the ForkJoin Pool Co.) to keep carrying more and more new Virtual Threads, instead of keeping the engine running while VTs are pinned. (At least as long as we can’t provide our own thread pools to carry VTs.) Spoiler alert: we’re going to use Testcontainers and Toxiproxy today!

How to enable Virtual Threads? During my talks about Java 19 (which have the mandatory part dedicated to Virtual Threads), I’ve been asked: how do I enable Virtual Threads in the JVM? quite a few times. This question carries an assumption that there’s some kind of switch, which has to be activated or hit to “magically” turn good ol' Threads into Virtual Threads. AFAICT there is no such thing right now, and I rather doubt there will be one in the future.

Let’s be honest: we’ve been waiting for the Virtual Threads quite some time. We’ve been waiting eagerly, we’ve seen names changing (they’re not fibers folks), but here there finally are: Virtual Threads. Some say the Project Loom is the biggest change Java has seen since version 8, lambdas, and streams. Some say it’s even bigger than that. Discussion aside, they are a huge change, it seems. I remember how we were excited (I was still at the university back then), that we could finally use some real Threads in Java on Windows.