Java starting slowly is mostly from all the cruft in the typical java app, with springboot, dependency injection frameworks, registries etc. You don't have to have those, it's just that most java devs use them and can't conceive of a world of low dependencies
Still not great for commandline apps, but java itself is much better than java devs
In contrast, "time" reports that rust takes 1ms, which is the limit of it's precision.
Python does Hello World in just 8ms, despite not having a separate AOT compilation step.
The general guidance I've seen for interaction is that things start to feel laggy at 100ms; so 30ms isn't a dealbreaker, but throwing a third of your time budget at the baseline runtime cost is a pretty steep ask.
If you want to use the application as a short lived component in a larger system, than 30ms on every invocation can be a massive cost.
Did they have like 100k tests?
https://mail.python.org/pipermail/python-dev/2014-May/134528...
30ms for a program to start, print hello world, and terminate on a modern computer is batshit insane, and it's crazy how many programmers have completely lost sight of even the principle of this.
Java's major competitors, C# and Go, both have had value types since day one and reified generics since they gained generics; this hasn't posed any major problems to either language (with the former being IMO already more complex than Java, but the latter being similarly or even less complex than Java).
If the technical side isn't that hard, I'd have expected the JVM to have implemented value types already, making it available to other less conservative languages like Kotlin, while work on smoothly integrating it in Java took as long as needed. Project Valhalla is over a decade old, and it still hasn't delivered, or even seems close to delivering, its primary goals yet.
Just to be clear, I don't think every language needs to meet every need. The lack of value types is not a critical flaw of Java in general, as it only really matters when trying to use Java for certain purposes. After all, C# is very well suited to this niche; Java doesn't have to fit in it too.
Yes (well, structs; not really value types), but at a significant cost to FFI and/or GC and/or user-mode threads (due to pointers into the stack and/or middle of objects). Java would not have implemented value types in this way, and doing it the way we want to would have been equally tricky had it been done in Java 1.0. Reified generics also come at a high price, that of baking the language's variance strategy into the ABI (or VM, if you want). However, value types will be invariant (or possibly extensible in some different way), so it would be possible to specialise generics for them without necessarily baking the Java language's variance model into the JVM (as the C# variance model is baked into the CLR).
Also, C# and Go didn't have as much of a choice, as their optimising compilers and GCs aren't as sophisticated as Java's (e.g. Java doesn't actually allocate every `new` object on the heap). Java has long tried to keep the language as simple as possible, and have very advanced compilers and GCs.
> If the technical side isn't that hard, I'd have expected the JVM to have implemented value types already, making it available to other less conservative languages like Kotlin, while work on smoothly integrating it in Java took as long as needed
First, that's not how we do things. Users of all alternative Java Platform languages (aka alternative JVM languages) combined make up less than 10% of all Java platform users. We work on the language, VM, and standard library all together (this isn't the approach taken by .NET, BTW). We did deliver invokedynamic before it was used by the Java language, but 1. that was after we knew how the language would use it, and 2. that was at a time when the JDK's release model was much less flexible.
Second, even if we wanted to work in this way, it wouldn't have mattered here. Other Java Platform languages don't just use the JVM. They make extensive use of the standard library and observability tooling. Until those are modified to account for value types, just a JVM change would be of little use to those languages. The JVM comprises maybe 25% of the JDK, while Kotlin, for example, makes use of over 95% of the JDK.
Anyway, Project Valhalla has taken a very long time, but it's making good progress, and we hope to deliver some of its pieces soon enough.
To avoid manually writing all the Panama boilerplate, you can instead write a C header file with the desired types, and then run jextract through it.
