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Coroutines and Loom behind the scenes by Roman Elizarov

Kotlin by JetBrains · 40.9K views · 2023-05-04 · 45:22

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Overview

Roman Elizarov compares Kotlin Coroutines with OpenJDK Project Loom virtual threads, looking at their design goals and how those translate into different implementations and tradeoffs. He addresses how the two can coexist.

On Hacker News

Pointed to in Java 21 and Loom discussions as the Kotlin lead's authoritative view on coroutines versus virtual threads.

Recommended by 1 HN people across 1 months · HN mentions 2023–2023

Topics

Python, Ruby & scripting languagesProgramming language designSoftware architecture & design
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kotlincoroutinesproject loomvirtual threadsjvm

What people said

dangets · 2023-08 · Recommendation

Here's a take from Roman Elizarov (Kotlin bias) - [VIDEO] I imagine a lot of the missing structured concurrency will get built up over time on the Java side, but it is an interesting talk regardless.

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simon_void · 2023-10 · Reference

here is the talk by Roman Elizarov, the Kotlin project lead, at KotlinConf 2023 about Coroutines vs VThreads: [VIDEO] short version: both were optimized for different things, so there is a place for both of them.

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jillesvangurp · 2023-08 · Reference

It's pretty hard to use Kotlin without co-routines these days. Most modern Kotlin frameworks tend to use them. And they work outside the JVM as well. Mostly we're talking about Java projects focusing on doing things the Java way that may or may not be using Kotlin for that. Kotlin mobile is unaffected; it won't get Loom any time soon (as far as I know) and things just don't work the same way there. Kotlin (and coroutines) are the go to solution there. I don't see that changing. And from having used coroutines with Spring extensively, I kind of like it. Works great. Makes everything easier. Especially the unholy mess that is web flux. There aren't a lot of things that loom does that Kotlin doesn't do already. Green threads. Check. Structured concurrency. Check. At best it will do them a little faster with loom in place, which isn't a bad thing of course. But it doesn't really fix a problem I have. Being able to use threaded and blocking IO things in a non blocking way with no threads is going to be nice. Great if you are stuck with a lot of legacy stuff. Roman Elizarov addressed a few things regarding Loom at the last KConf: [VIDEO]

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Sources

Video by Kotlin by JetBrains, played through YouTube.

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