[_old_dude_]

Unlike go routine, Loom virtual threads are not preempted by the scheduler. I believe you may be able to explicitly preempt a virtual thread but the last time i checked it was not part of the public API

[vips7L]

Unless I'm misunderstanding, virtual threads are preemptive: https://cr.openjdk.java.net/~rpressler/loom/loom/sol1_part1....

[_old_dude_]

By the OS, not by the scheduler see https://cr.openjdk.java.net/~rpressler/loom/loom/sol1_part2....

[vips7L]

What about pron's comments here then? https://news.ycombinator.com/item?id=27885569

> Second, Loom's virtual threads can also be forcibly preempted by the scheduler at any safepoint to implement time sharing

[_old_dude_]

For me, preemption by the Java scheduler is not currently supported but may be added in the future, after all the goroutine were not preempted at the beginning in Go.

The whole quote

> Second, Loom's virtual threads can also be forcibly preempted by the scheduler at any safepoint to implement time sharing. Currently, this capability isn't exposed because we're yet to find a use-case for it

I believe it's a reference to [1] but i may be wrong.

[1] https://download.java.net/java/early_access/loom/docs/api/ja...

[vips7L]

> The whole quote

Sorry I was skimming! Thanks!