Bluefin and concurrency

[maralorn]

Hey Tom, still loving your lib. (And loved your recent talk on effectful vs. bluefin.)

I am considering to port https://github.com/maralorn/nix-output-monitor to bluefin which currently uses transformers and streamly.

For this I noticed that bluefin currently does not mention concurrency anywhere. So I would like to know whether you have any recommendations for combining bluefin with concurrency. (e.g. can I just use it with async?)
I am especially curious about State and Stream and whether I can just pass them to different threads.

[tomjaguarpaw]

Hey Tom, still loving your lib. (And loved your recent talk on effectful vs. bluefin.)

Oh great, I'm pleased to hear it!

Bluefin's State is not thread safe so I wouldn't recommend just using async unless you're very careful.

This is a good opportunity for me to improve the concurrency story though. Could you tell me what concurrency patterns you want to use? And maybe point me to what you're doing with concurrency in the current version?

[maralorn]

Huh, well. I think all concurrency is limited to the function: <https://github.com/maralorn/nix-output-monitor/blob/main/lib%2FNOM%2FIO.hs#L228> And looking at it more concretely I don't see any weird interactions between handles and concurrency there. All data sharing between threads is done explicitly via STM. One part of that function builds and consumes a streamly stream. But that is not concurrent in itself I think. On the other hand I just use race_ und concurrently_ to launch the output and the input thread in parallel. So I could imagine just giving it a shot and telling you if encounter troubles. Am 24. November 2024 21:50:24 MEZ schrieb tomjaguarpaw ***@***.***>:

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> Hey Tom, still loving your lib. (And loved your recent talk on effectful vs. bluefin.) Oh great, I'm pleased to hear it! Bluefin's `State` is not thread safe so I wouldn't recommend just using `async` unless you're very careful. This is a good opportunity for me to improve the concurrency story though. Could you tell me what concurrency patterns you want to use? And maybe point me to what you're doing with concurrency in the current version? -- Reply to this email directly or view it on GitHub: #28 (comment) You are receiving this because you authored the thread. Message ID: ***@***.***>

[tomjaguarpaw]

All data sharing between threads is done explicitly via STM.

OK, in that case you will be fine to use withEffToIO and your favourite functions from async. Eventually I'd like to guarantee concurrency safety through the type system, but for now let's do it the simple way.

So I could imagine just giving it a shot and telling you if encounter troubles.

Sounds good. Please let me know how it goes!

[tomjaguarpaw]

See also #34 for some discussion on native concurrency primitives.