Make C-extension Ractor-safe

[mohamedhafez]

In planning ahead to the near future when TruffleRuby can run C-extensions marked with rb_ext_ractor_safe(true) in parallel, and for when Ractors are no longer just experimental, it would be great if the C-extension could be made Ractor-safe, or marked as such if it already is so!

[mohamedhafez]

From what I hear, @nirvdrum has been running an app using this gem at Shopify on TruffleRuby without the C-extension lock, meaning its getting run concurrently in multiple threads, and hasn't had issues, so I'm hoping there isn't much work to be done for this, and it just needs to be marked with rb_ext_ractor_safe(true)

[jhawthorn]

I agree we should be able to set rb_ext_ractor_safe(true). We do require that calls to a given Trilogy client are synchronized (done by the GVL) but I don't believe there is global state outside of them (so by Ractor rules, it should be safe).

Would you be interested in sending a PR?

[nirvdrum]

Sorry, I missed the ping on this. Yes, we've been running Trilogy on TruffleRuby for a project at Shopify and have done extensive load testing on it. TruffleRuby normally doesn't have a GVL, but imposes a lock for native extensions that don't declare that they don't need one, in order to avoid multi-threading issues. It's possible to override that with the --experimental-options --ruby.cexts-lock=false options for TruffleRuby, which is how I ran the load tests. We didn't see any issues running Trilogy that way over the course of hundreds of test executions.

This change will be really nice because TruffleRuby will know it doesn't need a lock when running Trilogy, which means that runtime option to override the default settings will not be needed.