Local in scala.concurrent

[scabug]

It would be nice to have something equivalent to Twitter's Local in scala.concurrent.

In other words, something like Java's ThreadLocal which follows the application flow (rather than JVM threads) when using scala.concurrent.Future?

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-9835?orig=1
Reporter: Mikael Ståldal (mikaelstaldal)
Affected Versions: 2.11.8

[eed3si9n]

Would you accept a PR for this? If so it might be a good first issue.

[viktorklang]

@eed3si9n I have some concerns, but it would be interesting to see what a solution would look like.

(I have some Future improvements in the works: https://github.com/viktorklang/scala-futures)

[SethTisue]

the usual gatekeeper on this is @viktorklang. I'll provisionally add the "good first issue" label because unlike many scala/scala repo things this is pretty self-contained, no big ramp-up required. but anyone interested should be advised that they should propose a design and run it by https://contributors.scala-lang.org before writing a bunch of code

[SethTisue]

I made a "concurrency" label, we strangely didn't have one.

[viktorklang]

@SethTisue Thanks for creating the label, Seth!

[mghildiy]

Does it need deep understanding of concurrency in Scala?

[SethTisue]

I don't know about "deep", but you should probably have some experience working with Future in order to propose a design.

[jsw]

• What are the design considerations for a good solution?
• What are the pros/cons of the Twitter implementation, and why did it not ultimately become part of the Scala SDK?
• Are there any links to previous discussion of this topic?