[Issue 20219] Idle D programs keep consuming CPU in Gcx.scanBackground

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20219

--- Comment #6 from Rainer Schuetze <r.sagitario at gmx.de> ---
(In reply to Vladimir Panteleev from comment #5)
> Then, would you agree that terminating the threads after a few seconds of
> inactivity would be appropriate?

I'd be ok with this (or maybe a slightly larger timeout) if it doesn't
complicate the handling too much.

> The situation on other platforms might very well be different. I don't think
> Windows has received nearly the same level of scrutiny about not wastefully
> using resources as FOSS operating systems. Would you suggest making the
> default behavior depend on the current OS?

Fine with me. My initial suggestion was actually to make it opt-in
(https://github.com/dlang/druntime/pull/2514#issuecomment-478285235), but there
were no complaints while it was enabled ;-) But maybe it wasn't stress tested
enough.

--