Simon Marlow

That sounds surprising, but I don't know of any issue with `mapConcurrently` that would lead to that behaviour. Suggest more investigation, have you tried ThreadScope?

I think we should also `SPECIALIZE` waitAnySTM and waitAnyCatchSTM to lists to avoid any performance regressions from the extra overloading.

The problem is that ThreadScope shows activity on each Haskell HEC, and while an FFI call is running the HEC might be doing something else, like running a different Haskell...

The OS thread that made the FFI call is running, and meanwhile a different OS thread is running the HEC. So the problem is that ThreadScope shows a HEC-centric view...

Does anyone have a standalone repro for this bug please?

pull requests are welcome :)

Happy to have this feature, it does sound useful. Perhaps `%inline(nt)` would be a better syntax? We probably shouldn't duplicate the code, how hard is it to abstract it? Do...

This isn't a particularly useful bug report. "Likely to be slow" - why? Have you benchmarked it? I'm inclined to close this without more details.

Strangely enough I've just been investigating this for some code that we're planning to open source. Here's the landscape at the moment: * To use c++ you can currently add...

I have no strong feelings... obviously it's a lot of hassle to fix it, but if you feel motivated then go for it.