[Haskell-cafe] threading question for ghc 7.0.2

oliver mueller oliver.mueller at gmail.com
Fri Mar 25 10:50:40 CET 2011

you are right that i need to fix the FFI problems.
but coming back to the threading stuff i do in my haskell code: do i
really need to use the threaded runtime here?
from the ghc-docs for the -threaded flag:
"Note that you do not need -threaded in order to use concurrency; the
single-threaded runtime supports concurrency between Haskell threads
just fine."
as i understand it i am not "switching off concurrency" as you said.
I suppose it is not needed for the haskell part. of course then there
might be problems when i call into libraries that make use of FFI and
need a threaded runtime.
e.g. a call to hGetBufNonBlocking. i found a strange note in the docs
for windows: "NOTE: on Windows, this function does not work correctly"
how can you tell if the -threaded option is necessary if you use other
libraries? and what about ghci...what is the default here?

in any case i'd really like to figure out the correct approach that is
portable (Mac/Linux/Windows) since i need to deploy to all those


On Mar 24, 11:19 am, Gregory Collins <g... at gregorycollins.net> wrote:
> On Thu, Mar 24, 2011 at 9:53 AM, oliver mueller
> <oliver.muel... at gmail.com> wrote:
> > if anybody knows of a better way please let me know!
> I'd recommending trying to fix your "obscure FFI problems" re: the
> threaded RTS and go back to using that. Switching concurrency off
> altogether is a curious response to dealing with an issue in
> multithreading, and you may not be doing yourself any favours in the
> long-term by piling on workarounds to get back the semantics you
> actually want.
> G
> --
> Gregory Collins <g... at gregorycollins.net>
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> Haskell-Cafe mailing list
> Haskell-C... at haskell.orghttp://www.haskell.org/mailman/listinfo/haskell-cafe

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