[Haskell-cafe] Re: Bug in runInteractiveProcess?
donn at drizzle.com
Wed Oct 17 11:46:41 EDT 2007
On Wed, 17 Oct 2007, Simon Marlow wrote:
> Note that forkProcess doesn't currently work with +RTS -N2 (or any value
> larger than 1), and it isn't likely to in the future. I suspect
> forkProcess should be deprecated.
> The POSIX spec is pretty strict about what system calls you can make in the
> child process of a fork in a multithreaded program, and those same
> restrictions apply in Haskell, and they apply not only to the Haskell code
> but also to the runtime (e.g. what if the child process needs more memory
> and the runtime calls mmap(), that's not allowed). We get away with it
> most of the time because the OSs we run on are less strict than POSIX.
> However, in general I think forking should be restricted to C code that you
> invoke via the FFI.
Just to be precise about it, though, there's nothing about Haskell per se
that causes trouble with fork, right? This is a GHC implementation issue.
Donn Cave, donn at drizzle.com
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