[Haskell-beginners] Signals and external bindings...

[Mike Meyer]

On Fri, 4 May 2012 12:54:00 -0400
Brandon Allbery <allbery.b at gmail.com> wrote:

> What the OP wants is for a signal to abort the C function and return
> control to the Haskell or Python runtime.

Not quite. What I want is for my code in Haskell or Python to run when
the signal arrives (basically, on the signal handler), as opposed to
waiting until the C code returns control to the Haskell or Python
runtime But that's just the first step.

> Do you understand why this requires arbitrary cleanup capability to
> be safe?

Well, it's clear to me that what I want to do requires arbitrary
cleanup capabilities. If the C library doesn't provide a mechanism to
shut itself down cleanly, nothing will work.

But I realized I never got a more fundamental question answered: when
does a signal handler written in Haskell run? Is it like C, in that it
runs when the signal arrives, even if I'm currently executing some
wrapped C code, and I have to deal with funky rules about what it can
do? Or is it like Python, and it will run the first time the Haskell
runtime gets control after the signal arrives?

      Thanks,
      <mike
-- 
Mike Meyer <mwm at mired.org>		http://www.mired.org/
Independent Software developer/SCM consultant, email for more information.

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