Interlanguage condition signalling and handling

>>>>> "Joerg-Cyril" == Joerg-Cyril Hoehle <Hoehle> writes:

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    Joerg-Cyril> E.g. suppose a signal handler or a callback is invoked while in foo. The handler calls Lisp code, which causes a GC. The address of the double float array passed to foo may not be valid anymore, leading to random crashes.


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This raises a question which is off the original topic, but related.
I have need of being able to signal a condition in a C library and
handle it in the calling CL form.  Is this possible, preferably using
UFFI constructs?  I asked Franz about this and was told it was very
hard to do; they suggested a solution that required wrapping every
function.  Since I am using a large library from an external source,
this is impractical.  If there is a portable solution, this would be
even better.  Do you have any small examples on how to do this?

Thank you.

Liam