One problem I ran into is that I use Unix signals to control the
various processes. In CPython, this causes a problem with extension
code because the python signal handler at the C level just note the
signal, then wait to run the Python "signal handler" the next time the
interpreter. Since my extensions are doing the heavy lifting, they
often run for long periods (by which I mean 10s of minutes). Meaning
the signal is ignored for long periods.
Since I expect to such extensions (the wrappers are available) and
want to leave the control mechanisms in place, I'd like to know if I'm
going to have similar problems in Haskell.
Yes, and in pretty much any other language that requires its own runtime as well. Cross-runtime borders are *always* a problem for signals and various resources that may need to be cleaned up.
You can use wrappers which save the old signal handlers and install new ones which clean up after your plugins and return. Doing so, and thereby learning the hard way what "clean up after your plugins" entails (unless you were very careful designing and writing them in the first place), will teach you why nobody tries to automatically handle it for you. (In the general case, your plugin has to track *everything* so it can unwind (or commit, as appropriate) memory and resource allocations on signal.)