FFI, signals and exceptions

Hello all, I am currently investigating techniques to nicely handle SIGINTs when FFI code is running. Yes, I know it sounds kind of crazy. Ignoring the problems of cleaning up the unceremoniously terminated C computation, I'm having difficulty getting the FFI to /stop/ running when I get the signal. I currently have some code like this: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=28422#a28422 which doesn't work, and which you guys can probably tell me doesn't work. :-) Throwing exceptions from the signal handler also doesn't work. Any suggestions for GHC source code to look at / techniques to try? Cheers, Edward