Quoth Brian Bloniarz
I just tested linux in this scenario, it gives EPIPE as I'd expect. Linux's SA_RESTART has been reliable in my limited experience. Do you have an OpenSolaris install to test by any chance? The code is below.
No, sorry! But I don't doubt that with the right compile options and so forth, that test would work fine on OpenSolaris. Without knowing what really caused the problem I mentioned, I can't guess how to duplicate the problem or test for it. (Cf. "hGetContents: resource exhausted", Haskell Cafe, lally.singh@gmail.com.) I know that's rather unhelpful. I hate unnecessary signals. On the bright side, your approach sure has some appealing points, compared to tracking down every place an execve(2) might happen. The only solution of greater elegance would be for GHC to simply leave SIGPIPE the way it was. A less elegant variaton on that would be to block SIGPIPE, instead of ignoring it. I don't have a great deal of practical experience with that, nor have I looked at how it would fit with GHC runtime code, but execve(2) does reset the signal mask, so it would have the inheritance properties you want. I tried sigprocmask() and pthread_sigmask(); either worked the same for me, but something like this needs more testing. Donn Cave, donn@avvanta.com