Wolfgang Thaller writes:
a) poll() is not supported on Mac OS X and (at least some popular versions of) BSD.
Are you certain? Just tried "man poll" on one of the MacOS X machines the SourceForge compile farm offers, and that one had it: "Darwin ppc-osx1 5.5 Darwin Kernel Version 5.5".
b) 'forkIO' in the threaded RTS would suffice in this case, as the poll() or select() system calls don't use any thread-local state. In the threaded RTS, "safe" foreign imports never affect other threads [...].
That would be really good news! I assumed that GHC's runtime system used one thread for _all_ FFI invocations? (Unless you start new ones.) So I thought calling poll() would block all other FFI invocations until it returned? Or is that only for "unsafe" FFI calls? Do you have an URL for me where I can find out more about this, by any chance? Peter