Re: [libvirt] mingw: test-poll pipe part fails

> I'm wondering if the problem here is that libvirt is trying to use the > pipe-to-self mechanism as a fundamental event loop idiom. That is, the > reason libvirt is calling poll is in order to minimize CPU until > something interesting happens, where interesting includes needing to > wake up a helper thread to do an action inside locks in response to the > receipt of a signal. > > Maybe you are on to something, and replacing all uses of pipe() with > virPipeToSelf() (which uses pipe() for efficiency on Linux, but > socketpair() on mingw), would allow libvirt to continue to use the > pipe-to-self idiom while also using fds that can actually be poll'd on > mingw. IIRC, we never resolved this for the last release. I think we should do as you suggest and just use socketpair() on Win32. Given the way in which libvirt uses these capabilities, I don't think the overheads of socketpair() vs pipe() are so onerous that we need worry about an even more fancy Win32 impl or eventfd for linux. Of course if someone wants todo a full job for gnulib meawhile, we won't complain...