loewis: I think your idea is the right answer.  I'm not worried about select/poll.  Surely no one uses select/poll and socket._fileobject.readline() on the same socket.  select/poll are for nonblocking sockets; this readline() method doesn't even catch EWOULDBLOCK.

...In fact even if you did use select/poll on the (blocking) socket after readline() threw EINTR--which no one should do--I think it would still work just as expected unless you were doing something truly weird.