Antoine Pitrou <pit...@free.fr> added the comment: Le mardi 14 septembre 2010 à 23:19 +0000, Giampaolo Rodola' a écrit : > I've never used socket.socket.makefile so I'm not sure, but its > documentation says: > > > The socket must be in blocking mode (it can not have a timeout). > > If the statement is there because EAGAIN/EWOULDBLOCK were originally > raised then it should be removed, otherwise I question whether > makefile() is actually supposed to support non-blocking sockets in > the first place.
If it wasn't supposed to, we can add that support. The statement comes from the 2.x doc; 2.x didn't have a notion of non-blocking file-like objects at all, so it makes sense. > IMO, I think it's a matter of figuring out whether makefile() should > provide a socket-like behavior or a file like-behavior first. Well, since it claims to implement RawIOBase, it should provide a RawIOBase-like behaviour :) (and, in any case, the only use of makefile() is to return something file-like. If you want socket-like behaviour, just use the socket) Returning None is what raw I/O objects are supposed to do when they fail reading or writing even a single byte. It is designed and documented as such. (the readinto() doc you mentioned lacked that precision, but I've just fixed it) The reason None is returned (rather than 0 or b'') is so that the caller can recognize the situation and take appropriate measures. For example, if read() returns None, it means some bytes *may* be following but we'll have to wait (select/poll/...) first; if read() returns 0, conversely, it means we've reached EOF (or, on a socket, that the peer has shutdown its side of the connection). These are two very different situations. ["file-like behaviour"] > otherwise they should be > silenced/handled internally or makefile() just fail immediately as > there's not such thing as "non-blocking files". Non-blocking files exist: >>> import fcntl, os, io >>> r, w = os.pipe() >>> fcntl.fcntl(r, fcntl.F_SETFL, os.O_NONBLOCK) 0 >>> os.read(r, 2) Traceback (most recent call last): File "<stdin>", line 1, in <module> OSError: [Errno 11] Resource temporarily unavailable (It seems that on regular files O_NONBLOCK may not have an effect; not under Linux anyway) ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue9854> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
