Trent Nelson <[EMAIL PROTECTED]> added the comment: [Updating the issue with relevant mailing list conversation] Interesting results! I committed the patch to test_socket.py in r62152. I was expecting all other platforms except for Windows to behave consistently (i.e. pass). That is, given the following:
import socket host = '127.0.0.1' sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.bind((host, 0)) port = sock.getsockname()[1] sock.close() del sock sock1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock1.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock1.bind((host, port)) sock2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock2.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock2.bind((host, port)) ^^^^ ....the second bind should fail with EADDRINUSE, at least according to the 'SO_REUSEADDR and SO_REUSEPORT Socket Options' section in chapter 7.5 of Stevens' UNIX Network Programming Volume 1 (2nd Ed): "With TCP, we are never able to start multiple servers that bind the same IP address and same port: a completely duplicate binding. That is, we cannot start one server that binds 198.69.10.2 port 80 and start another that also binds 198.69.10.2 port 80, even if we set the SO_REUSEADDR socket option for the second server." The results: both Windows *and* Linux fail the patched test; none of the buildbots for either platform encountered an EADDRINUSE socket.error after the second bind(). FreeBSD, OS X, Solaris and Tru64 pass the test -- EADDRINUSE is raised on the second bind. (Interesting that all the ones that passed have a BSD lineage.) I've just reverted the test in r62156 as planned. The real issue now is that there are tests that are calling test_support.bind_socket() with the assumption that the port returned by this method is 'unbound', when in fact, the current implementation can't guarantee this: def bind_port(sock, host='', preferred_port=54321): for port in [preferred_port, 9907, 10243, 32999, 0]: try: sock.bind((host, port)) if port == 0: port = sock.getsockname()[1] return port except socket.error, (err, msg): if err != errno.EADDRINUSE: raise print >>sys.__stderr__, \ ' WARNING: failed to listen on port %d, trying another' % port This logic is only correct for platforms other than Windows and Linux. I haven't looked into all the networking test cases that rely on bind_port(), but I would think an implementation such as this would be much more reliable than what we've got for returning an unused port: def bind_port(sock, host='127.0.0.1', *args): s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind((host, 0)) port = s.getsockname()[1] s.close() del s sock.bind((host, port)) return port Actually, FWIW, I just ran a full regrtest.py against trunk on Win32 with this change in place and all the tests still pass. Thoughts? Trent. __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue2550> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com