[Python-Dev] 2.4 asyncore headache (original) (raw)

Tim Peters tim.peters at gmail.com
Fri Aug 13 21:58:28 CEST 2004

asyncore gives me a headache. Windows sockets give me a headache. Zope's ZEO gives me a headache. The ZEO test suite gives me nightmares.

With that encouraging background, this ZEO test in ZODB 3.3 fails every time when run on Windows under Python 2.4, but never under Python 2.3.4:

checkReconnection (ZEO.tests.testConnection.MappingStorageConnectionTests) ... Traceback (most recent call last): File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\tests\zeoserver.py", line 217, in ? main() File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\tests\zeoserver.py", line 194, in main auth_realm=zo.auth_realm) File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\StorageServer.py", line 738, in init factory=self.new_connection) File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\zrpc\server.py", line 34, in init self._open_socket() File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\zrpc\server.py", line 43, in _open_socket self.bind(self.addr) File "C:\Code\python\lib\asyncore.py", line 304, in bind return self.socket.bind(addr) File "", line 1, in bind socket.error: (10048, 'Address already in use')

unittest doesn't notice that failure, but the test hangs there for a minute or so, and unittest does notice the subsequent:

Traceback (most recent call last): File "C:\Code\python\lib\unittest.py", line 260, in run testMethod() File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\tests\ConnectionTests.py", line 458, in checkReconnection self.startServer(create=0) File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\tests\ConnectionTests.py", line 202, in startServer zeoport, adminaddr, pid, path = forker.start_zeo_server( File "C:\Code\ZODB3.3\build\lib.win32-2.4\ZEO\tests\forker.py", line 149, in start_zeo_server s.connect(adminaddr) File "", line 1, in connect error: (10061, 'Connection refused')

failure.

Now somebody, for some reason, added this to 2.4's asyncore.py:

        if sys.platform == 'win32':
            reuse_constant = socket.SO_EXCLUSIVEADDRUSE
        else:
            reuse_constant = socket.SO_REUSEADDR

If I take away the new special case for Windows there, the checkReconnection test works fine again.

Now I don't understand any of this. Does anyone? From the looks of it, the error from bind() comes from trying to reuse an address, which used to work fine, but no longer works at all on Windows -- at least not in the way ZEO needs it to work. ZEO calls set_reuse_addr() because it needs to reuse ports quickly, and offhand it makes no sense to me to change the meaing of set_reuse_addr() on Windows to something that refuses to allow port reuse.

More information about the Python-Dev mailing list