[Python-Dev] sock.close() not closing?

[Sjoerd Mullender]

On 2008-05-07 13:37, Amaury Forgeot d'Arc wrote:
> Hello,
> 
> 2008/5/7 Sjoerd Mullender <sjoerd at acm.org>:
>> Why does sock.close() not actually close sock?
>>
>>  If I run the code
>>
>>  import socket
>>  sock = socket.socket()
>>  ...
>>  sock.close()
>>
>>  I would expect that a system call is done to actually close the socket and
>> free the file descriptor.  But that does not happen.  Look at the code in
>> socket.py.  It merely replaces the socket instance with a dummy instance so
>> that all subsequent calls on the sock object fail, but it does nothing else!
> 
> It does close the socket:
> 
> In socket.py, when self._sock is replaced, its __del__ method will be called.
> This __del__ is implemented in C, in socketmodule.c:
> 
> static void
> sock_dealloc(PySocketSockObject *s)
> {
> 	if (s->sock_fd != -1)
> 		(void) SOCKETCLOSE(s->sock_fd);
> 	Py_TYPE(s)->tp_free((PyObject *)s);
> }
> 
> 
> Of course, if you call sock.dup() or sock.makefile(),
> there is another reference to the underlying _sock, and you must
> close() all these objects.
> 

I have to question the design of this.  When I close() an object I
expect it to be closed there and then and not at some indeterminate
later time (well, it is determinate when you're fully aware of all
references, but often you aren't--trust me, I understand reference
counting).

Then there also seems to be a bug in imaplib.IMAP4_SSL since in its
shutdown method it closes the socket but leaves the sslobj untouched.  I
assume that that object keeps a reference to the socket.

But as I said, I expect the close() to actually close.

-- 
Sjoerd Mullender