Mysterious hang

[Johannes Bauer]

Hello group,

I'm pretty despereate right now and apologize for my diffuse question in
advance - but I do not know how to continue right now.

I'm writing a GUI client (pygtk) which talks to a server (TCP/IP),
fetches pictures (FITS format) and displays them. This works nicely.

Now I have a plugin which is called from a menu. The plugin also talks
to the server, then fetches a picture. However, when trying to fetch a
picture this way, the Python program hangs - every time, always at the
same position - and I have not the least clue why.

File "./guiclient.py", line 368, in on_Focus
self.__plugin_instances[0].run()
File "plugins/Focus.py", line 57, in run
img = result.fetch()
File "/home/joe/client/imgproto/Connection.py", line 54, in fetch
return self.__device.conn().getbindata()
File "/home/joe/client/imgproto/TransportLayerConnection.py", line
100, in getbindata
copied = self.__s.recv_into(result[pos:], remaining)

The debug output of my program indicates that *always* the last 1023
bytes are waited for. Wireshark however tells me they are sent!

Done, fetching '2009_06_15_11_12_12_picture'
Fetching...
Fetching remaining 659520 bytes
15360 bytes fetched
Fetching remaining 644160 bytes
16384 bytes fetched
Fetching remaining 627776 bytes
16384 bytes fetched
Fetching remaining 611392 bytes
16384 bytes fetched
Fetching remaining 595008 bytes
16384 bytes fetched
Fetching remaining 578624 bytes
16384 bytes fetched
Fetching remaining 562240 bytes
147456 bytes fetched
Fetching remaining 414784 bytes
49152 bytes fetched
Fetching remaining 365632 bytes
49152 bytes fetched
Fetching remaining 316480 bytes
49152 bytes fetched
Fetching remaining 267328 bytes
98304 bytes fetched
Fetching remaining 169024 bytes
49152 bytes fetched
Fetching remaining 119872 bytes
49152 bytes fetched
Fetching remaining 70720 bytes
49152 bytes fetched
Fetching remaining 21568 bytes
20545 bytes fetched
Fetching remaining 1023 bytes

I then tried to multithread that, which did not work either (showed even
more confusing behaviour). What in the world could possibly cause such
an error? How can I trace it?

Kind regards,
Johannes