[Mailman-Developers] race condition in locking ?
bwarsaw@python.org
bwarsaw@python.org
Tue, 2 May 2000 17:09:07 -0400 (EDT)
>>>>> "HM" == Harald Meland <Harald.Meland@usit.uio.no> writes:
>> I wonder though what happens if some impatient moderator
>> decides not to wait before the page finnishes loading, switches
>> to a differen webpage and therefor breaks the python cgi
>> process... will some approved posts stay in the queue instead?
>> Try it out ! ;) It depends on the exact behaviour of both the
>> webbrowser and the webserver.
HM> Yup. This might produce a SIGPIPE, and/or the corresponding
HM> IOError EPIPE, and I've experienced that these didn't always
HM> get caught -- an attempt at a fix is near the end of run_main
HM> in <URL:
HM> http://www.uio.no/~hmeland/tmp/mailman-userdb/scripts/driver>,
HM> but I'm by no means positive that it's the Right fix.
I've done a bit of testing using Apache and both NS and MSIE. What I
did was add a big sleep in admin.py, in main(), just before the
finally at the bottom of the function. I added some debug prints so I
could see what was going on.
As near as I can tell, if I hit the browser's stop button after
entering that big sleep, the CGI process gets kill stone cold. It
never reach the finally clause, doesn't get a SIGPIPE, nothing. Since
I can't reproduce this, I'm not sure what the right thing to do is.
Harald, what webserver are you running?
-Barry