On Sat, 15 Jan 2005, Danny Yoo wrote: > > > > I have only wrapped my lock around file-descriptor creations. Should I > > wrap it around closings too? Or the whole open -> close transaction? > > It sounds like error-prone work to do the latter. What am I missing? > > Hi Marilyn, > > Can you send a link to the source code to the Tutor list? I'm getting the > feeling that there's might be a design problem. Just adding locks > whenever something doesn't work is not a sustainable way to write a > multithreaded application. > > We have to see why your file descriptors being are being shared between > threads. Is there a reason why you need to share them as global > resources?
No. And I don't. They are often attributes of instantiations of classes; or they come and go quickly. Thank you for offering to look at the code. Start at: http://www.maildance.com/python/doorman/README Then, the daemon that creates the threads is: http://www.maildance.com/python/doorman/py_daemon.py I'm testing using calls to: http://www.maildance.com/python/doorman/route_mail.py http://www.maildance.com/python/doorman/doorman.py Other modules that open and close file descriptors from there are: http://www.maildance.com/python/doorman/db.py http://www.maildance.com/python/doorman/doorman_log.py http://www.maildance.com/python/doorman/exim.py http://www.maildance.com/python/doorman/move.py I'll be grateful for any improvements you suggest. But, I do know that some modules aren't well-documented, or are hardly documented at all yet. And db.py seems like a mess to me. But I'm not ready to straighten it up yet. But the most important one, py_daemon.py, I hope is very readable. Still though, I should confess, I am feeling a bit dismal about the thread situation, especially since searching around for info on critical code. The examples I found, before I gave up, were all trivial. Also, there is this article: http://linuxgazette.net/107/pai.html Which says that the performance is almost the same with threads as with single-threading. Boo. So suddenly, I have no idea why I'm down this road. We have a huge performance savings from setting up a daemon that reads a socket. But, unless something changes our minds soon, I'll rip threading out of our code. Still though, I am a teacher too, and a student. So any thoughts you have about our code will be treated like the pearls they are. Thank you again. Marilyn > > -- _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
