FWIW, we forked zope.sendmail a while back (with the intent of eventually merging these changes back upstream) as "repoze.sendmail". It does not use any thread to do queue processing. Instead, a separate process can be run to handle queue processing.
This is being actively maintained. http://repoze.org/viewcvs/repoze.sendmail/trunk/README.txt?rev=3688&view=markup On 9/3/09 10:07 PM, Gary Poster wrote: > Hi all. One of the contributors to the Launchpad project has > identified a problem with zope.sendmail and thread changes in Python > >= 2.5.1. Here is his description: > > """ > Description of the situation: > > Prior to Python 2.5.1, the atexit handlers were executed when the > *main* thread exits. However,http://bugs.python.org/issue1566280 was > then filed, the essence of which is that the atexit handlers could > tear down cross-thread resources that were still in use by other > threads. > > For this reason, the shutdown procedure was modified in Python 2.5.1 - > now, when the main thread exits, it first makes a private call to > threading._shutdown(), which waits until all non-daemon threads have > exited, and *only then* proceeds to run the atexit handlers. > > Herein lies the problem. zope.sendmail.delivery.QueueProcessorThread > attempts to use atexit to notify itself when it should shut down. > However, the Python runtime>= 2.5.1 will wait for the > QueueProcessorThread to exit before it calls the atexit handlers! > > Potential solutions: > > (1) To gain behaviour most similar to earlier Python versions, an evil > monkeypatch into Python internals like this: > http://bazaar.launchpad.net/~maxb/zope3/launchpad-3.4-py2.5/revision/9works > . > > (2) Make the QueueProcessorThread a daemon thread. It will be > terminated without notification when the interpreter exits, but the > current QueueProcessorThread does not attempt to ensure its queue is > completely flushed before shutdown anyway, so that should not matter. > > I will attach a small Python demo program useful for illustrating and > exploring the issue. > """ > > You can see the bug report, and his demo program, here: > > https://bugs.edge.launchpad.net/zope3/+bug/413335 > > I wasn't going to send this until I had investigated this myself, but > I have been taking too long and thought I'd at least send this out to > see if anyone has any thoughts. Otherwise, I'll look into it ASAP and > report back. > > Thanks > > Gary > _______________________________________________ > Zope-Dev maillist - Zope-Dev@zope.org > https://mail.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > https://mail.zope.org/mailman/listinfo/zope-announce > https://mail.zope.org/mailman/listinfo/zope ) > _______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org https://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - https://mail.zope.org/mailman/listinfo/zope-announce https://mail.zope.org/mailman/listinfo/zope )