Restrictions on use of signal.signal() to register signal handlers.

                 Key: MODPYTHON-224
             Project: mod_python
          Issue Type: New Feature
          Components: core
    Affects Versions: 3.3.1
            Reporter: Graham Dumpleton

Apache makes use of signals as an integral part of its process management and 
shutdown/restart mechanisms. At the minimum it uses the signals SIGTERM, 

Problem is that some Python web frameworks which were originally designed to 
operate using their own web server still register signal handlers even when not 
being used on top of their own web server. This is the case with CherryPy and 
TurboGears (which uses CherryPy).

The consequence of any Python package trying to register signal handlers for 
the above signals is that they interfere with the correct operation of Apache 
and can causes restarts and shutdowns to fail or not proceed correctly. Since 
there generally isn't a good reason for any Python package running under 
mod_python to be registering signal handlers in the first place, to protect 
against such packages screwing with Apache, it may make sense for mod_python to 
replace signal.signal() in any interpreters it creates such that signal handler 
registrations are ignored. A warning message can be logged to indicate that 
signal handler registration has been prevented. A directive could also be 
implemented to allow the restriction on registering signal handlers to be 
removed if still required for some reason.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

Reply via email to