Clean-up of threaded server

[Michael Ströder]

David Bolen wrote:
> 
> Michael Stroeder <michael at stroeder.com> writes:
> 
> > I have two problems:
> >
> > 1. The server process does not detach from the console anymore (fork
> > is used for that). This seems to work without the separate helper
> > thread.
> >
> I'm not sure about (1) (perhaps depending on environment, the other
> thread has its own reference to file handles that you normally close
> before detaching, and you could try closing them before starting up
> the thread?)

It seems that I have some problems with file handles. Hmm, but the
helper thread does not use file handles at all.

Is there a way to determine which and/or how many file handles are
used by a process/thread?

> > 2. For testing purposes the server process can be started
> > non-detached. In this case KeyboardInterrupt is catched by the main
> > thread to shut down the process. This does not work with the helper
> > thread but works without it.
> 
> But for (2) if you have multiple threads around, then Python is going
> to wait for those other threads to terminate when you try to exit
> (it's basically the same as you doing a join() on each thread).  So to
> properly exit, you would want to write your helper threads to look for
> some sort of sentinel or receive a message to tell them to exit when
> you want the script to exit.

I think that's what I have to do. Thanks for answering.

> Alternatively, threads can be marked as a "daemon" via the threading
> module setDaemon method, and those threads are permitted to still be
> executing when the script exits.

isDaemon() of the helper Thread object returns 0.

Ciao, Michael.