threading and atexit: different behaviour in python2.6 from 2.5

[MRAB]

Alan wrote:
> Hi there,
> 
> That's another try to get help about this issue I am facing. To help you 
> to help me here goes a simple example. This is a very simplification of 
> a very complex code.
> 
> -------------------- thread_ping.py -------------------- begin
> import time
> import sys
> import atexit
> from threading import Thread
> 
> class testit(Thread):
>    def __init__ (self,ip):
>       Thread.__init__(self)
>       self.ip = ip
>       self.status = 0
>    def run(self):
>       pingaling = os.popen("ping -q -c2 "+self.ip,"r")
>       while 1:
>         line = pingaling.readline()
>         if not line: break
>         igot = re.findall(testit.lifeline,line)
>         if igot:
>            self.status = int(igot[0])
> 
> def goodbye(t, report):
>     print 'Goodbye'
>     print "Status from ",t.ip,"is",report[t.status]
> 
> testit.lifeline = re.compile(r"(\d) packets received")
> report = ("No response","Partial Response","Alive")
> 
> ip = "209.85.227.104" # www.google.com <http://www.google.com> # try 
> with a failing IP if you want the test to last a bit longer
> 
> t = testit(ip)
> 
> atexit.register(goodbye, t, report)
> 
> t.start()
> 
> exit()
> -------------------- thread_ping.py -------------------- end
> 
> If one runs like:
> 
> amadeus[2579]:~/TMP% time python2.6 thread_ping.py
> Goodbye
> Status from  209.85.227.104 is Alive
> python2.6 thread_ping.py  0.02s user 0.02s system 3% cpu 1.056 total
> 
> (i.e., python2.6 wait till the thread finishes and leave... I don't want 
> this behaviour, see below)
> 
> and
> 
> amadeus[2580]:~/TMP% time python2.5 thread_ping.py
> Goodbye
> Status from  209.85.227.104 is No response
> python2.5 thread_ping.py  0.01s user 0.01s system 90% cpu 0.030 total
> 
> (i.e., python2.5 promptly quit, as desired)
> 
> Could someone tell me how to get python2.6 to have the same behaviour I 
> see with python2.5 for this example code?
> 
> Any hint would be very much appreciated indeed.
> 
> Many thanks in advance.
> 
The script won't exit while there are non-daemon threads running. You
can make a thread a daemon by setting its 'daemon' attribute to True
before starting the thread. If you want the script to be backwards
compatible with Python 2.5 then use the 'setDaemon' method instead.

I don't know why the script exited in Python 2.5 even though a
non-daemon thread was still running.