How to prevent a process from terminating on a KeyboardInterrupt?
I've been messing around with a Django project. What I want to achieve is the Django project starting up in another process while the parent process initiates a load of arbitary code I have written (the backend of my project). Obviously, the Django process and parent processes communicate. I'd like a dictionary to be read and written to by the processes.
I have the following code, based upon examples from here:
#!/usr/bin/env python
from multiprocessing import Process, Manager
import os
import time
from dj import manage
def django(d, l):
print "starting django"
d[1] = '1'
d['2'] = 2
d[0.25] = None
l.reverse()
manage.start()
def stop(d, l):
print "stopping"
print d
print l
if (__name__ == '__main__'):
os.system('clear')
print "starting backend..."
time.sleep(1)
print "backend start complete."
manager = Manager()
d = manager.dict()
l = manager.list(range(10))
p = Process(target=django, args=(d, l))
p.start()
try:
p.join()
except KeyboardInterrupt:
print "interrupt detected"
stop(d, l)
When I hit CTRL+C to kill the Django process, I'm seeing the Django server shut down, and stop()
being called. Then what I want to see is the dictionary, d
, and list, l
, being printed.
Output is:
starting bac开发者_如何学编程kend...
backend start complete.
starting django
Validating models...
0 errors found
Django version 1.3, using settings 'dj.settings'
Development server is running at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
^Cinterrupt detected
stopping
<DictProxy object, typeid 'dict' at 0x141ae10; '__str__()' failed>
<ListProxy object, typeid 'list' at 0x1425090; '__str__()' failed>
It can't find the dictionary or list after the CTRL+C event. Has the Manager process been terminated when the SIGINT is issued? If it is, is there anyway to stop it from terminating there and terminating with the main process?
I hope this makes sense. Any help greatly receieved.
Ok, as far I see no possibility to simply ignore exception. When you rise one, you always go straight into a "except" block if there is one. What I'm proposing here is something what will restart your django application on each ^C, but note, that there should be added some back door for leaving.
In theory, you can wrap each line with a try..except..
block and that would act like a restart of each line, what will not be as visible as restart of whole script. If anyone finds a really-working solution, I will be the first one to upvote him.
You can set all inside your if (__name__ == '__main__'):
into o main
function and leave something like this:
def main():
#all the code...
if (__name__ == '__main__'):
while True:
try:
main()
except KeyboardInterrupt:
pass
精彩评论