Apache Django Mod_Wsgi - auto reload

Question

I am trying to auto reload my django app which uses apache + mod_wsgi on my local windows machine.

I'd like to know where do I add this code that's referenced in the following article:

http://code.google.com/p/modwsgi/wiki/ReloadingSourceCode

def _restart(path):
    _queue.put(True)
    prefix = 'monitor (pid=%d):' % os.getpid()
    print >> sys.stderr, '%s Change detected to \'%s\'.' % (prefix, path)
    print >> sys.stderr, '%s Triggering Apache restart.' % prefix
    import ctypes
    ctypes.windll.libhttpd.ap_signal_parent(1)

Answer 1

You replace the restart function that is mentioned in the block of code above in the same article.

Answer 2

You replace the restart function in the following block of code you find on the page:

Monitoring For Code Changes

The use of signals to restart a daemon process could also be employed in a mechanism which automatically detects changes to any Python modules or dependent files. This could be achieved by creating a thread at startup which periodically looks to see if file timestamps have changed and trigger a restart if they have.

Example code for such an automatic restart mechanism which is compatible with how mod_wsgi works is shown below.

import os
import sys
import time
import signal
import threading
import atexit
import Queue

_interval = 1.0
_times = {}
_files = []

_running = False
_queue = Queue.Queue()
_lock = threading.Lock()

def _restart(path):
    _queue.put(True)
    prefix = 'monitor (pid=%d):' % os.getpid()
    print >> sys.stderr, '%s Change detected to \'%s\'.' % (prefix, path)
    print >> sys.stderr, '%s Triggering process restart.' % prefix
    os.kill(os.getpid(), signal.SIGINT)

Answer 3

Read:

http://blog.dscpl.com.au/2008/12/using-modwsgi-when-developing-django.html

It tells you exactly where to place the file when using Django. You just need to make the code change that everyone is pointing out to you in the source code reloading documentation section related to Windows. Also read:

http://blog.dscpl.com.au/2009/02/source-code-reloading-with-modwsgi-on.html

which explains the variations on the first related to Windows.