On 29/09/06, Matthew Warren <[EMAIL PROTECTED]> wrote:
> I have
> found that in real usage of other programs within the company that use
> lockfiles, it sometimes causes a bit of troubleshooting time when it stops
> working due to a stale lockfile.. This especially happens when the program
> is killed, the lockfile remains and causes minor annoyance (to somebody who
> knows that is, more annoyance to somebody who doesn't).
Then they were checking for the wrong thing :) Chcking for a lock
file's existance is prone to the above problem. Checking to see if
anyone "owns" the lock file is better, and if a running program
doesn't close gracefully it still releases the lock file.
def check_lock():
import os, sys
try:
os.remove({filename})
except:
if "Permission denied" in sys.exc_info()[1]:
print 'This program is already running'
sys.exit()
f_lock = open({filename},'w')
You may want to close the lock file properly during a gracefull shutdown.
HTH :)
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