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pythonpidlockfile

Python: module for creating PID-based lockfile?

I'm writing a Python script that may or may not (depending on a bunch of things) run for a long time, and I'd like to make sure that multiple instances (started via cron) don't step on each others toes. The logical way to do this seems to be a PID-based lockfile… But I don't want to re-invent the wheel if there is already code to do this.

So, is there a Python module out there which will manage the details of a PID-based lockfile?

Solution

  • If you can use GPLv2, Mercurial has a module for that:

    http://bitbucket.org/mirror/mercurial/src/tip/mercurial/lock.py

    Example usage:

    from mercurial import error, lock

try:
    l = lock.lock("/path/to/lock", timeout=600) # wait at most 10 minutes
    # do something
except error.LockHeld:
     # couldn't take the lock
else:
    l.release()