Lockfile hanling

[Matthew Ruffalo]

On 2015-03-31 10:50, Ervin Hegedüs wrote:
> there is an app, written in Python, which stores few bytes of
> datas in a single file. The application uses threads. Every
> thread can modify the file, but only one at a time. I'm using a
> lock file to prevent the multiple access.
>
> ...
>
> How can I prevent or avoid this issue? What's the correct way to
> handle the lockfile in Python?

Hi Ervin-

If only one instance of the app is running at a given time, and you only
need to ensure mutual exclusion between its threads, you should probably
not use a lock *file* for this. I would strongly recommend that you use
a threading.Lock as per
https://docs.python.org/2.5/lib/module-threading.html instead of a lock
file. This will also allow you to avoid a 0.2-second polling loop; a
call to threading.Lock.acquire() will block until it is released by
another thread.

MMR...