Re: [mpop-users] Explanation of the locking mechanism

[Martin Lambers <marlam@...1...>]

On Sun, 17. Feb 2008, 17:44:16 +0200, Dawn Light wrote:
> I want to run mpop using cron so I need to make sure locking is
> working properly so that mpop will not start a session while a
> previous session in running.
> 
> Look at this: [...]
>
> it seems as though the two mpop processes are running at the same
> time.

Mpop does not prevent running multiple instances in parallel. Instead,
it makes sure that running multiple instances cannot lead to problems.

Locking is used for the files that mpop must alter: the UIDLS file and
the MBOX file (if mails are delivered to an MBOX file).  Locking of the
POP3 account is done by the POP3 server. 

You can run mulitple instances of mpop without problems. If you
nevertheless want to make sure that this never happens, you can write a
small wrapper script that
1) exits immediately if a lock file exists
2) otherwise, creates a lock file, starts mpop, and deletes the lock
file when mpop finished.

Regards,
Martin