Re: [bug-mailutils] Lock with external program question

[Kostas Zorbadelos]

On Wed, Sep 21, 2005 at 01:42:57PM -0400, Alain Magloire wrote:
> 
> 
> > From: address@hidden [mailto:bug-mailutils-
> > Subject: Re: [bug-mailutils] Lock with external program question
> > 
> > On Wed, Sep 21, 2005 at 06:46:06PM +0300, Kostas Zorbadelos wrote:
> > 
> > Please discard this question. Our decision in not to use an external
> > program (as it will spawn an external process). Instead we would like
> > to implement another locking method or extend the ones found in
> > locker.c
> > 
> > Will lets you know and send patches.
> > 
> 
> Interesting, for mailbox locking, there are 2 types of locks that are
> recognized:
> - the dotlock: creating a known temporary file(with the PID as the content)
> - the fcntl/lockf: using the OS locking mechanism, with the caveat it may
> not work across distributed file system like NFS.
>

This is perfect.
 
> This seems to cover most cases, so the locker_t object did not allow to
> overload its behaviour besides, providing the behaviour with the flags at
> creation locker_create(..., flags);
> 
> I'm curious, what scenario did we not cover, with all the flags define in
> locker.h?
> 

The issue is that I want to use a combination of methods for locking
(dotlock WITH kernel fcntl). This need comes from the fact that the
various programs that access the mailboxes (imap server, pop server)
lock with different ways, so we want the mda to lock with all possible
ways when delivering to mailboxes.

>From what Sergey told me in a previous thread you have to use 2 locker
objects and handle the one 'by hand' (see
http://lists.gnu.org/archive/html/bug-mailutils/2005-07/msg00008.html)

I can do this in my mda where I handle delivery to the user's INBOX,
but I cannot do it in the sieve fileinto action, unless I tamper with
the fileinto action code (which is something I do not want).

Any suggestions are highly welcome.

Kostas

-- 
  Kostas Zorbadelos
  Systems Designer/Developer, Otenet SA 
  address@hidden contact: kzorba (at) otenet.gr
  
  Out there in the darkness, out there in the night
  out there in the starlight, one soul burns brighter
  than a thousand suns.