Re: flock, fcntl, lockf?

[Vincent Lefevre <vincent@vinc17.org>]

On 2008-01-27 14:20:26 +0000, Hendrik Boom wrote:
> On Tue, 15 Jan 2008 10:33:49 +0100, Vincent Lefevre wrote:
> > I also use symlink locking, which is also NFS safe, mainly in my shell
> > scripts, because this is quite easy in this context. And one can put
> > interesting information in the symlink contents (the symlink doesn't
> > have to point to a real file). See what Firefox does for instance (the
> > lock is in the profile).
> 
> What is symlink locking?

symlink is an atomic operation (even under NFS), and if a symlink of
the same name already exists, the system call fails. As a consequence,
it can be used for locking.

> If firefox uses it that probably accounts for the weird links I see
> around now and then. It does seem to unlock upon killall, too.
> Betcha it won't work in Windows :-)

IIRC, it is supported by Windows under some conditions. You can read
the whole discussion about this choice here:

  https://bugzilla.mozilla.org/show_bug.cgi?id=76431

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Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
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