FWIW, this won't protect you from the case where two processes open the file at about the same time. The unlinked file won't be openable by other processes, since the namespace entry will be gone, but the two processes which already have it opened can continue to access it.

The first process will do it's thing and then delete the file. The second process will grab the lock on the still opened file, and then process as if it had the lock -- it won't know the file has been unlinked. If you can live with this, that's fine. If you want "exactly once" semantics, it's not.

FWIW, in general it's not a good idea to try to use an object's lock to synchronize the destruction of that object -- it is easy to overlook a race condition. You might get away with this in certain cases, but in general you'll rest easier if you use a different way. See one of the other methods described above (e.g. Ovid's 'sentinel', file renaming, etc.)

In reply to Re: Re: Re: correct usage of flock? by bluto
in thread correct usage of flock? by cLive ;-)

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