Re: lfs (CVS version) compilation error under Ununtu-9.04 Jaunty

[David Given <dg@...>]

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Fabio Mascarenhas wrote:
[...]
> Obviously I am not married to this solution, so if you have a suggestion
> on how to implement exclusive locks that works both inside the same
> process (even in the same thread) and across processes, for both POSIX
> and Windows, I am all ears. :-)

We did this at work. On Unix our solution was to create a dummy file and
then use advisory locks with fcntl(_, F_SETLKW, _) locking across the
whole file. These have the nice behaviour of being automatically
unlocked if the app terminates unexpectedly. Allegedly these even work
across NFS these days.

For Windows we used named semaphores --- there's an atomic
lookup-by-name-or-create-if-not-found function call. Then you just use
them like an ordinary mutex.

If you want to lock *between* Windows and a Posix subsystem? Pass, I'm
afraid...

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