Problem with ksycoca on windows

David Faure faure at
Fri Feb 15 12:39:28 GMT 2008

On Friday 15 February 2008, Ralf Habacker wrote:
> > We can also dump our mmap code since QFile has mmap support now in 4.4.
> >   
> You are refering to QSharedMemory class or something else ?

No he's talking about the current solution for ksycoca: a file that is mmap'ed by all processes,
so that they don't have to load the complete file upfront (like you want to do on Windows :).

But I don't think it will help with the problem of replacing the file while it's being used (on Windows),
so it's a bit orthogonal to this discussion.

I'm fine with the patch being committed with a TODO for now (and an explanation in the code, too;
the problem is not that windows doesn't support mmap in itself, but that we can't replace the file while the
app is using it).
Using shared memory is an interesting alternative (for unix too), I wonder how portable QSharedMemory is.

David Faure, faure at, sponsored by Trolltech to work on KDE,
Konqueror (, and KOffice (

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