Re: [patch] munmap-before-rename, cygwin need

> "Yakov Lerner" <iler.ml@gmail.com> writes:
>
> > I found that mmap() works on cygwin, but needs a patch.
> > On Cygwin, rename() fails if target file has active mmap().
> > The patch below adds  munmap() before rename().
>
> This is interesting in three counts.
>
>  - I from time to time test Cygwin version on my day-job machine
>   (W2K) and my wife's machine (XP); on both machines I usually
>   have less than two weeks old Cygwin installation, and I have
>   not seen the breakage.  I wonder how reproducible this is.
>   Also previously people reported mmap() works for some and
>   fake mmap is needed for others.  Would this patch make things
>   work for everybody?
>
>  - The part you patched is commit_index_file().  This typically
>   is called just before program exit, but some callers, like
>   apply.c, may want to still look at the index after calling
>   it, fully aware that the changes after commit_index will not
>   be written out.  Although I haven't traced the codepath fully
>   in apply.c yet, unmapping would break the access to the index
>   (i.e. active_cache[]).  Does apply still work with your
>   patch?