[PATCH] Kneecap win32 locks

[Martin Pool]

2009/7/3 Martin (gzlist) <gzlist at googlemail.com>:
> This patch removes most of the protection file locks provide on
> windows, particularly of write locks from being read.
>
> Before:
>    Ran 20719 tests in 3007.156s
>
>    FAILED (failures=43, errors=156, known_failure_count=13)
>    2024 tests skipped
>
> After:
>    Ran 20719 tests in 3067.453s
>
>    FAILED (failures=22, errors=29, known_failure_count=12)
>    2023 tests skipped
>
> The change is fundamentally a bad idea, but it is interesting to see
> that of 199 windows failures and errors, three quarters are related to
> incorrect assumptions about locks.
>
> Also makes `bzr shelf` work, amoungst other things.

That is interesting to see.

Unfortunately the point of the lock is that writers must exclude
readers if they plan to update the file in place.  We need a format
change to avoid that.  Maybe after 2a is baked.

-- 
Martin <http://launchpad.net/~mbp/>