Mail Archives: cygwin/2012/08/16/12:35:22
> >> This recent wish for SQLite on Cygwin to act more Unix-like is the
> >> first such request I've received, and I don't remember it being an
> >> issue with the previous maintainer, either.
> >
> > Maybe the reason is because subversion didn't use SQLite before?
>
> That's mere happenstance. There's nothing special about Subversion
> in this regard. It could have happened with any other pair of
> SQLite based programs. The fact that it hasn't until now means the
> DITCW principle isn't buying us much in this case.
>
> Understand Corinna, I see your point, and Achim's. Remember that I
> accepted Achim's patch and released 3.7.12.1-1 including it. Making
> Cygwin SQLite behave in a POSIXy way feels right. But, given that
> the new locking behavior causes actual people actual problems,
> purity alone isn't looking like such a good reason to keep the new
behavior.
>
> If we discard purity as a reason to do this, all we're left with is
> the actual problem brought up by one person (Achim) in N years. We
> can't solve that problem without causing problems for many others.
>
> > This behaviour breaks concurrency with other Cygwin executables
> > using POSIX calls for file locking.
>
> I agree, in principle, the 3.7.3/13-1 locking behavior is Wrong (tm).
>
> >> Advisory locking only works when all players cooperate. We can't
> >> assume that on Windows, unless we set up an insular Cygwin ghetto.
> >
> > So, are you saying that Cygwin should use mandatory file locking?
>
> In a situation like this, you have three choices:
>
> 1. Use mandatory locking in the Cygwin program. Ugly, but useful
> work gets done.
>
> 2. Tell all users of the Cygwin program to stop using the native
> Windows program or switch to a Cygwin alternative. This is a bad
> choice as a rule, since it tells the world Cygwin doesn't play well
> with others. It's worse in this case due to N years of the Cygwin
> program playing well with the Windows program. Additionally, there
> is no GUI Subversion client in the Cygwin package repo.
>
Corina is correct, Cygwin is supposed to be a Posix compliant environment so
the SQLite package should follow the Posix standard as the default
behavior. If you want to use Windoze tools, why are you using Cygwin? If
you really must, why not set up Apache under Cygwin and access the Cygwin
Subversion repository through the defined http server interface and the
issue of file locking becomes moot.
Cygwin is not a Windoze/Posix program compatability matching system; it is a
Posix environment on the Windoze platform. There is no intention to have
Windoze only application work directly to Cygwin applications (nor is there
an intention to prevent this either).
As a worst case scenario, why can't the direct SVN access locking behavior
be determined by setting an environment variable. If users want it to work
with Windoze programs (i.e. in a non-posix way), have them set an
environment variable for hard locks; other wise, let the rest of us who want
a Posix experience use the advisory locks. If this solution isn't
acceptable, Cygwin Subversion should use a different DB and drop SQLite.
Sincerely,
Brian S. Wilson
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