RE: why does tortoise, wcng and cygwin break from icon caching?

Cygwin abstracts the windows io layer and then puts a UNIX like io layer on
top.

Sqlite then uses that io layer instead of the windows io layer it was
optimized for.

I'm certainly not surprised if you then see slight differences in locking
behavior if both implementations use the same database at the same time.

Bert Huijben (Cell phone)
------------------------------
From: Stefan Fuhrmann
Sent: 6-7-2012 10:05
To: Neels J Hofmeyr
Cc: Subversion Development; dev_at_tortoisesvn.tigris.org
Subject: Re: why does tortoise, wcng and cygwin break from icon caching?

On Fri, Jul 6, 2012 at 12:58 AM, Neels J Hofmeyr <neels_at_elego.de> wrote:

> Today Random Person on #svn reported a problem and later its apparent
> solution, and it struck me as rather peculiar:
>
> [[[
> <yates`> when trying to do an svn cleanup, i get a strange message:
> svn: E200030: disk I/O error, executing statement 'COMMIT TRANSACTION;'
>
> I suspect a reader / writer locking issue with Sqlite.
The I/O error as such might be related to the win7 /
cygwin combination requiring more retries or such.

> this is under win7 using the cygwin svn client
> and also tortoisesvn is installed
>
> ...
>
> <yates`> neels: i found the issue
>
> strangely, there is an interaction between tortoisesvn and the cli svn
> under
> cygwin
>
> you must disable tortoisesvn's icon caching, then the problem goes away.
> http://www.mail-archive.com/cygwin@cygwin.com/msg123745.html
> ]]]
>

I.e. they disabled the background process that will
open the working copy soon after the OS detected
some file change. The scan itself may take a very
long time. Depending on OS and wc details, the db
may get opened at some very inconvenient time
while the commit is still in progress / in some critical
stage.

> and
>
> "I've confirmed what others have stated that it's only a problem with
> v3.7.12.1 and NOT a problem with v3.7.3."
>
> Hmm, disable icon caching to not break wc-ng? Why!?
>
> I think to remember that access to WCNG is much
more exclusive than it used to be in 1.6. But I don't
know whether that is actually true not the details.

-- Stefan^2.

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