Re: [Libreoffice] Trying to diagnose base running extremely slowly

On Thu, 2012-01-12 at 10:44 +0100, Stephan Bergmann wrote:
> > I think the best solution here would be to change the LibO hsqldb code,
> > to call Attach/DetachCurrentThread rarely rather than frequently, but
> > according to Ocke Janssen (who used to maintain that code) that was no
> > easy option.
>
> One rather easy fix would be to confine the 
> com.sun.star.comp.sdbc.JDBCDriver UNO code to a thread-affine apartment, 
> see the attached patch.  That way, all code related to this UNO service 
> (which is the code that calls Attach/DetachCurrentThread so frequently 
> and thus causes the performance degradation) is run in a single, 
> dedicated thread.

        That sounds like a rather elegant fix to me :-) as long as that thread
is not the "main thread" - we use rather deep stacks in the calc code
there & this is how the original bug was found etc. it'd be a good fix.

> One drawback of using the thread-affine apartment is that all code 
> related to the JDBC driver is effectively serialized, removing any 
> potential performance advantage from accessing the driver from multiple 
> treads.  I do not know whether that is acceptable or not.

        Given the generally tangled locking everywhere I would expect that
virtually everything is serialised anyway ;-) so ...

        It'd be great to have a fix for the base guys I guess.

        Thanks !

                Michael.

-- 
michael.meeks@suse.com  <><, Pseudo Engineer, itinerant idiot