[Xorg] Damage/Composite + direct rendering clients

[mcnichol at austin.ibm.com]

> From: Egbert Eich <eich at pdx.freedesktop.org>
> 
> Jim Gettys writes:
>  > 
>  > Which is why avoiding server grabs is imporant, as much
>  > as possible.  It takes a global lock out on the X server and
>  > needs to be used with great care.
> 
> But you cannot rule out that some legacy client apps don't use server
> grabs for strange purposes. 
> It may in fact be necessary to make some 'priviledged' clients like
> the composition manager immune to server grabs.
> 

Please pardon my ignorance on this subject, but this discussion
raises the question in my mind about why the composition manager
is a client, rather than being part of the Xserver.

Is there a write up on this somewhere?

Thanks
Dan