[Mesa-dev] [PATCH v3 1/2] configure.ac: Enable GLX_USE_TLS if possible.

[tom fogal]

On 02/15/2012 05:15 PM, Matt Turner wrote:
> On Wed, Feb 15, 2012 at 7:52 AM, tf (mobile)<tfogal at sci.utah.edu>  wrote:
>> Even if the system supports tls, the x server may not have been built with it.  As i recall, there is an issue with mismatching tls between x and drivers... Can a non-tls server load a tls driver?
>
> I don't think mismatching TLS/non-TLS Mesa and X server works, but I
> don't think that's a combination anyone cares to support (or is
> possible to support?).

Depends on the mismatch.  If X is TLS and Mesa isn't, no problem.  If 
Mesa is TLS and X isn't, drivers won't load.  There was some vague 
interest on getting that to work a while back, but nobody wanted to do 
the work and it wasn't considered very important.

>> Anyway, if there's an issue there, this check must be more complicated -- it can't be just, "does the system support this",  it would instead need to be "can the system support this and is it enabled in the x server."
>
> The X server isn't required to compile Mesa, so it doesn't make sense
> to try to check if the X server supports TLS.

This is a silly argument: we can very easily detect the cases in which 
Mesa is built to be used as an X driver or not.

 > I think the idea is, if
> the system supports TLS, let's default to enabled for both Mesa and
> the X server, and if you do something else and it breaks then you get
> to keep the pieces.

I am concerned about systems which --disable-tls when building X, and 
omit such a flag when building Mesa in a relevant configuration.  I 
think we should have an AC_MSG_ERROR for that case.

-tom