On 22/06/15 19:51, Emil Velikov wrote:
On 22 June 2015 at 15:01, Jose Fonseca <jfons...@vmware.com> wrote:
On 19/06/15 23:09, Emil Velikov wrote:

On 19 June 2015 at 21:26, Jose Fonseca <jfons...@vmware.com> wrote:

On 19/06/15 20:56, Emil Velikov wrote:


Hi all,

A lovely series inspired (more like 'was awaken to send these out') by
Pal Rohár, who was having issues when building xlib-libgl (plus the now
enabled gles*)

So here, we teach the final two static glapi users about shared-glapi,
plus some related fixes. After this is done we can finally start
transitioning to shared-only glapi, with some more details as mentioned
in one of the patches:

       XXX: With this one done, we can finally transition with enforcing
       shared-glapi, and

        - link the dri modules against libglapi.so, add --no-undefined to
       the LDFLAGS
        - drop the dlopen(libglapi.so/libGL.so, RTLD_GLOBAL) workarounds
       in the loaders - libGL, libEGL and libgbm.
        - start killing off/cleaning up the dispatch ?

       The caveats:
       1) up to what stage do we care about static libraries
        - libgl (either dri or xlib based)
        - osmesa
        - libEGL

       2) how about other platforms (scons) ?
        - currently the scons uses static glapi,
        - would we need the dlopen(...) on windows ?

Hope everyone is excited about this one as I am :-)



Maybe I missed the context of this changes, but why this matters or is an
improvement?

If one goes the extra mile (which this series doesn't) - one configure
option less, substantial some code de-duplication and consistent use
of the code amongst all components provided. This way any
improvements/cleanups made to the shared glapi will be available to
osmesa/xlib-libgl.


I'm perfectly happy with removing the configure option.

And I understand the benefits of unified code paths, but I believe that for
this particular case, the difference in requirements really demands the
separate code paths.

In summary, having the ability of using a shared glapi sounds great, but
forcing shared glapi everywhere, sounds a bad idea.

I'm suspecting that people might be keen on the following idea - use
static glapi for osmesa/xlib-libgl and shared one everywhere else?


Yes, that sounds reasonable for me.  (Needs libgl-gdi too.)

Indeed. Everything gdi is build only via scons so we'll touch it only if needed.


I fear that this will lead to further separation/bit-rot between the
different implementations, but it seems like the bester compromise.


I don't feel strongly between: a) using the same source code for both
static/shared glapi (switched by a pre-processor define), or b) only share
the interface but have shared/static glapi implementations.  I'm actually
not that familiar with that code.


Either way, we can have two glapi build targets (a shared-glapi and a
static-glapipe) side-by-side, so that there are no more source-wide
configure flags.

In theory it should be fine, in practise... I'm rather cautious as
mapi is the most convoluted part in mesa, and with the
"subdir-objects" option being toggled soon things may go (albeit
unlikely) subtly haywire.


I believe a lot of the complexity of that code comes from assembly.  I
wonder if it's really justified nowadays (and even if it is, whether it
would be better served with GNU C assembly.) Futhermore, I believe on
Windows we use any assembly, so if we split shared/static glapi source code,
we could probably abandon assembly from the static-glapi.

I'm not 100% sure but I'd suspect that Cygwin might use it when
combined with swrast_dri. Don't know what others use - iirc some of
the BSD folks are moving over to llvm. That I aside there is a massive
amount of #ifdef spaghetti, apart from the assembly code.

Can I have your ack/nack on the idea of having shared-glapi available
for xlib-libgl (patches 2, 3 and 4), until we have both glapi's built
in in parallel ? As mentioned originally, currently we fail to build
if one enabled gles* and xlib-libgl and adding another hack in
configure.ac is feel like flocking up a dead horse.

I rarely use auto conf myself, but the mentioned 2-4 patches look OK to me.

Acked-by: Jose Fonseca <jfons...@vmware.com>

_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev

Reply via email to