Re: [Mesa3d-users] undefined symbol in egl/egl_x11_swrast.so and init problems

[Chia-I Wu <ol...@gm...>]

On Wed, Mar 31, 2010 at 05:59:16PM +0200, Andreas Pokorny wrote:
> Its me again,
> 2010/3/12 Chia-I Wu <ol...@gm...>:
> > On Fri, Mar 12, 2010 at 6:02 AM, Andreas Pokorny
> > <and...@gm...> wrote:
> >> 2010/3/11 Chia-I Wu <ol...@gm...>:
> >>> On Thu, Mar 11, 2010 at 10:06 PM, Andreas Pokorny
> >>> <and...@gm...> wrote:
> >>>> I work on: b8656c4825b9e054f05258773ba012e41d4fcdee
> >>>> I have two rather strange problems using egl. I have implemented a
> >>>> egl/es2/libX11 based renderer shared object file. The shared object
> >>>> file gets loaded and initialized using dlopen/dlsym. Then when the
> >>>> renderer is supposed to initialize EGL, and to create a window I run
> >>>> into runtime symbol lookup errors.
> >>>> ./Startup: symbol lookup error: /usr/local/lib/egl/egl_x11_swrast.so:
> >>>> undefined symbol: _eglInitDriverFallbacks
> >>> It seems _eglInitDriverFallbacks in libEGL.so is not resolved when
> >>> egl_x11_swrast.so is loaded.  I am not quite sure about your setup (who dlopen
> >>> who?).  Do you have a sample code that reproduces your setup or the issue?
> >> My applicatin dlopens a shared object files that links against EGL and
> >> ES2. I was just writing a sample code that turns progs/es2/xegl/tri.c
> >> into a shared library. Then I dlopen the lib with
> >> dlopen(RTLD_LAZY|RTLD_LOCAL);  - and then i try to execute an exported
> >> function of tri.c (turned main into a function with visibility
> >> default) as it seems RTLD_LOCAL causes the issue. I have to use
> >> RTLD_GLOBAL instead.  So now it works.
> >> I have no idea why i used RTLD_LOCAL in the first place.
> > Glad you solved your problem.  dlopen()ing is one of the part in EGL that I
> > haven't looked at.  I don't have enough experiences on various setups or Unixes
> > to say that EGL is doing the right thing.
> According to git bisect the fix of chaning RTLD_LOCAL to RTLD_GLOBAL
> causes a crash in a different es2/egl implementation.
> What is bad about explicitly linking to libEGL.so in the egl driver?
> From my limited point of view it work without breaking anything.
Sorry for the late response.

Could the crash happen to be a version mismatch between libEGL and the
driver?  There is no version checking done right now..

As for linking back to libEGL, I was worried about cyclic linking.
Currently, EGL drivers require back-linking to libEGL

http://sourceware.org/autobook/autobook/autobook_172.html

It is assumed to be a bad design.  I hope to fix this intead of linking
back to libEGL.

-- 
ol...@Lu...