Fast thread-local storage for OpenGL drivers

[Gareth Hughes]

Dan Kegel wrote:
> 
> It does look like the TLS model does what you want it to,
> and no new methods are needed.  Can you explain in more detail
> why your new proposal is needed, if you still think it is?

To be clear, what I'm proposing requires ZERO code changes to Wine and
glibc.  It will work today, with Wine implementations already in the field.
All I'm proposing we do is make sure it continues to work in the future,
irrespective of the decision made regarding the use of glibc's new __thread
variable support.

As I said in my last email, there are some unresolved issues with using
__thread variables:

1) We need fast TLS access on platforms where __thread variables are not
supported.
2) libGL.so must be able to be dynamically loaded.  Failing to dlopen
libGL.so will, at the very least, make the entire Linux gaming community
very unhappy :-)
3) It is unclear how online generated code can interact with __thread
variables.  Perhaps this is simpler than I think...

--
Gareth Hughes (gareth at nvidia.com)
OpenGL Developer, NVIDIA Corporation