libgcj and the NPTL posix threads implementation

[Jeff Sturm]

On Mon, 1 Mar 2004, Andrew Haley wrote:
>  > If "we" == "Linux distribution vendors", then yes definitely.  But
>  > I'd expect nearly everyone building and using their own gcj would
>  > want Anthony's patch.
>
> I don't think so.  I have worked fairly recently on systems that have
> a working NPTL but gdb doesn't grok NPTL threads.

Oh, yuck!  I wasn't considering broken systems at all.  (Does NTPL require
TLS, or vice versa?  Both require kernel support, I understand...)

> It should be simple to use a function pointer to switch _Jv_ThreadSelf
> to different personalities, and the runtime cost would not be huge.

What can you reliably test for, besides catching a signal if TLS isn't
available?

Jeff