[slime-devel] Re: [Sbcl-devel] Slime and :sb-futex on recent CVS SBCLs

[dan at telent.net]

This isn't just about CVS SBCL; SB-FUTEX was removed last month before 
the 0.8.21 release

On Tue, Apr 19, 2005 at 01:56:21PM +0200, Vincent Arkesteijn wrote:
> A somewhat related problem, which will be uncovered by fixing the
> one that Andreas describes, surfaces when running SLIME+SBCL on
> a non-NPTL 2.4 kernel. :sb-thread is still on *features*, so
> swank:*communication-style* will be set to :spawn, but calling
> make-thread will then fail. Not nice.
> 
> Possible solutions:
> 1) Remove :sb-thread from *features* when running on a non-NPTL
>    kernel.

I think this (and the consequently necessary changes to the fasl
compatibility checker) is probably TRT, but not this close to a
release.

> 2) Add some function or variable to SBCL that can be used to check
>    whether threads actually work, and change SLIME to use that.

* (defun communication-style () (if (and (member :sb-thread *features*) (not (sb-alien:extern-alien "linux_no_threads_p" sb-alien:boolean))) :spawn :fd-handler))

COMMUNICATION-STYLE
* (communication-style)

:SPAWN

... but note that this uses implementation-internal stuff and is not
guaranteed to stay working.  As the useful working life of any SLIME 
version on SBCL rarely exceeds three months anyway, that might not be 
such a big deal


-dan