[Sbcl-devel] [SBCL-devel] Building SBCLt with Lutexes on Ubuntu64

[David L. R. <ra...@cs...>]

Greetings SBCL-Devel,

This post is related to my earlier question about writing a patch for
timed waiting on semaphores and condition variables [visible at
http://sourceforge.net/mailarchive/forum.php?thread_name=633...@ma...&forum_name=sbcl-help
]

I attempted to build the lutex version of SBCL and received an error
about PTHREAD_MUTEX_ERRORCHECK being undeclared.  It looks like the
compiler needs C flag USE_UNIX98 to enable the inclusion of that
constant.  So, I first tried adding the flag "XOPEN_SOURCE=500" to the
CFLAGS variable in line 26 of src/runtime/GNUmakefile.  After that
failed, I tried instead adding the flag "GNU_SOURCE".  This second
change seems to work [suggested changes taken from
http://ipozgaj.blogspot.com/2006/08/posix-threads-and-manual-pages-rant.html
].

Is building the lutex version of threaded SBCL 1.0.33 on Linux 64 bit
machines known to have this problem?  I had the same difficulty with
version 1.0.30.  Does the second change look reasonable?  Do we know
whether such a change would introduce performance problems?

In the long run, I don't expect to need to manually enable lutexes on
my Ubuntu64 setup.  It's just that I need to get the lutex version to
work before I can test the addition of timed waiting to lutexes, and
it seems like modifying the GNUMakefile could also have benefits for
others.

Thanks,
David