weak implementation of threads has problems - kse fix attached

[Sean McNeil]

On Mon, 2004-06-07 at 22:34, Daniel Eischen wrote:
> On Tue, 8 Jun 2004, John Birrell wrote:
> 
> > [ cross-post lists cut back, ports added 8-) ]
> > 
> > On Mon, Jun 07, 2004 at 11:48:45PM -0500, Dan Nelson wrote:
> > > A good addition to bsd.port.mk, right next to the "possible network
> > > server" etc checks, might be to run ldd on all installed shared
> > > libraries and print a warning if any threads libraries show up.  There
> > > are a huge number of ports that install shlibs linked to libpthreads.
> > 
> > Good idea.
> 
> Just picking a message at random to reply to...
> 
> In case anyone wonders why we don't use strong references, I chose to
> mimic what Solaris does:
> 
>   bash-2.05$ nm /lib/libpthread.so.1 | grep pthread_mutex_lock
>   0000000000003c80 T _pthread_mutex_lock
>   0000000000003c80 W pthread_mutex_lock
> 
>   bash-2.05$ nm /lib/libc.so.1 | grep pthread_mutex_lock
>   0000000000096c38 W _pthread_mutex_lock
>   0000000000096c38 W pthread_mutex_lock
> 
> It is also easy to provide your own version of pthread_foo() without
> having any strong references override it.

OK, that is what I was wondering.  In that case, you have failed to
mimic Solaris:

[sean at wrsparc sean]$ uname -a
SunOS wrsparc.mcneil.com 5.7 Generic_106541-12 sun4u sparc SUNW,Ultra-5_10

[sean at wrsparc sean]$ nm /lib/libpthread.so.1 | grep select
[201]   |     21328|       8|FUNC |GLOB |0    |8      |select

[sean at wrsparc sean]$ nm /lib/libc.so.1 | grep select
[213]   |    320732|    1420|FUNC |LOCL |0    |12     |_libc_select
[4534]  |    320732|    1420|FUNC |GLOB |0    |12     |_select
[3556]  |    320732|    1420|FUNC |WEAK |0    |12     |select
[1385]  |         0|       0|FILE |LOCL |0    |ABS    |select.c
[4404]  |    322152|    1920|FUNC |GLOB |0    |12     |select_large_fdset
[1387]  |         0|       0|FILE |LOCL |0    |ABS    |select_large_fdset.c

Same thing with open or any of the other libc functions.

That is why Solaris works correctly and FreeBSD does not.