running threaded tasks in dynamically linked objects from a non-threaded app

[Jeremy Messenger]

On Sun, 02 Mar 2008 10:38:51 -0600, John E Hein <jhein at timing.com> wrote:

> I am having some issues with an application that uses...
>   [1] perl to run test scripts
>   [2] with eventually call modules in C modules
>   [3] which link with a lib that contains pthread* references.
>
> When the tests run, one gets undefined references to pthread calls
> from the run-time linker.
>
> [1] the perl port was not built WITH_THREADS=yes (non-threaded
>     is the default)
> [3] this lib was built with -pthread, but this does not contain
>     an explicit dependency on any threading library.  That's
>     how our -pthread works (so one can decide at the time an
>     application is linked which threading lib to use)
>
> workarounds:
>  - LD_PRELOAD=/usr/lib/libthr.so (or libpthread.so if desired)
>  - require perl to be built WITH_THREADS=yes for
>    users of this application
>  - build the lib in [3] with -lthr or -lpthread.  This
>    can break if perl in built WITH_THREADS=yes and
>    the threading libs in [1] and [3] don't match.
>
> These all have weaknesses in one facet or another.
> Are there any different solutions?

Are you using FreeBSD 6.x or below? I think it has been fixed in FreeBSD  
7.x and above with GCC 4.x. I only have tested it with Ruby.

Cheers,
Mezz


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