[boost] [python] threading-related failures on Linux

From: Vladimir Prus (ghost_at_[hidden])
Date: 2006-03-14 03:50:30

The OSL2-V2 test results show a few link failiures for Python tests, for 
example the 'bases' test:

    http://tinyurl.com/nyqv7

Looks like Boost.Python library wants multi-threading for some reason. In V1, 
those tests are linked with -pthread, and in V2, they are not. The logic	
responsible for this in V1 is in python.jam:

    # Force statically-linked embedding applications to be multithreaded
    # on UNIX.
    rule python-static-multithread ( toolset variant : properties * )
    {
        if ! $(PYTHON_WINDOWS)
        {
            local x = <define>BOOST_PYTHON_STATIC_LIB <threading>single ;
            if $(x) in $(properties)
            {
                properties = [ difference $(properties) : <threading>single ]
                                <threading>multi ;
            }
        }
        return $(properties) ;
    }

And I don't understand some things:

1. What's the point of this at all? The comment is not very clear, it seems it 
means static linking to Boost.Python, not statically linked application in 
the usual sense (no shared libs at all). The comment does not say why 
threading multi is needed.

2. In V2, shared linking to Boost.Python is used, and the application is fully 
shared. So, where does the link error come from? Is comment even more 
inaccurate?

3. On my system, the test works just fine. Why does it fail elsewhere/

4. The test in question, bases.cpp, has nothing but static asserts. It's not 
clear to me why it should link to Boost.Python at all.

Can somebody explain this to me?

Thanks in advance,
Volodya