Re: [Boost-build] v2 Python toolset doesn't faithfully reproduce v1

From: Vladimir Prus (ghost_at_[hidden])
Date: 2006-07-13 12:17:17

On Thursday 13 July 2006 20:05, David Abrahams wrote:
> Vladimir Prus <ghost_at_[hidden]> writes:
> > On Thursday 13 July 2006 18:09, David Abrahams wrote:
> >> Vladimir Prus <ghost_at_[hidden]> writes:
> >> > We've being though this before, and you basically agreed that this
> >> > comment is not accurate. Please see the attached message. This topic
> >> > then died.
> >>
> >> Do we need it to un-die, or do you think all the problems are
> >> resolved?
> >
> > I think we need it to un-die. The two current issues are:
> >
> > 1. I've modified Boost.Python tests Jamfile.v2 to have <threading>multi.
> > I think that fixes the errors, but is not a clean solution. I'd prefer
> > direct linking to pthread.
>
> Why?  For example, do you believe the other options that
> <threading>multi might add are inappropriate, and if so, why do you
> think that?

The apparent problem we see that that Python wants symbols from the pthread 
library. The apparent solution is to add that library.

The <threading>multi, applied to my main executable, means I pay for thread 
safety, even if my executable is single-threaded. 

> > 2. I noticed that in V2 Boost.Python links to Python library.
>
> Too vague to understand.

On Unix, the Boost.Python's so library is created, there's -lpython2.3 option
on linkers' command line. This in in V2, and in V1 this is not done.

> * Windows, Unix, both...?
>
> * You mean the boost_python.so/dll links to libpython.a/pythonXX.lib?

I think on my system libpython is actually .so.

> > This sounds potentially problematic, I'm not sure if Python
> > interpreter will completely hide all symbols from Python shared lib.
>
> Sorry, you lost me completely here.  Whose symbols?  How would a
> Python interpreter hide symbols?

Python interpreter has almost the same set of functions as Python dynamic 
library (the Py_* functions). If Python interpreter loads an extension which 
links to Boost.Python which is linked to Python library, you get two copies 
of each function. And I have no idea if this is going to work, or create some 
problems.

- Volodya