harold fellermann <harold@[...].de>  writes:

>  Hello,
> 
>  I got your address from
>  http://mail.python.org/pipermail/c++-sig/2002-June/001311.html -- so I
>  don't know whether you are the right person to ask.

"We" are the right people to ask.  You sent it to the appropriate
place: c++-sig@[...].org.

>  I think I have found an error in the boost.python's dict-interface.
> 
>  My following code-snippet runs into segmantation fault:
> 
>  #include <stdlib.h>
>  #include <boost/python/dict.hpp>
> 
>  using namespace boost::python;
> 
>  int main()
>  {
>     dict x[750];
> 
>     return 0;
>  }


Do you really mean to construct an array of 750 dicts?  I think if
you're going to do that from a program (as opposed to an extension
module) you'll need to call some things like PyInitialize() first.
See libs/python/test/embedding.cpp for an example.

>  The problem seems to concern the garbage collector from the
>  Python/C-API, as
>  my debugger tells me, the program crashes in _PyObject_GC_New():
> 
> 
>  (gdb) run
>  Starting program: /home/tsb/harold/c_network/pytest
>  [New Thread 1024 (LWP 25905)]
> 
>  Program received signal SIGSEGV, Segmentation fault.
>  [Switching to Thread 1024 (LWP 25905)]
>  0x0809a909 in PyErr_Occurred ()
>  (gdb) bt
>  #0  0x0809a909 in PyErr_Occurred ()
>  #1  0x080addca in _PyObject_GC_New ()
>  #2  0x08064edc in PyDict_New ()
>  #3  0x4003b1f4 in boost::python::detail::dict_base::dict_base() ()
>      from /usr/local/lib/libboost_python.so.1.29.0
>  #4  0x080c6c6c in main () at pytest.c:9
>  #5  0x401744a2 in __libc_start_main () from /lib/libc.so.6
> 
> 
>  I tried this with a couple of python-objects and all containers (dict,
>  list, ...)
>  crashed in exactly the same way. Interestingly the program behaves
>  normal when
>  I reduce the number of objects within my array to approx. 700.

Very interesting, but inconclusive.

>  My configuration looks as follows:
>  - python 2.2.1 (#1, Sep 10 2002, 17:49:17)
>  - gcc 3.2
>  - boost version 1.29.0
> 
>  Do you have any idea what is going on here? Is this a known bug,
>  maybe even a nowadays fixed one? Or is it only a question of
>  configuration?  Any help will be appreciated!

It's hard to imagine any bug in Boost.PYthon that would depend on the
size of the array being small; maybe one in the compiler or in Python
could do that.

This works on my system:

#include <stdlib.h> 
#include <boost/python/dict.hpp> 

using namespace boost::python;

void test()
{
    // Initialize the interpreter
    Py_Initialize();
    dict d[750];
}

int main()
{
    if (handle_exception(test))
    {
        if (PyErr_Occurred())
            PyErr_Print();
        return 1;
    }
    return 0;
}

HTH,
-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com


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