Inter-module exception name resolution through boost python does not work?

Question

Here is my problem:

I have two C++ modules, A and B, which are built as dynamically-linked libraries. A offers basic math functions, and custom exception types. B is a higher level module that uses A.

B::someFunction() calls a function from A, and tries to catch custom exception A:MyExceptionFromA in order to convert it into a custom type B:MyExceptionFromB (since users of module B do not need to know about the implementation details of A).

Everything works fine as long as I remain in the C++ domain. However, if I expose B::someFunction() in python via boost python, the exception is not caught anymore in the C++ module.

I can catch std::runtime_error, from which A:MyExceptionFromA derives, and call typeid(e).name() to get the retrieve the correct mangled name, so I know the correct exception is thrown. Therefore I suspect that the problem comes from resolving this mangled symbol into the correct exception type.

I have found this link, which explains that "python uses [the insular] model to open extension modules, so that extension module writers don't need to know what symbols other extension modules might be using.". I'm suspecting this is part of the problem/solution, but I do not know enough about symbol resolution to figure out how to solve my problem.

Any ideas?

Answer 1

I found a work-around to my problem. Based on this and link text, I figured out that adding

import sys, dl
sys.setdlopenflags(dl.RTLD_NOW|dl.RTLD_GLOBAL)

before my includes solves the problem, by forcing python to open libraries in immediate, global mode. But I'm still hoping for an alternative solution, if there's one. As mentioned in the first link, I'm suspicious that this could have unforeseen effects (I already know that name clashing could be a problem, and I suspect performance can be affected as well, but are there other side effects?)