Re: [Boost-users] [serialization] Polymorphic serialization with polymorphic archives problem...

Subject: Re: [Boost-users] [serialization] Polymorphic serialization with polymorphic archives problem...
From: Bogdan (bogdan.indy_at_[hidden])
Date: 2010-02-23 07:32:52

> Bogdan wrote:
> 
> > 3. serialization files in a separate dll. Both the main executable and
> > my dll link with the dll version of the serialization library:
> >
> >    main.exe
> >        my_serialization.dll
> >        boost_serialization.dll
> >
> >    my_serialization.dll
> >        boost_serialization.dll
> >
> > Builds OK but FAILS at runtime , at run time I get a C++ exception
> > BEFORE main() in basic_serializer_map.cpp around the line 48:
> >
> > 'archive_exception::multiple_code_instantiation with the message "code
> > instantiated in more than one module - polymorphic_base"'
> 
> This would indicate that the serialization for polymorphic_base is
included in BOTH the
> mainline and the DLL.  Check that the serialization function is NOT an
inline definition.
> the polymorphic_base.cpp should only be needed when compiling the DLL.
> 
> option 1
> 
> include serialization definition for polymorphic_base in
my_serialization.dll
> 
> option 2
> 
> include serialization definition for polymorphic_base in it's own dll.
> 
> 
> > 4. serialization files in a separate dll. Both the main executable and
> > my dll link with the static version of the serialization library:
> >
> >    main.exe
> >        my_serialization.dll
> >        boost_serialization.lib
> >
> >    my_serialization.dll
> >        boost_serialization.lib
> >
> > Builds OK but FAILS at runtime while trying to serialize with the
> > following exception thrown in oserializer.hpp(line 424):struct
> > polymorphic::save():
> >
> > 'unregistered void cast class polymorphic_derived1<-polymorphic_base
> > in function 'int __cdecl main(int,char *[])''
> 
> This is probably failing due to the compiler stripping out code not
explicitly referred to.
> Since it's not referrred to, the linking doesn't include it from the
library.

====================================================

Hello Robert,

Thank you for your reply. The serialization functions are not inline: their
bodies are defined inside the DLL.

I did the following experiments:

- I skipped manually the registration exception in the debugger and it turns
out that all the serialized classes have their serializers registered twice.
- if in the main function I do not call serialize/deserialize, the program
runs ok; I agree with you, the program doesn't do anything but it proves
that the registration is triggered by the actual usage of the serialization
functionality and not by any eventual inline.

I am under the impression I followed all the directions in the documentation
and yet I keep hitting that glitch.

Thank you,

Bogdan

PS.
As for the case where boost serialization links as a static inside a user
DLL, it fails, indeed, due to the compile stripping out code. Is there a
workaround for this you would suggest?