[Boost-users] [Serialization, Signals?] Memory leaks while deserializing derived type

25 Jul 2008

      I'm getting memory leaks when deserializing objects and I can't figure out
what I'm doing wrong.  I'm using VC++ 2005. I've boiled it down to the
following code:

#include <fstream>

// include headers that implement a archive in simple text format
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/serialization/vector.hpp>
#include <boost/serialization/shared_ptr.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/signal.hpp>

// memory leak detection
#ifdef _MSC_VER
#   include <valarray> // doesn't like the free() replacement macro
#   define _CRTDBG_MAP_ALLOC
#   include <stdlib.h>
#   include <crtdbg.h>
#endif

using boost::signal;

class Base : public boost::enable_shared_from_this<Base>
{
public:
    typedef boost::shared_ptr<Base> sptr;
    //virtual ~Base() { }  // uncommmenting this causes leaks to disappear

private:

    virtual int virt() = 0; // commenting this line causes leaks to
disappear

    friend class boost::serialization::access;
    template<class Archive>
    void serialize(Archive & ar, const unsigned int version) { }
};

class Derived : public Base
{
private:

    int virt() { return 0; }

    friend class boost::serialization::access;
    template<class Archive>
    void serialize(Archive & ar, const unsigned int version)
    {
        ar & boost::serialization::base_object<Base>(*this);
    }

    signal<void (int, const Base::sptr&)> m_derivedSignal1;
};

int main(int argc, const char* argv[])
{
#ifdef _MSC_VER
    _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
#endif

    { Base::sptr loose_derived(new Derived()); } // no leak

    // create and open a character archive for output
    std::ofstream ofs("temp_serialize_file");

    Base::sptr d_instance(new Derived()); // no leak

    std::vector<Base::sptr> d_list;
    d_list.push_back(d_instance);

    // save data to archive
    {
        boost::archive::text_oarchive oa(ofs);
        oa.register_type<Derived>();

        // write class instance to archive
        oa & d_list;
        // archive and stream closed when destructors are called
    }

    // load data from archive
    std::vector<Base::sptr> loaded_d;
    {
        std::ifstream ifs("temp_serialize_file", std::ios::binary);
        boost::archive::text_iarchive ia(ifs);
        ia.register_type<Derived>();

        // read class state from archive
        ia & loaded_d;
        // archive and stream closed when destructors are called

        // loaded instance has leak in memory allocated in boost signals
    }

    return 0;
}

Any ideas would be very appreciated.

Brad Anderson