static variables empty when using dynamic loading of library - c++

Question

I have this setup:
ClassA.h - belongs to libA.dll
class ClassA
{
public:
static std::vector<std::string> getStrings();
~ClassA();
static void addToVector(std::string s);
static void setAddAllowed(bool addAllowed);
private:
ClassA();
};
extern "C"
{
extern void addToStrings(std::string s);
}
ClassA.cpp
#include<ClassA.h>
#include<vector>
static std::vector<std::string> strings;
static bool addAllowed = false;
std::vector<std::string> ClassA::getStrings()
{
return strings;
}
void ClassA::addToVector(std::string s)
{
if (addAllowed)
{
strings.push_back(s);
}
}
void ClassA::setAddAllowed(bool add)
{
addAllowed = add;
}
extern void addToStrings(std::string s)
{
ClassA::addToVector(s);
}
ClassB.h - belongs to libB.dll
class ClassB
{
public:
static void addString(std::string s);
};
ClassB.cpp
#include<ClassB.h>
#include<ClassA.h> //not present if libA is dynamically loaded.
void ClassB::addString(std::string s)
{
addToStrings( s ); // problem if addToStrings is called with a function pointer obtained from dynamic loading of libA.dll - libB doesn't depend on libA actually.
}
ClassC.h
class ClassC
{
public:
static void setAddAllowed(bool add);
};
ClassC.cpp
#include<ClassA.h>
#include<ClassC.h>
void ClassC::setAddAllowed(bool addAllowed)
{
ClassA::setAddAllowed(addAllowed);
}
Main.cpp
int main()
{
ClassB::addString("example1");
ClassC::setAddAllowed( true );
ClassB::addString("example2");
ClassB::addString("example3");
std::vector<std::string> v = ClassA::getStrings();
}
with this setup, every thing works fine, I could get the strings in ClassA::getStrings(). But the problem appears - the vector is empty, if I add the strings in ClassB using function pointer obtained from dynamically loaded dll of libA. I get the symbol of extern function addToStrings as function pointer and make a call. In that case, the vector v is empty.
Example code for loading libA and calling the function:
typedef void (*addToStringsFP) (std::string s);
addToStringsFP fp = NULL;
Handle libHandle = NULL;
libHandle = LoadImage("libA",0);
fp = (addToStringsFP)FindSymbol(libHandle,"addToStrings");
This is only to demonstrate how I am loading libA and calling the function pointer. LoadImage, FindSymbol are similar to dlopen(), dlsym() - I can't post actual names.
What am I misunderstanding here ?

Answer 1

I found the answer.
The LoadImage function that I am using is loading a new image into the process instead of looking at already loaded dlls first and then load.
I had to use a different version of the LoadImage which loads the image that is currently in the process- basically a shared image. That solved the problem.
I thought it might be useful to someone who may have some problem albeit not much probable I think.