Design for repeating whole process which includes global Singletons

I have a relatively long (10k lines) C++ code in which I use three global singletons.

ClassA Singleton_A;
ClassB Singleton_B;
ClassC Singleton_C;

int main(int argc, char* argv[])
{
   // DoStuff with argc and argv
}

I would now like to modify the code to loop through DoStuff more than once which would be given as first argument of argv. I am unsure how to deal with my global singletons.

One way to go would be to encompass the whole current code in a class with something like

class Process
{
    ClassA Singleton_A;
    ClassB Singleton_B;
    ClassC Singleton_C;

    int main(int argc, char* argv[])
    {
        // DoStuff with argc and argv
    }
};

int main(int argc, char* argv[])
{
   Process process;

   int NbRepeats = std::stoi(std::string(argv[0]));
   for (int repeat ; repeat < NbRepeats; repeat++)
   {
       process.main(argc--, argv++);
   }
}

Does it seem like a good design?