I would like for it to be impossible for my executable to have more than 1 instance at a time. I am currently attempting with SDL's SDL_CreateMutex() method but I can't get it to work.
int main(int argc, char* argv[]){
    SDL_mutex* mutex = SDL_CreateMutex();
    if(SDL_LockMutex(mutex) == 0){
        Game game;
        game.Initialize();
        game.Run();
        game.Destroy();
        SDL_UnlockMutex(mutex);
    } 
    SDL_DestroyMutex(mutex);
    return 0;
}