void call_it() {
    ......
    SV* re = POPs;
    Perl_sv_dump(my_perl,re);
    SvREFCNT_inc(re);
    ......
}

int main(......) {
    ......
    // calling the first time
    printf("first time\n");
    call_it();
    
    // call again
    printf("again\n");
    call_it();
    
    // call again
    printf("and again\n");
    call_it();
    ......
}