#include <stdio.h>

void handle_open_port(unsigned int x);
void handle_close_port(unsigned int x);

unsigned long previous_x = 0;

void kernel_recursion(unsigned int x) {
  unsigned int current_previous_x = *(unsigned int *)((unsigned long)previous_x);
  //printf("PREVIOUS_X: %u ADDRESS: %ld CURRENT_ADDRESS: %ld\n", current_previous_x, previous_x, (long)&x);
  previous_x = (unsigned long)&x;
  if (x < current_previous_x) {
    handle_open_port(x); ++x;
    kernel_recursion(current_previous_x);--x;
    handle_close_port(x);
  } else if (current_previous_x < x) {
    handle_open_port(current_previous_x);
    kernel_recursion(current_previous_x + 1); --x;
    handle_close_port(current_previous_x);
  } else {
    handle_open_port(current_previous_x);
    handle_close_port(current_previous_x);
  }
}
void kernel(unsigned int x) {
  previous_x = (unsigned long)&x;
  kernel_recursion(0);
}

int main() { kernel(10); }

void handle_open_port(unsigned int x) { printf("OPENING: %u\n", x); }
void handle_close_port(unsigned int x) { printf("CLOSING: %u\n", x); }