shared: bool flag[] = { false, false };
        // Do I want to be in the C.S.


  Process 0              |   Process 1
-------------------------+--------------------------
  flag[0] = true;        |   flag[1] = true;
  while (flag[1])        |   while (flag[0])
    pause();             |     pause();
  C.S.                   |   C.S.
  flag[0] = false;       |   flag[1] = false;
                         |