// Indicate the intent to enter the critical section
bIWantToEnter = true;
while (bHeWantsToEnter)
{
  // If the other process indicates the same intent and
  // it is not our turn, back off to give the other
  // process a chance
  if (iWhoseTurn != MY_TURN)
  {
    bIWantToEnter = false;
    while (iWhoseTurn != MY_TURN) { }
    bIWantToEnter = true;
  }
}

// Code of critical section comes here
...

iWhoseTurn = HIS_TURN;
bIWantToEnter = false;