Peterson algorithm implements mutually exclusive access by pure software. But it only illustrates the mutual exclusion between the two processes, as shown below

-sharpdefine FALSE 0
-sharpdefine TRUE 1
-sharpdefine N 2

int turn;
int interested[N];

void enter_region(int process)
{
    int other;
    other = 1 - process;
    intersted[process] = TRUE;
    turn = process;
    while(turn == process && interested[other] == TRUE);
}

void leave_region(int process)
{
    interested[process] = FALSE;
}

how to extend to multiple processes?