This is the version of Peterson's synchronization algorithm
for 2 processes, process 0 and process 1.  As seen in the text,
the algorithm can easily be extended to support any number of 
processes (the Bakery algorithm on page 163).  The two processes
using the code below repeatedly enter their critical sections,
do their critical sections and then leave their critical sections.
Assume that when i == 0, j == 1 and when  j == 0, i == 1.

GLOBALS:
	var flag: array [0..1] of boolean;
      	turn: 0..1;

	repeat
	    /* try and enter critical section */
		flag[i] := true;
		turn := j;
		while ( flag [j] and turn == j ) do  no_op ( );   /*spin */

	    /******** do critical section ********/

	    /* leave critical section */
		flag [i] := false;

 	until false;