临界区算法 Peterson

int c1 = 0, c2 = 0, will_wait;
//cobegin
p1: while (1)
 {
  c1 = 1;
  will_wait = 1;
  while (c2 && (will_wait == 1));
  CS1; c1 = 0; program1;
 }

p2: while (1)
 {
  c2 = 1;
  will_wait = 2;
  while (c1 && (will_wait == 2));
  CS2; c2 = 0; program2;
 }