11 static volatile int shared[2];  variable
41 	shared[0] = 22;  in main()
42 	shared[1] = 77;  in main()
44 	pthread_create(&a, NULL, t1, (void *)&shared[0]);  in main()
45 	// a steals shared[0] from root thread, so is excl(a)	  in main()
46 	pthread_create(&b, NULL, t2, (void *)&shared[1]);  in main()
47 	// b steals shared[1] from root thread, so is excl(b)	  in main()
50 	// b's stuff (shared[1]) still belongs to b, so is excl(b)  in main()
52 	// ret is excl(root), and shared[0] is re-acquired as excl(root)  in main()
55 	ret += shared[0];	/* no error - a is finished */  in main()
57 	// but shared[1] is excl(b); hence we're reading excl(b)  in main()
60 	ret += shared[1];	/* expect error - b has not finished,  in main()
61 				   so we can't touch shared[1] yet */  in main()