1 #include <lib9.h>
2 #include <thread.h>
3 
4 Channel *c[3];
5 
6 
7 void
8 pingpong(void *v)
9 {
10 	int n;
11 	Channel **c;
12 
13 	c = v;
14 	do{
15 		n = recvul(c[0]);
16 		sendul(c[1], n-1);
17 	}while(n > 0);
18 	exit(0);
19 }
20 
21 void
22 threadmain(int argc, char **argv)
23 {
24 	c[0] = chancreate(sizeof(ulong), 1);
25 	c[1] = chancreate(sizeof(ulong), 1);
26 	c[2] = c[0];
27 
28 	proccreate(pingpong, c, 16384);
29 	threadcreate(pingpong, c+1, 16384);
30 	sendul(c[0], atoi(argv[1]));
31 }