1 #include <u.h>
2 #include <libc.h>
3 
4 #define	NFN	33
5 static	int	(*onnot[NFN])(void*, char*);
6 static	Lock	onnotlock;
7 
8 static
9 void
10 notifier(void *v, char *s)
11 {
12 	int i;
13 
14 	for(i=0; i<NFN; i++)
15 		if(onnot[i] && ((*onnot[i])(v, s))){
16 			noted(NCONT);
17 			return;
18 		}
19 	noted(NDFLT);
20 }
21 
22 int
23 atnotify(int (*f)(void*, char*), int in)
24 {
25 	int i, n, ret;
26 	static int init;
27 
28 	if(!init){
29 		notify(notifier);
30 		init = 1;		/* assign = */
31 	}
32 	ret = 0;
33 	lock(&onnotlock);
34 	if(in){
35 		for(i=0; i<NFN; i++)
36 			if(onnot[i] == 0) {
37 				onnot[i] = f;
38 				ret = 1;
39 				break;
40 			}
41 	}else{
42 		n = 0;
43 		for(i=0; i<NFN; i++)
44 			if(onnot[i]){
45 				if(ret==0 && onnot[i]==f){
46 					onnot[i] = 0;
47 					ret = 1;
48 				}else
49 					n++;
50 			}
51 		if(n == 0){
52 			init = 0;
53 			notify(0);
54 		}
55 	}
56 	unlock(&onnotlock);
57 	return ret;
58 }