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
notifier(void * v,char * s)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
atnotify(int (* f)(void *,char *),int in)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 }
59