1 #include <pthread.h>
2 #include "libc.h"
3 #include "lock.h"
4 
5 static struct atfork_funcs {
6 	void (*prepare)(void);
7 	void (*parent)(void);
8 	void (*child)(void);
9 	struct atfork_funcs *prev, *next;
10 } *funcs;
11 
12 static volatile int lock[1];
13 
__fork_handler(int who)14 void __fork_handler(int who)
15 {
16 	struct atfork_funcs *p;
17 	if (!funcs) return;
18 	if (who < 0) {
19 		LOCK(lock);
20 		for (p=funcs; p; p = p->next) {
21 			if (p->prepare) p->prepare();
22 			funcs = p;
23 		}
24 	} else {
25 		for (p=funcs; p; p = p->prev) {
26 			if (!who && p->parent) p->parent();
27 			else if (who && p->child) p->child();
28 			funcs = p;
29 		}
30 		UNLOCK(lock);
31 	}
32 }
33 
pthread_atfork(void (* prepare)(void),void (* parent)(void),void (* child)(void))34 int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))
35 {
36 	struct atfork_funcs *new = malloc(sizeof *new);
37 	if (!new) return -1;
38 
39 	LOCK(lock);
40 	new->next = funcs;
41 	new->prev = 0;
42 	new->prepare = prepare;
43 	new->parent = parent;
44 	new->child = child;
45 	if (funcs) funcs->prev = new;
46 	funcs = new;
47 	UNLOCK(lock);
48 	return 0;
49 }
50