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