1#include <pthread.h>
 2#include <errno.h>
 3#include "libc.h"
 4#include "lock.h"
 5
 6#define malloc __libc_malloc
 7#define calloc undef
 8#define realloc undef
 9#define free undef
10
11static struct atfork_funcs {
12	void (*prepare)(void);
13	void (*parent)(void);
14	void (*child)(void);
15	struct atfork_funcs *prev, *next;
16} *funcs;
17
18static volatile int lock[1];
19
20void __fork_handler(int who)
21{
22	struct atfork_funcs *p;
23	if (!funcs) return;
24	if (who < 0) {
25		LOCK(lock);
26		for (p=funcs; p; p = p->next) {
27			if (p->prepare) p->prepare();
28			funcs = p;
29		}
30	} else {
31		for (p=funcs; p; p = p->prev) {
32			if (!who && p->parent) p->parent();
33			else if (who && p->child) p->child();
34			funcs = p;
35		}
36		UNLOCK(lock);
37	}
38}
39
40int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))
41{
42	struct atfork_funcs *new = malloc(sizeof *new);
43	if (!new) return ENOMEM;
44
45	LOCK(lock);
46	new->next = funcs;
47	new->prev = 0;
48	new->prepare = prepare;
49	new->parent = parent;
50	new->child = child;
51	if (funcs) funcs->prev = new;
52	funcs = new;
53	UNLOCK(lock);
54	return 0;
55}