source: asp3_tinet_ecnl_arm/trunk/musl-1.1.18/src/thread/pthread_atfork.c@ 352

#include <pthread.h>
#include "libc.h"

static struct atfork_funcs {
        void (*prepare)(void);
        void (*parent)(void);
        void (*child)(void);
        struct atfork_funcs *prev, *next;
} *funcs;

static volatile int lock[2];

void __fork_handler(int who)
{
        struct atfork_funcs *p;
        if (!funcs) return;
        if (who < 0) {
                LOCK(lock);
                for (p=funcs; p; p = p->next) {
                        if (p->prepare) p->prepare();
                        funcs = p;
                }
        } else {
                for (p=funcs; p; p = p->prev) {
                        if (!who && p->parent) p->parent();
                        else if (who && p->child) p->child();
                        funcs = p;
                }
                UNLOCK(lock);
        }
}

int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))
{
        struct atfork_funcs *new = malloc(sizeof *new);
        if (!new) return -1;

        LOCK(lock);
        new->next = funcs;
        new->prev = 0;
        new->prepare = prepare;
        new->parent = parent;
        new->child = child;
        if (funcs) funcs->prev = new;
        funcs = new;
        UNLOCK(lock);
        return 0;
}