fork_hook
struct fork_hook *next;
static fork_hook *sPrepareHooks, *sParentHooks, *sChildHooks;
static fork_hook *sLastParentHook, *sLastChildHook;
add_fork_hook(fork_hook **_hooks, fork_hook **_lastHook, void (*function)(void))
fork_hook *hook = (fork_hook *)malloc(sizeof(struct fork_hook));
fork_hook *last = *_hooks;
call_fork_hooks(fork_hook *hook)