pthread_atfork (U9t5kJAWPnA, aerolib) appends the prepare, parent and
child handlers to a process-wide list under a lock and returns 0, or
ENOMEM when the entry cannot be allocated, as FreeBSD 11.4's
_pthread_atfork does (lib/libthr/thread/thr_fork.c:78-100, freebsd-src
8c639945a44588f6cfdddfb057bb5aad88735da0). Null handlers are accepted;
FreeBSD's fork skips them. The handlers never run: fork
(libkernel_sys) throws and vfork is absent, so no child process is
created. The list is kept, in registration order, for a later fork
(PthreadAtforkHandlers_nid_no_patch); recorded in TechnicalDebt.
XPSemu (PPSA97358) calls it from a constructor, before main
(ZiZc3/XPSemu 8eec07b4, util/rcu.c:488-495):
static void __attribute__((__constructor__)) rcu_init(void)
{
smp_mb_global_init();
#ifdef CONFIG_POSIX
pthread_atfork(rcu_init_lock, rcu_init_unlock, rcu_init_child);
#endif
rcu_init_complete();
}
so a throwing export would stop the title before main. Predicted stop
removed (registry index 255, not run):
FAIL: unresolved ELF import U9t5kJAWPnA from libkernel.prx
guest_pthread_atfork checks registration order, null handlers,
concurrent registration from four threads and that no handler runs.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
(cherry picked from commit f37bccf6efd76edcde5d582800c89b83fdd30472)
e8fd542f03