__cxa_thread_atexit
extern "C" int __cxa_thread_atexit(void (*)(void *), void *, void *);
__cxa_thread_atexit(again, arg, &output);
extern "C" int __cxa_thread_atexit(void (*)(void *), void *, void *);
__cxa_thread_atexit(again, arg, &output);