__pthread_cleanup_handler
struct __pthread_cleanup_handler *handler);
extern struct __pthread_cleanup_handler *__pthread_cleanup_pop_handler(void);
struct __pthread_cleanup_handler *previous;
struct __pthread_cleanup_handler __handler; \
struct __pthread_cleanup_handler *cleanup_handlers;
struct __pthread_cleanup_handler* handler
__pthread_cleanup_push_handler(__pthread_cleanup_handler* handler)
__pthread_cleanup_handler*
__pthread_cleanup_handler* handler = thread->cleanup_handlers;