thr_once
#define _PROP_ONCE_RUN(x,f) thr_once(&(x), (void(*)(void))f);
thr_once(&arc4random_global.once, &arc4random_initialize);
thr_once(&db_opened, devname_dbopen);
thr_once(&rpc_call_once, rpc_call_setup);
thr_once(&nc_once, __nc_error_setup);
thr_once(&rce_once, __rpc_createerr_setup);
thr_once(&__rpc_getconfigp_once, __rpc_getconfigp_setup);
thr_once(&clnt_broadcast_once, clnt_broadcast_setup);
thr_once(&strerror_once, strerror_setup);