result = __libc_writev (fd, vector, count);
writev (fd, vector, count)     int fd;     const struct iovec *vector;     int count;{  int oldtype;  ssize_t result;  CANCEL_ASYNC (oldtype);#ifdef INTERNAL_SYSCALL  result = INTERNAL_SYSCALL (writev, 3, fd, vector, count);  if (INTERNAL_SYSCALL_ERROR_P (result)      && __builtin_expect (count > UIO_FASTIOV, 0))#elif defined INLINE_SYSCALL  result = INLINE_SYSCALL (writev, 3, fd, vector, count);  if (result < 0 && errno == EINVAL      && __builtin_expect (count > UIO_FASTIOV, 0))#endif    result = __libc_writev (fd, vector, count);  CANCEL_RESET (oldtype);  return result;}