rb_fd_resize     2194 thread.c           rb_fd_resize(n, fds);
rb_fd_resize     2228 thread.c               rb_fd_resize(n - 1, readfds);
rb_fd_resize     2232 thread.c               rb_fd_resize(n - 1, writefds);
rb_fd_resize     2236 thread.c               rb_fd_resize(n - 1, exceptfds);