rb_fd_isset 338 include/ruby/intern.h #define rb_fd_isset(n, f) rb_w32_fdisset((n), (f)->fdset) rb_fd_isset 355 include/ruby/intern.h #define rb_fd_isset(n, f) FD_ISSET((n), (f)) rb_fd_isset 3502 thread.c rb_fd_isset(int n, const rb_fdset_t *fds)