rb_thread_fd_writable  421 ext/socket/rubysocket.h #  define rsock_maybe_fd_writable(fd) rb_thread_fd_writable((fd))
rb_thread_fd_writable  444 include/ruby/intern.h int rb_thread_fd_writable(int);
rb_thread_fd_writable 1155 io.c           	rb_thread_fd_writable(f);
rb_thread_fd_writable 1296 io.c               if (fptr->stdio_file != stderr && !rb_thread_fd_writable(fptr->fd))