rb_io_check_writable  161 ext/io/wait/wait.c     rb_io_check_writable(fptr);
rb_io_check_writable 1441 ext/openssl/ossl_ssl.c     rb_io_check_writable(fptr);
rb_io_check_writable  134 include/ruby/io.h void rb_io_check_writable(rb_io_t*);
rb_io_check_writable 1447 io.c               rb_io_check_writable(fptr);
rb_io_check_writable 1469 io.c               rb_io_check_writable(fptr);
rb_io_check_writable 2693 io.c               rb_io_check_writable(fptr);
rb_io_check_writable 4659 io.c               rb_io_check_writable(fptr);
rb_io_check_writable 10629 io.c           	rb_io_check_writable(dst_fptr);