rb_w32_is_socket   34 ext/io/wait/wait.c #define FIONREAD_POSSIBLE_P(fd) rb_w32_is_socket(fd)
rb_w32_is_socket  210 include/ruby/win32.h extern int    rb_w32_is_socket(int);
rb_w32_is_socket  202 io.c           #define is_socket(fd, path)	rb_w32_is_socket(fd)