do_select        3764 thread.c           return do_select(max, read, write, except, timeout);
do_select        3041 win32/win32.c  		r = do_select(nfds, rd, wr, ex, &zero); // polling
do_select        3063 win32/win32.c  		r = do_select(nfds, rd, wr, ex, &zero);	// polling