rem: exit_cleanup(1);
add: exit_cleanup(RERR_STREAMIO);
context: void io_start_multiplex_in(int fd){	multiplex_in_fd = fd;	io_flush();	if (read_buffer_len) {		fprintf(stderr,"ERROR: data in read buffer at mplx start\n");		exit_cleanup(1);	}	io_multiplexing_in = 1;}