- * if queue is empty and world.turn is unequal world.last_update_turn, update
- * output file at world.path_out (and update world.last_update_turn), then read
- * file at world.path_in for the next load of bytes to put onto the input queue.
- *
- * Reading the file at world.path_in may put many \0-terminated strings on the
- * queue at once. Successive calls of io_round() will make these available one
- * by one. Each such call cuts off bytes from the beginning of world.queue, up
- * to and including the last \0 byte that is followed by a non-\0 byte or ends
- * the queue. If the queue starts with a \0 byte, it and its \0 followers are
- * cut and a NULL pointer is returned. Reading from the input file stops only
- * when one or more byte were read and the next read returns 0 bytes. If the
- * re-filled queue does not end in a \0 byte, a \0 byte is appended to it.
+ * if queue is empty and world.do_update is set, update world state file (and
+ * unset world.do_update) and write a single dot line to server out file, then
+ * read server in file for the next load of bytes to put onto the input queue.