-/* EVENTS for the output state */
-void chan_rcvd_ieof(Channel * c);
-void chan_write_failed(Channel * c);
-void chan_obuf_empty(Channel * c);
+
+/* Channel EVENTS */
+typedef void chan_event_fn(Channel * c);
+
+/* for the input state */
+extern chan_event_fn *chan_rcvd_oclose;
+extern chan_event_fn *chan_read_failed;
+extern chan_event_fn *chan_ibuf_empty;
+
+/* for the output state */
+extern chan_event_fn *chan_rcvd_ieof;
+extern chan_event_fn *chan_write_failed;
+extern chan_event_fn *chan_obuf_empty;
+
+int chan_is_dead(Channel * c);
+void chan_mark_dead(Channel * c);