 first of which will be set by glib to the
g-io-channel object constructed for the watch and the second of which
will be set to the GIOCondition (&rsquo;out or &rsquo;err) provided by glib which
caused the watch to activate.  It is intended to be called in a
waitable procedure invoked by a-sync.  The watch is multi-shot - it is
for the user to bring it to an end at the right time by calling
g-source-remove in the waitable procedure on the id tag returned by
this procedure.  Any port for the file descriptor 