+ /* Now fdarray[].realfd is pipe end for service in case service
+ * wants it. If it's an input pipe, then .holdfd is the other
+ * (writing) end of the pipe - we keep it around so that the service
+ * doesn't get an apparently clean EOF if the caller disappears (eg
+ * due to a file read error) or the like (ie so that on disconnect
+ * we can guarantee to send the service SIGHUP before it gets EOF on
+ * the input fd). Otherwise, .holdfd=-1.
+ */