Re: Returner key question Bill Frantz (frantz@netcom.com)
Mon, 29 Apr 1996 14:24:44 -0700

At 3:30 PM 4/28/96 -0400, Jonathan S. Shapiro wrote:
>for the keykos folks:
>
>On the "Return from Public Service" invocation, must the key in slot 4
>be a resume key, or can it be any key (i.e. should I think of the
>invocation as just recursing normally)? In particular, if the caller
>of the service FORK's the service and passes a start key or a red seg
>key in the fourth slot, and the service returns via the returner,
>should it work?
>
>Presumably, if the caller passes the RETURNER in the fourth slot under
>these conditions, we just deliver the response to the void :-)

In KeyKOS, the public service is responsible for using RETURNER to return to its caller. It doesn't matter how a resume key gets in the 4th slot. A public service can be pipelined as follows:

(1) Component A of the pipeline is CALLED by the service user. (2) When it completes its job, it RETURNs to compontent B passing the 4th key of the service user. 

(3) The rest of the compontents act like in (2).
(4) The last component completes its service and RETURNs to the 4th
(resume) key of the service user using the returner.  N.B. This last is the
only invocation of that key.

Regards - Bill 

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