[coyotos-dev] Endpoints and replies

[Norman Hardy]

In the context of Keykos as it was implemented we thought about
but did not implement the following idea.
It seems that we did not write it down either.

A new sort of node key called a "multiplexor key" that designates
a node full of start keys to a presumably fungible set of serving  
domains.
Perhaps "dispatcher" would be a better name.

If a domain invokes a multiplexor key and while all of the server  
domains are
busy then the invoker stalls.
Otherwise the kernel delivers the message from the invoker to one of  
the available domains.
(Probably the most recently used one as determined by some kernel  
heuristic.)

One disadvantage to this is that it is a kernel object that cannot be  
implemented
outside the kernel since sensing busyness is not possible outside the  
kernel.
Such objects complicate security arguments.
We didn't see security problems however.
Perhaps multiplexors could be cascaded.

This is somewhat like the idea mentioned by Bas Wijnen but there were no
analogs to endpoints or threads.