Re: libports on L4

[Gernot Heiser]

On Sat, 11 Nov 2000 19:45:10 +0100, address@hidden (Niklas H?glund) wrote,

niklas> Farid Hajji <address@hidden> writes:
niklas> 
niklas> > We should probably consider the whole of the Hurd as running in a 
single
niklas> > clan. This way, we get maximum independence of the L4-ABI (think of 
X.0
niklas> > in L4Ka right now!). One other advantage is that we run separate OS-
niklas> > personalities in different clans (sub-hurds too), effectively 
maintaining
niklas> > a single entry-point to each personality.
niklas> 
niklas> I think I've read somewhere that clans can be used to set up a
niklas> distributed system. If we want to set up a two computer distributed
niklas> system with computer A and B, for example, we add a "B" clan to the A
niklas> system. All tasks on the A system that want to send messages to tasks
niklas> that are located on the B system send them like normal local L4
niklas> messages to the B clan. The B clan leader then intercepts these
niklas> messages and passes them on to the B system using another messaging
niklas> system. This way sending remote messages can be done exactly the same
niklas> way as sending local ones. (You'd need to have unique task ID's for
niklas> every task on the distributed system, though.)

Yes, that's a model.

However, clans are mostly an access control mechanism for IPC. And
don't get stuck into them too deeply, they're marked for removal (to
be replaced by a more general, more flexible mechanism).

Gernot


Gernot Heiser                ,--_|\   School of Computer Sci. & Engin.
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