I'm not familiar with the details of the Coyotos interface, but I'll see what I can figure out without too much trouble. I read up through chapter 2. The endpoint identifier is the OID field in an endpoint capability? So the implementing process gets to see that, but not the invoker, unless they are authorized to use CapBits on it? It looks like Coyotos itself doesn't need to care what constitutes an object implemented by an application. It just needs to faithfully report the (uninterpreted) protected payload and OID to the appropriate process.
On Fri, Jul 4, 2014 at 4:45 PM, Jonathan S. Shapiro <[email protected]> wrote: > In KeyKOS/EROS, the "discrim" capability (which implements EQ) was closely > held. In Coyotos we were more liberal, and we haven't gotten into trouble > yet. But in general we leave it up to the object developer to decide whether > they want one capability on their "thing" to acknowledge whether it > designates the same "thing" as a second capability. The point being that applications usually wouldn't use Discrim? In that case how would Coyotos applications usually implement object identity comparison? Say, to determine if images linked from two parts of a document are the same? (And assuming that this document is hooked together with Coyotos capabilities, which, for all I know, is an antipattern.) Maybe the image capabilities would have an operation on their interface to return an identifier? > Doc for discrim: > > http://coyotos.org/docs/ukernel/spec.html#coyotos.Discrim > > > There is a "capbits" capability that is VERY closely held. There's actually > only one object that wields it in production: > > http://coyotos.org/docs/ukernel/spec.html#coyotos.CapBits Does Discrim.compare agree with bit comparison of the results of CapBits.get on the two capabilities? > The operation that inspires "guarded open" is the identifyEntryWithBrand > operation on Coyotos processes: > > http://coyotos.org/docs/ukernel/spec.html#coyotos.Process So the brand is the guard, and it might provide authority because it reveals the endpoint's protected payload and ID? I'm not sure why you showed me this. It seems like Coyotos doesn't have much to say about object identity for application-specific objects. _______________________________________________ bitc-dev mailing list [email protected] http://www.coyotos.org/mailman/listinfo/bitc-dev
