Jonathan S. Shapiro wrote:
This is a response to several messages (from Volkmar, Rudy, Hermann) at once. The delay has partly been due to other demands on my time, and partly because I wanted to consider how to answer.
It seems to me (but this needs to be confirmed in face to face discussions in January, I am now confused about the many "id"s) that both, EROS and the "Generalized Mappings" proposal, replace (in relation to original L4) thread-id by some other "id" as an unforgable part of messages. The "other id" is protected by the kernel and managed by user level processes. In EROS, it is managed by the server, in "Generalized Mappings" by the pager providing the mappings. In "Generalized Mapping", the size of this "id" is under user control as well. Thus no problem with register payload, the "id" can become even smaller than the original thread-id in specific cases. In EROS, these "id"s are under complete control of the process providing a service, in L4 "Generalized Mapping" the pagers can restrict the "id" spaces of their clients in a pager hierarchy.
I do not understand the relation of this "id" to "user-level object invocation" as a first class EROS citizen.
Merry Chrismas to all of you
--hermann