Re: Reliability of RPC services

[Jonathan S. Shapiro]

On Sun, 2006-04-30 at 03:58 +0200, Bas Wijnen wrote:
> On Sat, Apr 29, 2006 at 09:26:50PM -0400, Jonathan S. Shapiro wrote:
> > On Sat, 2006-04-22 at 19:55 +0200, Marcus Brinkmann wrote:
> > > Here is, in an informal manner, one of the invariants I mean: When a
> > > process is in a call, and waiting on a reply (send-once) capability,
> > > from a global system perspective one can identify a process "on which"
> > > the caller is waiting: Namely the process holding the reply
> > > capability. 
> > 
> > But in a scheduler activation design no process is ever waiting in this
> > fashion. How should this be specified in a context of scheduler
> > activations?
> 
> I think Marcus was talking about a single-copy reply-capability here.  So
> there's only one process holding it.

Perhaps, but this does not change the fact that the process is not
waiting!

> Even if technically the process isn't "waiting" for the reply, in practice it
> will in fact be waiting in the sense that it cannot continue with something
> until it received a reply.  This doesn't mean it doesn't do other things, but
> it's waiting nonetheless.

But the test of interest here is not "is it waiting for a reply". That
is harmless. The test of interest here is "is it prevented from getting
useful work done".


shap