[coyotos-dev] Status and roadmap

[Jonathan S. Shapiro]

On Fri, 2007-01-19 at 12:19 -0500, Jonathan Adams wrote:

> > What happens if a process has designated itself as its exception handler
> > and faults in a non-activated state, then subsequently faults in the
> > activated state while handling the non-activated fault.  Does the FCRB
> > get overwritten by the activated fault, and the previous message get
> > lost?  Potentially confusing the handler when it tries to resume itself
> > after handling the exception it recieved while activated.
> 
> Remember that a process can have multiple FCRBs.  In this particular
> case, the first fault would be delivered directly to the process'
> activation handler, without using any kind of FCRB.  If the activation
> handler faulted while processing the first fault, a message is sent to
> the handler FCRB.
> 
> If the handler FCRB is *blocked*, then the process will block waiting
> for it to become unblocked.  If the handler FCRB is *unblocked*, then it
> will be sent the fault message.
> 
> At this point, if the handler FCRB points to the process, we will
> deadlock, since the activation handler will never run to process the
> "fault" message.

This description is accurate, but probably more complicated than it
needs to be. You may want to look at my other answer first and then try
to work through this one.
-- 
Jonathan S. Shapiro, Ph.D.
Managing Director
The EROS Group, LLC
+1 443 927 1719 x5100