You can (and often do) have a priority based system
without application specified events and/or times.
However, it does not preclude to use priority
for both event and time driven profiles as an indicator for
importance of the communication activity.
Currently, MPI does not schedule the communication of the
backplane and (at best) only the send and receive activities
(with necessary extras) at the nodes. Since most of the nodes
OS support priorities and events (for example, timer expiration),
the priority model is as supportable as event/time driven model.
So, for now, I suggest we stick to two independent models:
priority and time driven models.
However, time driven model should be viewed ( and implemented)
as a subset of event driven model where events are application
specified time instances (later we will include other events,
like completion of some computation/communication activity and so on).
Arkady
> From mpi-realtime-human@mcs.anl.gov Sun Mar 3 00:05:06 1996
> Date: Sat, 2 Mar 1996 22:58:52 -0600
> From: Tony Skjellum <tony@Aurora.CS.MsState.Edu>
> To: mpi-realtime@mcs.anl.gov
> Subject: New thought
> Sender: owner-mpi-core@mcs.anl.gov
> Content-Length: 232
>
> In our last local discussion on MPI realtime issues, it was
> suggested that we reformulate the chapter as follows:
>
> 1) Event driven profile
> 2) Time driven profile
>
> and that priorities be considered for both.
>
> Thoughts on this?
> -Tony
>