Re: uniform input device packets?

Allanah Myles (dossy@panoptic.com)
Wed, 24 Jun 1998 01:59:54 -0400


On 1998.06.23, Vojtech Pavlik <vojtech@twilight.ucw.cz> wrote:
> The timestamp - it is needed, so that an application knows in what
> order events happened, and what time apart they are. Imagine detecting
> a double click with heavily loaded, and swapping machine. It might be
> impossible without timestamps.

Is this necessarily true? Your specific example of "system under load"
really doesn't necessitate timestamping of events. You're supposing
that when a system is loaded, it will always immediately process it's
I/O events and preempt whatever is currently executing (probably
whatever is causing the load at the moment). You may very well be
correct, but I have a funny feeling that the way things currently
work is that the I/O queues up, and is drained at next chance. In
which case, two single-clicks will arrive one after another and
appear to be a double-click - I haven't verified this but I'm just
guessing.

If this *is* the case, then timestamping events in this new protocol
will be unnecessary. Also - if the system *did* actually immediately
process all input from devices, then a device generating spurious
output could starve the rest of the system of cycles. This sounds
like a serious problem, which is why I'm guessing the behavior is
as I predicted.

-Dossy

-- 
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