operating system integrity (coming from Nuke Redmond)

From: John Tinker <jtinker_at_coin.org>
Date: Sat Jan 13 15:48:26 2001

I would think that a properly layered system would look after its own
integrity. To say that an app took down a system is by definition an
indictment of the system, in my, perhaps idealistic, opinion. Why this
happens otherwise, is the topic of all other explaination of system failure.
Putting it in such simple terms accomplishes the broad stokes of the first
analysis.

I've always wanted to hear a os programmer tell me whether allowing multiple
preemption is a fundamental flaw in certain operating systems. I'm thinking
that multiple preemption might be a contradiction in terms. Intuitively I
would expect the operating system itself to have the ultimate preemption,
expressed as its servicing of hardware interrupts. I would expect that it
would only be able to delegate its authority to be preemptive to *any*
application if *every* other application running agrees to the proposition.
But I do not have experience with that level of the operation of the various
operating systems. In my own applications programming I am quite conscious of
sometimes rather complex notions of "when". At the processor level, I am
aware of the clock's relationship to read and write operations on RAM, and to
higher-order symbols of phase completion of higher-order processes. I would
expect the heart of an operating system to deal with similar indications of
its own state(s) of integrity. I'm curious what people think about this.
Thanks, -- John Tinker
Received on Sat Jan 13 2001 - 15:48:26 GMT