Re: Multitasking theory question

[Kilgallen@SpamCop.net (Larry Kilgallen)]

In article <3D173788.8758A005@san.rr.com>, Darren New <dnew@san.rr.com> writes:
> AG wrote:
>> However, what I was driving at is a sort of a virtual machine:
>> - *assuming* it runs at all, and lets you do some basic things
>> like Turing machine, where does an OS come into it?
> 
> The places where a machine isn't a turing machine. I.e., Input/Output.
> 
>> Sure, it
>> may take ages for anything to happen if the computer is sufficiently
>> slow but you still can implement whatever scheduling you like.
> 
> Uh, no. If you have a 3rd party device driver that blocks, then you can't do
> non-blocking I/O to that device, regardless of what cleverness you set up in
> your part of the program.

In that case, you should switch to an operating system that does not
allow device drivers to block.