On Friday 05 September 2008, William Pearson wrote: > 2008/9/5 Mike Tintner <[EMAIL PROTECTED]>: > > By contrast, all deterministic/programmed machines and computers > > are guaranteed to complete any task they begin. > > If only such could be guaranteed! We would never have system hangs, > dead locks. Even if it could be made so, computer systems would not > always want to do so. Have you every had a programmed computer system > say to you. "This program is not responding, do you wish to terminate > it". There is no reason in principle why the decision to terminate > the program couldn't be made automatically.
These errors are computed. "Do what I mean, not what I say" is a common phrase thrown around in programming circles. The errors are not because that suddenly the ALU decided to not be present, and the errors are not because it suddenly lost its status as a Turing machine (although if you drove a rock through it, this is quite likely). Rather this is because you failed to write a good kernel. And yes, the decision to terminate programs can be made automatically, and I sometimes choose scripts on my clusters to kill things that haven't been responding for a certain amount of time, but usually I prefer to investigate it by hand since it's so rare. > > Very different kinds of machines to us. Very different paradigm. > > (No?) > > We commonly talk about single program systems because they are > generally interesting, and can be analysed simply. My discussion on > self-modifying systems ignored the interrupt driven multi-tasking > nature of the system I want to build, because that makes analysis a > lot more hard. I will still be building an interrupt driven, multi > tasking system. That's an interesting proposal, but I'm wondering about something. Suppose you have a cluster of processors, and they are all communicating with each other in some way to divide up tasks and compute away. Now, given the ability to send interrupts from one another, and given the linear nature of each individual unit, is it really multitasking? At some point it has to integrate all of the results together at a single node for writing at a single address on the hdd (or something) so that the results are in one single place, that or the reading function of the results must do this. Is it really then multi-tasking and parallel? - Bryan ________________________________________ http://heybryan.org/ Engineers: http://heybryan.org/exp.html irc.freenode.net #hplusroadmap ------------------------------------------- agi Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: https://www.listbox.com/member/?member_id=8660244&id_secret=111637683-c8fa51 Powered by Listbox: http://www.listbox.com
