Re[2]: [Am-info] O/S 2 support - slightly off topic (my apologies)

[John Poltorak]

On Sat, Mar 16, 2002 at 03:35:08PM -0600, Eric M. Hopper wrote:
> On Sat, 2002-03-16 at 15:28, John Poltorak wrote:
> > On Sat, Mar 16, 2002 at 03:13:00PM -0600, Eric M. Hopper wrote:
> > > On Sat, 2002-03-16 at 14:12, Mitch Stone wrote:
> > > > Allow me to ask a simple-minded technical question: what if anything is 
> > > > the relationship between multithreading and preemptive multitasking?
> > > 
> > > Multithreading and preemptive scheduling are, in one sense, strongly
> > > related, and in another, orthogonal concepts.  Most people do not think
> > > of cooperative multithreading as multithreading at all. 
> > 
> > I have never previously heard the phrase 'coopertive multithreading' and 
> > suspect you really mean 'cooperative multitasking'...
> 
> No, I mean cooperative multithreading.  As I said, almost nobody thinks
> of cooperative multithreading as being that.  

Well the concept is lost on me. I have no idea what it means at all.

> Cooperative vs. preemptive
> are CPU scheduling techniques.  Multitasking vs. multithreading are
> about sharing memory between tasks, and not CPU scheduling at all.

OS/2 is both multitasking and multithreading, where every task consists of 
one or more threads. Those tasks share CPU not memory AFAIAA. The only 
time that memory is shared is when it is overcommitted and a task is 
swapped out to disk.

 
> Have fun (if at all possible),
> -- 
> The best we can hope for concerning the people at large is that they
> be properly armed.  -- Alexander Hamilton
> -- Eric Hopper (hopper@omnifarious.org 
> http://www.omnifarious.org/~hopper) --


-- 
John