Re: Concurrency in Gnat 3.05?

[cosc19z5@Bayou.UH.EDU (Spasmo)]

Robert Dunn (red@satcom.whit.org) wrote:
: In article <4sjqte$3mu@masala.cc.uh.edu>,
:  on 17 Jul 1996 22:53:34 GMT,
:  Spasmo <cosc19z5@Bayou.UH.EDU> writes:
: >Hey all.
: >
: >Is Gnat 3.05 (for DOS) truly concurrent when executing tasks?  I'm
: >asking because I've written some tasking code (finally got it
: >to link) and when I ran the code, the tasks didn't run
: >concurrently at all.  I'm running in a Win95 DOS box.  One task
: >runs to completion before the other task starts up.  I've also
: >tried some sample code including Feldman's Twotasks program
: >and they exhibit the same behavior.  Is there a way to get
: >tasks to run concurrently, or would I have to look for a
: >GNAT that's native to something like WinNT/95 that can
: >handle multi-tasking?
: >
: >

: Ok, here is how you answer that question.  Go get yourself both a
: phillips and a t-15 screwdriver.  Now, remove the cover from your
: Win95/DOS7.0 Box.  Count the number of processors.  If you counted
: one, you are absolutely correct.  Now, ask yourself, how many
: operations can run on one processor at a time.  If you answered one
: again, you now have two points.  ;>

: Now, for the big question?  Can one processor run two (or more) tasks
: concurrently?  If you answered no, you have just won the grand prize.

: The question that now remains is, How do you make a single processor
: seem as if it is doing more than one thing at a time.  Did you say
: time slicing?  Well, that is correct.  And what is time slicing
: synonomyous (ok so I can't spell) with?  OVERHEAD!!!

Ok, Time slicing -- whatever :).  Still, with Linux I could easily
write C programs that used time slicing on my processor courtesy
of fork(), so I had assumed that GNAT also did something similar
with tasks.  Somebody (I forgot the name) emailed me and did
bring up the suggestion of modifying task priorities dynamically
to pre-empt and thus achieve the effect of time slicing.  


: The logical conclusion therefore is to save the overhead by allowing
: a task to run until a natural break (eg completion, accept, call, etc).

: Yes, it would be nice to have true multi-tasking.

Well others did manage to do it, so I had assumed that GNAT
was the same.  Still it's a shame not having tasks that
time slice, I mean it doesn't really seem all that big a
deal to have tasking when they don't appear to run
concurrently.  Entries into them and all are allright,
but still without time slicing...


: Sorry if this sounds harsh, it is designed to entertain.  Of course,
: I have yet to meet a programmer who didn't have a unique sence of humor.


Np.

Thanks for the response.


--
Spasmo
"Here's a present just for you
When you open it, you'll be through"
	"Letter Bomb" by the Circle Jerks