Re: Polling, Interrupts, DMA, Synchronous, Asynchronous I/O Definitions

From: Alex McDonald (alex_mcd_at_btopenworld.com)
Date: 07/15/04 

Date: Thu, 15 Jul 2004 11:38:04 +0000 (UTC)

"Jim Carlock" <anonymous@127.0.0.1> wrote in message
news:%HmJc.45681$IX4.5329356@twister.tampabay.rr.com...
> "Frank Kotler" wrote:
> > In any case, this discussion prompts a philosophical question for
> > the LuxAsm team... If it were possible to speed up LuxAsm by
> > being "inconsiderate" and hogging resources, would this be an
> > acceptable method of speeding up LuxAsm? (I suppose the
> > answer depends on "how much?"...)
>
> I'm seeing mention of Interrupts... which may or may not be
> hardware requests for attention. And with the definitions of polling,
> I'll add another definition to interrupts... I translate most into an
> Event... and from what I see, I see a lot of passing control to the
> OS via DoEvents in timer operations or in waiting for info routines.
> The DoEvents in VB programming passes some kind of control
> to the operating system and that's how you'd get a processor
> intensive routine to return control to the OS. I put in an infinite
> loop in one app on an XP machine and without the DoEvents
> control the App took a second or two to close down, but with
> the DoEvents, it responded immediately.
>
> I've tried to follow what a DoEvents exactly is but it's beyond
> my current current attention span. If you'd like a copy of a program
> that goes into an infinite loop with the DoEvents code in it, I
> can send you a copy. You'll need a Windows machine and
> the VB runtimes. :-)

It probably calls SwitchToThread, which relinquishes control for a
timeslice. If you're in a compute intensive loop, it will make your system
much more responsive.

>
> --
> Jim Carlock
> http://www.911forthetruth.com/
> Post replies to the newsgroup.
>
>

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