OpenEuphoria

Re: Someone changed my Thread Manager writeup?

• Posted by Al Getz <Xaxo at aol.com> Aug 12, 2005
• 554 views

Pete Lomax wrote:
> 
> On Wed, 10 Aug 2005 07:10:31 -0700, Matt Lewis
> <guest at RapidEuphoria.com> wrote:
> 
> <snip>
> I have to agree with Matt on this. The main thing I would say here is
> that if Rob offers something like this in 2.6, I'll not be happy. I
> certainly don't want him to start thinking that now Al Getz's "Thread
> Manager" is in the archives, I don't have to bother.
> 
> >Al Getz wrote:
> >BTW, what single word name would you use to describe these pseudo 'threads'?
> "Background task manager", basically a time()-based wrapper around
> doEvents() (or the WinClass equivalent). Multiple background tasks can
> be started, but the last one started must complete before any previous
> can resume. In particular, blocked I/O (still) stalls the entire app.
> 
> >It does in fact use:
> >"Preemptive Multitasking"
> >ie uses some criteria to decide how long any one task should run 
> >before giving another task a turn to use the operating system.
> No, it does not. At best you might claim it is "Dualtasking", between
> the top of the background task stack and the GUI message loop, but
> *Multi* tasking is just downright misleading.
> 
> >I guess i could add a scheduling mechanism if that would make more
> >people happy :)
> I'd be very surprised if you could.
> 
> >I really think you should try a few applications using this kind of
> >technique before you pass judgement.  
> I don't need to, since I already know how to call doEvents() )
> 
> >Note that if thread 2 is almost done when thread 3 is initiated,
> >after thread 3 is complete thread 2 completes rather quickly
> >because it's almost done.
> Which begs the question: Why bother with a stack of time() values?
> Why not just have a single atom?
> 
> Some other notes:
> There should be a built-in single procedure call for:
> }}}
<eucode>
>       if CheckThread() then
>         if QueryQuitMessage(0) then
>         end if
>         ContinueThread(TimeSlice)
>       end if
> <font color="#330033"></eucode>
{{{
</font>
> rather than having to code the whole of that in every task loop.
> 
> Here is the win32lib equivalent:
> }}}
<eucode>
> atom TimeSlice
> atom EndSlice
> 
> global procedure StartThread(atom t)
>     TimeSlice = t
>     EndSlice=time()+TimeSlice
> end procedure
> 
> global procedure CheckThread()
>   if time()>EndSlice then
>     EndSlice=time()+TimeSlice
>     doEvents(0)
>   end if
> end procedure
> <font color="#330033"></eucode>
{{{
</font>
> 
> Regards,
> Pete
> 
> 

Hello Pete,


Sorry, i just dont feel like arguing about this anymore.
It's in the archives -- download it and try it, or assume
you know what it does and dont.


Take care,
Al

And, good luck with your Euphoria programming!

My bumper sticker: "I brake for LED's"