Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!keith
From: keith@Apple.COM (Keith Rollin)
Newsgroups: comp.sys.mac.programmer
Subject: Re: DA loses resource file on accRun
Keywords: MultiFinder DAs context switches
Message-ID: <33407@apple.Apple.COM>
Date: 24 Jul 89 02:47:33 GMT
References: <1989Jul17.045641.20314@lth.se> <2932@internal.Apple.COM> <14573@dartvax.Dartmouth.EDU> <33359@apple.Apple.COM> <2808@murtoa.cs.mu.oz.au>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 37

In article <2808@murtoa.cs.mu.oz.au> jkjl@murtoa.UUCP (John Keong-Jin Lim) writes:
>In article <33359@apple.Apple.COM> keith@Apple.COM (Keith Rollin) writes:
>>Background applications get the minor switch because they can be optimized
>>for background time. First of all, background applications don't get null
>>events unless the canBackground bit is set. 
>
>There is a bit you can set in the dCtlFlags that allows you to
>control whether accRun is called at all (this is from memory - I
>dont have IM here, so i cant guarantee 100% accuracy).
>
>>Second, there is the 'sleep'
>>parameter of WaitNextEvent. Both of these help prevent numerous minor
>
>DAs have the dCtlDelay to tell the DA how long to sleep.
>
>>switches. DA's don't have these options available to them, so saving time had
>>to be done in this other way.
>
>What you said above just isnt true, Keith. Apple has provided ways of
>making background tasks in DAs very friendly. Why not have a resource
>in DAs like the sysz resource in inits to inform MF that it is friendly ??

Hmmm...that's what I get for talking about something I know very little about.
Personally, I've never written a driver or DA. Nasty little things. I believe
you are correct in the things you say. There's the 'drvrDelay' field and the
'dNeedTime' bit. There's even the accCursor message to take the place of 
mouseMoved events.

I just tried forwarding on what I'd heard from someone else. I guess I'd better
stick to answering MPW and MacApp questions...

------------------------------------------------------------------------------
Keith Rollin  ---  Apple Computer, Inc.  ---  Developer Technical Support
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"Argue for your Apple, and sure enough, it's yours" - Keith Rollin, Contusions