Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!dutrun!duteca4!thomas
From: thomas@duteca (Thomas Okken)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Application defined events in Multifinder
Message-ID: <1244@duteca4.UUCP>
Date: 28 Feb 91 00:24:43 GMT
References: <1CE00001.ieuttv@tbomb.ice.com>
Organization: Delft University of Technology, Netherlands
Lines: 21

> In article <1991Feb23.140420.20707@ux1.cso.uiuc.edu>, resnick@cogsci.uiuc.edu (Pete Resnick) writes:
>> I can't seem to find any documentation on this one. It appears that
>> PostEvent can be called at interrupt, so that I can post app1Evt's
>> from asynchronous completetion routines in my program to signal that
>> events have occurred. It is not clear, however, how I am to distinguish
> 
> I believe that with the advent of MultiFinder, applications are not
> supposed to be using the appEvt's. Unfortunately, I do not have my
> MF Doc at hand...

Well, I don't remember offhand where I read this - must've been either
"Programmer's Guide to MultiFinder" or some technote, but the answer is:
You can't use app[1-4]evts under MultiFinder, because all events will be passed
to the foreground application. So if your app is in the background, waiting
to be notified by an app1evt (to be posted by a VBL task doing some useful
thing), it can wait forever: the app1evt is sent to the foreground app, which
will probably ignore it.
If communication between an interrupt-time task an your application is needed,
use globals as semaphores. Have fun trying to keep track of A5! ;-)

 - Thomas (thomas@duteca.et.tudelft.nl)