Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!jesup
From: jesup@cbmvax.commodore.com (Randell Jesup)
Newsgroups: comp.sys.amiga.tech
Subject: Re: What does this guru mean?
Message-ID: <13430@cbmvax.commodore.com>
Date: 25 Jul 90 18:30:32 GMT
References: <2599@mindlink.UUCP>
Reply-To: jesup@cbmvax (Randell Jesup)
Organization: Commodore, West Chester, PA
Lines: 30

In article <2599@mindlink.UUCP> a275@mindlink.UUCP (Travers Naran) writes:
>> DrBob@cup.portal.com writes:
>> I'm hoping someone out there can enlighten me on the true meaning of
>> this guru meditation number:  87000004 265F48F1
...
>> My program is a dos handler for tape drives, written in C.  It also opens
>> a CON: window and Write()s messages to it.  Three Write()s successfully
>> execute, then the fourth one prints its message in the window but never
>> returns to my program; instead I get the "task held" requester, then guru.
>> To add a bizarre note to this story, it only fails on A2000's and 2500s;
>> it has never failed on my home A1000+Supra system.

	You CANNOT make most dos calls (specifically those that cause packets
to be sent) from within a handler.  The problem is that you have the process
port receiving asynchronous messages while Dos is trying to use it synchronously
to handle your dos call.

>Well, unexpected packet recieved means (I think) the packet that was sent
>internally was not expected to be recieved from within a device process.
>Something new in 1.3 I guess. Playing with packets has always been a dangerous
>business.

	Almost everyone who plays with handlers gets AN_AsynchPacket
eventually.  It's not new in 1.3 - 1.3 was (essentially) a WB release.  It's
been there since 1.0.

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com  BIX: rjesup  
Common phrase heard at Amiga Devcon '89: "It's in there!"