Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!uw-beaver!cornell!batcomputer!riley
From: riley@batcomputer.tn.cornell.edu (Daniel S. Riley)
Newsgroups: comp.sys.amiga
Subject: Re: Modem/VT100 problem
Keywords: vt100 bugs
Message-ID: <5205@batcomputer.tn.cornell.edu>
Date: 17 Jun 88 22:18:19 GMT
References: <6512@jhunix.HCF.JHU.EDU> <1108@damask.UUCP>
Reply-To: riley@tcgould.tn.cornell.edu (Daniel S. Riley)
Organization: Cornell Theory Center, Cornell University, Ithaca NY
Lines: 30

In article <1108@damask.UUCP> hardie@damask.UUCP (Peter Hardie ) writes:
>I have a Hayes smartmodem 1200 and have had this problem for a long time
>now with several other modem/terminal programs. 
>It only happens when the remote end drops the carrier and this occasionally
>causes the amiga to go bye-bye. The mouse can still be moved around but trying
>to terminate vt100 by clicking on the left-hand button don't work anymore.
>I can't remember if pushing the window to the back still works, but I suspect
>not because I always have to reboot.

I know that there are a number of places within vt100 where it will
AbortIO() a request,
Wait() for the signal associated with the port for that IO request, then
WaitIO() on that IO request.
This sequence can lead to obscure vt100 lock-ups if the IO happens to
complete and the signal is cleared somewhere else in the program before
this code gets executed.  However, this only causes vt100 to hang, not
any other part of the system, and it's fairly rare and timing dependent.
I took all the Wait()'s out of these sequences after I was burned a few
times aborting scripts, and have had no problems with vt100 hanging
since then.  Hopefully I'll remember to complain to Tony before the
next version comes out.

While I'm on the subject, there's also a bug in the Kermit bye routine--
when it's invoked from the menu (or keyboard equivalent), it either uses
memory that's been freed (if you've done a kermit transfer that session)
or scribbles all over low memory (if it's the first kermit operation that
session).  It's also on my list to tell Tony about.

-Dan Riley (dsr@lns61.tn.cornell.edu, dsr@crnlns.bitnet)
-Wilson Lab, Cornell U.