Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: pedro@stl.stc.co.uk (Peter Jackson)
Newsgroups: comp.sys.sun
Subject: Any advice on problem with longjmp, please
Keywords: Software
Message-ID: <1250@acer.stl.stc.co.uk>
Date: 30 Mar 89 01:12:48 GMT
References: <8901280205.AA00199@Saigon.Versatc.uucp>
Sender: usenet@rice.edu
Organization: STC Technology Limited, London Road, Harlow, Essex, UK
Lines: 18
Approved: Sun-Spots@rice.edu
Original-Date: 13 Mar 89 09:59:43 GMT
X-Sun-Spots-Digest: Volume 7, Issue 213, message 6 of 15

I have some software developed for a range of different flavours of Unix,
including Sun, which contains a lightweight tasking package; it was
developed under Sun 3.x and so does not contain the sun lightweight
tasking, nor for portability reasons do I wish to convert it to use the
same.

The package `malloc's stack areas, and then uses setjmp and longjmp to
switch between tasks/stacks.  This seemed to work fine on the developers
machine, but on our 4.0.1 system produces illegal instruction errors in
longjmp when I try to restore a previously saved context from setjmp.  I
wonder if longjmp is performing some checking of the stack area or
something like that.

Does anyone know anything about this -- has longjmp changed in 4.0/4.0.1,
is there a fix??

     Peter Jackson
     STC Technology, London Road, Harlow,UK (+44 279 29531)