Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!julius.cs.uiuc.edu!rpi!zaphod.mps.ohio-state.edu!samsung!uunet!bony1!richieb From: richieb@bony1.bony.com (Richard Bielak) Newsgroups: comp.databases Subject: Re: Any TUXEDO users here? Summary: Shared memory bad? Message-ID: <1991Jan29.191908.8928@bony1.bony.com> Date: 29 Jan 91 19:19:08 GMT References: <2060008@hpcuhc.cup.hp.com> <1991Jan23.205907.5477@tfic.bc.ca> Reply-To: richieb@bony1.UUCP (Richard Bielak) Organization: Bank of New York Lines: 40 In article <1991Jan23.205907.5477@tfic.bc.ca> clh@tacitus.UUCP (Chris Hermansen) writes: > >One of the big uglies with CICS was (is?) (on VS1, at least) that, using >one large enclosing batch job, all user programs linked in had the potential >of stomping all over other user programs (they all used the same protect key). >Usually, programs so ill behaved merely resulted in an addressing exception, >but I always wondered about program segments going off the ends of arrays... >(WHAT! What do you mean, my bank balance is zero!?!?!). It's my understanding >that MVS may have fixed this problem. What VS1 shops used to do was have >two CICS partitions (out of a maximum of 15, I believe) - one for testing, >one for production. When you had a new program to test, you got the system >manager to relink the test CICS and start up a fresh copy. When you had it >"working", you put in a request to have it linked to the production CICS, >which usually would happen just after backups when the system was brought >back up. Point being, there was no dynamic linking... [...stuff deleted...] From reading few of the TUXEDO manuals (I only have manuals, no software), I know that TUXEDO uses shared memory for client/server communications (at least for processes on one machine). Can a program using TUXEDO corrupt the shared memory with runaway pointer error and mess up the entire system? Or is the shared memory protected? In the distant past I worked on a PDP-11/RSX-11M system, where the TP monitor used shared memory. If some program had a bug and corrupted the shared memory, the whole system went down the tubes. Just wondering. ...richie -- +----------------------------------------------------------------------------+ | Richie Bielak (212)-815-3072 | "The sights one sees at times makes one | | Internet: richieb@bony.com | wonder if God ever really meant for | | Bang: uunet!bony1!richieb | man to fly." -- Charles Lindbergh |