I'm fowarding this to the list so someone more experienced with processes
hopefully can answer it.

-- Bert

---------- Forwarded message ----------
Date: Sat, 3 Mar 2001 12:28:05 -0500
From: Elzbieta Chludzinska <elzbieta at operamail.com>
To: Bert Freudenberg <bert at isg.cs.uni-magdeburg.de>
Subject: RE: [PROBLEM] code generation & processes???

Our mail server has had some problems lately, so I don't know if this got 
through and I'm re-sending it! ---Elzbieta


Bert,

First of all, DANKE!

I'm working on a parallel sim wargame using what is called conservative time 
synchronization.  The algorithm is a modified Chandy-Misra-Bryant algorithm 
and it depends on the sending of null messages (events) to keep the "logical 
processes" (LP) synchronized - in Smalltalk/Squeak each LP corresponds to an 
image.

When I experience this "phenomena" (problem) NONE of the LP's advances in time 
- they stop executing events.  If I try using "self halt" to debug, the LP's 
proceed to advance their clocks - execute events. If I try adding debugging 
code, again the LP's start executing events.

It's a little like quantum mechanics - I can't observe the "process" without 
effecting the results.  If you have ANY suggestions - I'M LISTENING! I've 
tried playing with the priorities of the 3 Processes running in each image but 
to no avail.  How could moving what is in essence a no-op statement change the 
behavior of the processes?

DANKE! - DZIEKUJE!

Elzbieta


>===== Original Message From Bert Freudenberg <bert at isg.cs.uni-magdeburg.de>
    =====
>On Fri, 2 Mar 2001, Elzbieta Chludzinska wrote:
>
>> The #send:to: places the null event (after it's been packed into
>> ByteArray) on a SharedQueue.  The packed null event is taken off the
>> instance of SharedQueue by another Process which sends it to the other
>> image.
>
>What does it do when it fails?
>
>-- Bert

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>===== Original Message From Bert Freudenberg <bert at isg.cs.uni-magdeburg.de> 
=====
>On Fri, 2 Mar 2001, Elzbieta Chludzinska wrote:
>
>> The #send:to: places the null event (after it's been packed into
>> ByteArray) on a SharedQueue.  The packed null event is taken off the
>> instance of SharedQueue by another Process which sends it to the other
>> image.
>
>What does it do when it fails?
>
>-- Bert