[Oberon] ETH Oberon/Gadgets: System Freeze in unloading

[Felix Friedrich]

Hi Patrick

>However, in several years of working with Oberon, I have only found three 
>ways to produce C-like system freezes
>apart from using the unsafe SYSTEM feature:
>A) calling C programs from within Oberon
>B) passing very large arrays as value parameters in procedure headings
>C) unloading modules whereby some visual gadget is still hanging around 
>somewhere, as mentioned above.
>I feel system stability is a prominent one of the many highlights of 
>Oberon, so the points B and C hurt the more...

I agree. By the way problem B) occurs because the max stacksize of an 
Oberon.Thread (in Windows) is approx. like 100kB. I have increased that 
value to 1MB in my threads, but anyway, the best "solution" is to take 
VAR-pars or Pointers. As far as I know, in Windows-Oberon it is a 
Windows-Problem, since the Windows-thread crashes when the size of the 
stack is too small. Maybe there should be some built in range-check for the 
stack in Oberon. (possible?)
Do you see a solution for C) ?

Felix.
--

Felix Friedrich

Institut für Biomathematik und Biometrie
GSF - Forschungszentrum für Umwelt und Gesundheit, GmbH
Ingolstädter Landstraße 1, D-85764 Neuherberg

Tel:      ++49 89 3187 2436
email:  friedrich at gsf.de

--