Re: tasking with GNAT 3.14p on windows

[Jano <nono@celes.unizar.es>]

Chad R. Meiners dice...
> oops darn send button.

:)

> hmm.  I think I miscommunicated my point.  First, writing operating system
> independent multi-tasking program is not obvious since tasking is often
> misunderstood.  For example an common error is placing potentially blocking
> system calls (such as file IO) within a protected action.  On most compilers
> however wrapping your put_lines in a protected object does not cause any
> problems, but some compilers might be able to detect that a blocking call is
> being made at runtime and raise a Program_Error exception.  Care needs to
> taken to implement a multi-tasking program in a way that its OS calls are
> properly syncronized with the tasking system reguardless of the OS or
> compiler

Yes, one can always made mistakes. I'm more concerned about programs 
which doesn't use OS things nor do blocking calls inside protected 
objects. Programs which should be (fairly?) portable.

> btw, what workarounds are you refering to?

I was referring to the two first points in my other post: the need to 
raise your base priority to realtime class (with the danger it is if 
your program is buggy), and to know what are the mapping between the 31 
priorities in system.priority and the 7 in NT, which I have not handy, 
BTW, but could look if you are interested.

All this begins because at my college they use Ada to teach the real 
time programming subject. In the past we used ms-dos, meridian Ada (I 
think), and some hardware ad-hoc to simulate a vehicle and a dam. Later, 
when everything was being upgraded to windows, they found these things. 
I don't know what they are doing currently, but I suspect they never 
used windows in the end for the subject.

-- 
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Jano
402450.at.cepsz.unizar.es
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