Re: tasking with GNAT 3.14p on windows

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

Ole-Hjalmar Kristensen dice...

> Unless Microsoft has significantly improved the Pthreads support, it's
> not a good idea to implement the GNAT runtime on top of Pthreads on
> Windows.  From a quick look at the GNAT runtime, it seems like the
> native NT interface is used, not Pthreads.

Docs says that Ada tasks are mapped to native threads, I don't know if 
that leaves room for pthreads (which I ignore).

I tried recently something like that:

select
   delay 10.0;
   put_line("aborted);
then abort
   get_line(text, last);
end select;

trying to know the behavior with blocking I/O. In XP with -gnatP, you 
get indefinite wait for user input, but if more than 10 seconds has 
passed when you hit enter, you get also the "aborted" print.

Is that expected behavior? Gnat docs say that polling implements calls 
in each loop iteration / function call. Should I assume that if you 
haven't loops / calls, abort will never work properly?

I feel nevertheless very unsafe using anything else than trivial tasks 
in NT. The priority system of NT messes things greatly out of 
real_time_class, and that, for example, is never pointed in Gnat docs 
(in my knowledge).

Also, the faulty ceiling_priority model for protected objects is 
mentioned or not? I can't remember...

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