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From: Natasha Kerensikova <lithiumcat@instinctive.eu>
Newsgroups: comp.lang.ada
Subject: Re: =?UTF-8?Q?GNAT=C2=A0and?= Tasklets
Date: Fri, 19 Dec 2014 08:39:44 +0000 (UTC)
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Xref: news.eternal-september.org comp.lang.ada:24134
Date: 2014-12-19T08:39:44+00:00
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Hello,

On 2014-12-18, Randy Brukardt <randy@rrsoftware.com> wrote:
> [...]                           That's true of *any* Ada object -- without 
> documentation and/or code to manage it, it should be assumed to only work 
> with one task at a time.

That's a bit at odds with a recent (or not so recent) discussion, where
I didn't find in the RM where it is written that concurrent read-only
basic operations (like access dereference, array indexing, etc) are
task-safe, and the answer was that everything should work as expected
unless explicitly noted otherwise, even when concurrency is involved.

For example, I wrote Constant_Indefinite_Ordered_Maps (available at
https://github.com/faelys/natools/blob/trunk/src/natools-constant_indefinite_ordered_maps.ads )
which is an ordered map based on a binary search in a sorted array.
It is meant to be task-safe without any code to manage it, basing its
safety solely under the assumption that concurrent access dereference
and concurrent array indexing are safe.

I hope it's not a brittle assumption...


Natasha