Re: GNAT for MS Visual Studio

[Maciej Sobczak <see.my.homepage@gmail.com>]

On 2 Pa , 22:45, Pascal Obry <pas...@obry.net> wrote:

> > The fact that I cannot have
> > concurrent tasks operating in read-only mode on the shared container
> > is a fatal mistake. This is something even C++ can do, which
> > ironically does not even officially support threads.
>
> ????? I must be missing your point as this is definitely possible with
> Ada tasking.

It is not::

http://www.adaic.org/standards/05aarm/html/AA-A-18.html

4.o/2:

"Library packages must be reentrant - multiple tasks can use the
packages as long as they operate on separate containers. Thus, it is
only necessary for a user to protect a container if a single container
needs to be used by multiple tasks."

There is no distinction between "use" and "modification", even though
one might try to deduce it from the fact that in some container
operations the container itself is passed as "in" parameter. Without
this distinction spelled out black on white the only thing the
programmer can do is to protect the container systematically whenever
he performs *any* operation on it.

John Barnes writes about this in the relevant chapter of "Programming
in Ada 2005" as well.

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com