Re: Ada.Text_IO and protected objects (Was: [newbie question] tasks and protected types)

["fabio de francesco" <fmdf@tiscali.it>]

Egil H. Høvik wrote:
> "Jacob Sparre Andersen" <sparre@nbi.dk> wrote in message
> news:m2acnhn43i.fsf_-_@hugin.crs4.it...
> > Adrien Plisson wrote:
> > > Jacob Sparre Andersen wrote:
> >
> > > > If calls to Ada.Text_IO _are_ potentially blocking operations,
> > > > that means that one has to move the calls to a task.
> > >
>
> RM 9.5.1(18):
> Certain language-defined subprograms are potentially blocking. In
> particular, the subprograms of the language-defined input-output
> packages that manipulate files (implicitly or explicitly) are
potentially
> blocking.
>
>
> >
> > I thought entries of protected objects also were "protected
actions".
> > Unfortunately RM 9.5.1 isn't so clear on that question, that I am
sure
> > if that is actually the case or not.
> >
>
> RM 9.5.3(8):
> ... For a call on an entry of a protected object, a new protected
action
> is started on the object (see 9.5.1).
>
>
> ~egilhh

Thank you all for every insight on the subject. Anyway I don't yet
understand whether you mean that potentially "blocking" subprograms
should be put in a protected object or inversely they shouldn't.

In this thread I've been suggested to put the IO in a protected object.
Is it needed to do so?

What do you mean by "blocking"? I suppose you mean that OS can put that
process in a wait queue and switch to a new one, may be because the
first is waiting for some event like device IO. Is it correct?

Ciao,

fabio de francesco