From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM
	autolearn=ham autolearn_force=no version=3.4.4
X-Google-Thread: 103376,c3c4ae45442f569e
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII
Path: 
 g2news1.google.com!postnews.google.com!o13g2000cwo.googlegroups.com!not-for-mail
From: "fabio de francesco" <fmdf@tiscali.it>
Newsgroups: comp.lang.ada
Subject: Re: Ada.Text_IO and protected objects (Was: [newbie question] tasks
 and protected types)
Date: 29 Apr 2005 14:57:21 -0700
Organization: http://groups.google.com
Message-ID: <1114811841.250745.71870@o13g2000cwo.googlegroups.com>
References: <1114747457.868019.93210@f14g2000cwb.googlegroups.com>
   <m23bt9dik6.fsf@hugin.crs4.it>
   <42720DCD.6030304@mailinator.com>
   <m2y8b1bzdt.fsf@hugin.crs4.it>
   <4272260d$0$30463$ba620e4c@news.skynet.be>
   <m2acnhn43i.fsf_-_@hugin.crs4.it>
   <d4tftf$m7i$1@kda-news.kongsberg.com>
NNTP-Posting-Host: 80.181.52.213
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
X-Trace: posting.google.com 1114811849 28593 127.0.0.1 (29 Apr 2005 21:57:29
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Fri, 29 Apr 2005 21:57:29 +0000 (UTC)
In-Reply-To: <d4tftf$m7i$1@kda-news.kongsberg.com>
User-Agent: G2/0.2
Complaints-To: groups-abuse@google.com
Injection-Info: o13g2000cwo.googlegroups.com; posting-host=80.181.52.213;
   posting-account=Lp02jQ0AAABMd3TAghNf0TM2YBZqD_JE
Xref: g2news1.google.com comp.lang.ada:10839
Date: 2005-04-29T14:57:21-07:00
List-Id: <comp.lang.ada>


Egil H. H=F8vik 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