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
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 border1.nntp.dca.giganews.com!nntp.giganews.com!goblin2!goblin.stu.neva.ru!reality.xs3.de!news.jacob-sparre.dk!loke.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Safety of unprotected concurrent operations on constant objects
Date: Wed, 7 May 2014 22:45:35 -0500
Organization: Jacob Sparre Andersen Research & Innovation
Message-ID: <lkeukv$66d$1@loke.gir.dk>
References: <slrnlm6mkg.i0l.lithiumcat@nat.rebma.instinctive.eu>
 <7403d130-8b42-43cd-a0f1-53ba34b46141@googlegroups.com>
 <slrnlmals8.i0l.lithiumcat@nat.rebma.instinctive.eu>
 <lya9aybkxc.fsf@pushface.org> <lk41jr$1vl$1@dont-email.me>
 <slrnlmbs1n.i0l.lithiumcat@nat.rebma.instinctive.eu>
 <Xmx9v.1015937$kp1.584730@fx14.iad>
 <1jbqe7sd9d13f.1p91l6pdkv6fz.dlg@40tude.net>
NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net
X-Trace: loke.gir.dk 1399520736 6349 69.95.181.76 (8 May 2014 03:45:36 GMT)
X-Complaints-To: news@jacob-sparre.dk
NNTP-Posting-Date: Thu, 8 May 2014 03:45:36 +0000 (UTC)
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157
Date: 2014-05-07T22:45:35-05:00
List-Id: <comp.lang.ada>

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:1jbqe7sd9d13f.1p91l6pdkv6fz.dlg@40tude.net...
> On Sun, 04 May 2014 14:25:26 -0600, Shark8 wrote:
>
>> On 04-May-14 01:46, Natasha Kerensikova wrote:
>>> I have some shared resources indexed by a string, described in a
>>> file, and considered as constant throughout the lifetime of the program
>>> (with the standard scheme "restart for changes to take effect").
>>
>> What's the problem, then, with making the entire map constant?
>
> That is not enough. Technically speaking all operations must be reentrant.
> All arguments being immutable does not make a subprogram reentrant.

Right. And "constant" doesn't have that effect (of immutability) for private 
types anyway. It just prevents assigning to the whole object *from the 
current view*. But it's easy to get a variable view for immutably limited 
types, and not hard for controlled types. Not to mention access-to-variable 
components. And you cannot assume that there aren't any controlled 
components or access-to-variable components for a private type.

                   Randy.