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=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,e81fd3a32a1cacd2
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news4.google.com!news.glorb.com!solaris.cc.vt.edu!news.vt.edu!newsfeed-00.mathworks.com!nntp.TheWorld.com!not-for-mail
From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: Arguments for single-mutex-exclusion on protected types (Was:
 Does Ada tasking profit from multi-core cpus?)
Date: Mon, 26 Mar 2007 19:24:10 -0400
Organization: The World Public Access UNIX, Brookline, MA
Message-ID: <wcc3b3r8u79.fsf@shell01.TheWorld.com>
References: <rgcukvs1j6ck$.1vjj69zzy1h56$.dlg@40tude.net>
 <yfydnaboycG2YHHYnZ2dnUVZ_tadnZ2d@comcast.com> <pKiHh.734$PF.381@attbi_s21>
 <ygey7lxb6tg.fsf_-_@hugsarin.dmusyd.edu> <XZKKh.21401$PF.13827@attbi_s21>
 <wcczm6bss2i.fsf@shell01.TheWorld.com> <eths7k$c9n$1@jacob-sparre.dk>
 <wccmz2azb7j.fsf@shell01.TheWorld.com> <etn0dq$i5n$1@jacob-sparre.dk>
 <5iGLh.26236$PF.18838@attbi_s21> <etndns$13j$1@jacob-sparre.dk>
NNTP-Posting-Host: shell01.theworld.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: pcls6.std.com 1174951461 378 192.74.137.71 (26 Mar 2007 23:24:21 GMT)
X-Complaints-To: abuse@TheWorld.com
NNTP-Posting-Date: Mon, 26 Mar 2007 23:24:21 +0000 (UTC)
User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (irix)
Cancel-Lock: sha1:b4YfLWGrK/9NO/rbpser+SvsDM0=
Xref: g2news1.google.com comp.lang.ada:14645
Date: 2007-03-26T19:24:10-04:00
List-Id: <comp.lang.ada>

"Randy Brukardt" <randy@rrsoftware.com> writes:

> Nothing serious, but it's less than ideal:
> (1) It complicates the interface; it makes the client worry about something
> that they probably don't care about.
> (2) It doesn't work for a protected interface (no discriminants);
> (3) It doesn't work as well if the protected object is wrapped in a tagged
> type, because tagged types can't have defaults on their discriminants -
> meaning that it always has to be specified. This also applies to any
> protected object that defines an interface (it can have discriminants, but
> no defaults, as it is considered tagged).

These problems with discriminants go away in Ada 2005, because we have
limited constructor functions.  A very cool feature, IMHO.

- Bob