From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=3.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.5-pre1
Path: eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED.2uCIJahv+a4XEBqttj5Vkw.user.gioia.aioe.org!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: is there a version of unix written in Ada
Date: Thu, 1 Oct 2020 18:06:48 +0200
Organization: Aioe.org NNTP Server
Message-ID: <rl4uql$1569$1@gioia.aioe.org>
References: <e3c51e65-b71e-4623-bd58-c94cdbcc3ba6o@googlegroups.com>
 <00cd3aaa-d518-43a2-b321-58d6fae70aebo@googlegroups.com>
 <db65f550-c1d9-4ddb-b128-7e4e9c1f818bn@googlegroups.com>
 <57eb7a65-51ea-4624-b9dc-9c4dda0fee59n@googlegroups.com>
 <rkq9gr$s0u$1@gioia.aioe.org> <5f70fd3b$0$13541$426a74cc@news.free.fr>
 <rks433$ndr$1@gioia.aioe.org>
 <daa04c57-0dfa-4c95-84ef-0e90f3c1732cn@googlegroups.com>
 <rkst48$171u$1@gioia.aioe.org> <87wo0d3iac.fsf@nightsong.com>
 <rkth03$uk5$1@gioia.aioe.org> <87sgb02l7b.fsf@nightsong.com>
 <rl1f1i$le8$1@gioia.aioe.org> <875z7vyy1u.fsf@nightsong.com>
 <rl2n2q$ddt$1@gioia.aioe.org> <87wo0bkns3.fsf@nightsong.com>
 <rl2rqt$jdq$1@gioia.aioe.org> <rl31jv$cue$1@franka.jacob-sparre.dk>
 <rl47f9$1nn9$2@gioia.aioe.org> <rl49ar$q51$1@dont-email.me>
 <rl4ajp$1d9d$1@gioia.aioe.org> <htltdlFel31U1@mid.individual.net>
 <rl4jd8$1h4s$1@gioia.aioe.org> <htmbf4FhiacU1@mid.individual.net>
NNTP-Posting-Host: 2uCIJahv+a4XEBqttj5Vkw.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.3.1
Content-Language: en-US
X-Notice: Filtered by postfilter v. 0.9.2
Xref: reader02.eternal-september.org comp.lang.ada:60366
List-Id: <comp.lang.ada>

On 01/10/2020 17:38, Niklas Holsti wrote:

> If the protected procedures belong to different protected objects, yes 
> it is legal. But not if they belong to the same object, as J-P noted.

But then you have a problem when two independently running protected 
procedures of *different* objects call a procedure of a third object. 
You must serialize these calls, and that is effectively blocking.

>> A simpler approach is to flush the queue by the first call to an 
>> unprotected variant of Trace. I believe Debug.adb does just this.
> 
> That is ok for programs that run for a short while, then terminate. Most 
> of my programs are non-terminating embedded programs so the log has to 
> be emitted from RAM to some larger storage continuously as the program 
> is running.

In my case the embedded program keeps on tracing all the time. Tracing 
from a protected action is rather an exception, sometimes literally, 
e.g. from a GNAT's exception handler.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de