From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: is there a version of unix written in Ada
Date: Thu, 1 Oct 2020 14:51:54 +0200 [thread overview]
Message-ID: <rl4jd8$1h4s$1@gioia.aioe.org> (raw)
In-Reply-To: htltdlFel31U1@mid.individual.net
On 01/10/2020 13:38, Niklas Holsti wrote:
> On 2020-10-01 13:21, Dmitry A. Kazakov wrote:
>> On 01/10/2020 11:59, J-P. Rosen wrote:
>>> Le 01/10/2020 à 11:28, Dmitry A. Kazakov a écrit :
>>>> BTW, I still do not know to design an Ada-conform tracing/logging
>>>> facility such that you could trace/log from anywhere, protected action
>>>> included, and without knowing statically which protected object is
>>>> involved.
>>>>
>>> Did you have a look at package Debug?
>>> (https://www.adalog.fr/en/components#Debug)
>>
>> Thanks
>>
>>> It features, among others, a trace routine which is guaranteed to not be
>>> potentially blocking.
>>
>> It calls a protected operation on a different protected object, yes,
>> this is non-blocking, and I considered same, but is this legal?
>
> Yes.
>
> If the program is using ceiling-priority-based protection, the priority
> of the calling object must be less or equal to the priority of the
> called object.
My mental picture was protected procedure calls executed concurrently on
different cores of a multi-core processor. Would that sort of
implementation be legal?
If so, then let there be protected procedure P1 of the object O1 and P2
of O2. If P1 and P2 call to P3 of O3 that would be a problem. Ergo ether
wandering or concurrent protected protected calls must be illegal.
> 1. A LIFO queue of log entries implemented in a protected object of
> highest priority. The object has a procedure "Write_Log_Entry".
Yes, that was what I thought and what Debug.adb does. However Debug.adb
allocates the body of the FIFO element in the pool. I would rather use
my implementation of indefinite FIFO which does not use pools. I don't
want allocators/deallocators inside protected stuff.
> 2. A task that empties the LIFO queue into a log file. The task calls an
> entry of the LIFO protected object to get a log entry from the queue,
> but executes the file-writing operations in task context, not in a
> protected operation.
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.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2020-10-01 12:51 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <e3c51e65-b71e-4623-bd58-c94cdbcc3ba6o@googlegroups.com>
2020-07-25 7:37 ` is there a version of unix written in Ada mockturtle
2020-07-26 19:45 ` Stéphane Rivière
2020-07-26 22:15 ` Jeffrey R. Carter
2020-07-27 7:40 ` Stéphane Rivière
2020-07-28 13:08 ` DrPi
2020-07-28 16:48 ` Simon Wright
2020-07-28 17:00 ` Fabien Chouteau
2020-07-29 9:21 ` DrPi
2020-07-29 9:28 ` Fabien Chouteau
2020-07-29 15:02 ` DrPi
2020-07-29 15:11 ` Fabien Chouteau
2020-07-29 20:41 ` DrPi
2020-07-29 9:20 ` DrPi
2020-07-29 16:53 ` Simon Wright
2020-07-29 20:42 ` DrPi
2020-07-25 8:47 ` Niklas Holsti
2020-07-25 9:36 ` Stéphane Rivière
2020-07-25 10:41 ` Luke A. Guest
2020-07-25 14:43 ` Jesper Quorning
2020-07-25 19:20 ` Andreas ZEURCHER
2020-07-27 7:40 ` Stéphane Rivière
2020-07-27 15:00 ` nobody in particular
2020-07-27 14:58 ` nobody in particular
2020-07-27 20:28 ` Shark8
2020-07-30 0:57 ` gdotone
2020-07-31 14:01 ` Shark8
2020-09-23 17:39 ` Olivier Henley
2020-09-25 15:06 ` DrPi
2020-09-25 17:31 ` Andreas ZEURCHER
2020-09-26 8:50 ` DrPi
2020-09-27 18:55 ` Luke A. Guest
2020-09-27 19:07 ` Luke A. Guest
2020-09-27 18:53 ` Luke A. Guest
2020-09-27 14:25 ` Shark8
2020-09-27 15:01 ` Dmitry A. Kazakov
2020-09-27 20:59 ` DrPi
2020-09-28 7:41 ` Dmitry A. Kazakov
2020-09-28 13:48 ` Olivier Henley
2020-09-28 14:48 ` Dmitry A. Kazakov
2020-09-28 16:28 ` Olivier Henley
2020-09-28 20:30 ` Dmitry A. Kazakov
2020-09-28 21:06 ` Shark8
2020-09-28 17:47 ` Paul Rubin
2020-09-28 20:27 ` Dmitry A. Kazakov
2020-09-29 23:54 ` Paul Rubin
2020-09-30 8:18 ` Dmitry A. Kazakov
2020-09-30 17:27 ` Paul Rubin
2020-09-30 19:42 ` Dmitry A. Kazakov
2020-09-30 20:33 ` Paul Rubin
2020-09-30 21:03 ` Dmitry A. Kazakov
2020-09-30 22:42 ` Randy Brukardt
2020-10-01 9:28 ` Dmitry A. Kazakov
2020-10-01 9:59 ` J-P. Rosen
2020-10-01 10:21 ` Dmitry A. Kazakov
2020-10-01 11:38 ` Niklas Holsti
2020-10-01 11:52 ` Niklas Holsti
2020-10-01 12:51 ` Dmitry A. Kazakov [this message]
2020-10-01 14:18 ` J-P. Rosen
2020-10-01 15:44 ` Dmitry A. Kazakov
2020-10-01 22:10 ` Randy Brukardt
2020-10-02 5:36 ` J-P. Rosen
2020-10-02 6:56 ` Dmitry A. Kazakov
2020-10-02 7:42 ` J-P. Rosen
2020-10-03 3:14 ` Randy Brukardt
2020-10-01 15:38 ` Niklas Holsti
2020-10-01 16:06 ` Dmitry A. Kazakov
2020-10-01 17:01 ` Niklas Holsti
2020-10-01 17:37 ` Dmitry A. Kazakov
2020-10-01 22:13 ` Randy Brukardt
2020-10-01 11:48 ` J-P. Rosen
2020-10-01 12:54 ` Dmitry A. Kazakov
2020-10-01 7:57 ` Paul Rubin
2020-10-01 9:26 ` Dmitry A. Kazakov
2020-10-01 9:46 ` Paul Rubin
2020-10-01 10:35 ` Dmitry A. Kazakov
2020-10-01 19:02 ` DrPi
2020-10-01 23:12 ` Paul Rubin
2020-10-01 21:54 ` Randy Brukardt
2020-10-01 23:14 ` Paul Rubin
2020-10-01 21:36 ` Brian Drummond
2020-10-02 6:56 ` Dmitry A. Kazakov
2020-10-02 18:34 ` Brian Drummond
2020-10-02 21:24 ` Paul Rubin
2020-10-06 23:54 ` Brian Drummond
2020-10-03 6:54 ` Dmitry A. Kazakov
2020-10-05 14:03 ` Shark8
2020-10-07 11:56 ` Olivier Henley
2020-10-09 12:35 ` Olivier Henley
2020-10-09 14:41 ` Brian Drummond
2020-09-28 18:40 ` Vincent Marciante
2020-09-28 20:28 ` Dmitry A. Kazakov
2020-09-28 17:04 ` DrPi
2020-09-28 17:30 ` Olivier Henley
2020-09-28 18:05 ` Olivier Henley
2020-09-28 19:36 ` Shark8
2020-09-03 10:32 ` c+
2020-09-12 4:30 ` sumde121
2020-09-19 14:09 ` erchetan33
2020-10-01 22:21 Randy Brukardt
2020-10-02 6:55 ` Dmitry A. Kazakov
2020-10-03 3:09 ` Randy Brukardt
2020-10-03 6:42 ` Dmitry A. Kazakov
2020-10-03 7:44 ` Niklas Holsti
2020-10-03 8:16 ` Dmitry A. Kazakov
2020-10-03 10:44 ` Niklas Holsti
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