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: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: tasking design considerations
Date: Fri, 20 Jan 2017 09:42:33 +0100
Organization: Aioe.org NNTP Server
Message-ID: <o5sihq$19ul$1@gioia.aioe.org>
References: <396469b6-6efe-49e7-914b-9226637e031e@googlegroups.com>
NNTP-Posting-Host: vZYCW951TbFitc4GdEwQJg.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 6.1; WOW64; rv:45.0) Gecko/20100101
 Thunderbird/45.6.0
X-Notice: Filtered by postfilter v. 0.8.2
Xref: news.eternal-september.org comp.lang.ada:33102
Date: 2017-01-20T09:42:33+01:00
List-Id: <comp.lang.ada>

On 20/01/2017 09:07, rrr.eee.27@gmail.com wrote:
> I am still trapped in old school linear thinking and I am facing a
> tasking design problem.
>
> On channel A I receive messages in a irregular way. I then have to
> collect all messages of a given time frame T, process the messages that
> lie within the time frame and then send out the result to channel B.
 >
> For the ease of reasoning you can assume typically around 0 .. 20
> messages (the maximum certainly << 1000 messages) per time frame T. The
> cycle time of T is fixed now to 1 minute, but might go down in the
> future to 1 second. Channel B of course has exactly one message per T.
> The channels are TCP sockets. Reception of a single complete message in
> channel A activates callback function in my program.
>
> I want now create a protected object stack. The callbacks from
> channel  A fill the stack on the top. A cyclic task with a cycle time T reads and
> removes all collected messages from the bottom of the stack. The task
> processes the messages and sends out the result.
>
> Does that sound like a reasonable and feasable design? I'm looking
> forward to any feedback.

Yes. Two minor notes:

1. It is not a stack (LIFO) it a FIFO, I suppose you want to keep the 
messages ordering.

2. You don't need a protected object or other locking method because a 
FIFO with a single writer and a single reader is task-safe (can be 
designed lock-free).

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