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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: PubSub
Date: Sat, 31 Oct 2020 19:38:09 +0100
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On 31/10/2020 18:58, DrPi wrote:

> Another question indirectly concerning GUI programming : Does a Ada 
> "PubSub" package exist ?

Yes. We have a commercial middleware 100% in Ada. We use that thing in 
automation and control systems. Naturally, it provides 
publisher/subscriber services, distributed or not with controlled QoS. 
That is so to say horizontal communication between applications or 
tasks. It also has a vertical communication aspect abstracting 
hardware/protocols from application. E.g. you can publish/subscribe to a 
MQTT topic, or to an EtherCAT object, or to a CANOpen dictionary object 
etc without even knowing if that really the thing, something else or 
another application.
  Having said that, for horizontal communication inside single process 
you do not need that in Ada. Many things done for other languages are 
not needed in Ada.

Ada protected objects and tasks provide much more efficient, safer 
(typed) and easier to use way to communicate between tasks.

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