Re: Musings on RxAda

[Hadrien Grasland <hadrien.grasland@gmail.com>]

Le mercredi 21 octobre 2015 21:35:26 UTC+2, Dmitry A. Kazakov a écrit :
> On Wed, 21 Oct 2015 12:09:58 -0700 (PDT), Hadrien Grasland wrote:
> 
> > So you would essentially store a pipeline of data and operations in some
> > container, then perform all of them on the same thread when the output of
> > the pipeline is requested ?
> 
> I don't know your requirements. In a FIFO scenario, yes, the publisher
> pushes the object. The subscriber pulls it out. In a blackboard scenario
> (non-blocking) the publisher pushes the object and the subscribers scan the
> blackboard for updates.
> 
> Of course in a modern typed language like Ada you would not mess with "data
> and operations." There are objects for that. The type of the object
> determines the operations.
> 
> > This seems much more complex to implement to me, since your operation
> > queue needs to be able to store data of any type and operation function
> > pointers, all in a type-safe way. As far as I can tell, you cannot use
> > streams for that because a stream requires you to know what you are
> > reading from it.
> 
> That is because you are trying to think about it in terms of C. Ada is not
> C, luckily. It is quite straightforward to marshal T'Class objects with a
> dispatching operation Do_It. And yes, it is as much easy to marshal handles
> to reference-counted objects if objects are expected large (and you have
> shared memory).
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Ah, I see. I agree that an object oriented solution could indeed solve this serialization problem well !