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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: How to transfer Class-Wide object to a Task ?
Date: Tue, 15 Oct 2019 09:21:48 +0200
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Date: 2019-10-15T09:21:48+02:00
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On 2019-10-14 22:58, William FRANCK wrote:

> Here is the multitasking part (simplified) (working, no issue)
> for reading the datafile, and writing it back (after some data-process)
> 
> My first intention was : while Writing.Bloc is busy writing on the 
> output file, Reading.Bloc can take 1 record in advance

That is what OS asynchronous I/O does already. But that is aside.

> Now I have to insert the class-wide object passing in the Bloc.

Stream attributes 'Input and 'Output would do.

> As You mentionned, should I use a protected type (FIFO)  instead of 2 // 
> tasks ?

A protected object to synchronize two tasks:

    Producer -> FIFO -> Consumer
     Block put <- PO -> Block get
     when full          when empty

FIFO does not need interlocking in this scenario. Protected object is 
only to prevent busy waiting at the ends.

Since you are working with streams you can use a storage stream instead 
of raw FIFO:

    Producer -> Storage stream -> Consumer
    Block write when full    Block read when empty

I still do not understand why you serialize and deserialize insted of 
copying bytes as they are.

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