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From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Termination of tasks waiting on a protected queue
Date: Sun, 18 May 2014 14:54:13 -0700
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Date: 2014-05-18T14:54:13-07:00
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On 05/18/2014 12:54 PM, Natasha Kerensikova wrote:
>
> This is a library-level queue and a library level task providing a
> service to the whole application. So there is no object whose
> finalization can be used as a trigger for the task shutdown order.
> The only solution I see is to provide an explicit Shudown procedure that
> sends the task shutdown signal, but it is fragile: what if the client
> forgets to call it? or if an exception make control flow jump around it?
> and what if the client calls it too early, and more jobs are added to
> the queue?

I had no access to the pool tasks once they were created, so calling a task 
entry was not possible. The Control PO was library level, and was called so the 
function returned True when the system was shutting down. There were 
library-level tasks, too, so it wasn't the finalization of a controlled object 
that made that call. The system knew when it was time to stop.

If you don't have that knowledge, then things get interesting. You may have to 
accept the failings you discuss and push the responsibility off to the client.

-- 
Jeff Carter
"If I could find a sheriff who so offends the citizens of Rock
Ridge that his very appearance would drive them out of town ...
but where would I find such a man? Why am I asking you?"
Blazing Saddles
37