Re: requeue with abort and timed call

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 29 Dec 2008 03:17:32 -0800 (PST), christoph.grein@eurocopter.com
wrote:

> On 29 Dez., 11:55, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:
>> My understanding is that for the observer (the caller) servicing is
>> semantically an atomic operation which ends with the last rendzevous or
>> protected action. It is not abortable during a rendezvous or a protected
>> action, but between them it well is (unless it was requeued without abort).
> 
> But this is exactly what I meant to say.
> 
> Time line is like following;
>  0.0 The call of Original_Call
> *1.0 The expiration time of original call, so no abort, because in
> rendezvous
>  3.0 Complete Original_Call
> *3.0 Queued on Requeued_Call, which is never serviced, but which is
> also not abortable (no delay active).
> 
> So I do not see a problem with the behavious as shown in the OP's
> example.
> 
> *3.0 Queued on Requeued_Call - hm, you think the delay is still
> active? We need a language lawyer to enlighten us.

Yes, that is another way to say it. In my view the delay is always active,
because the caller cannot distinguish original and following calls. There
is only one call which can be logically aborted at any time before its
completion. Rendezvous and protected actions are considered semantically
instant for the caller. So servicing for the caller semantically consists
solely out of waiting for completion, there is no other visible components
in it.

A dual case is how internal protected actions are dealt with. When an
internal protected action is requeued to a closed entry, that ends the
action and will start a new one when the entry will open. The caller's
delay alternative can be selected before this new action start.

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