Re: protected objects and external call

["Jean-Pierre Rosen" <rosen@adalog.fr>]

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"Robert A Duff" <bobduff@shell01.TheWorld.com> a �crit dans le message de
> > This is why it is considered a potentially blocking operation, and as
> > such disallowed in a protected operation.
>
> No, I don't think that's quite right.  Entry calls are potentially
> blocking, and you're not supposed to call them from inside a protected
> procedure.  (Actually, it's a bounded error, and some compilers allow
> it.)  But a protected procedure can call another protected procedure
> with an external call.  It's up to the programmer to make sure it's not
> the same protected object.  (You also have to obey the priority
> ceiling rules.)
>
> In other words, merely grabbing the lock of a PO is *not* considered
> blocking or potentially blocking in Ada, and no queue-ing need be
> involved.
>
9.5.1(16): [Potentially blocking operations]
an external call on a protected subprogram (or an external requeue) with the same target object as that of the protected action;

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           J-P. Rosen (rosen@adalog.fr)
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