Re: Reprise: 'in out' parameters for functions

["Robert I. Eachus" <rieachus@comcast.net>]

Dmitry A. Kazakov wrote:

> This has nothing to do with abstraction inversion. The problem here is that
> Ada does not have multiple protected actions. Same problem with tasks,
> there cannot be rendezvous with multiple tasks. It is much work to solve
> that. Especially to convince people that prefix notation is inherently bad.

Not quite right.  A decision was made early in the development of Ada 
that a CALLING task can only rendezvous with a single task.  A task can 
accept arbitrarily many calls simultaneously.  You might prefer that the 
rule worked the other way around, but we felt that we had to choose one 
or the other.  Many-to-many rendezvous looked just too messy to contemplate.

AFAIK, the only pattern that uses this feature is the one where you have 
multiple servers and a task that allocates requesting tasks to servers. 
  I have actually used this pattern.

-- 

                                           Robert I. Eachus

"The terrorist enemy holds no territory, defends no population, is 
unconstrained by rules of warfare, and respects no law of morality. Such 
an enemy cannot be deterred, contained, appeased or negotiated with. It 
can only be destroyed--and that, ladies and gentlemen, is the business 
at hand."  -- Dick Cheney