Re: Private or public task ?

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

Hibou57 (Yannick Duch�ne) a �crit :
> [...]
> Sure a procedure of a protected type or object should be short and
> quick to execute, but it seems to still remains potentially blocking.

There are two kinds of blockings: bounded and unbounded. The idea is
that when computing a time budget, you can account for bounded
blockings, but not unbounded ones.

protected procedures are bounded, because if you know the processing
time and the maximum number of tasks waiting, you know the WCET of the
procedure. Entries are unbounded, because they depend on a guard whose
condition can be anything.

The "potentially blocking" phrase should be understood as really meaning
unbounded.  This all boils down to: "an operation with a bounded
execution time is not allowed to call an operation with an unbounded
execution time".

Makes more sense?

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