Re: Finalization of library level tasks

["J-P. Rosen" <rosen@adalog.fr>]

Le 16/04/2018 à 17:26, Dmitry A. Kazakov a écrit :
> The only place RM explains 'Callable is in ARM C.7.1:riddle:
> 
> "(10.a.1/1):Ramification: {8652/0115} {AI95-00206-01} These routines can
> be called with an argument identifying the environment task.
> Is_Terminated will always be False for such a call, but Is_Callable
> (usually True) could be False if the environment task is waiting for the
> termination of dependent tasks. Thus, a dependent task can use
> Is_Callable to determine if the main subprogram has completed."
> 
> At least for the environment task 'Callable is defined this (reasonable)
> way. It seems that GNAT uses this definition for all task.

The environment task calls the main subprogram. Therefore, after the
main subprogram has returned, the environment task may be waiting for
other tasks to terminate, and is thus no more callable. But I don't see
how this relates to your example.

One thing to keep in mind is the meaning of "or terminate": it means
that no task could possibly call an entry of the task, and therefore
that the task is blocked forever. In this case, it is better to
terminate it. If you had an else part, there is a way to revive it, and
therefore it cannot be terminatable.

-- 
J-P. Rosen
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