Re: Interresting difference in Normal-Returns/Expression-Functions and Extended-Returns.

[Adam Beneschan <adam@irvine.com>]

On Tuesday, April 23, 2013 9:52:04 AM UTC-7, Simon Wright wrote:
> 
> > The upshot of all this is that, by 7.6.1(4) and 9.3(2), in Make_ER,
> > the task created by the allocator *depends* *on* the body of Make_ER,
> > and therefore the body of Make_ER cannot complete until the task has
> > completed.  That should be enough to explain the results.
> 
> Yes, but there are other similar side effects: in the tests, OP wrote
> 
>     declare
> 	function Make(Input : in String) return not null access Testing
> 	       renames Make_EF;
> 
> 	P : constant array (Positive range <>) of
> 	  not null access constant Testing:=
> 	    ( Make("Bob"), Make("Steve"), Make("Dave"), Make("Joey") );
>     begin
>        null;
>     end TEST_1;
> 
> and the code doesn't exit the declare block until all the tasks have
> completed.

I don't see a language reason for that.  The tasks are all created with allocators, and the type of the allocator alone should determine what master the tasks depend on--not a block declaring an array that contains the access objects.  If it's true that the block doesn't exit until all the tasks created by allocators have completed, then it's probably a GNAT bug.  I'd need to study it more carefully to make sure, though.  There may be some relevant language rules I'm missing, or something else I'm missing.

                              -- Adam