Re: Safety of unprotected concurrent operations on constant objects

["Randy Brukardt" <randy@rrsoftware.com>]

"Natasha Kerensikova" <lithiumcat@instinctive.eu> wrote in message 
news:slrnlmft61.i0l.lithiumcat@nat.rebma.instinctive.eu...
...
> But what about dereferencing an access value? Is it safe to concurrently
> dereference the same access value from multiple tasks?
>
> It's hard to imagine dereferencing a pointer to be unsafe, but as we all
> know access are more than mere pointers, with accessibility checks and
> custom storage pools and what not.

The language only allows specific things to *not* be task-safe. You can read 
9.10 and Annex A to find out what they are. (And then tell the rest of us, 
9.10 is impentrable. :-) In particular, if 9.10 doesn't include something in 
the possible erroneous execution, then it has to be task safe. (For the 
obvious reason that the language spells out what *doesn't* have to work --  
everything else has to work in all conditions.)

> By the way, are implicit subprograms calls, like the storage pool thing
> on dereference, also covered by the non-guarantee of concurrent read 
> safety?

Yes. There's nothing special about calls to Allocate or Finalize or similar 
routines.

                           Randy.