Re: RFC 130 (v4) Transaction-enabled variables for Perl6

[Bart Lateur]

On Tue, 05 Sep 2000 11:48:38 -0400, Dan Sugalski wrote:

>>- two-phase  commit handler,  rollback coordinator  (the above  two is
>>   connected to this: very simple algorhythm!)
>
>Here's the killer. This is *not* simple. At all. Not even close.
>
>Doing this properly with data sources you completely control in a 
>multi-access situation (read: with threads) is *hard*.

Is it?

Here's some high-level emulation of what it should do.

        eval {
                my($_a, $_b, $c) = ($a, $b, $c);
                ...
                ($a, $b, $c) = ($_a, $_b, $_c);
        }

Now, "all" that needs to be taken care of, is make sure that the final
assignment from the localized and changed variables to their
outer-scoped counterparts happens in *one step*, i.e. no task switching
while this is going on.

-- 
        Bart.