[Python-Dev] Proposed PEP on concurrent programming support
jimjjewett at gmail.com
Wed Jan 4 15:41:19 CET 2012
(I've added back python-ideas, because I think that is still the
>.... A new
> suite type - the ``transaction`` will be added to the language. The
> suite will have the semantics discussed above: modifying an object in
> the suite will trigger creation of a thread-local shallow copy to be
> used in the Transaction. Further modifications of the original will
> cause all existing copies to be discarded and the transaction to be
> restarted. ...
How will you know that an object has been modified?
The only ways I can think of are
(1) Timestamp every object -- or at least every mutable object -- and
hope that everybody agrees on which modifications should count.
(2) Make two copies of every object you're using in the suite; at the
end, compare one of them to both the original and the one you were
operating on. With this solution, you can decide for youself what
counts as a modification, but it still isn't straightforward; I would
consider changing a value to be changing a dict, even though
nothing in the item (header) itself changed.
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