[Python-Dev] PEP 509: Add a private version to dict

[Victor Stinner]

2016-01-21 1:08 GMT+01:00 Brett Cannon <brett at python.org>:
> On Wed, 20 Jan 2016 at 15:46 Victor Stinner <victor.stinner at gmail.com>
>> The worst case is when a value different than the watched value is
>> modified between each guard check. In this case, we always need a dict
>> lookup. An heuristic can be chosen to decide to give up after N tries.
>> Currently, fat.GuardDict always retries.
>
> Does "retries" mean "check if the value really changed, and if it hasn't
> then just update the version ID the guard checks"?

If the dict version changes (because a value different than the
watched value is modified) each time that the guard is checked, the
guard always require a dict lookup to check if the watched value
changed.

Victor