Re: Custom GUCs still a bit broken

Where are we on this?

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Andrew Dunstan wrote:
>
> It seems like Custom GUCs are still in need of some work, as shown in my
> recent email. In particular, they are not transaction safe - if a
> transaction attempts to do DefineCustomFooVariable() and that
> transaction aborts, the placeholder setting that it used is already gone
> by the time it tries to roll back GUC settings. I think this code at the
> end of define_custom_variable()
>
> /*
> * Free up as much as we conveniently can of the placeholder
> structure
> * (this neglects any stack items...)
> */
> set_string_field(pHolder, pHolder->variable, NULL);
> set_string_field(pHolder, &pHolder->reset_val, NULL);
>
> free(pHolder);
>
>
> needs to be removed and instead we need to save pHolder in a list along
> with the GUC level, to be processed later by AtEOXact_GUC(), which would
> do the right thing according to whether or not it had a commit or an abort.
>
> I want to get this fixed before we consider custom settings for plperl
> that have possible security implications.
>
> Thoughts?
>
> cheers
>
> andrew
>
>
>
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--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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