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@momjian.us>        http://momjian.us EnterpriseDB
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