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



--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to