Re: Fix for memory leak in dblink

Joe Conway <mail@joeconway.com>

From: Joe Conway <mail@joeconway.com>
To: Takahiro Itagaki <itagaki.takahiro@oss.ntt.co.jp>
Cc: pgsql-hackers@postgresql.org
Date: 2010-01-22T00:57:52Z
Lists: pgsql-hackers
On 01/11/2010 07:43 PM, Takahiro Itagaki wrote:
> There is a memory leak in dblink when we cancel a query during
> returning tuples. It could leak a PGresult because memory used
> by it is not palloc'ed one. I wrote a patch[1] before, but I've
> badly used global variables to track the resource.
> 
> The attached is a cleaned up patch rewritten to use a tuplestore
> (SFRM_Materialize mode) to return tuples suggested at [2]. Since
> we don't return from the dblink function in tuplestore mode, we
> can surely release the PGresult with a PG_CATCH block even on error.
> 
> Also, dblink_record_internal() and dblink_fetch() are rearranged
> to share the same code to return tuples for code refactoring.
> 
>   [1] http://archives.postgresql.org/pgsql-hackers/2009-06/msg01358.php
>   [2] http://archives.postgresql.org/pgsql-hackers/2009-10/msg00292.php

This looks good to me. I'll commit in the next 24 hours if there are no
objections.

Thanks,

Joe