Re: Probable memory leak with ECPG and AIX - Mailing list pgsql-hackers

From Noah Misch
Subject Re: Probable memory leak with ECPG and AIX
Date
Msg-id 20220102000750.GB54621@rfd.leadboat.com
Whole thread Raw
In response to Re: Probable memory leak with ECPG and AIX  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Probable memory leak with ECPG and AIX
Re: Probable memory leak with ECPG and AIX
List pgsql-hackers
On Sat, Jan 01, 2022 at 11:35:02AM -0500, Tom Lane wrote:
> Noah Misch <noah@leadboat.com> writes:
> > I get the same results.  The leak arises because AIX freelocale() doesn't free
> > all memory allocated in newlocale().  The following program uses trivial
> > memory on GNU/Linux, but it leaks like you're seeing on AIX:
> 
> Bleah.
> 
> > If you have access to file an AIX bug, I recommend doing so.  If we want
> > PostgreSQL to work around this, one idea is to have ECPG do this newlocale()
> > less often.  For example, do it once per process or once per connection
> > instead of once per ecpg_do_prologue().
> 
> It's worse than that: see also ECPGget_desc().  Seems like a case
> could be made for doing something about this just on the basis
> of cycles expended, never mind freelocale() bugs.

Agreed.  Once per process seems best.  I only hesitated before since it means
nothing will free this storage, which could be annoying in the context of
Valgrind and similar.  However, ECPG already has bits of never-freed memory in
the form of pthread_key_create() calls having no pthread_key_delete(), so I
don't mind adding a bit more.



pgsql-hackers by date:

Previous
From: Zhihong Yu
Date:
Subject: Re: Collecting statistics about contents of JSONB columns
Next
From: Fabien COELHO
Date:
Subject: Re: pg_ls_tmpdir to show directories and shared filesets (and pg_ls_*)