Re: [Dbdpg-general] Fwd: [sf-perl] Perl module"s END block clobbered (and stuff)

On Wed, 6 Aug 2003, Paul Makepeace wrote:
> On Mon, Aug 04, 2003 at 01:30:46PM -0400, Rudy Lippan wrote:
> > On Mon, 4 Aug 2003, David Wheeler wrote:
> >
> > > Begin forwarded message:
> > >
> > > > From: Paul Makepeace
> > > >
> > > > I'm getting this error in Apache's main error logs. I have seen no
> > > > other reference to it on Google.
> > > >
> > > > [warning] Perl module's END block clobbered perl_destruct_level
> > > > (buggy DBD::Pg?)
> > > >
> >
> > I just tried grepping the perl, mod_perl & apache sources, & I don't
> > see "clobbered" comming form any of them. Do you know where the
> > message might be comming from?
>
> [xposting to MySQL folks since this affects DBD::mysql too]
>
> Further to this and my last message at
> http://gborg.postgresql.org/pipermail/dbdpg-general/2003-Aug ust/000286.html
>

Looks like two different issues here.

1. The putenv() issue and
2. the perl_destruct_level issue.

I think the diff that you posted is if for the second bug. The date on the
bug resolution was Dec, 2002 and the next diff after that is the May 2003,
so both fixes where include in the difffile... I don't know what the
workaround for the first one was...

Looking over http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=48069 It
seems that there is/was a problem libpq calling putenv(), but given, that
this is 3 years old, I am assuming that this was fixed in perl already; am
I right to assume this?


> ..it turns out this originates in both DBD::Pg and DBD::mysql's
> dbd_discon_all() where perl_destruct_level is reset. In Debian's
> DBD::Pg's libdbd-pg-perl this has been patched (removed):
> http://bugs.debian.org/cgi-bin/bugreport.cgi?archive=no&bug= 167148
>
> Severity: important
>
> In dbdimp.c:dbd_discon_all is this code:
>
> if (perl_destruct_level) {
> perl_destruct_level =3D 0;
> }
>
> It looks like this is because it doesn't support being told to clean up.
>
> Resetting perl_destruct_level is absolutely wrong; this is the cause of
> the 3MB or more memory leaked every time you SIGHUP a mod_perl server
> using DBD::Pg. Removing this code fixes the problem but I don't know
> what affect it'll have on DBD::Pg; I didn't see any adverse effects but
> I didn't test it very well.
>
> Does anyone know why this reset is there? Can it be removed from the sources?
> It's not in DBD::Oracle certainly since 1.06 dated 2000/07.

Since dbd_discon_all() is the same between DBD::mysql & DBD::Pg, I am
going to assume that this bit of code was inhereted from an old version of
DBD::Oracle. I don't see anything in the DBD::Oracle docs about
perl_destruct_level, so I don't know (if or when) it was removed from
DBD::Oracle; however, I did see ' No longer sets perl_destruct_level
unless debug set >= 4.' in the DBI Changelog, so maybe that was in there
to work with dbi chaing destruct levels???

Given that dbd_discon_all is just about the same in DBD::Pg, DBD::mysql
DBD::Oracle, should/could it be brought into driver.xst?



Rudy.



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Re: [Dbdpg-general] Fwd: [sf-perl] Perl module"s END block clobbered (and stuff)

On Wed, Aug 06, 2003 at 04:47:42PM -0400, Rudy Lippan wrote:
> > In dbdimp.c:dbd_discon_all is this code:
> >
> > if (perl_destruct_level) {
> > perl_destruct_level =3D 0;
> > }
> >
> > It looks like this is because it doesn't support being told to clean up.
> >
> > Resetting perl_destruct_level is absolutely wrong; this is the cause of
> > the 3MB or more memory leaked every time you SIGHUP a mod_perl server
> > using DBD::Pg. Removing this code fixes the problem but I don't know
> > what affect it'll have on DBD::Pg; I didn't see any adverse effects but
> > I didn't test it very well.
> >
> > Does anyone know why this reset is there? Can it be removed from the sources?
> > It's not in DBD::Oracle certainly since 1.06 dated 2000/07.
>
> Since dbd_discon_all() is the same between DBD::mysql & DBD::Pg, I am
> going to assume that this bit of code was inhereted from an old version of
> DBD::Oracle. I don't see anything in the DBD::Oracle docs about
> perl_destruct_level, so I don't know (if or when) it was removed from
> DBD::Oracle; however, I did see ' No longer sets perl_destruct_level
> unless debug set >= 4.' in the DBI Changelog, so maybe that was in there
> to work with dbi chaing destruct levels???

I can't remember the details now. But there's certainly no good reason
for a driver to ever _lower_ the value of perl_destruct_level.

> Given that dbd_discon_all is just about the same in DBD::Pg, DBD::mysql
> DBD::Oracle, should/could it be brought into driver.xst?

It already is to some extent. And note that disconnect_all is not
a documented part of the DBI spec so the current "set error if
called explicitly" behaviour isn't mandated anywhere.

All you need to do is stop #defining dbd_discon_all then the
DBI's default disconnect_all method will be called instead,
which does... nothing.

Tim.

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Re: [Dbdpg-general] Fwd: [sf-perl] Perl module"s END block clobbered (and stuff)

On Wed, Aug 06, 2003 at 04:47:42PM -0400, Rudy Lippan wrote:
> > In dbdimp.c:dbd_discon_all is this code:
> >
> > if (perl_destruct_level) {
> > perl_destruct_level =3D 0;
> > }
> >
> > It looks like this is because it doesn't support being told to clean up.
> >
> > Resetting perl_destruct_level is absolutely wrong; this is the cause of
> > the 3MB or more memory leaked every time you SIGHUP a mod_perl server
> > using DBD::Pg. Removing this code fixes the problem but I don't know
> > what affect it'll have on DBD::Pg; I didn't see any adverse effects but
> > I didn't test it very well.
> >
> > Does anyone know why this reset is there? Can it be removed from the sources?
> > It's not in DBD::Oracle certainly since 1.06 dated 2000/07.
>
> Since dbd_discon_all() is the same between DBD::mysql & DBD::Pg, I am
> going to assume that this bit of code was inhereted from an old version of
> DBD::Oracle. I don't see anything in the DBD::Oracle docs about
> perl_destruct_level, so I don't know (if or when) it was removed from
> DBD::Oracle; however, I did see ' No longer sets perl_destruct_level
> unless debug set >= 4.' in the DBI Changelog, so maybe that was in there
> to work with dbi chaing destruct levels???

I can't remember the details now. But there's certainly no good reason
for a driver to ever _lower_ the value of perl_destruct_level.

> Given that dbd_discon_all is just about the same in DBD::Pg, DBD::mysql
> DBD::Oracle, should/could it be brought into driver.xst?

It already is to some extent. And note that disconnect_all is not
a documented part of the DBI spec so the current "set error if
called explicitly" behaviour isn't mandated anywhere.

All you need to do is stop #defining dbd_discon_all then the
DBI's default disconnect_all method will be called instead,
which does... nothing.

Tim.

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