I briefly looked at the DBD::Pg rt ticket
https://rt.cpan.org/Ticket/Display.html?id=60863 and I'm not sure this
is a bug in DBD::Pg and think it might be in DBI. Since
ShowErrorStatement set causes the leak and unset the leak goes away I
isolated it to some code in DBI.xs:
if ( DBIc_has(imp_xxh, DBIcf_ShowErrorStatement)
&& !is_unrelated_to_Statement
&& (DBIc_TYPE(imp_xxh) == DBIt_ST || ima_flags & IMA_SHOW_ERR_STMT)
&& (statement_svp = hv_fetch((HV*)SvRV(h), "Statement", 9, 0))
&& statement_svp && SvOK(*statement_svp)
) {
SV **svp = 0;
sv_catpv(msg, " [for Statement \"");
sv_catsv(msg, *statement_svp);
/* fetch from tied outer handle to trigger FETCH magic */
/* could add DBIcf_ShowErrorParams (default to on?) */
#ifdef THIS_ONE_STOPS_LEAK
if (!(ima_flags & IMA_HIDE_ERR_PARAMVALUES)) {
svp =
hv_fetch((HV*)DBIc_MY_H(imp_xxh),"ParamValues",11,FALSE);
if (svp && SvMAGICAL(*svp))
mg_get(*svp); /* XXX may recurse, may croak. could
use eval */
}
#endif
if (svp && SvRV(*svp) && SvTYPE(SvRV(*svp)) == SVt_PVHV &&
HvKEYS(SvRV(*svp))>0 ) {
#ifndef THESE_TWO_WITHOUT_ABOVE_DOES_NOT_STOP_LEAK
SV *param_values_sv =
sv_2mortal(_join_hash_sorted((HV*)SvRV(*svp), "=",1, ", ",2, 1, -1));
#endif
sv_catpv(msg, "\" with ParamValues: ");
#ifndef THESE_TWO_WITHOUT_ABOVE_DOES_NOT_STOP_LEAK
sv_catsv(msg, param_values_sv);
#endif
sv_catpvn(msg, "]", 1);
}
else {
sv_catpv(msg, "\"]");
}
}
I was suspicious about _join_hash_sorted but it appears if you just take
THESE_TWO_WITHOUT_ABOVE_DOES_NOT_STOP_LEAK out it still leaks.
If you just take THIS_ONE_STOPS_LEAK (which obviously also takes out the
other 2) the leak goes away.
I've not duplicated the problem with any other DBDs as yet but I'm
running the exact code in the RT.
I've no idea as yet what the actual problem is.
I was running Perl 5.10.1 on Linux (32bit) but no one who has tried this
yet (on multiple Perls in Linux) has failed to see the issue.
With THIS_ONE_STOPS_LEAK defined I get:
martin@bragi:/tmp/DBD-Pg-2.17.2$ perl -I blib/lib -I blib/arch leak.pl
Cycles: 2000 Proc size: 13700K
Cycles: 4000 Proc size: 13700K
Cycles: 6000 Proc size: 13700K
Cycles: 8000 Proc size: 13700K
Cycles: 10000 Proc size: 13700K
Cycles: 12000 Proc size: 13700K
Cycles: 14000 Proc size: 13700K
Cycles: 16000 Proc size: 13700K
Cycles: 18000 Proc size: 13700K
and a stock DBI from trunk) I get:
martin@bragi:/tmp/DBD-Pg-2.17.2$ perl -I blib/lib -I blib/arch leak.pl
Cycles: 2000 Proc size: 16792K
Cycles: 4000 Proc size: 19892K
Cycles: 6000 Proc size: 22980K
Cycles: 8000 Proc size: 26200K
Cycles: 10000 Proc size: 29296K
Cycles: 12000 Proc size: 32376K
Cycles: 14000 Proc size: 35472K
Cycles: 16000 Proc size: 38692K
Cycles: 18000 Proc size: 41796K
Martin
