I've added this as a note:
Note that the ChildHandles array holds weak references and that 'from
time to time' the old slots get freed up. This isn't a leak, it just
appears to be if you're not familiar with the caching that DBI does
internally. You can rest assured that if the DBI did have a real leak
a) a great many people would be affected and b) it would get fixed very
quickly.
I think 'from time to time' is every 120 or so newly created child handles.
Tim.
On Tue, May 26, 2015 at 07:57:53AM -0300, Steve Cookson - gmail wrote:
> It seems to be further documented here, together with a solution:
>
> http://stackoverflow.com/questions/13338308/perl-dbi-memory-leak,
>
> But the solution does not seem to be reliable. Sometimes it works sometimes
> not.
>
> I'll update you when I know more.
>
> Regards,
>
> Steve.
>
> On 26/05/15 07:07, Steve Cookson - gmail wrote:
> >Hi Guys,
> >
> >You may have seen part of this post on PerlMonks. If so apologies for the
> >duplication. This started off as a general search for leaks in my code,
> >and resulted in a few hits, one of which was attached to every database
> >access.
> >
> >A simple "select ATT_RECORD_NAME_TXT from TBL_TEST; " results in the leak
> >of one scalar value. It seems to be attached to the ->prepare statement.
> >
> >At first I assumed it was down to my Firebird driver, which is relatively
> >new, so I switched the driver to ODBC::Firebird, with the same result.
> >Finally I changed to mysql and again got a memory leak. The only thing I
> >can assume is that either my code is generically wrong (and I hope this is
> >the case), or there is a leak in dbi, which I would be surprised by.
> >
> >I would appreciate some advice.
> >
> >Test code follows. Please install Devel::Leak to pick up leaked scalars
> >and update the dsn to the dsn of your choice.
> >
> >Thanks for your help.
> >
> >Regards,
> >
> >Steve.
> >
> >#! /usr/bin/perl
> >
> >package main;
> >use strict;
> >use warnings;
> >use DBI;
> >#use DBD::Firebird;
> >use DBD::ODBC;
> >use Devel::Leak;
> > my $handle;
> > my $count_start;
> > my $count_stop;
> > my $gl_dbh;
> >
> > # Just do this 5 times to make sure there is no contribution to
> >$handle count from Devel::Leak
> > for (1..10){
> > print "Handle init: ", Devel::Leak::NoteSV($Launch::handle),"\n";
> > }
> >#my $loc_dsn = <<DSN;
> >#dbi:ODBC:Driver=Firebird;Dbname=/home/image/Documents/Endoscopia/DB/newEndo.fdb;
> >
> >#ib_dialect=3;
> >#DSN
> >my $loc_dsn = <<DSN;
> >DBI:mysql:database=new_schema_test;
> >host=localhost;
> >port=3306";
> >DSN
> > $Launch::gl_dbh=DBI->connect($loc_dsn,"root","password", {
> > PrintError => 1, # Report errors via warn
> > RaiseError => 1 # Report errors via Die
> > }
> > ) or die;
> >
> > my @loc_sql_string =();
> > $loc_sql_string[0]="CREATE TABLE TBL_TEST_LEAK ( ATTR_RECORD_ID_TXT
> >VARCHAR(10) NOT NULL, ATT_RECORD_NAME_TXT VARCHAR(255), CONSTRAINT
> >PK_TBL_TEST_LEAK PRIMARY KEY (ATTR_RECORD_ID_TXT) ); ";
> > $loc_sql_string[1]="GRANT DELETE, INSERT, REFERENCES, SELECT, UPDATE
> >ON TBL_TEST_LEAK TO SYSDBA WITH GRANT OPTION";
> > $loc_sql_string[2]="INSERT INTO TBL_TEST_LEAK (ATTR_RECORD_ID_TXT,
> >ATT_RECORD_NAME_TXT) VALUES ('206', 'Delay Test 1' )";
> > $loc_sql_string[3]="select ATT_RECORD_NAME_TXT from TBL_TEST_LEAK; ";
> > $loc_sql_string[4]= $loc_sql_string[3];
> > $loc_sql_string[5]= $loc_sql_string[3];
> > $loc_sql_string[6]= $loc_sql_string[3];
> > $loc_sql_string[7]= $loc_sql_string[3];
> > $loc_sql_string[8]= $loc_sql_string[3];
> > $loc_sql_string[9]="drop table TBL_TEST_LEAK; ";
> >
> > for (my $i=1;$i<=9;$i++){
> > $count_start=Devel::Leak::NoteSV($Launch::handle);
> > print "DBD start: ", $count_start,"\n";
> > print $loc_sql_string[$i], "\n";
> > dbd_select($loc_sql_string[$i]);
> > # You can use
> > #$count_stop=Devel::Leak::CheckSV($Launch::handle);
> > $count_stop=Devel::Leak::NoteSV($Launch::handle);
> > print "Handle stop: ", $count_stop,"\n";
> > print "Count difference: ", $count_stop-$count_start,"\n";
> > }
> > $Launch::gl_dbh->disconnect;
> >
> >sub dbd_select{
> > my $loc_sql_string=shift;
> > my $loc_sth=$Launch::gl_dbh->prepare($loc_sql_string) or die;
> > #$loc_sth->execute() or die;
> > #$loc_sth->finish();
> > return;
> >}
> >
> >1;
> >
> >
>
