Re: threads,dbi 1.30,odbc 0.43, perl 5.8 (AS)

[Tim Bunce]

On Tue, Dec 03, 2002 at 03:47:29PM -0500, Trey Gregory wrote:
> Here is a short example. Short overview is: main connects, queries, then spawns 
>thread (test_thread) which creates a new connection and attempts to query. The error 
>received is:
> 
> thread failed to start: DBD::ODBC::dr connect failed: handle 1 is owned by thread 
>15d6d7c not current thread 32c814c (handles can't be shared between threads and your 
>driver may need a CLONE method ad
> ded) at D:/perl/site/lib/DBI.pm line 503.

Looks like DBD::ODBC doesn't have a CLONE method to clear out the
driver handle in the new thread. So the new thread tries to use the
inherited driver handle.

Try version 0.45_18.

Tim.

Re: threads,dbi 1.30,odbc 0.43, perl 5.8 (AS)

[Trey Gregory]

Here is a short example. Short overview is: main connects, queries, then spawns thread 
(test_thread) which creates a new connection and attempts to query. The error received 
is:

thread failed to start: DBD::ODBC::dr connect failed: handle 1 is owned by thread 
15d6d7c not current thread 32c814c (handles can't be shared between threads and your 
driver may need a CLONE method ad
ded) at D:/perl/site/lib/DBI.pm line 503.


use threads;
use DBI;

my $dbh;
if (!($dbh = DBI->connect("dbi:ODBC:my_dsn",
  "loginpw",
  "loginpw",
  {PrintError => 1}
  ))) {
print "Can't connect:  $DBI::errstr" if $DEBUG;

exit;
}

my $sql = qq[
select * from account_t
];

my $result;

if (!($result = executeCommand($dbh,$sql))) {
print "error $sql\n";
}


my $thr = threads->new(\&test_thread);
$thr->join;

exit;


sub test_thread {

my $dbh;
if (!($dbh = DBI->connect("dbi:ODBC:my_dsn",
  "loginpw",
  "loginpw",
  {PrintError => 1}
  ))) {
print "Can't connect:  $DBI::errstr" if $DEBUG;

exit;
}

my $sql = qq[
select * from account_t
];

my $result;

if (!($result = executeCommand($dbh,$sql))) {
return undef;
}
}


sub executeCommand {
my ($dbh, $query_str) = @_;

my $sth;
if (!($sth = $dbh->prepare($query_str))) {
return undef;
}

my $rc;
if (!($rc = $sth->execute)) {
return undef;
}

my $resultsARef;
if (!($resultsARef = $sth->fetchall_arrayref)) {
return undef;
}

$sth->finish;
return $resultsARef;
}

Re: threads,dbi 1.30,odbc 0.43, perl 5.8 (AS)

[Tim Bunce]

Please show a (very) small example script.

Tim.

On Tue, Dec 03, 2002 at 02:31:01PM -0500, Trey Gregory wrote:
> I'm sure this has been answered before, but I wasn't able to find anything in the 
>archives. (Is there a search interface available?)
> 
> I have a multithreaded program. My problem is this: if I create a connection in the 
>parent, then create a thread which creates a new dbh, I get an error message about 
>the handle not being owned by the (current) child thread. Since I was creating a new 
>connection in the child, I thought I would be creating a new handle as well, but this 
>does not seem to be the case.
> 
> What is the proper way to work with DBI in this multithreaded environment?
> 
> 
> Thanks,
> Trey