in reply to Re^2: Shared variables between threads
in thread Shared variables between threads

From that it seems that you are receiving a bless scalar reference. Older versions of threads shared did not allow you to assign bless references (objects) to shared variables for technical reasons.

A recent change by jdhedden alleviated this restriction, but (unless you've already done so) you will need to download the latest versions from CPAN to be able to do this: 

print $threads::VERSION, $threads::shared::VERSION;;
1.67 1.14

[download]
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

Replies are listed 'Best First'.
Re^4: Shared variables between threads
by Saladino (Beadle) on Nov 05, 2007 at 10:36 UTC
    I have updated my threads and threads::shared packages but no way.
    threads version -> 1.67 threads::shared version -> 1.14
Invalid value for shared scalar at RTP_media.pl line 23.

    [download]
    lines 22-23
    my $capobj:shared;
$capobj = Net::Pcap::open_live($dev,1024,0,0,\$err);

    [download]
[reply]
[d/l]
[select]

      You will need to threads::shared::share it before you'll be able to assign it to a shared variable. 

      #! perl -slw
use strict;
use threads;
use threads::shared;

print "threads: $threads::VERSION threads::shared:$threads::shared::VE
+RSION";

{
    my $scalar = 0xdeadbeef;
    my $blessed = bless \$scalar, 'main';
    print 'Scalar: ', $blessed;
    my $shared :shared = &share( $blessed );
    print 'Scalar: ', $shared;
}

__END__
C:\test>t-blessed.pl
threads: 1.67 threads::shared:1.14
Scalar: main=SCALAR(0x1824624)
Scalar: main=SCALAR(0x1824624)

      [download]

      For your case that should look something like: 

      my $capobj:shared;
$capobj = &share( Net::Pcap::open_live($dev,1024,0,0,\$err) );

      [download]

      Or just 

      my $capobj:shared = &share( Net::Pcap::open_live($dev,1024,0,0,\$err) 
+);

      [download]

      The ampasand on &share() is necessary to defeat the prototype.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
[select]
        Am I doing something wrong? Here is a full script and its output. 
        #!/usr/bin/perl

use strict;
use warnings;
use threads;
use threads::shared;
use Net::Pcap;

my $err;
my $dev = Net::Pcap::lookupdev(\&err);
my ($address,$netmask);
Net::Pcap::lookupnet($dev,\$address,\$netmask,\$err);
my $filter;

print "threads version -> ".$threads::VERSION." threads::shared versio
+n -> ".$threads::shared::VERSION."\n";

my $capobj:shared  = &share(Net::Pcap::open_live($dev,1024,0,0,\$err))
+;
print "shared $capobj\n";

my $capthread = threads->new(\&capture);
sleep 5;
Net::Pcap::breakloop($capobj);
print "$capobj breakloop\n";

$capthread->join();
print "Capture thread finalized\n";

sub capture {

        print "capture->$capobj\n";
        Net::Pcap::compile($capobj,\$filter,'host XX.XX.XX.XX && port 
+7777 && udp',1,$netmask);
        Net::Pcap::setfilter($capobj,$filter);
        Net::Pcap::loop($capobj,0,\&capture_callback, 0);
        print "Outside the loop\n";
        Net::Pcap::close($capobj);


}

sub capture_callback {

}

        [download]
        And the output: 
        $perl test3.pl
threads version -> 1.67 threads::shared version -> 1.14
shared pcap_tPtr=SCALAR(0x8ee08f8)
capture->pcap_tPtr=SCALAR(0x8f223b4)

        [download]
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom