#!/usr/bin/perl
use warnings;
use strict;
use Time::HiRes qw[ time ];
use threads;
use threads::shared;
use Data::Dumper;

my $href = &share({});

sub sub1 {
  sleep 1;
  print threads->tid(), ' : ',  time, $/;
  print Dumper $href;
  print threads->tid(), ' : ',  time, $/;
}

$href->{a} = &share({});

print threads->tid(), ' : ',  time, $/;
my $th1 = threads->new('sub1');
print threads->tid(), ' : ',  time, $/;
$href->{b} = &share({});
print threads->tid(), ' : ',  time, $/;
my $th2 = threads->new('sub1');
print threads->tid(), ' : ',  time, $/;

$th1->join();
$th2->join();


##</code><code>##

C:\test>junk2
0 : 1227891440.24088 } 
0 : 1227891440.26269 } 22 milliseconds to start a thread
0 : 1227891440.26288
0 : 1227891440.28761 } 24 milliseconds to start a thread

1 : 1227891441.27213  }
$VAR1 = {
          'a' => {},
          'b' => {}
        };
1 : 1227891441.27275  } 62 microseconds to dump the hash

2 : 1227891441.28775  }
$VAR1 = {
          'a' => {},
          'b' => {}
        };
2 : 1227891441.28835  } 60 microseconds to dump the hash