use strict;
use warnings;
use Logfile;
use Communication;

my $log = new Logfile (...);
my $com = new Communication ($log, ...);
$log->open(...);
$log->write(...) if($log->is_open());

$com->do_something();

$log->close(...);

....
package Communication;

sub new
{
  my $class=shift;
  my $log=shift;
  ....
  $self->{LOG}=$log;
  ....
  bless($self, $class);
  return $self;
}

sub do_something
{
 my $self=shift;
  ....
  my $log=$self->{LOG};
  $log->write(...) if($log && $log->is_open());
  ....
}

....