sub processdir(){
my $pm = new Parallel::ForkManager(5);
    $pm->run_on_finish( sub { my ($pid, $exit_code, $ident) = @_; $tmp
+Files[$ident] = undef; } );
    foreach my $i (0..$#Files) {
      # Forks and returns the pid for the child:
      my $pid = $pm->start($i) and next;
      $SIG{INT} = 'DEFAULT';
      my $filename = $Files[$i]->filename();

      my $file = IO::File->new("<$filename") or die "Can't open $filen
+ame\n";
      while((my $line) = $file->getline()) {
        last unless defined($line);
        chomp $line;
        my ($dir, $file) = split(/\t/, $line);
        $processor->($dir, $file, $config, $log);
      }
      $pm->finish; # Terminates the child process
    }
    $pm->wait_all_children;
return;
  }
  
  processdir($input_dir,$logfile,\&clean_value);
  
  sub clean_value(){
  $logfile->print("-- Reading '$input_file' file\n");
}
[download]

Here all the process executes,writes together and input file name overlaps in the file name
How to avoid overlapping of file names into the $logfile.
In which portion should I use locks or how to avoid averlapping of filename