open(PID, "> $CONF{upd_lockfile}") ;
flock(PID, 2);
seek(PID, 0, 2);
for my $a (@pids) {
    print(PID "$a\n") if ($a != $$);
}
flock(PID, 8);

##</code><code>##

use Fcntl qw( LOCK_EX );

sub remove_pid {
   open(my $PID, '+>>', $CONF{upd_lockfile}") or die $!;
   flock($PID, LOCK_EX) or die $!;
   seek($PID, 0, SEEK_SET) or die $!;
   chomp( my @pids = <$PID> );
   @pids = grep $_ != $$, @pids;
   seek($PID, 0, SEEK_SET) or die $!;
   print($PID "$_\n") for @pids;
   truncate($PID, tell($PID)) or die $!;
   kill(CONT => $parend_pid) or die $! if !@pids;
   close($PID) or die $!;
}