my $logfile = "/foo/bar.log";
my $loops=0;
open(FOO, ">>$logfile") || die "Could not open $logfile: $!\n";
flock(FOO, 1) or die "Could not lock $logfile: $!\n";
print FOO "**Begin timestamping**\n";
{
  print FOO "**", scalar localtime, "**\n";
  flock(FOO, 8) or die "Could not unlock $logfile: $!\n";
  $loops>500 and last;
  sleep(60*(rand(6)+5));
  flock(FOO, 1) or die "Could not lock $logfile: $!\n";
  redo;
}
close(FOO);
exit;