tie my @in_array, 'Tie::File', $fileA, mode => O_RDWR or die $!;
my $f_cnt = scalar(@in_array);
my $retries;
do {
##have removed lines for simplicity
##
$retries++;
if ($retries > 3) { print "3 attempts are failed.\n"; exit(); }

 } while ($f_cnt > 1 );
untie @in_array;