Hello Wise Monks! Here's the code I use to count. Somehow it resets to zero when 10 or more instances of it run at the same time. What's wrong with my code?

$completeadd = "counter.txt";
open(MFILE, "$completeadd") || die "file open failed: $!\n";
flock(MFILE, LOCK_EX) || die "Lock failed: $!";
@filedata1=<MFILE>;
chomp @filedata1;
close(MFILE);
if ($filedata1[0])
{
  $filedata1[0]=$filedata1[0] + 1;
}
else
{
  $filedata1[0] = 1;
}
open(MFILE, ">$completeadd") || die "file open failed: $!\n";
flock(MFILE, LOCK_EX) || die "Lock failed: $!";
print MFILE "$filedata1[0]";
close(MFILE);

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In reply to Safe Counter Follow Up by Anonymous Monk
in thread Safe Counter by Gorby

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