Personally, I like LockFile::Simple.

Works great for me...

use LockFile::Simple qw(lock trylock unlock);

$lockmgr = LockFile::Simple->make(-format => '%f.lck',
    -max => 20, -delay => 1, -stale => 1);
    
# first program to get the lock the file gets the chance to run it    
+       
if($lockmgr->trylock("$eventsLogFile")){

    my @bytes= split(//, $serial_data); 
    $lockmgr->unlock("$eventsLogFile");
}
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