Someone

<?php
    $file = dirname(__FILE__)."/asdf.php";
    $fp = fopen($file,'r+');

    if (!flock($fp,LOCK_SH)) {
        echo "no lock\n";
    }

    if (!file_exists("$file.lock")) {
        touch ("$file.lock");
        $lockOwner = true;
    }else echo 'the file is locked, move on';

    flock($fp,LOCK_UN);

    if ($lockOwner) {
        echo fread($fp,filesize($file));
        sleep(10)
        echo 'i am done';
        unlink("$file.lock");
    }

?>