I have socket server script that continuously running listening for the GPS device that runs in PHP CLI,my problem is that my socket will freeze if it executes long time,how do I prevent this so that my script will not freeze.I have no idea on this socket.this is the first time that I use socket connection.

I appreciate someone can help my problem.

<?php

error_reporting(-1);
ini_set('display_errors', 1);



set_time_limit (0);


    $address_server = 'xxx.xxx.xx.xx';
    $port_server = xxxx;
    $isTrue = true;
    socketfunction($address_server,$port_server,$isTrue);






function  socketfunction($address,$port,$done){


    $sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

    socket_set_option($sock, SOL_SOCKET, SO_REUSEADDR, 1);

    socket_bind($sock, $address, $port);



    socket_listen($sock);



    $clients = array($sock);



    while ($done ) {
        $file = fopen('txt.log','a');
        $read = $clients;

        $write = NULL;
        $except = NULL;
        $tv_sec = 0;




        if (socket_select($read, $write , $except,  $tv_sec) < 1){

           continue;
         }




        // checking client
        if (in_array($sock, $read)) {

            $clients[] = $newsock = socket_accept($sock);


            $key = array_search($sock, $read);
            unset($read[$key]);


        }

        //handle client for reading
        foreach ($read as $read_sock) {


            $data = @socket_read($read_sock, 1024, PHP_NORMAL_READ);


            if ($data === false) {

                $key = array_search($read_sock, $clients);

                unset($clients[$key]);

                echo "client disconnected.\n";
                echo  "Remaining ".(count($clients) - 1)."client(s) connected\r\n";

                continue;
            }



            $data = trim($data);


            if (!empty($data)) {


                echo("Returning stripped input\n");
                fwrite($file,$data."\n");

              }




        } // end of reading foreach

        fclose($file);

    }//end while

    socket_close($sock);
}


?>

Thank you in advance.