Socket error

I have a system that uses web socket in php for real-time chat and notification communication. It works, but it usually does peaks and the server from time to time drops the service.

I'm going to post my code here and I beg you to help me understand what can be improved, what is wrong, etc.

<?php
$host = '216.172.XXX.XXX';
$port = '2703';
$null = NULL;

$pem_passphrase = '';
$pemfile = 'http://216.172.XXX.XXX/~vendemodac/ssl/certs/vendemoda.pem';
$context = stream_context_create();

stream_context_set_option($context, 'ssl', 'local_cert', $pemfile);

// Pass Phrase (password) of private key
stream_context_set_option($context, 'ssl', 'passphrase', $pem_passphrase);
stream_context_set_option($context, 'ssl', 'allow_self_signed', true);
stream_context_set_option($context, 'ssl', 'verify_peer', false);

// Create the server socket
$socket = stream_socket_server(
    'ssl://'.$host.':'.$port,
    $errno,
    $errstr,
    STREAM_SERVER_BIND|STREAM_SERVER_LISTEN,
    $context
);

//Create TCP/IP sream socket
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
//reuseable port
socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);

//bind socket to specified host
socket_bind($socket, 0, $port);

//listen to port
socket_listen($socket);

//create & add listning socket to the list
$clients = array($socket);

//start endless loop, so that our script doesn't stop
while (true) {
    //manage multipal connections
    $changed = $clients;
    //returns the socket resources in $changed array
    socket_select($changed, $null, $null, 0, 10);

    //check for new socket
    if (in_array($socket, $changed)) {
        $socket_new = socket_accept($socket); //accpet new socket
        $clients[] = $socket_new; //add socket to client array

        $header = socket_read($socket_new, 2048); //read data sent by the socket
        perform_handshaking($header, $socket_new, $host, $port); //perform websocket handshake

        //socket_getpeername($socket_new, $ip); //get ip address of connected socket
        $response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' connected'))); //prepare json data
        send_message($response); //notify all users about new connection

        //make room for new socket
        $found_socket = array_search($socket, $changed);
        unset($changed[$found_socket]);
    }

    //loop through all connected sockets
    foreach ($changed as $changed_socket) { 

        //check for any incomming data
        while(socket_recv($changed_socket, $buf, 2048, 0) >= 1)
        {
            $received_text = unmask($buf); //unmask data
            $tst_msg = json_decode($received_text);

            $user_id_cliente = $tst_msg->id_cliente;
            $empresa_id = $tst_msg->empresa_id;
            $loja_id = $tst_msg->loja_id;
            $user_time_mensagem = $tst_msg->time_mensagem;
            $user_conteudo_mensagem = $tst_msg->conteudo_mensagem;
            $user_nome_cliente = $tst_msg->nome_cliente;
            $quem_esta_enviado = $tst_msg->quem_envia;
            $produto_detalhes = $tst_msg->produto_detalhes;
            $grupo_men = $tst_msg->grupo_mensagem;
            $nome_empresa = $tst_msg->nome_empresa;

            $regra_empresa = $tst_msg->regra_empresa;
            $atacado_empresa = $tst_msg->atacado_empresa;
            $min_empresa = $tst_msg->min_empresa;
            $cidade_cliente = $tst_msg->cidade_cliente;
            $valor_pedido = $tst_msg->valor_pedido;
            $pedido_mandar = $tst_msg->pedido_mandar;

            //prepare data to be sent to client
            $response_text = mask(json_encode(array('nome_empresa'=>$nome_empresa,'grupo_mensagem'=>$grupo_men,'loja_id'=>$loja_id,'pedido_mandar'=>$pedido_mandar,'regra_empresa'=>$regra_empresa,'atacado_empresa'=>$atacado_empresa,'min_empresa'=>$min_empresa,'cidade_cliente'=>$cidade_cliente,'valor_pedido'=>$valor_pedido,'produto_detalhes'=>$produto_detalhes,'quem_envia'=>$quem_esta_enviado,'empresa_id'=>$empresa_id,'id_cliente'=>$user_id_cliente, 'time_mensagem'=>$user_time_mensagem, 'conteudo_mensagem'=>$user_conteudo_mensagem, 'nome_cliente'=>$user_nome_cliente)));
            send_message($response_text); //send data
            break 2; //exist this loop
        }

        $buf = @socket_read($changed_socket, 2048, PHP_NORMAL_READ);
        if ($buf === false) { // check disconnected client
            // remove client for $clients array
            $found_socket = array_search($changed_socket, $clients);
            //socket_getpeername($changed_socket, $ip);
            unset($clients[$found_socket]);

            //notify all users about disconnected connection
            $response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' disconnected')));
            send_message($response);
        }
    }
}

socket_close($socket);

function send_message($msg)
{
    global $clients;
    foreach($clients as $changed_socket)
    {
        @socket_write($changed_socket,$msg,strlen($msg));
    }
    return true;
}


function unmask($text) {
    $length = ord($text[1]) & 127;
    if($length == 126) {
        $masks = substr($text, 4, 4);
        $data = substr($text, 8);
    }
    elseif($length == 127) {
        $masks = substr($text, 10, 4);
        $data = substr($text, 14);
    }
    else {
        $masks = substr($text, 2, 4);
        $data = substr($text, 6);
    }
    $text = "";
    for ($i = 0; $i < strlen($data); ++$i) {
        $text .= $data[$i] ^ $masks[$i%4];
    }
    return $text;
}

function mask($text)
{
    $b1 = 0x80 | (0x1 & 0x0f);
    $length = strlen($text);

    if($length <= 125)
        $header = pack('CC', $b1, $length);
    elseif($length > 125 && $length < 65536)
        $header = pack('CCn', $b1, 126, $length);
    elseif($length >= 65536)
        $header = pack('CCNN', $b1, 127, $length);
    return $header.$text;
}

function perform_handshaking($receved_header,$client_conn, $host, $port)
{
    $headers = array();
    $lines = preg_split("/\r\n/", $receved_header);
    foreach($lines as $line)
    {
        $line = chop($line);
        if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
        {
            $headers[$matches[1]] = $matches[2];
        }
    }

    $secKey = $headers['Sec-WebSocket-Key'];
    $secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
    //hand shaking header
    $upgrade  = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
    "Upgrade: websocket\r\n" .
    "Connection: Upgrade\r\n" .
    "WebSocket-Origin: $host\r\n" .
    "WebSocket-Location: ws://$host:$port/demo/shout.php\r\n".
    "Sec-WebSocket-Accept:$secAccept\r\n\r\n";
    socket_write($client_conn,$upgrade,strlen($upgrade));
}