socket_recv (): невозможно прочитать с сокета [0]: операция успешно завершена

Я новый разработчик с сокетом PHP.

Теперь я должен отправить данные из моего кода PHP на сервер сокетов, но произошла ошибка:

Это мой PHP-код для отправки сообщения на сервер сокетов.

$host = 'localhost'; //host
$port = '9000'; //port
//create socket
$sock=socket_create(AF_INET,SOCK_STREAM,0) or die("Could not create the socket\n");

//connect to the server
$csock=socket_connect($sock,$host,$port) or die("Could not connect to server\n");
echo "Client socket connected!<br>";$msg = mask(json_encode(array('type'=>'usermsg', 'name'=>'udom1', 'message'=>'Hello word', 'color'=>'FF7000')));

socket_send($csock,$msg,strlen($msg),0);
socket_write($csock, $msg);
socket_close($csock);

Это мой скрипт сервера сокетов PHP:

Используется для отправки и получения данных со стороны клиента.

<?php
$host = 'localhost'; //host
$port = '9000'; //port
$null = NULL; //null var

//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, 1024); //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, 1024, 0) >= 1)
{
$received_text = unmask($buf); //unmask data
$tst_msg = json_decode($received_text); //json decode
$user_name = $tst_msg->name; //sender name
$user_message = $tst_msg->message; //message text
$user_color = $tst_msg->color; //color

//prepare data to be sent to client
$response_text = mask(json_encode(array('type'=>'usermsg', 'name'=>$user_name, 'message'=>$user_message, 'color'=>$user_color)));
send_message($response_text); //send data
break 2; //exist this loop
}

$buf = @socket_read($changed_socket, 1024, 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($response);
}
}
}
// close the listening socket
socket_close($socket);

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

//Encode message for transfer to client.
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;
}

//handshake new client.
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));
}
?>

Как я могу исправить эту проблему?

Пожалуйста, помогите мне.

Заранее спасибо.