ios push notification performance - php

Question

This is my php push notification code for ios below:
<?php
// Put your device token here (without spaces):
$deviceToken = "********************************************";
// Put your private key's passphrase here:
$passphrase = "********";
function pushIOSNotification($message)
{
GLOBAL $deviceToken;
GLOBAL $passphrase;
$ctx = stream_context_create();
$path = dirname(__FILE__).'/ck.pem';
//echo $path;
stream_context_set_option($ctx, 'ssl', 'local_cert', $path);
stream_context_set_option($ctx, 'ssl', 'passphrase', $passphrase);
// Open a connection to the APNS server
$fp = stream_socket_client(
'ssl://gateway.sandbox.push.apple.com:2195', $err,
$errstr, 60, STREAM_CLIENT_CONNECT|STREAM_CLIENT_PERSISTENT, $ctx);
if (!$fp)
exit("Failed to connect: $err $errstr" . PHP_EOL);
//echo 'Connected to APNS' . PHP_EOL;
// Create the payload body
$body['aps'] = array(
'alert' => $message,
'sound' => 'default'
);
// Encode the payload as JSON
$payload = json_encode($body);
// Build the binary notification
$msg = chr(0) . pack('n', 32) . pack('H*', $deviceToken) . pack('n', strlen($payload)) . $payload;
// Send it to the server
$result = fwrite($fp, $msg, strlen($msg));
if (!$result)
echo 'Message not delivered' . PHP_EOL;
else
echo 'Message successfully delivered' . PHP_EOL;
// Close the connection to the server
fclose($fp);
}
This code is only for one device,
if I need send to everyone and support localization,
this code will be like these below.
foreach($deviceTokens as $deviceToken){
$deviceOS = "query this device os from memcache";
if($deviceOS == "ios")
{
$lang = "query this device langauge from memcache";
$message = $messageData[$lang];
pushIOSNotification($deviceToken,$message);
}
}
but I doubt this performance of this code,
because deviceTokens length is the number of all members.