phpfsockopen并发,该如何处理

if (isset($_GET['act']) && $_GET['act'] == 'sendMail') {
    sendEmail();// 发送邮件操作
}

function fSockGet($url, $timeout = 3)
{
    $info = parse_url($url);
    extract($info);
    $query = isset($query) ? trim($query) : '';
    $path = isset($path) ? trim($path) : '';

    $fp = fsockopen($host, 80, $errno, $errstr, $timeout);
    if (!$fp) {
        exit("$errstr ($errno)
\n");
    }

    $write = fwrite($fp, "GET {$path}?{$query} HTTP/1.0\r\nHost: {$host}\r\n\r\n");

//    while (!feof($fp)) {
//        echo fread($fp, 4096);
//    }
}


$url = "http://mydir.com/index.php?act=sendMail";
$emailList = array(...);
foreach ($emailList as $email) {
    fSockGet($url);
}