php怎么实现异步

<?php
function request_by_fsockopen($url,$post_data=array(),$debug=false){
    $url_array = parse_url($url);
    $hostname = $url_array['host'];
    $port = isset($url_array['port'])? $url_array['port'] : 80;
    @$requestPath = $url_array['path'] ."?". $url_array['query'];
    $fp = fsockopen($hostname, $port, $errno, $errstr, 10);
    if(!$fp){
        echo "$errstr ($errno)";
        return false;
    }
    $method = "GET";
    if(!empty($post_data)){
        $method = "POST";
    }
    $header = "$method $requestPath HTTP/1.1\r\n";
    $header.="Host: $hostname\r\n";
    if(!empty($post_data)){
        $_post = strval(NULL);
        foreach($post_data as $k => $v){
            $_post[]= $k."=".urlencode($v);//必须做url转码以防模拟post提交的数据中有&符而导致post参数键值对紊乱
        }
        $_post = implode('&', $_post);
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";//POST数据
        $header .= "Content-Length: ". strlen($_post) ."\r\n";//POST数据的长度
        $header.="Connection: Close\r\n\r\n";//长连接关闭
        $header .= $_post; //传递POST数据
    }
    else{
        $header.="Connection: Close\r\n\r\n";//长连接关闭
    }
    fwrite($fp, $header);
    //-----------------调试代码区间-----------------
    //注如果开启下面的注释,异步将不生效可是方便调试
    if($debug){
        $html = '';
        while (!feof($fp)) {
            $html.=fgets($fp);
        }
        echo $html;
    }
    //-----------------调试代码区间-----------------
    fclose($fp);
}
$data=array('name'=>'guoyu','pwd'=>'123456');
$url='http://localhost/test/other.php';
request_by_fsockopen($url,$data,true);

<?php
header("content-type:text/html;charset=utf-8");
//error_reporting(0);
//ini_set('html_errors',false);
//ini_set('display_errors',false);
$name = isset($_POST['name'])?$_POST['name']:'';
$pwd = isset($_POST['pwd'])?$_POST['pwd']:'';
echo $name.$pwd;
echo 'success ok';
die;