php select socket

因为客户端是长连接，如果客户端非正常断开，服务端会在socket_accept阻塞，现在使用select非阻塞模式socket,读取客户端信息。

<?php 
date_default_timezone_set("Asia/Shanghai");
include_once "Db.php";
$sfd = socket_create(AF_INET, SOCK_STREAM, 0); 
socket_bind($sfd, "192.168.191.1", 9001); 
socket_listen($sfd, 10); //监听10个
socket_set_option($sfd, SOL_SOCKET, SO_REUSEADDR, 1); //重用端口
socket_set_nonblock($sfd); //非阻塞
$rfds = array($sfd); 
$wfds = array(); 
do{ 
    $rs = $rfds;  
    $ws = $wfds; 
    $es = array(); 
    $ret = socket_select($rs, $ws, $es, 3); 
    //read event 
    foreach($rs as $fd){
            
        if($fd == $sfd){ 
            $cfd = socket_accept($sfd); 
            socket_set_nonblock($cfd); 
            $rfds[] = $cfd; 
            echo "new client coming, fd=$cfd
"; 
        }else{
            //获取客户端IP地址
            socket_getpeername($fd, $addr, $port);
            //读取客户端信息
            $msg = socket_read($fd, 1024); 
            echo date("H:i:s")." $fd $msg";
            $arr=explode(",", $msg);
            //更新到数据库 
            $sql = "update test set wendu = $arr[0],shidu = $arr[1], green = $arr[2],yellow=$arr[3] ,red=$arr[4],dianliu=$arr[5],
　　　　　　　　　　　　　dianya=$arr[6] where ip = '$addr'" ;
            Db::query($sql); 
        } 
    } 
 
 
}while(true);