PHP 并发获取(stream_select)信息程序代码

<?php
$url = "www.ite5e.com";
if(array_key_exists(url,$_GET)){
$url = $_GET[url];
}
$hosts = array("www.xunlei.com", "www.qq.com", "www.163.com","www.baidu.com","www.kaixin.com","vip.xunlei.com");
#$hosts = array($url);
$timeout = 5;
$status = array();
$retdata = array();
$sockets = array();
$e = array();
/* Initiate connections to all the hosts simultaneously */
foreach ($hosts as $id => $host) {
$errno = 0;
$errstr = "";
$s = stream_socket_client("$host:80", $errno, $errstr, $timeout,STREAM_CLIENT_ASYNC_CONNECT|STREAM_CLIENT_CONNECT);
if ($s) {
$sockets[$id] = $s;
$status[$id] = "in progress";
} else {
$status[$id] = "failed, $errno $errstr";
}
$retdata[$id] = ;
}
/* Now, wait for the results to come back in */
while (count($sockets)) {
$read = $write = $sockets;
/* This is the magic function - explained below */
$n = stream_select($read, $write, $e, $timeout);
if ($n > 0) {
/* readable sockets either have data for us, or are failed connection attempts */
foreach ($read as $r) {
$id = array_search($r, $sockets);
$data = fread($r, 8192);
if (strlen($data) == 0) {
if ($status[$id] == "in progress") {
$status[$id] = "failed to connect";
}
fclose($r);
unset($sockets[$id]);
} else {
$retdata[$id] .= $data;
}
}
/* writeable sockets can accept an HTTP request */
foreach ($write as $w) {
if(!is_resource($w))continue;
$id = array_search($w, $sockets);
fwrite($w, "GET / HTTP/1.0 Host: ".$hosts[$id]." ");
$status[$id] = "waiting for response";
}
} else {
/* timed out waiting; assume that all hosts associated
* with $sockets are faulty */
foreach ($sockets as $id => $s) {
$status[$id] = "timed out " . $status[$id];
}
break;
}
}
foreach ($hosts as $id => $host) {
#echo "Host: $host ";
#echo "Status: " . $status[$id] . " ";
#echo "Retdata: " . $retdata[$id] . " ";
$strs = explode(" ",$retdata[$id],2);
echo isset($strs[1])?$strs[1]:$retdata[$id];
}
function debug($i){
var_dump($i);
var_dump(gettype($i));
var_dump(is_resource($i));
}
?>

补充：Web开发 , php ,