再分享一种利用php curl实现多线程的方法，具体方法如下：

/*
 * http://www.phpernote.com/php-function/388.html
 * php Curl 多线程类
 */ 
class MultiHttpRequest{
    public $urls=array();
    public $curlopt_header=1;
    public $method="GET";
    function __construct($urls=false){
        $this->urls=$urls;
    }
    function set_urls($urls){
        $this->urls=$urls;
        return $this;
    }
    function is_return_header($b){
        $this->curlopt_header=$b;
        return $this;
    }
    function set_method($m){
        $this->medthod=strtoupper($m);
        return $this;
    }
    function start(){
        if(!is_array($this->urls) || count($this->urls)==0){
           return false;
        }
        $curl=$text=array();
        $handle=curl_multi_init();
        foreach($this->urls as $k=>$v){
           $curl[$k]=$this->add_handle($handle,$v);
        }
 
        $this->exec_handle($handle);
        foreach($this->urls as $k=>$v){
            curl_multi_getcontent($curl[$k]);
            echo $curl[$k]."\n";
            //$text[$k]= curl_multi_getcontent($curl[$k]);
            //echo $text[$k],"\n\n";
            curl_multi_remove_handle($handle,$curl[$k]);
        }
        curl_multi_close($handle);
    }
    private function add_handle($handle,$url){
        $curl=curl_init();
        curl_setopt($curl,CURLOPT_URL,$url);
        curl_setopt($curl,CURLOPT_HEADER,$this->curlopt_header);
        curl_setopt($curl,CURLOPT_RETURNTRANSFER,1);
        curl_multi_add_handle($handle,$curl);
        return $curl;
    }
    private function exec_handle($handle){
        $flag=null;
        do{
           curl_multi_exec($handle,$flag);
        } while ($flag > 0);
    }
}

该类的具体使用方法如下：

$urls=array(
'http://www.phpernote.com/php-function/665.html',
'http://www.phpernote.com/php-function/392.html',
'http://www.phpernote.com/php-function/281.html');
$mp=new MultiHttpRequest($urls);
$mp->start();