详解：使用pthreadsPHP扩展PHP真正多线程的使用

　　2、给出一段PHP多线程、与For循环，抓取百度搜索页面的PHP代码示例：

  class test_thread_run extends Thread 
  {
      public $url;
      public $data;


      public function __construct($url)
      {
          $this->url = $url;
      }


      public function run()
      {
          if(($url = $this->url))
          {
              $this->data = model_http_curl_get($url);
          }
      }
  }


  function model_thread_result_get($urls_array) 
  {
      foreach ($urls_array as $key => $value) 
      {
          $thread_array[$key] = new test_thread_run($value["url"]);
          $thread_array[$key]->start();
      }


      foreach ($thread_array as $thread_array_key => $thread_array_value) 
      {
          while($thread_array[$thread_array_key]->isRunning())
          {
              usleep(10);
          }
          if($thread_array[$thread_array_key]->join())
          {
              $variable_data[$thread_array_key] = $thread_array[$thread_array_key]->data;
          }
      }
      return $variable_data;
  }


  function model_http_curl_get($url,$userAgent="") 
  {
      $userAgent = $userAgent ? $userAgent : 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2)'; 
      $curl = curl_init();
      curl_setopt($curl, CURLOPT_URL, $url);
      curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
      curl_setopt($curl, CURLOPT_TIMEOUT, 5);
      curl_setopt($curl, CURLOPT_USERAGENT, $userAgent);
      $result = curl_exec($curl);
      curl_close($curl);
      return $result;
  }


  for ($i=0; $i <100; $i++) 
  { 
      $urls_array[] = array("name" => "baidu", "url" => "http://www.baidu.com/s?wd=".mt_rand(10000,20000));
  }


  $t = microtime(true);
  $result = model_thread_result_get($urls_array);
  $e = microtime(true);
  echo "多线程：".($e-$t)."\n";


  $t = microtime(true);
  foreach ($urls_array as $key => $value) 
  {
      $result_new[$key] = model_http_curl_get($value["url"]);
  }
  $e = microtime(true);
  echo "For循环：".($e-$t)."\n";
?>