set_time_limit(0); //這句很重要, 不至于運行超時while (true) {  if (hasNewMessage()) {    echo json_encode(getNewMessage());    break;  }  usleep(100000);   //避免太過頻繁的查詢}

<script type="text/javascript">  (function longPolling() {    $.ajax({      'url': 'server.php',      'data': data,      'dataType': 'json',      'success': function(data) {        processData(data);        longPolling();      },      'error': function(data) {        longPolling();      }    });  })();</script>

<?phpnamespace church/LongPolling;use Closure;use church/LongPolling/Queue/RedisQueue;use Symfony/Component/HttpFoundation/Request;use Symfony/Component/HttpFoundation/JsonResponse;class Server{  public $event = [];  public $redisQueue = null;  public $request = null;  public $response = null;  public function __construct()  {    $this->redisQueue = new RedisQueue();    $this->request = Request::createFromGlobals();    $this->response = new JsonResponse();  }  public function on($event, Closure $closure)  {    if (is_callable($closure)) {      $this->event[$event][] = $closure;    }  }  public function fire($event)  {    if (isset($this->event[$event])) {      foreach ($this->event[$event] as $callback) {        call_user_func($callback, $this);      }    }  }  public function sendMessage($data)  {    switch ($data['type']) {      case 'unicast':   //單播        $this->unicast($data['target'], $data['data'], $data['resource']);        break;      case 'multicast':    //組播        foreach ($data['target'] as $target) {          $this->unicast($target, $data['data'], $data['resource']);        }        break;      case 'broadcast':    //廣播        foreach ($this->redisQueue->setQueueName('connections') as $target) {          $this->unicast($target, $data['data'], $data['resource']);        }        break;    }    $this->fire('message');  }  public function unicast($target, $message, $resource = 'system')  {    $redis_queue = new RedisQueue();    $redis_queue->setQueueName($target)->push($resource . ':' . $message);  }  public function getMessage($target)  {    return $this->redisQueue->setQueueName($target)->pop();  }  public function hasMessage($target)  {    return count($this->redisQueue->setQueueName($target));  }  public function run()  {    $data = $this->request->request;    while (true) {      if ($data->get('action') == 'getMessage') {        if ($this->hasMessage($data->get('target'))) {          $this->response->setData([            'state' => 'ok',            'message' => '獲取成功',            'data' => $this->getMessage($data->get('target'))          ]);          $this->response->send();          break;        }      } elseif ($data->get('action') == 'connect') {        $exist = false;        foreach ($this->redisQueue->setQueueName('connections') as $connection) {          if ($connection == $data->get('data')) {            $exist = true;          }        }        if (! $exist) {          $this->redisQueue->setQueueName('connections')->push($data->get('data'));        }        $this->fire('connect');        break;      }      usleep(100000);    }  }}