我希望进行长时间轮询以将某些数据“推送”到客户端,并且我还在与长轮询并行的情况下对服务器进行其他无关的AJAX调用.在长轮询收到响应(来自响应或超时)之前,我的其他AJAX调用似乎无法完成.当我单步执行Javascript时,似乎第二个AJAX请求是在适当的时间发送的,但是在长轮询请求得到响应之前没有收到响应.知道发生了什么事吗？

以下是长轮询部分的代码：

服务器端：

    function getPlaylistTracksIfChanged($playlist_id,$numClientTracks) {
  $reportChange = false;
  for($i = 0; $i < 10; $i++) {
   $numServerTracks = $this->PlaylistTrack->find('count',array(
     'conditions' => array('playlist_id' => $playlist_id)
    )
   );

   if($numClientTracks != $numServerTracks) {
    $reportChange = true;
    break;

   }

   sleep(3);

  }

  if($reportChange) {
   $playlist_tracks = $this->PlaylistTrack->find('all',array(
    'conditions' => array('playlist_id' => $playlist_id),'order' => array('PlaylistTrack.position') 
    )
   );

   $this->set('playlist_tracks',$playlist_tracks);
   $this->layout = false;
   $this->render('show_playlist_tracks_list');

  } else {
   $this->autoRender = false;
   return 'false';
  }

 }

客户端：

function checkForChangesOnServer() {
 $.post('/getResultsIfChanged/' + playlist_id + '/' + $('#sortable_tracks').children().size(),function(results) {

  if(results == 'false') {
   //alert('no change');
  } else {
   //alert('change');
  }

  checkForPlaylistChangesOnServer();

 });
}

以及另一个AJAX调用的示例：

服务器端：

    function getLibraryTracksStartingWithLetter($user_id,$letter) {
  $results = $this->Track->find(
   'all',array(
    'conditions' => array(
     'user_id' => $user_id,'OR' => array(
      'Track.artist LIKE' => $letter . '%','Track.name LIKE' => $letter . '%'
     )
    ),'order' => array('case when Track.artist = "" then 1 else 0 end','Track.artist','Track.name')
   )
  );

  $this->set('results',$results);
  $this->layout = false;
  $this->render('show_library_results_list');
 }

客户端：

    function loadLibraryResultsForLetter(letter) {
 highlightLetterFilter(letter);

 $.post('/getLibraryTracksStartingWithLetter/' + user_id + '/' + letter,function(results) {
  updateLibraryResults(results);
 });
}