PHP - длинный опрос, сеанс уничтожен

    ini_set('max_execution_time', 0);
    ignore_user_abort(false);

    $isUptodate = (bool) file_get_contents($this->uptodateFile);

    while ($isUptodate === true)
    {
      sleep(1);
      $isUptodate = (bool) file_get_contents($this->uptodateFile);
    }

    $updateUptodateFile = fopen($this->uptodateFile, 'w');
    fwrite($updateUptodateFile, 'true');

    $jsonData = json_decode(file_get_contents($this->updateFile), true);

    echo json_encode(['updates' => count($jsonData)]);

    checkForUpdates: function ()
    {
      var that = this;

      $.ajax({
        url: 'updates.php',
        type: 'GET',
        dataType: 'json',
        timeout: 10000
      }).done(function (data)
      {
        console.info('data received');
        if (data.updates)
        {
          alert('nouveau message');
          setTimeout(function () { that.checkForUpdates() }, 5000);
        }
      }).fail(function (data)
      {
        console.info(data);
        setTimeout(function () { that.checkForUpdates() }, 10000);
      });
    }