用Twisted阻止Twisted调用

Question

我有一个使用TTwisted协议的Twisted/Thrift服务器。我希望保持从客户端的连接打开，直到一个给定的事件发生(通过回调Twisted反应堆通知我这个事件)。

class ServiceHandler(object):
    interface.implements(Service.Iface)

    def listenForEvent(self):
        """
        A method defined in my Thrift interface that should block the Thrift
        response until my event of interest occurs.
        """
        # I need to somehow return immediately to free up the reactor thread,
        # but I don't want the Thrift call to be considered completed. The current
        # request needs to be marked as "waiting" somehow.

    def handleEvent(self):
        """
        A method called when the event of interest occurs. It is a callback method
        registered with the Twisted reactor.
        """
        # Find all the "waiting" requests and notify them that the event occurred.
        # This will cause all of the Thrift requests to complete.

如何快速地从我的处理程序对象的方法返回，同时保持阻塞的线程调用的错觉？

我从Twisted启动触发器初始化了trigger处理程序：

def on_startup():
    handler = ServiceHandler()                      
    processor = Service.Processor(handler)                                   
    server = TTwisted.ThriftServerFactory(processor=processor,                  
        iprot_factory=TBinaryProtocol.TBinaryProtocolFactory())                 
    reactor.listenTCP(9160, server)

我的PHP客户端连接：

  $socket = new TSocket('localhost', 9160);
  $transport = new TFramedTransport($socket);
  $protocol = new TBinaryProtocol($transport);
  $client = new ServiceClient($protocol);
  $transport->open();
  $client->listenForEvent();

最后一次调用($client->listenForEvent())成功地转移到服务器并运行ServiceHandler.listenForEvent，但即使该服务器方法返回twisted.internet.defer.Deferred()实例，客户端立即收到一个空数组，我得到了异常：

异常'TTransportException‘与消息'TSocket:超时从本地主机9160读取4个字节到本地端口38395'

Answer 1

您应该能够从listenForEvent返回一个延迟推断。稍后，handleEvent应该触发返回延迟推断(或那些返回的Deferreds)的对象来实际生成响应。

Answer 2

您所看到的错误似乎表明传输没有帧(Twisted需要它来预先知道每条消息的长度)。此外，Th深层服务器支持从处理程序返回延迟，因此这更奇怪。您是否尝试过返回defer.succeed(“一些值”)并查看延迟是否有效？然后，您可以转到这里来检查它是否完全工作：

    d = defer.Deferred()
    reactor.callLater(0, d.callback, results)
    return d