pyzmq公司接收插座（）带有NOBLOCK标志behaviou

Question

我使用pyzmq创建了简单的客户机/服务器。在

有一件事我不确定，.recv()没有接收到消息，即使它是从服务器发送的。它只是忽略它，抛出一个我觉得奇怪的错误。在

客户端.py

try:
    socket = context.socket(zmq.REQ)
    socket.connect("tcp://localhost:2222")
    print("Sending request")
    socket.send(b"send the message")
    message = socket.recv(flags=zmq.NOBLOCK)
    print("Received reply %s " % message)
except Exception as e:
    print(str(e))

服务器.py

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我认为客户机应该接收Ack并打印它，而不是抛出异常。在

文件上说

With flags=NOBLOCK, this raises ZMQError if no messages have arrived

显然，服务器在收到消息后立即用“Ack”响应。在

信息就是错误

Resource temporarily unavailable

Answer 1

Q : say the server is not up in that case the recv() in the client will be blocked forever which I don't want.

ZeroMQ是在分布式系统中进行智能信令/消息传递的极好框架

让我们描绘一个主要是非阻塞的操作方法的演示，并给出一些关于在进程终止之前如何获得资源以及如何优雅地释放资源的一些启示。在

也许阅读一下部分的主要概念差异也会有所帮助。在

希望您能喜欢这个和更深入的实验StackOverflow resources如何最好地利用ZeroMQ Zen of Zero的所有能力：

Server.py

 aContext     = zmq.Context()
 aLightHouse  =    aContext.socket( zmq.PUB )
 aRepSocket   =    aContext.socket( zmq.REP )
 aRepSocket.setsockopt(             zmq.LINGER,   0 )
 aRepSocket.setsockopt(             zmq.COMPLETE, 1 )
 aRepSocket.bind(                  "tcp://*:2222" )
 aLightHouse.bind(                 "tcp://*:3333" )
 aLightHouse.setsockopt(            zmq.LINGER,   0 )
 aLightHouse.setsockopt(            zmq.CONFLATE, 1 )
 aLightHouse_counter = 0
 #                              
 print( "INF: Server InS: ZeroMQ({0:}) going RTO:".format( zmq.zmq_version() )  )
 #                              
 while True:
    try:
        aLightHouse_counter += 1
        aLightHouse.send( "INF: server-RTO blink {0:}".format( repr( aLightHouse_counter ) ),
                           zmq.NOBLOCK
                           )
        if ( 0 < aRepSocket.poll( 0, zmq.POLLIN ) ):
            try:
                message = aRepSocket.recv(         zmq.NOBLOCK ); print( "INF: .recv()ed {0:}".format( message ) )
                pass;     aRepSocket.send( b"Ack", zmq.NOBLOCK ); print( "INF: .sent() ACK" )
            except:
                # handle EXC: based on ...
                print(  "EXC: reported as Errno == {0:}".format( zmq.zmq_errno() ) )
        else:
            # NOP / Sleep / do other system work-units to get processed during the infinite-loop
    except:
        # handle EXC:
        print(  "EXC: will break ... and terminate OoS ..." )
        break
#                              
print( "INF: will soft-SIG Server going-OoS..." )
aLightHouse.send(   "INF: server goes OoS ... " )
#                              
print( "INF: will .close() and .term() resources on clean & graceful exit..." )
Sleep( 0.987654321 )
aRepSocket.unbind(  "tcp://*:2222" )
aRepSocket.close()
aLightHouse.unbind( "tcp://*:3333" )
aLightHouse.close()
aContext.term()
#                              
print( "INF: over and out" )

Client.py

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