您好我在Python类中包含一些ZMQ拉客户端时遇到了一些问题。这些类通过多处理模块在Subprocess中实例化并调用。当客户端是函数时，所有函数都可以工作，但是当它们是类时，poller.poll（）会挂起。
下面的代码有两个版本：一个有效，另一个没有。为什么呢？
import zmq
import time
import sys
import random
from multiprocessing import Process
def server_push(port="5556"):
context = zmq.Context()
socket = context.socket(zmq.PUSH)
socket.bind("tcp://*:%s" % port)
print "Running server on port: ", port
# serves only 5 request and dies
for reqnum in range(10):
if reqnum < 6:
socket.send("Continue")
else:
socket.send("Exit")
break
time.sleep (1)
def server_pub(port="5558"):
context = zmq.Context()
socket = context.socket(zmq.PUB)
socket.bind("tcp://*:%s" % port)
publisher_id = random.randrange(0,9999)
print "Running server on port: ", port
# serves only 5 request and dies
for reqnum in range(10):
# Wait for next request from client
topic = random.randrange(8,10)
messagedata = "server#%s" % publisher_id
print "%s %s" % (topic, messagedata)
socket.send("%d %s" % (topic, messagedata))
time.sleep(1)
class Client:
def __init__(self,port_push, port_sub):
context = zmq.Context()
self.socket_pull = context.socket(zmq.PULL)
self.socket_pull.connect ("tcp://localhost:%s" % port_push)
print "Connected to server with port %s" % port_push
self.socket_sub = context.socket(zmq.SUB)
self.socket_sub.connect ("tcp://localhost:%s" % port_sub)
self.socket_sub.setsockopt(zmq.SUBSCRIBE, "9")
print "Connected to publisher with port %s" % port_sub
# Initialize poll set
def __call__(self):
poller = zmq.Poller()
poller.register(self.socket_pull, zmq.POLLIN)
poller.register(self.socket_sub, zmq.POLLIN)
# Work on requests from both server and publisher
should_continue = True
print "listening"
while should_continue:
print "hello"
socks = dict(poller.poll())
print poller
if self.socket_pull in socks and socks[self.socket_pull] == zmq.POLLIN:
message = self.socket_pull.recv()
print "Recieved control command: %s" % message
if message == "Exit":
print "Recieved exit command, client will stop recieving messages"
should_continue = False
if self.socket_sub in socks and socks[self.socket_sub] == zmq.POLLIN:
string = self.socket_sub.recv()
topic, messagedata = string.split()
print "Processing ... ", topic, messagedata
def client(port_push, port_sub):
context = zmq.Context()
socket_pull = context.socket(zmq.PULL)
socket_pull.connect ("tcp://localhost:%s" % port_push)
print "Connected to server with port %s" % port_push
socket_sub = context.socket(zmq.SUB)
socket_sub.connect ("tcp://localhost:%s" % port_sub)
socket_sub.setsockopt(zmq.SUBSCRIBE, "9")
print "Connected to publisher with port %s" % port_sub
# Initialize poll set
poller = zmq.Poller()
poller.register(socket_pull, zmq.POLLIN)
poller.register(socket_sub, zmq.POLLIN)
# Work on requests from both server and publisher
should_continue = True
while should_continue:
socks = dict(poller.poll())
if socket_pull in socks and socks[socket_pull] == zmq.POLLIN:
message = socket_pull.recv()
print "Recieved control command: %s" % message
if message == "Exit":
print "Recieved exit command, client will stop recieving messages"
should_continue = False
if socket_sub in socks and socks[socket_sub] == zmq.POLLIN:
string = socket_sub.recv()
topic, messagedata = string.split()
print "Processing ... ", topic, messagedata
if __name__ == "__main__":
# Now we can run a few servers
server_push_port = "5556"
server_pub_port = "5558"
Process(target=server_push, args=(server_push_port,)).start()
Process(target=server_pub, args=(server_pub_port,)).start()
#~ Process(target=client,args=(server_push_port,server_pub_port)).start()
Process(target=Client(server_push_port,server_pub_port)).start()
答案 0 :(得分：2)
编辑1：这不太正确...给我一些时间来做对......
我认为您可能以错误的方式调用Client类。我不是这方面的专家，但我认为你的客户端应该从Process子类化，然后使用.start（）函数运行。因此，定义您的Client类，如下所示：
class Client(Process):
def __init__(self, port_push, port_sub):
(...) # your class init code here...make sure indentation is correct
然后在运行服务器的最后，创建Client类的实例并按如下所示启动它：
client_class = Client(port_push, port_sub)
client_class.start()
Edit2：这是fccoelho代码的编辑版，对我有用。
最大的问题似乎是ZMQ初始化内容需要在__call__方法中完成，而不是在__init__中。我怀疑这是由于多处理中如何分配内存，因为__init__函数将在父进程中完成，而__call__函数在子进程中使用单独的内存空间完成。显然ZMQ不喜欢这个。我还添加了一些等待时间，以防止客户端在服务器准备就绪之前连接到服务器，并防止服务器在客户端订阅之前发送消息。还使用127.0.0.1而不是localhost（由于某种原因，我的电脑不喜欢localhost）。还删除了客户端中轮询调用周围令人讨厌的打印消息，并修复了客户端在pubsub套接字上检查轮询结果的缩进问题。
import zmq
import time
import sys
import random
from multiprocessing import Process
def server_push(port="5556"):
context = zmq.Context()
socket = context.socket(zmq.PUSH)
socket.bind("tcp://127.0.0.1:%s" % port)
print "Running server on port: ", port
time.sleep(1.0)
# serves only 5 request and dies
for reqnum in range(10):
if reqnum < 6:
socket.send("Continue")
else:
socket.send("Exit")
print 'Push server sent "Exit" signal'
break
time.sleep(0.4)
def server_pub(port="5558"):
context = zmq.Context()
socket = context.socket(zmq.PUB)
socket.bind("tcp://127.0.0.1:%s" % port)
socket.setsockopt(zmq.HWM, 1000)
publisher_id = random.randrange(0,9999)
print "Running server on port: ", port
time.sleep(1.0)
# serves only 5 request and dies
for reqnum in range(10):
# Wait for next request from client
topic = random.randrange(8,10)
messagedata = "server#%s" % publisher_id
print "%s %s" % (topic, messagedata)
socket.send("%d %s" % (topic, messagedata))
time.sleep(0.4)
class Client:
def __init__(self,port_push, port_sub):
self.port_push = port_push
self.port_sub = port_sub
# Initialize poll set
def __call__(self):
time.sleep(0.5)
print 'hello from class client!'
context = zmq.Context()
self.socket_pull = context.socket(zmq.PULL)
self.socket_pull.connect ("tcp://127.0.0.1:%s" % self.port_push)
print "Connected to server with port %s" % self.port_push
self.socket_sub = context.socket(zmq.SUB)
self.socket_sub.connect ("tcp://127.0.0.1:%s" % self.port_sub)
self.socket_sub.setsockopt(zmq.SUBSCRIBE, "9")
print "Connected to publisher with port %s" % self.port_sub
poller = zmq.Poller()
poller.register(self.socket_pull, zmq.POLLIN)
poller.register(self.socket_sub, zmq.POLLIN)
# Work on requests from both server and publisher
should_continue = True
print "listening"
while should_continue:
# print "hello"
socks = dict(poller.poll())
# print poller
if self.socket_pull in socks and socks[self.socket_pull] == zmq.POLLIN:
message = self.socket_pull.recv()
print "Recieved control command: %s" % message
if message == "Exit":
print "Recieved exit command, client will stop recieving messages"
should_continue = False
if self.socket_sub in socks and socks[self.socket_sub] == zmq.POLLIN:
string = self.socket_sub.recv()
topic, messagedata = string.split()
print "Processing ... ", topic, messagedata
def client(port_push, port_sub):
print 'hello from function client!'
context = zmq.Context()
socket_pull = context.socket(zmq.PULL)
socket_pull.connect ("tcp://127.0.0.1:%s" % port_push)
print "Connected to server with port %s" % port_push
socket_sub = context.socket(zmq.SUB)
socket_sub.connect ("tcp://127.0.0.1:%s" % port_sub)
socket_sub.setsockopt(zmq.SUBSCRIBE, "9")
print "Connected to publisher with port %s" % port_sub
# Initialize poll set
poller = zmq.Poller()
poller.register(socket_pull, zmq.POLLIN)
poller.register(socket_sub, zmq.POLLIN)
# Work on requests from both server and publisher
should_continue = True
while should_continue:
socks = dict(poller.poll(1000))
if socket_pull in socks and socks[socket_pull] == zmq.POLLIN:
message = socket_pull.recv()
print "Recieved control command: %s" % message
if message == "Exit":
print "Recieved exit command, client will stop recieving messages"
should_continue = False
if socket_sub in socks and socks[socket_sub] == zmq.POLLIN:
string = socket_sub.recv()
topic, messagedata = string.split()
print "Processing ... ", topic, messagedata
if __name__ == "__main__":
# Now we can run a few servers
server_push_port = "5556"
server_pub_port = "5558"
Process(target=server_push, args=(server_push_port,)).start()
Process(target=server_pub, args=(server_pub_port,)).start()
# Process(target=client,args=(server_push_port,server_pub_port)).start()
Process(target=Client(server_push_port,server_pub_port)).start()
最后，这是一个更简洁的多进程pubsub实现，但更清楚地展示了事情：
import zmq
from multiprocessing import Process
import time
class ServerPubSub(Process):
def __init__(self, port, n):
Process.__init__(self)
self.port = port
self.n = n
def run(self):
self.context = zmq.Context()
self.pub = self.context.socket(zmq.PUB)
self.pub.bind('tcp://127.0.0.1:%d' % self.port)
self.pub.setsockopt(zmq.HWM, 1000)
time.sleep(1)
end = False
for i in range(self.n):
print 'SRV: sending message %d' % i
self.pub.send('Message %d' % i)
print 'SRV: message %d sent' % i
time.sleep(0.2)
self.pub.close()
class ClientPubSub(Process):
def __init__(self, port, n):
Process.__init__(self)
self.port = port
self.n = n
def run(self):
self.context = zmq.Context()
self.sub = self.context.socket(zmq.SUB)
self.sub.connect('tcp://127.0.0.1:%d' % self.port)
self.sub.setsockopt(zmq.SUBSCRIBE, '')
self.poller = zmq.Poller()
self.poller.register(self.sub, zmq.POLLIN)
end = False
count = 0
while count < self.n:
ready = dict(self.poller.poll(0))
if self.sub in ready and ready[self.sub] == zmq.POLLIN:
msg = self.sub.recv()
print 'CLI: received message "%s"' % msg
count += 1
self.sub.close()
if __name__ == "__main__":
port = 5000
n = 10
server = ServerPubSub(port, n)
client = ClientPubSub(port, n)
server.start()
client.start()
server.join()
client.join()