Python pyzmq REQ/REP，带有异步IO等待变量

我第一次在python中使用asyncio，并尝试将其与ZMQ结合起来

基本上，我的问题是我有一个REP/REQ系统，在一个

async def

中，有一个我需要等待的函数。如何不更新该值。 下面是一段代码来说明：

#Declaring the zmq context
context = zmq_asyncio.Context()
REP_server_django = context.socket(zmq.REP)
REP_server_django.bind("tcp://*:5558")

我将这个对象发送给一个类，并在这个函数中获取它

async def readsonar(self, trigger_pin, REP_server_django):
        i= 0
        while True:

            ping_from_view = await REP_server_django.recv()  # line.1
            value = await self.board.sonar_read(trigger_pin) # line.2
            print(value)                                     # line.3
            json_data = json.dumps(value)                    # line.4
            #json_data = json.dumps(i)                       # line.4bis
            REP_server_django.send(json_data.encode())       # line.5
            i+=1                                             # line.6
            await asyncio.sleep(1/1000)                      # line.7

声纳读取正在使用pymata\u express读取超声波传感器。如果我对

行.2

和

行.4

进行注释，我会得到

I

的正确值。如果我评论

行.1

和

行.5

则

打印（值）

从

声纳读取打印正确的值。但是，当我如图所示运行它时，
值不会更新

我错过什么了吗


编辑：
编辑了有关行注释的类型。我的意思是，如果我只读取声纳并打印数值。它很好用。如果我只使用
.recv（）
和
.send（json.dumps（I）.encode（））
，它就可以工作。但是如果我试着从声纳发送数据。它锁定到未更新的给定值


EDIT2:（对艾伦·约林克斯的回答）：这是MWE，它考虑了您在课堂上发送的关于
zmq
声明的内容。它取自
pymata_express
示例

要再现错误，请在两个不同的终端中运行这两个脚本。您需要安装一个arduino板。如果一切顺利，
第A部分。
只应在
mve_req.py
末尾吐出相同的值。您可以编辑不同的块（A、B或C部分）以查看其行为

mve_代表py

#ADAPTED FROM PYMATA EXPRESS EXAMPLE CONCURRENTTAKS
#https://github.com/MrYsLab/pymata-express/blob/master/examples/concurrent_tasks.py
import asyncio
import zmq
import json
import zmq.asyncio as zmq_asyncio
from pymata_express.pymata_express import PymataExpress


class ConcurrentTasks:

    def __init__(self, board):


        self.loop = board.get_event_loop()
        self.board = board

        self.ctxsync = zmq.Context()
        self.context = zmq.asyncio.Context()
        self.rep = self.context.socket(zmq.REP)
        self.rep.bind("tcp://*:5558")

        self.trigger_pin = 53
        self.echo_pin = 51

        loop.run_until_complete(self.async_init_and_run())

    async def readsonar(self):
        i = 0
        while True:


            #PART. A. WHAT I HOPE COULD WORK
            rep_recv = await self.rep.recv()                       # line.1
            value = await self.board.sonar_read(self.trigger_pin)  # line.2
            print(value)                                           # line.3
            json_data = json.dumps(value)                          # line.4
            # json_data = json.dumps(i)                            # line.4bis
            await self.rep.send(json_data.encode())                # line.5
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7


            '''
            #PART. B. WORKS FINE IN UPDATING THE SONAR_RAED VALUE AND PRINTING IT
            value = await self.board.sonar_read(self.trigger_pin)  # line.2
            print(value)                                           # line.3
            json_data = json.dumps(value)                          # line.4
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7
            '''

            '''
            #PART. C. WORKS FINE IN SENDING THE i VALUE OVER ZMQ
            rep_recv = await self.rep.recv()                       # line.1
            json_data = json.dumps(i)                              # line.4bis
            await self.rep.send(json_data.encode())                # line.5
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7
            '''



    async def async_init_and_run(self):

        await self.board.set_pin_mode_sonar(self.trigger_pin, self.echo_pin)

        readsonar = asyncio.create_task(self.readsonar())
        await readsonar

        # OTHER CREATED_TASK GO HERE, (removed them in the MVE, but they work fine)


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    my_board = PymataExpress()
    try:
        ConcurrentTasks(my_board)
    except (KeyboardInterrupt, RuntimeError):
        loop.run_until_complete(my_board.shutdown())
        print('goodbye')
    finally:
        loop.close()

import zmq
import time
import json

def start_zmq():
    context = zmq.Context()
    REQ_django  = context.socket(zmq.REQ)
    REQ_django.connect("tcp://localhost:5558")

    return REQ_django, context

def get_sonar(REQ_django):
    REQ_django.send(b"server_django")
    ping_from_server_django = REQ_django.recv()
    return ping_from_server_django.decode()

if __name__ == '__main__':

    data = {"sensors":{}}

    REQ_django, context = start_zmq()
    while REQ_django:

            data['sensors']['sonar'] = get_sonar(REQ_django)
            json_data = json.dumps(data)
            print(data)

            #DO OTHER WORK
            time.sleep(1)

    REQ_django.close()
    context.term()

mve_要求py

#ADAPTED FROM PYMATA EXPRESS EXAMPLE CONCURRENTTAKS
#https://github.com/MrYsLab/pymata-express/blob/master/examples/concurrent_tasks.py
import asyncio
import zmq
import json
import zmq.asyncio as zmq_asyncio
from pymata_express.pymata_express import PymataExpress


class ConcurrentTasks:

    def __init__(self, board):


        self.loop = board.get_event_loop()
        self.board = board

        self.ctxsync = zmq.Context()
        self.context = zmq.asyncio.Context()
        self.rep = self.context.socket(zmq.REP)
        self.rep.bind("tcp://*:5558")

        self.trigger_pin = 53
        self.echo_pin = 51

        loop.run_until_complete(self.async_init_and_run())

    async def readsonar(self):
        i = 0
        while True:


            #PART. A. WHAT I HOPE COULD WORK
            rep_recv = await self.rep.recv()                       # line.1
            value = await self.board.sonar_read(self.trigger_pin)  # line.2
            print(value)                                           # line.3
            json_data = json.dumps(value)                          # line.4
            # json_data = json.dumps(i)                            # line.4bis
            await self.rep.send(json_data.encode())                # line.5
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7


            '''
            #PART. B. WORKS FINE IN UPDATING THE SONAR_RAED VALUE AND PRINTING IT
            value = await self.board.sonar_read(self.trigger_pin)  # line.2
            print(value)                                           # line.3
            json_data = json.dumps(value)                          # line.4
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7
            '''

            '''
            #PART. C. WORKS FINE IN SENDING THE i VALUE OVER ZMQ
            rep_recv = await self.rep.recv()                       # line.1
            json_data = json.dumps(i)                              # line.4bis
            await self.rep.send(json_data.encode())                # line.5
            i += 1                                                 # line.6
            await asyncio.sleep(1 / 1000)                          # line.7
            '''



    async def async_init_and_run(self):

        await self.board.set_pin_mode_sonar(self.trigger_pin, self.echo_pin)

        readsonar = asyncio.create_task(self.readsonar())
        await readsonar

        # OTHER CREATED_TASK GO HERE, (removed them in the MVE, but they work fine)


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    my_board = PymataExpress()
    try:
        ConcurrentTasks(my_board)
    except (KeyboardInterrupt, RuntimeError):
        loop.run_until_complete(my_board.shutdown())
        print('goodbye')
    finally:
        loop.close()

import zmq
import time
import json

def start_zmq():
    context = zmq.Context()
    REQ_django  = context.socket(zmq.REQ)
    REQ_django.connect("tcp://localhost:5558")

    return REQ_django, context

def get_sonar(REQ_django):
    REQ_django.send(b"server_django")
    ping_from_server_django = REQ_django.recv()
    return ping_from_server_django.decode()

if __name__ == '__main__':

    data = {"sensors":{}}

    REQ_django, context = start_zmq()
    while REQ_django:

            data['sensors']['sonar'] = get_sonar(REQ_django)
            json_data = json.dumps(data)
            print(data)

            #DO OTHER WORK
            time.sleep(1)

    REQ_django.close()
    context.term()

（O/p MCVE问题的定义更进一步——然而，{sensors | actors}控制系统的协调问题，无论优先与否，使用分布式自治代理设计的系统在专业上越复杂，就越容易产生有缺陷的“捷径”或陷入困境
最好在不到五秒钟的时间内首先阅读层次结构和关于相互死锁阻塞

阅读Pieter HINTJENS的精彩著作《连接的代码：第1卷》对任何系统设计师都具有巨大的价值）

“…非常有趣，因为它已经实现了异步，所以我可以像以前一样添加异步zmq。我错了吗？”

是的，没有“只添加异步”的快捷方式，控制系统是非常有趣的学科，而是一个复杂的学科。总是。很抱歉不得不直说。一些复杂性可能在教科书示例或琐碎的项目中对用户隐藏。然后，通过添加一个或几个更为琐碎的功能，锤子就可以尝试扩展它们。复杂性突然浮出水面，这是以前从未见过的


O/P多代理的正式映射-
[A、B、C、D]
-系统代码（原样）
将正式地图放在一个全屏编辑器上，以便看到所有相互冲突的依赖关系和相互竞争的控制循环的大图。延迟是最简单的部分。无法解决的死锁阻塞风险的几个地方是核心。ZeroMQ，因为v2.x有避免其中一些问题的工具，所以软件设计师有责任适当地缓解所有其他问题。控制系统（机器人或其他）必须证明这种鲁棒性和对错误的恢复能力，并安全地“生存”所有“外部”事故

最好从第1行汇编语言指令中表达的旧黄金法则开始：

;ASSUME NOTHING

并努力仔细设计其余的部分


并运行一系列100个声纳测试，以获得潜伏期的最小值、平均值、标准差、最大值读数，所有这些读数都在
[us]中，因为这些值是最基本的，以防设计一些控制回路时不考虑声纳传感器数据

[ aFun( [ sonarBeep()[1] for _    in range( 100 ) ]
        )                for aFun in ( np.min, np.mean, np.std, np.max )
  ]

系统架构和子系统协调：
最后，但并非最不重要的一点是，可以在一个绝对独立的事件循环中读取和存储声纳数据，与任何其他操作不协调，只从这样的存储中读取一个状态变量，设置在一个独立工作的子系统中（如果作为独立的系统行为这样做不会极大地节省电源的话）

每当人们试图紧密地协调独立事件流时（在具有不协调或弱协调代理的分布式系统中最糟糕的情况），设计必须增强对错误和时间错误对齐的鲁棒性以及错误恢复能力。否则，系统可能很快就会死锁/活锁

如果有疑问，可以学习施乐帕洛阿尔托研究中心MVC分离的最初理念，
模型的
部分可以（并且大部分时间在GUI框架中，自198x+以来）接收许多独立于其他系统组件更新的状态变量，只要读取/使用实际状态变量的数据就可以了。类似地，如果功率预算允许，声纳可以连续扫描场景并将读数写入任何本地寄存器，并让其他组件来请求或获得最后一次实际声纳读数的请求

ZeroMQ zen也是如此

如果这可能有帮助，请检查本地侧消息存储的
zmq.CONFLATE
模式是否按此方式工作

一个小提示：有人可能已经注意到，
sleep（1/1000）
是一个非常昂贵、重复执行的步骤，而且非常危险，因为在py2.x中，由于整数除法，它实际上不会休眠。
我不确定这是否能解决您的问题，但我确实发现了一些潜在的问题

目前尚不清楚readsonar的使用情况
import asyncio
import zmq
import json


class Play:
    def __init__(self):
        self.context = zmq.asyncio.Context()
        self.REP_server_django = self.context.socket(zmq.REP)
        self.REP_server_django.bind("tcp://*:5558")
        self.event_loop = asyncio.get_event_loop()
        self.event_loop.run_until_complete(self.readsonar(4))

    async def readsonar(self, trigger_pin):
        i = 0
        while True:
            ping_from_view = await self.REP_server_django.recv()  # l.1
            value = await self.board.sonar_read(trigger_pin)  # l.2
            print(value)  # l.3
            json_data = json.dumps(value)  # l.4
            # json_data = json.dumps(i) # l.4bis
            await self.REP_server_django.send(json_data.encode())  # l.5
            i += 1  # l.6
            await asyncio.sleep(1 / 1000)  # l.6

#ADAPTED FROM PYMATA EXPRESS EXAMPLE CONCURRENTTAKS
#https://github.com/MrYsLab/pymata-express/blob/master/examples/concurrent_tasks.py
import asyncio
import zmq
import json
import zmq.asyncio as zmq_asyncio
from pymata_express.pymata_express import PymataExpress


class ConcurrentTasks:

    def __init__(self, board):


        self.loop = board.get_event_loop()
        self.board = board

        self.ctxsync = zmq.Context()
        self.context = zmq.asyncio.Context()
        self.rep = self.context.socket(zmq.REP)
        self.rep.bind("tcp://*:5558")

        self.trigger_pin = 53
        self.echo_pin = 51

        loop.run_until_complete(self.async_init_and_run())

    ### START:  NEW CODE THAT RESOLVED THE ISSUE
    async def pingsonar(self):
        value = await self.board.sonar_read(self.trigger_pin)
        return value

    async def readsonar(self):
        while True:
            rep_recv = await self.rep.recv() 
            value = await asyncio.wait([self.pingsonar()])
            valuesonar = list(value[0])[0].result()
            json_data = json.dumps(valuesonar) 
            await self.rep.send(json_data.encode()) 
            await asyncio.sleep(1 / 1000) #maybe this line isn't necessary

    ### END : NEW CODE THAT RESOLVED THE ISSUE

    async def async_init_and_run(self):

        await self.board.set_pin_mode_sonar(self.trigger_pin, self.echo_pin)

        readsonar = asyncio.create_task(self.readsonar())
        await readsonar

        # OTHER CREATED_TASK GO HERE, (removed them in the MVE, but they work fine)


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    my_board = PymataExpress()
    try:
        ConcurrentTasks(my_board)
    except (KeyboardInterrupt, RuntimeError):
        loop.run_until_complete(my_board.shutdown())
        print('goodbye')
    finally:
        loop.close()

import argparse
import signal
import sys
import threading
import time

from python_banyan.banyan_base import BanyanBase


class HCSR04(BanyanBase, threading.Thread):
    def __init__(self, **kwargs):
        """
        kwargs contains the following parameters
        :param back_plane_ip_address: If none, the local IP address is used
        :param process_name: HCSR04
        :param publisher_port: publishing port
        :param subscriber_port: subscriber port
        :param loop_time: receive loop idle time
        :param trigger_pin: GPIO trigger pin number
        :param echo_pin: GPIO echo pin number
        """

        self.back_plane_ip_address = kwargs['back_plane_ip_address'],
        self.process_name = kwargs['process_name']
        self.publisher_port = kwargs['publisher_port']
        self.subscriber_port = kwargs['subscriber_port'],
        self.loop_time = kwargs['loop_time']
        self.trigger_pin = kwargs['trigger_pin']
        self.echo_pin = kwargs['echo_pin']
        self.poll_interval = kwargs['poll_interval']

        self.last_distance_value = 0

        # initialize the base class
        super(HCSR04, self).__init__(back_plane_ip_address=kwargs['back_plane_ip_address'],
                                     subscriber_port=kwargs['subscriber_port'],
                                     publisher_port=kwargs['publisher_port'],
                                     process_name=kwargs['process_name'],
                                     loop_time=kwargs['loop_time'])

        threading.Thread.__init__(self)
        self.daemon = True

        self.lock = threading.Lock()

        # subscribe to receive messages from arduino gateway
        self.set_subscriber_topic('from_arduino_gateway')

        # enable hc-sr04 in arduino gateway
        payload = {'command': 'set_mode_sonar', 'trigger_pin': self.trigger_pin,
                   'echo_pin': self.echo_pin}
        self.publish_payload(payload, 'to_arduino_gateway')

        # start the thread
        self.start()

        try:
            self.receive_loop()
        except KeyboardInterrupt:
            self.clean_up()
            sys.exit(0)

    def incoming_message_processing(self, topic, payload):
        print(topic, payload)
        with self.lock:
            self.last_distance_value = payload['value']

    def run(self):
        while True:
            with self.lock:
                distance = self.last_distance_value
            payload = {'distance': distance}
            topic = 'distance_poll'
            self.publish_payload(payload, topic)
            time.sleep(self.poll_interval)


def hcsr04():
    parser = argparse.ArgumentParser()
    # allow user to bypass the IP address auto-discovery.
    # This is necessary if the component resides on a computer
    # other than the computing running the backplane.
    parser.add_argument("-b", dest="back_plane_ip_address", default="None",
                        help="None or IP address used by Back Plane")
    parser.add_argument("-i", dest="poll_interval", default=1.0,
                        help="Distance polling interval")
    parser.add_argument("-n", dest="process_name", default="HC-SRO4 Demo",
                        help="Set process name in banner")
    parser.add_argument("-p", dest="publisher_port", default="43124",
                        help="Publisher IP port")
    parser.add_argument("-s", dest="subscriber_port", default="43125",
                        help="Subscriber IP port")
    parser.add_argument("-t", dest="loop_time", default=".1",
                        help="Event Loop Timer in seconds")
    parser.add_argument("-x", dest="trigger_pin", default="12",
                        help="Trigger GPIO pin number")
    parser.add_argument("-y", dest="echo_pin", default="13",
                        help="Echo GPIO pin number")

    args = parser.parse_args()

    if args.back_plane_ip_address == 'None':
        args.back_plane_ip_address = None
    kw_options = {'back_plane_ip_address': args.back_plane_ip_address,
                  'publisher_port': args.publisher_port,
                  'subscriber_port': args.subscriber_port,
                  'process_name': args.process_name,
                  'loop_time': float(args.loop_time),
                  'trigger_pin': int(args.trigger_pin),
                  'echo_pin': int(args.echo_pin),
                  'poll_interval': int(args.poll_interval)
                  }

    # replace with the name of your class
    HCSR04(**kw_options)


# signal handler function called when Control-C occurs
def signal_handler(sig, frame):
    print('Exiting Through Signal Handler')
    raise KeyboardInterrupt


# listen for SIGINT
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)

if __name__ == '__main__':
    hcsr04()