EOFError:退出课堂内的输入

我有以下代码,我需要一次读取多个传感器.我已经设置了线程和多处理来为我完成这项任务.当线程和多重处理代码在主类之外时,它可以正常工作,但是类不能使用它所检索的数据.当我把mutlithreading代码insdie这个类时,我遇到了一个EOFError: Ran out of input错误.

这是代码:

import os
import multiprocessing
from multiprocessing import Process, Pool
import threading
import queue
import tkinter as tk
from tkinter import *
from tkinter import ttk
import time
import minimalmodbus
import serial
minimalmodbus.CLOSE_PORT_AFTER_EACH_CALL = True
THREAD_LOCK = threading.Lock()

class Application(tk.Frame):
    def __init__(self, master=None):
        super().__init__(master)

        self.pack()

        self.first_gas_labelframe = LabelFrame(self, text="Gas 1", width=100)
        self.first_gas_labelframe.grid(row=0, column=0)

        self.value_label = Label(self.first_gas_labelframe, text="Value")
        self.value_label.grid(row=0, column=0)

        self.unit_label = Label(self.first_gas_labelframe, text="Unit")
        self.unit_label.grid(row=1, column=0)

        self.temp_label = Label(self.first_gas_labelframe, text="Temp")
        self.temp_label.grid(row=2, column=0)

        self.temp_label6 = Label(self.first_gas_labelframe6, text="Temp")
        self.temp_label6.grid(row=2, column=0)

        self.timer_button = tk.Button(self, text='Start', command=self.start_run)
        self.timer_button.grid(row=2, column=0)


    def start_run(self):
        self.all_thread()

    def all_thread(self):
        thread = threading.Thread(target=self.all_process)
        thread.start()

    def all_process(self):
        all_ports = port_num()
        gas = minimalmodbus.Instrument("COM3", 1)
        gas.serial.baudrate = 9600
        gas.serial.bytesize = 8
        gas.serial.parity = serial.PARITY_NONE
        gas.serial.stopbits = 1
        gas.serial.timeout = 0.25
        gas.mode = minimalmodbus.MODE_RTU

        gas_list = [gas]
        processes = []
        while len(gas_list) > 0:
            val = 1
            with THREAD_LOCK:
                for sen in gas_list:
                    proc = Process(target=self.main_reader, args=(sen, val))
                    processes.append(proc)
                    proc.start()
                    val += 1
                for sen in processes:
                    sen.join()
                time.sleep(1)

    def main_reader(sen, val):
        try:
            read = sen.read_registers(0,42)
        except OSError:
            read = "Communication Error"
        except ValueError:
            read = "RTU Error"
        print(read)

if __name__ == '__main__':
    root = tk.Tk()
    root.geometry("1000x600")
    app = Application()
    app.mainloop()

通过一些调试,问题发生在proc.start()但proc有数据.这些列表也有数据,这就是为什么我很困惑为什么它输出不足的原因.注意:在我的代码中有六个条目gas_list

你不能使用那样的多处理(嗯,你可以,但结果将是不可预测的) - 当你创建一个新的进程时,你minimalmodbus.Instrument的列表中的对象不会作为引用传递,而是作为一个完整的新对象传递.Python本质上运行一个全新的Python解释器实例,无论何时你start()是一个multiprocess.Process实例,并且由于不同的进程得到不同的堆栈,它们无法共享内部内存,所以Python实际上腌制传递的参数,将它们发送到进程,然后在那里进行unpickles创建一个两个进程(父进程和子进程)具有相同数据的错觉.

您可以自己观察它,而不是创建一个新的multiprocessing.Process调用self.main_reader(pickle.loads(pickle.dumps(sen)), val)(val也被腌制但作为通用它在这里没有任何重要性).

同样的过程也发生在Application.main_reader()方法上(虽然奇怪地定义了) - 你设置它的方式是你的整个Application实例实际上在子进程中重新创建,以便Python可以调用它的main_reader()方法.

你可以做的是传递所需的参数来重新创建原始对象到子进程函数,然后在函数启动时创建对象.例如,如果您将Application.all_process()方法修改为:

def all_process(self):
    gas = {"__init__": ("COM3", 1)
           "serial": {
               "baudrate": 9600,
               "bytesize": 8,
               "parity": serial.PARITY_NONE,
               "stopbits": 1,
               "timeout": 0.25
           },
           "mode": minimalmodbus.MODE_RTU}

    gas_list = [gas]
    processes = []
    while len(gas_list) > 0:
        val = 1
        for sen in gas_list:
            # we'll be calling the main_reader function outside of the Application instead
            proc = multiprocessing.Process(target=main_reader, args=(sen, val))
            processes.append(proc)
            proc.start()
            val += 1
        for sen in processes:
            sen.join()
        time.sleep(1)
        # you do plan to exit this loop, right?

然后将您的main_reader()函数定义在Application类之外:

def main_reader(data, val):  # notice it's outside of the Application scope
    sen = minimalmodbus.Instrument(*data["__init__"])  # initialize Instrument
    for k, v in data["serial"].items():  # apply the serial settings
        setattr(sen.serial, k, v)
    sen.mode = data["mode"]  # set the mode
    try:
        read = sen.read_registers(0, 42)
    except OSError:
        read = "Communication Error"
    except ValueError:
        read = "RTU Error"
    print(read)

它应该停止抛出错误.此外,您已经使用threading.Lock了原始代码 - 我不知道您尝试使用它实现了什么,但它肯定不会按照您的想法执行.