如何使用PYCHARM/python中的多处理模块并行使用定时器

Question

我正在尝试与主线程并行运行计时器

关于该计划：

我想从服务器向客户端发送一个映像。图像通过UDP套接字以数据包的形式发送到客户端。 定时器的作用是控制变速箱。 如果发送数据包所用的时间大于10毫秒，计时器将停止，因此数据包将重新发送。例如，假设在第100次数据包传输期间，故意延迟1秒以检查程序，此时，计时器应重置（因为10ms是阈值），并且应重新发送数据包

我曾经

multirocesssing.Process(target=countdown), 
process = []

p1.start将启动该进程 process.append(p1)将p1进程添加到列表中

为了在流程之间进行通信，我将flag用作全局变量，也用作流程值

flag = multiprocessing.Value()

你能帮忙吗

我使用多处理模块来实现这个目标

附加代码

  def countdown(flag):
    process_ID = os.getpid()        #This module in Python will get the process ID when called.
    print(f"Process ID: {process_ID}")
    system_time = time.time()
    timeout = system_time + 1
    while True:
        if flag.Value == 1:
            break
        if (time.time() > timeout) and (flag.Value == 0):
            flag.Value = 1
            break

    def make_packet(outgoing_file, file_size):  # The make packet function takes two arguments; 
                                                    those two arguments are also specified by the client.
        global clientAddress, p1
        flag = multiprocessing.Value('i', 1)

        packet = outgoing_file.read(1024)  # Making the first packet by 1024 bytes.
        num_of_try = 0  # Number of tries to send the total number of packets 100%
        packet_num = 0
        fake_checksum = hashlib.md5(packet).hexdigest()  # Fake checksum to make errors intentionally.
        processes = []
        while packet_num != file_size:
        p1 = multiprocessing.Process(target=countdown, args=(flag,))

        print("-----------------------------------------------------------------------------------------")
        if packet_num % 2 == 0:
            seq_num = '0'  # Current Sequence number.
        else:
            seq_num = '1'  # Next Sequence number.

        check_sum = hashlib.md5(packet).hexdigest()  # Calculating the checksum value using hashlib
        rdt_send(seq_num, packet, check_sum)  # Preparing seq_num, packet and checksum for transmission.
        flag.Value = 0                                                   #Start the timer
        processes.append(p1)
        p1.start()
        #
        if num_of_try == 554:
            print("MESS UP")            #Creating a delay of 1second to deliberately make TIMEOUT.
            time.sleep(1)

        received_ack, clientAddress = serverSocket.recvfrom(1024)  # Receiving the request from the client throuh serverSocket and moving it to the holder "message".
        received_ack = received_ack.decode()  # Decoding the response from the client.
        print("Received ack - " + received_ack)  # Printing the received ack
        checksum_of_received_ack = hashlib.md5(received_ack.encode('utf-8')).hexdigest()  # Calculating the checksum of the received ACK.
        print("CALCULATED Checksum of the received ACK - " + str(checksum_of_received_ack))
        received_checksum_from_client, clientAddress = serverSocket.recvfrom(1024)  # Receiving checksum of the ACK from the client
        received_checksum_from_client = received_checksum_from_client.decode()  # Decoding the checksum received from the client.
        received_checksum_from_client = str(received_checksum_from_client)  # Converting the received checksum from
        print("Received checksum of the ACK - " + received_checksum_from_client)
        # print("Flag is " + str(flag))

        if flag.Value == 1:                   #If timeout happens, then flag is set to 1
            print("flag became 1 - Timeout happened")
            dupe_ack = received_ack     # Receiving the request from the client through serverSocket and moving it to the holder "message".
            dupe_checksum = received_checksum_from_client
            continue

        if checksum_of_received_ack == received_checksum_from_client:  # Comparing 'calculated checksum of the ACK' and the 'received checksum of the ACK from the client'.
            print("Entered first condition")
            if received_ack == seq_num:  # If the checksums match, then comparing 'received ack' and 'sequence number generated'
                print("Entered second condition")
                flag.Value = 1              #STOPPING THE TIMER
                # p1.join()
                next_packet = outgoing_file.read(1024)  # The next packet (1024 bytes) is read.
                packet = next_packet  # After receiving the positive Acknowledge, the next packet becomes the current packet.
                packet_num = packet_num + 1
                # print("GOOD ACK, FLAG IS " + str(flag))
                #flag.Value = 0             #RESTARTING THE TIMER
            # else:
                # flag.Value = 1        #BAD ACK, THEN STOP THE TIMER.
                # p1.join()
                # flag = 0      #THEN RESTART THE TIMER.
        # else:
            # flag.Value = 1            #BAD ACK, THEN STOP THE TIMER.
            # t1.join()
        num_of_try = num_of_try + 1  # Incrementing the number of try
        print("Packet number is : " + str(packet_num))
        print("number of try - " + str(num_of_try))

    # while packet_num != 0:
    #     p1.join()

    outgoing_file.close()  # Outgoing_file is closed.

****ERRORS I RECEIVED****

这就是我每次编译程序时收到的错误

 File "C:\Users\Siyal\Phase_3\Phase_4_Server.py", line 13, in <module>
    serverSocket.bind((serverName, serverPort))  # Binding the IP and Port.
OSError: [WinError 10048] Only one usage of each socket address (protocol/network address/port) is normally permitted
Traceback (most recent call last):
  File "<string>", line 1, in <module>
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 105, in spawn_main
    exitcode = _main(fd)
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 114, in _main
    prepare(preparation_data)
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 225, in prepare
    _fixup_main_from_path(data['init_main_from_path'])
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
    run_name="__mp_main__")
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\Siyal\Phase_3\Phase_4_Server.py", line 13, in <module>
    serverSocket.bind((serverName, serverPort))  # Binding the IP and Port.
OSError: [WinError 10048] Only one usage of each socket address (protocol/network address/port) is normally permitted
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 105, in spawn_main
    exitcode = _main(fd)
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 114, in _main
    prepare(preparation_data)
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 225, in prepare
    _fixup_main_from_path(data['init_main_from_path'])
  File "C:\Users\Siyal\Python 3.7.3\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
    run_name="__mp_main__")
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Users\Siyal\Python 3.7.3\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)