Python多进程Pipe报错“管道已关闭”如何解决？

import os
from multiprocessing import Process, Pipe


def start_child_process(child_conn):
    # 模拟长时间运行的任务
    # run_server_for_long_time()
    child_conn.send({"port": 123, "ret": 1, "pid": os.getpid()})

    try:
        signal = child_conn.recv()
        if signal:
            child_conn.close()
    except EOFError as err:
        print(f"Caught EOFError: {err}")


class Server:
    def __init__(self):
        self.child_conn = None
        self.child = None
        self.parent_conn, self.child_conn = Pipe()

    def run(self):
        self.child = Process(target=start_child_process, name="my_child_process", args=(self.child_conn,))
        self.child.start()

        data = self.parent_conn.recv()
        result = {
            "endpoints": {
                "http": f"http://127.0.0.1:{data['port']}/cmd",
                "ws": f"ws://127.0.0.1:{data['port']}/api",
            }
        }
        return result

    def stop(self):
        self.parent_conn.send(True)
        self.child.join()
        self.child = None


if __name__ == "__main__":
    server = Server()
    r = server.run()
    print("r:", r)

from service import Server
import time


def main():
    server = Server()
    result = server.run()
    print("r:", result)
    time.sleep(5)
    # server.stop()  # 解注释后，问题依然解决


if __name__ == "__main__":
    main()