请教 concurrent.Future()线程池重启的问题

v2 的跟帖似乎无法用 markdown 语法？ 所以就重新开个帖子请教这个问题。。。

# coding=utf-8
import codecs
import difflib
import os.path
import re
import time
import string
import chardet
import shutil
import copy
from concurrent.futures import ProcessPoolExecutor

import datetime

def PrintCount(PName):
    if PName == '甲':
        DelayTime = 0.9
    if PName == '乙':
        DelayTime = 1.2
    if PName == '丙':
        DelayTime = 1.7
    if PName == '丁':
        DelayTime = 2
    if PName == '戊':
        DelayTime = 2.5

    countt = 0
    while True:
        countt += 1
        time.sleep(DelayTime)
        print(f'{PName}池:->',f'{countt}')


if __name__ == '__main__':

    StartTime = time.clock()
    FutureDict = {}
    FutureRetDict = {}
    FutureTimeRecoderDict = {}

    PoolNameList = ["甲", "乙", "丙", "丁", "戊"]

    # 初始化进程池
    for i in range(len(PoolNameList)):
        # 进程
        FutureDict.update({PoolNameList[i]: ProcessPoolExecutor(max_workers=1)})
        # 进程 Ret
        FutureRetDict.update({PoolNameList[i]: futures.Future()})
        # 进程启动时间
        FutureTimeRecoderDict.update({PoolNameList[i]: None})

    # 模拟测试清空进程池的信号
    closeflag = True

    # 开始工作
    while True:
        ProcessNum = 0

        # 增加任务
        for ProcessName,FutureRet in FutureRetDict.items():

            # 模拟 40 秒后终结 [乙] 进程池
            if closeflag == True:
                if time.clock() - StartTime >= 40: # 在启动 40 秒后触发
                    print(f"开始强制结束 [乙] 进程池")
                    for pid, process in FutureDict['乙']._processes.items():
                        process.terminate()
                        FutureDict['乙'].shutdown()
                    closeflag = False
                    time.sleep(15)

            # 如果进程池在运行
            if FutureRet.running() == True:
                pass
            else:
                # 增加任务
                FutureRetDict[ProcessName] = FutureDict[ProcessName].submit(PrintCount,ProcessName)
                print(f'{ProcessName} 进程池提交了开始.')
                time.sleep(2)
                break
        time.sleep(3)

40 秒之后，乙进程池的确被停了，但是再向乙进程池提交任务的时候，会提示：

甲池:-> 57
甲池:-> 58
丙池:-> 25
戊池:-> 13
甲池:-> 59
丁池:-> 19
甲池:-> 60
丙池:-> 26
Traceback (most recent call last):
File "D:/TestForMu.py", line 80, in <module>
FutureRetDict[ProcessName] = FutureDict[ProcessName].submit(PrintCount,ProcessName)
File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\lib\concurrent\futures\process.py", line 452, in submit
raise BrokenProcessPool('A child process terminated '
concurrent.futures.process.BrokenProcessPool: A child process terminated abruptly, the process pool is not usable anymore
甲池:-> 61
戊池:-> 14
丁池:-> 20
丙池:-> 27

应该要做些什么事情，再次启用？
原谅我这样设计流程，也许不是科学的。。。^_^ 谢谢大家解答！