多处理管理器字典没有更新

我试图通过传递 Manager.dict 来捕获每个进程的开始和结束时间。当我使用fun 时，它没有按预期工作，但对于fun_1 来说，它工作正常。我在 python 3.7 (IDE VS Code) 上运行此代码

import time
from multiprocessing import Manager
from multiprocessing.pool import Pool


def fun(a, d):
    if a not in d:
        d[a] = list()

    d[a].append(time.time())
    time.sleep(1)
    d[a].append(time.time())


def fun_1(a, d):

    s = time.time()
    time.sleep(1)
    e = time.time()
    d[a] = [s, e]


if __name__ == '__main__':
    pool = Pool(4)
    m = Manager()
    d = m.dict()
    pool.starmap(fun, [(i, d) for i in range(10)])
    print(d) # {3: [], 0: [], 2: [], 1: [], 4: [], 5: [], 6: [], 7: [], 8: [], 9: []}

看起来我错过了一些东西。提前致谢