Python进程超时行为异常：与被调用函数返回值相关

import multiprocessing
import time
from multiprocessing import Process
import numpy as np


def run_process_timeout_wrapper(function, args, timeout):

    def aux(n, out_q):
        res = function(*n)
        out_q.put(res)  # to get result back from thread target

    result_q = multiprocessing.Queue()

    p = Process(target=aux, args=(args, result_q))
    p.start()
    x = result_q.get()
    p.join(timeout=timeout)
    p.terminate()

    if p.is_alive():
        p.terminate()
        raise multiprocessing.TimeoutError("Timed out after waiting for {}s".format(timeout))

    return x


def foo(x):
    return [(np.random.rand(50000), 0.993) for _ in range(10)]


def bar(x):
    return x

def foobar(x):
    res = [(np.random.rand(50000), 0.993) for _ in range(10000)]
    return res


if __name__ == '__main__':
    t1 = time.time()
    res = run_process_timeout_wrapper(foo, (110,), 40)
    print(time.time() - t1)

    t1 = time.time()
    res1 = run_process_timeout_wrapper(bar, (110,), 40)
    print(time.time() - t1)

    t1 = time.time()
    res2 = run_process_timeout_wrapper(foobar, (110,), 1)
    print(time.time() - t1)

原问题 #

运行上述程序时，第一个调用foo的进程耗时40秒，第二个调用bar的进程耗时接近0秒。虽然明白返回大数组比单个值耗时更长，但这两个函数的实际计算时间都远小于40秒，对此结果感到困惑。

更新问题 #

感谢关于调整result_q.get()与p.join()顺序的解答，但又出现新问题：foobar任务本应在1秒后超时终止并抛出TimeoutError，但实际无法终止进程。

内容的提问来源于stack exchange，提问作者julian