如何在线程里嵌套多进程并获取返回值

import threading
from multiprocessing import Process, Manager

def child_func(name, queue):
    result = name
    queue.put(result)

def thread_func(queue):
    p1 = Process(target=child_func, args=("Child 1", queue))
    p2 = Process(target=child_func, args=("Child 2", queue))

    p1.start()
    p2.start()

    p1.join()
    p2.join()

    results = []
    while not queue.empty():
        result = queue.get()
        print(result)
        results.append(result)

    print("Thread finished.")
    return results

if __name__ == '__main__':
    manager = Manager()
    queue = manager.Queue()

    t = threading.Thread(target=thread_func, args=(queue,))
    t.start()
    t.join()

    results = []
    while not queue.empty():
        result = queue.get()
        results.append(result)

    print("Main process finished.")
    print("Results:", results)

但是无法获取到返回值

用回调函数改进后

import threading
from multiprocessing import Process, Manager

def child_func(name, queue):
    result = name
    queue.put(result)

def thread_func(callback,queue):
    p1 = Process(target=child_func, args=("Child 1", queue))
    p2 = Process(target=child_func, args=("Child 2", queue))

    p1.start()
    p2.start()

    p1.join()
    p2.join()

    # results = []
    # while not queue.empty():
    #     # result = queue.get()
    #     # print(result)
    #     callback(queue)

    print("Thread finished.")
    # return results

def callback(queue):
    # 从队列中获取结果
    results = []
    while not queue.empty():
        result = queue.get()
        results.append(result)
        print(f"The result is {result}")
        
    return results

if __name__ == '__main__':
    manager = Manager()
    queue = manager.Queue()

    # t = threading.Thread(target=thread_func, args=(queue,))
    t = threading.Thread(target=thread_func, args=(callback,queue,))

    t.start()
    t.join()

    results = []
    # while not queue.empty():
    #     result = queue.get()
    #     results.append(result)
    results = callback(queue)
    print("Main process finished.")
    print("Results:", results)