Multiprocessing problems with flet build windows executable

[xuying-92]

Duplicate Check

• [X] I have searched the opened issues and there are no duplicates

Describe the bug

Hello Flet community,

I am using multiprocessing in my app, but after build the executable using flet build windows, and run the resulting executable, it shows the following error with 2 flet windows.

PathAccessException: Deletion failed, path = 'C:\Users\XUYI27~1\AppData\Local\Temp\multi-1.0.0-1\app' (OS Error: The process cannot access the file because it is being used by another process. , errno = 32)

Code

Below is a demo I wrote to demonstrate this problem. My actual app also uses Process, Queue and Event from multiprocessing.

import queue
import random
import time
from multiprocessing import Queue, Event, Process, freeze_support

import flet as ft

STOP_EVENT = Event()
RESULT_QUEUE = Queue()


def gen_rand(q: Queue, stop_event: Event):
    stop_gen = False
    while not stop_gen:
        if stop_event.is_set():
            stop_gen = True
        random_number = random.randint(0, 100)
        q.put(random_number)
        time.sleep(1)


def main(page: ft.Page):
    def on_window_event(e):
        if e.data == 'close':
            STOP_EVENT.set()
            while not RESULT_QUEUE.empty():
                RESULT_QUEUE.get()
            RESULT_QUEUE.close()
            process_gen.join(5)
            page.window.destroy()

    page.window.prevent_close = True
    page.window.on_event = on_window_event

    process_gen = Process(target=gen_rand, args=(RESULT_QUEUE, STOP_EVENT))
    process_gen.start()

    while not STOP_EVENT.is_set():
        try:
            rand_number = RESULT_QUEUE.get(timeout=5)
            page.add(ft.Text(f'Generated Number: {rand_number}'))
        except queue.Empty:
            pass


if __name__ == '__main__':
    freeze_support()
    ft.app(main)

To reproduce

1. build the executable with flet build windows
2. run the resulting exe

Expected behavior

A Test control with random number added to the app window every second, the same behavior as running the python script using python main.py or flet run

Screenshots

Operating System

Windows

Operating system details

Windows 10

Flet version

0.23.1

Regression

I'm not sure / I don't know

Suggestions

No response

Additional details

No response