python multiprocessingを使うと( [WinError 5] アクセスが拒否されました。)と出る

環境
win10
コマンドプロントから実行

import numpy as np
import time
import torch.multiprocessing as mp
import torch.nn as nn


class main(nn.Module):
    def __init__(self):
        
        super(main, self).__init__()
        self.flan=True

def process1(main):
    print(main.flan,"pro")
    main.flan=False
if __name__ == '__main__':
    main=main()
    main.share_memory()
    process1 = mp.Process(target=process1, args=(main,))

    process1.start()
    process1.join()
    print(main.flan,"ok")

Traceback (most recent call last):
  File "shead_testR.py", line 23, in <module>
    process1.start()
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\process.py", line 112, in start
    self._popen = self._Popen(self)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\context.py", line 223, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\context.py", line 322, in _Popen
    return Popen(process_obj)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\popen_spawn_win32.py", line 89, in __init__
    reduction.dump(process_obj, to_child)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\reduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
_pickle.PicklingError: Can't pickle <function process1 at 0x0000017D0E3FF438>: it's not the same object as __main__.process1
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\spawn.py", line 99, in spawn_main
    new_handle = reduction.steal_handle(parent_pid, pipe_handle)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\reduction.py", line 87, in steal_handle
    _winapi.DUPLICATE_SAME_ACCESS | _winapi.DUPLICATE_CLOSE_SOURCE)
PermissionError: [WinError 5] アクセスが拒否されました。

.share_memory(を試していたのですが
[WinError 5] アクセスが拒否されました　と出てしまい

[WinError 5] アクセスが拒否されました。について調べても出てくるのは.exe関連ばかりで
どうすればいいかわかりません

一応動いたやつ(.share_memoryは使ってない）

import numpy as np
import torch
from torch.multiprocessing import Process, Queue,Pipe

def f(b):
    print(b.recv())
    b.send([torch.tensor([1,2,3,4,5]),np.array([1,2,3,4,5,5,7,8])])

if __name__ == '__main__':
    a, b = Pipe()
    a.send([1, 'hello'])
    a.send([2, 'hello'])
    a.send([3, 'hello', None])
    p = Process(target=f, args=(b,))
    
    p.start()
    he,num=a.recv()
    print(he,num,"my")    # prints "[42, None, 'hello']"
    print(num.shape,he.size())

    p.join()

[1, 'hello']
tensor([1, 2, 3, 4, 5]) [1 2 3 4 5 5 7 8] my
(8,) torch.Size([5])
[1]
[2]

追記
いくつか修正を加えましたが　新たなエラーになりました
パラメーターが間違っています。
となっていますが　どこが間違えてるのかわかりませんprocess1.start()に入れる
変数はなかったはずです

import numpy as np
import time
import torch.multiprocessing as mp
import torch.nn as nn


class main_(nn.Module):
    def __init__(self):
        
        super(main_, self).__init__()
        self.flan=True

def process1(main):
    print(main.flan,"pro")
    main.flan=False
if __name__ == '__main__':
    main=main_()
    main.share_memory()
    process1 = mp.Process(target=process1, args=(main,))

    process1.start()
    process1.join()
    
    print(main.flan,"ok")

Traceback (most recent call last):
  File "shead_testR.py", line 23, in <module>
    process1.start()
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\process.py", line 112, in start
    self._popen = self._Popen(self)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\context.py", line 223, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\context.py", line 322, in _Popen
    return Popen(process_obj)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\popen_spawn_win32.py", line 89, in __init__
    reduction.dump(process_obj, to_child)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\reduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
_pickle.PicklingError: Can't pickle <function process1 at 0x000002570CDCF438>: it's not the same object as __main__.process1

(testpyflan) C:\Users\PC_User\Desktop\AGI>Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\spawn.py", line 99, in spawn_main
    new_handle = reduction.steal_handle(parent_pid, pipe_handle)
  File "C:\Users\PC_User\Anaconda3\envs\testpyflan\lib\multiprocessing\reduction.py", line 82, in steal_handle
    _winapi.PROCESS_DUP_HANDLE, False, source_pid)
OSError: [WinError 87] パラメーターが間違っています。