Hi, If you are on windows, I recall that we can’t use multiprocessing inside a function, it should be in the main body of code or after if ‘__name__’ == ‘__main__’ block. Also, it is necessary to ensure that the function being used with multiprocessing can be pickled, if it cant be multiprocessing won’t work with it. On Tue, 6 May 2025 at 1:39 am, Ran Waidman via Python.NET < pythonnet@python.org> wrote:

Hi, I am using Python.Runtime in C#,

I would like to call 1 function from my script, this function must work in multip process. when I call it, it looks like that the sw keep opening new processes forever till my computer has to be restarted it is like a virus,

my python code: import math import multiprocessing import time from multiprocessing import pool

import cv2 import numpy as np import os from PIL import Image

from GraininessFunction import GraininessFunction

#multiprocessing.set_start_method('spawn', force=True) # or 'fork' on Unix

def getString():

return "Hello from Python!"

def worker(x): print(f"Processing {x} in PID {os.getpid()}") return x * x

def multiProcessTest(): multiprocessing.freeze_support() #multiprocessing.freeze_support() args = [1,2,3,4] processes = []

print(f"multiProcessTest in PID {os.getpid()}")

for item in args: print("creating process for:"+str(item)) p = multiprocessing.Process(target=worker, args=(item,)) p.start() processes.append(p)

for p in processes: p.join() #with multiprocessing.Pool(processes=2) as pool: # pool.map(worker, args)

#multiprocessing.freeze_support() #if multiprocessing.get_start_method(allow_none=True) != 'spawn': # multiprocessing.set_start_method('spawn', force=True)

my C# code:

var ret = module.getString();

Console.WriteLine($"Result from Python: {ret}");

module.multiProcessTest();

Console.WriteLine($"end multiProcessTest"); _______________________________________________ Python.NET mailing list -- pythonnet@python.org To unsubscribe send an email to pythonnet-leave@python.org https://mail.python.org/mailman3/lists/pythonnet.python.org/ Member address: nikhilgarg.gju@gmail.com