Python Multiprocessing (Flask) - Calling a function from main process

Question

This is my code:

from flask import Flask, render_template, url_for, redirect, request, flash, Markup, make_response, Response
from multiprocessing import Process, Value

def getCookie():
    return request.cookies.get('username')

def worker(state):
    if state.value == 1:
        while True:
            print(getCookie())

if __name__ == '__main__':
    processValues = Value('i', 1)
    p = Process(target=worker, args=(processValues, ))
    p.start()
    app.run()
    p.join()

So worker is the function started by Multiprocessing and it's trying to call function getCookie() which uses a function by Flask .

It seems to throw me an error saying

RuntimeError: Working outside of request context.

This typically means that you attempted to use functionality that needed
an active HTTP request.  Consult the documentation on testing for
information about how to avoid this problem.

Anyway I can fix this?

UPDATE

Also, Ive tried sending the request function in the args like so

from flask import Flask, render_template, url_for, redirect, request, flash, Markup, make_response, Response
from multiprocessing import Process, Value

def worker(state, req):
    if state.value == 1:
        while True:
            print(req.cookies.get('username'))

if __name__ == '__main__':
    processValues = Value('i', 1)
    p = Process(target=worker, args=(processValues, request ))
    p.start()
    app.run()
    p.join()

And this just throws me another error.

Answer 1

if you need to only read this cookie then you could send it as argument

p = Process(target=worker, args=(processValues, getCookie()))

or directly

p = Process(target=worker, args=(processValues, request.cookies.get('username'))

But you have to get it in worker as

def worker(state, username):

---

Similar way you could try to send full request

p = Process(target=worker, args=(processValues, request))

BTW: as I know multiprocessing uses pickle to send arguments as file.