mp.py

from logging import logMultiprocessing
import time
import threading
import logging
import math
from multiprocessing.pool import Pool
import multiprocessing as mp
from multiprocessing.sharedctypes import Value
from os import getpid
import logboot

def do_cpu_intesive(num):
    threading.currentThread().setName(f"cpu-{num}-{getpid()}")
    i = 10_000_000
    start = time.perf_counter()
    logging.info(f"starting {i} iterations")
    block_size = int(i / 10)
    for it in range(1,i+1):
        x = math.cos(99)
        if it % block_size == 0:
            iterations.value = iterations.value + block_size
            logging.info(f"iteration={it:,}  global={iterations.value:,}")
    duration = round(time.perf_counter() - start, 2)
    logging.info(f"done in {duration}")
    return (num, duration)

def init_globals(it):
    logging.info("init globals")
    global iterations
    iterations = it



def do_it_all(useFork=False):
    start = time.perf_counter()
    i = [1, 2]
    global iterations
    iterations = Value('i', 0)
    if useFork:
        mp.set_start_method("fork", True)
        with Pool(processes=2, ) as p:
            results = p.map(func=do_cpu_intesive, iterable=i)
    else:
        mp.set_start_method("spawn", True)
        with Pool(processes=2, initializer=init_globals, initargs=[iterations]) as p:
            results = p.map(func=do_cpu_intesive, iterable=i)

    duration = round(time.perf_counter() - start, 2)
    logging.info(f'Finished in {duration} seconds')
    return results

if __name__ == '__main__':
    do_it_all()