import concurrent.futures
import time
import multiprocessing

num_cores = multiprocessing.cpu_count()

def is_prime(num):
    if num <= 1:
        return False
    elif num <= 3:
        return True
    elif num%2 == 0 or num%3 == 0:
        return False
    i = 5
    while i*i <= num:
        if num%i == 0 or num%(i+2) == 0:
            return False
        i += 6
    return True

def find_sum(num):
    sum_of_primes = 0

    ix = 2

    while ix <= num:
        if is_prime(ix):
            sum_of_primes += ix
        ix += 1
    print("{} : Sum = {}".format(num, sum_of_primes))
    return sum_of_primes

def sum_primes_thread(nums):
    with concurrent.futures.ThreadPoolExecutor(max_workers = num_cores) as executor:
        executor.map(find_sum, nums)

def sum_primes_process(nums):
    with concurrent.futures.ProcessPoolExecutor(max_workers = num_cores) as executor:
        executor.map(find_sum, nums)

if __name__ == '__main__':
    nums = [1000000, 900000, 800000, 700000, 600000, 500000, 400000, 300000, 200000, 100000]
    print("Using multithreading (num_threads = num_cores):")
    start = time.time()
    sum_primes_thread(nums)
    print("Time taken = {0:.5f}".format(time.time() - start))
    print("Using multiprocessing (num_processes = num_cores):")
    start = time.time()
    sum_primes_process(nums)
    print("Time taken = {0:.5f}".format(time.time() - start))