When will the GIL be removed?

[consuli]

Many thanks, snippsat!

I've been able to reproduce the concurrent.futures.ProcessPoolExecutor example from the python manual.

import concurrent.futures
import math

PRIMES = [
    112272535095293,
    112582705942171,
    112272535095293,
    115280095190773,
    115797848077099,
    1099726899285419]

def is_prime(n):
   if n % 2 == 0:
       return False

   sqrt_n = int(math.floor(math.sqrt(n)))
   for i in range(3, sqrt_n + 1, 2):
       if n % i == 0:
           return False
   return True

def main():
   with concurrent.futures.ProcessPoolExecutor(max_workers= 2) as executor:
       for number, prime in zip(PRIMES, executor.map(is_prime, PRIMES)):
           print('%d is prime: %s' % (number, prime))

if __name__ == '__main__':
   main()

However, concurrent futures computing on 2 cores as shown above is NOT significantly faster than serial processing.

for i in range(0, len(PRIMES)):
print (PRIMES[i], is_prime(PRIMES[i]))

Thus, the big head from calling a process (which is only necessary because of the GIL) makes parallel computing in Python unattractive until the GIL is removed.

Quod erat demonstrandum.