What is GIL

Global interpreter lock.

• ensuring a single threaded operation in Python.

The GIL does not have much impact on the performance of I/O-bound multi-threaded programs as the lock is shared between threads while they are waiting for I/O.

Instead, a multi-processing may increase performance.

• Each Python process gets its own Python interpreter and memory space so the GIL won’t be a problem.

# multi-thread
from threading import Thread

t1 = Thread(target=countdown, args=(COUNT//2,))
t2 = Thread(target=countdown, args=(COUNT//2,))

# multi-process
from multiprocessing import Pool

if __name__ == '__main__':
    pool = Pool(processes=2)