import gc
import pickle
import sys
import threading
import time

#sys.setswitchinterval(1e-1)
#gc.disable()


def bg_func():
    while True:
        time.sleep(1e-3)
        print("x", end='', flush=True)

t = threading.Thread(target=bg_func, daemon=True)
t.start()

def main():
    N = 10_000_000
    data = [None] * N

    clock = time.process_time
    times = []
    for i in range(4):
        t1 = clock()
        pickle.dumps(data, protocol=3)
        dt = clock() - t1
        times.append(dt)

    print("min / max: {:.1f} / {:.1f} ms".format(min(times) * 1e3, max(times) * 1e3))


main()