py37_gc_freeze_test.py

## prepare as:
# conda create -n py37 -c anaconda python=3.7
# source activate py37
# python --version
# python py37_gc_freeze_test.py

from multiprocessing import Process
import gc
import time

a = None
def foo():
  print('worker started')
  time.sleep(5)
  s = 0
  for it in range(100):
    for i in a:
      s += i
    print("%d) s=%d" % (it, s))

if __name__ == '__main__':
  gc.freeze()
  a = []
  for i in range(50000000):
    a.append(i**2)
  print('a construncted, %d freezed objects' % gc.get_freeze_count())
  time.sleep(5)
  processes = []
  for i in range(8):
    p = Process(target=foo, args=())
    p.start()
    processes.append(p)

  for p in processes:
    p.join()
    print('process completed')

  print('all processes completed')