#!/usr/bin/env python# -*- coding: utf-8 -*-import multiprocessingfrom multiprocessing import Barrier, Lock, Processfrom time import timefrom datetime import datetimedef test_with_barrier(synchronizer, seializer):    name = multiprocessing.current_process().name    synchronizer.wait()    now = time()    with serializer:        print("process %s -----> %s" % (name, datetime.fromtimestamp(now)))def test_without_barrier():    name = multiprocessing.current_process().name    now = time()    print("process %s -----> %s" % (name, datetime.fromtimestamp(now)))def worker(dictionary, key, item):    dictionary[key] = item    print(key, item)if __name__ == ‘__main__‘:    synchronizer = Barrier(2)    serializer = Lock()    Process(name=‘p1 - test_with_barrier‘, target=test_with_barrier, args=(synchronizer, serializer)).start()    Process(name=‘p2 - test_with_barrier‘, target=test_with_barrier, args=(synchronizer, serializer)).start()    Process(name=‘p3 - test_without_barrier‘, target=test_without_barrier).start()    Process(name=‘p4 - test_without_barrier‘, target=test_without_barrier).start()    mgr = multiprocessing.Manager()    dictionary = mgr.dict()    jobs = [multiprocessing.Process            (target=worker, args=(dictionary, i, i*2))            for i in range(10)            ]    for j in jobs:        j.start()    for j in jobs:        j.join()