lockとRlock

import logging
import threading
import time

logging.basicConfig(level=logging.DEBUG, format='%(threadName)s: %(message)s')


def worker1(d, lock):
    logging.debug('start')

    #with lockのブロック内の処理が終わるまで他のスレッドは処理されない
    with lock:
        i = d['x']
        time.sleep(5)
        d['x'] = i + 1
        logging.debug(d)

        #main関数でlock = threading.Lock()とした場合は処理が進まなくなる
        with lock:
            d['x'] = i + 1
    logging.debug('end')

def worker2(d, lock):
    logging.debug('start')

    #lock.acuire()とlock.releaseで囲まれた部分の処理が終わるまで他のスレッドは処理されない
    lock.acquire()
    i = d['x']
    d['x'] = i + 1
    logging.debug(d)
    lock.release()
    logging.debug('end')


if __name__ == '__main__':
    d = {'x': 0}
    lock = threading.RLock()
    t1 = threading.Thread(target=worker1, args=(d, lock))
    t2 = threading.Thread(target=worker2, args=(d, lock))
    t1.start()
    t2.start()

出力

Thread-1: start
Thread-2: start
Thread-1: {'x': 1}
Thread-1: end
Thread-2: {'x': 2}
Thread-2: end