多进程+信号量Semaphore

from multiprocessing import Process
from multiprocessing import Semaphore
import datetime
import time
import multiprocessing

def worker(s, i):
    s.acquire()
    print(multiprocessing.current_process().name + " acquire",datetime.datetime.now())
    time.sleep(i)
    print(multiprocessing.current_process().name + " release",datetime.datetime.now(),"\n")
    s.release()

if __name__ == "__main__":
    s = multiprocessing.Semaphore(2)
    for i in range(5):
        p = multiprocessing.Process(target = worker, args=(s, i*2))
        p.start()