python 线程信号量

线程信号量和进程信号量相似

# 线程信号量
import time
from threading import Semaphore
from threading import Thread

def test(n, se):
    se.acquire()
    print(pow(n, 2))
    time.sleep(1)
    se.release()

se = Semaphore(4)
for i in range(10):
    t = Thread(target=test, args=(i, se))
    t.start()