python3 线程事件Event

# -*- coding: utf-8 -*-
import time
import threading
from threading import Thread, Event


def conn_mysql():
    '''连接数据库'''
    print("(%s) start to conn_mysql" % threading.current_thread().getName())
    event.wait()
    print("(%s conn_mysql successful)" % threading.current_thread().getName())


def check_msyql():
    '''检查mysql数据状态'''
    print("(%s) checking mysql" % threading.current_thread().getName())
    time.sleep(4)
    event.set()


if __name__ == '__main__':
    '''事件默认是关闭状态,执行set则为开启状态'''
    event = Event()
    c1 = Thread(target=conn_mysql)
    c2 = Thread(target=conn_mysql)
    c3 = Thread(target=conn_mysql)
    c4 = Thread(target=check_msyql)
    c1.start()
    c2.start()
    c3.start()
    c4.start()
    
    
# (Thread-1) start to conn_mysql
# (Thread-2) start to conn_mysql
# (Thread-3) start to conn_mysql
# (Thread-4) checking mysql
# (Thread-3 conn_mysql successful)
# (Thread-1 conn_mysql successful)
# (Thread-2 conn_mysql successful)